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Beneficial effects of soy protein consumption for renal function
Abstract
Alterations in dietary protein intake have an important role in prevention and management of several forms of kidney disease. Using soy protein instead of animal protein reduces development of kidney disease in animals. Reducing protein intake preserves kidney function in persons with early diabetic kidney disease. Our clinical observations led us to the soy-protein hypothesis that "substitution of soy protein for animal protein results in less hyperfiltration and glomerular hypertension with resulting protection from diabetic nephropathy." These components of soy protein may lead to the benefits: specific peptides, amino acids, and isoflavones. Substituting soy protein for animal protein usually decreases hyperfiltration in diabetic subjects and may reduce urine albumin excretion. Limited data are available on effects of soy peptides, isoflavones, and other soy components on renal function on renal function in diabetes. Further studies are required to discern the specific benefits of soy protein and its components on renal function in diabetic subjects.
... Increased activation of brain microglia and pro-inflammatory cytokine levels in serum were previously reported in clinical and experimental studies of this disease (Meng et al. 2017;Tomar et al. 2020). Furthermore, the role of apoptosis in the neuropathology of SCZ had been found to involve both intrinsic (mitochondrial damage) and extrinsic (death receptor) pathways (Anderson 2008;Frey et al. 2006). Oxidative stress, NMDA dysfunction, glutamate excitotoxicity, decreased BDNF levels, and increased calcium influx can, individually or together, produce a pro-apoptotic environment (Abekawa et al. 2008). ...
... Alongside its direct deleterious effect, AMPH can induce apoptosis in the hippocampus, which consists of a key process in the pathogenesis of SCZ (Anderson 2008). Methamphetamine-induced hippocampal apoptosis associated with increased Bax levels and decreased Bcl-2 levels has been confirmed by this study's histopathological findings. ...
... Methamphetamine-induced hippocampal apoptosis associated with increased Bax levels and decreased Bcl-2 levels has been confirmed by this study's histopathological findings. This apoptotic effect may result from oxidants, reactive oxygen, NO radicals, and activated NMDA receptors triggered by excess glutamate and DA released by methamphetamine (Abekawa et al. 2008;Anderson 2008). Additionally, oxidative damage alters the mitochondrial permeability with subsequent secondary excitotoxicity (Grewal et al. 2021). ...
Schizophrenia (SCZ), a multifactorial neuropsychiatric disorder, is treated with inefficient antipsychotics and linked to poor treatment outcomes. This study, therefore, investigated the combined administration of prodigiosin (PDG) and selenium (Na2SeO3) against SCZ induced by amphetamine (AMPH) in rats. Animals were allocated into four groups corresponding to their respective 7-day treatments: control, AMPH (2 mg/kg), PDG (300 mg/kg) + Na2SeO3 (2 mg/kg), and AMPH + PDG + Na2SeO3. The model group exhibited biochemical, molecular, and histopathological changes similar to those of the SCZ group. Contrastingly, co-administration of PDG and Na2SeO3 significantly increased the time for social interaction and decreased AChE and dopamine. It also downregulated the gene expression of NMDAR1 and restored neurotrophin (BDNF and NGF) levels. Further, PDG combined with Na2SeO3 improved the antioxidant defence of the hippocampus by boosting the activities of SOD, CAT, GPx, and GR. These findings were accompanied by an increased GSH, alongside decreased MDA and NO levels. Furthermore, schizophrenic rats having received PDG and Na2SeO3 displayed markedly lower IL-1β and TNF-α levels compared to the model group. Interestingly, remarkable declines in the Bax (pro-apoptotic) and increases in Bcl-2 (anti-apoptotic) levels were observed in the SCZ group that received PDG and Na2SeO3. The hippocampal histological examination confirmed these changes. Collectively, these findings show that the co-administration of PDG and Na2SeO3 may have a promising therapeutic effect for SCZ. This is mediated by mechanisms related to the modulation of cholinergic, dopaminergic, and glutaric neurotransmission and neurotrophic factors, alongside the suppression of oxidative damage, neuroinflammation, and apoptosis machinery.
... The pathogenesis of acute renal failure especially those of glycerol-induced myoglobinuric acute renal failure involves, among other causes, ischemia, vascular congestion, and reactive oxygen metabolites [4]. Intake of leguminous foods such as soy bean or its constituent slows or prevents development of kidney disease in several different animal models [5]. ...
... Legumes are a very healthy food because it is low in fat and high in protein. Legumes are also very high in fibre and other nutrients [6,7].Few studies have shown that renal function can be affected by consuming legumes, particularly soybean protein and fibre, and also other bean fibre [5]. Soybean seeds Glycine max (L)Merris a member of family Fabaceae [8]. ...
... Soybean is known as the "Golden bean" of the twentieth century, it contains very small amounts of saturated fatty acids but do not contain any trans fatty acids [8]. Omega-6 and omega-3 fatty acids are present in soybean, which are also rich in iron, phosphorus, magnesium, vitamin B12 and folate [8].It is one of the best vegetarian sources of total proteins containing all essential amino acids required in the human dietand also has many beneficial effects on the body tissues [5,8]. ...
The health benefit of soybean consumption has currently gained the attention of researchers. The aim of this study was to investigate the effect of soymilk onrenal biochemical parameters and histopathology of glycerol-induced acute renal injury in rats. In this study, twenty-four (24) albino wistar rats weighing (200-250g) were divided into four (4) groups with six (6) animals per cage: group A served as normal control group and received only distilled water, group Bas positive control and was given glycerol plus vitamin C (200mg/kg, oral), group C, the negative control was given 50% glycerol alone (10ml/kg, i.m.), and group D, the test group was given glycerol plus soymilk (2000mg/kg, oral). Renal injury was assessed by analysing renal histopathology and biochemical parameters such as: Na + , K + , Cl-, HCO 3-, creatinine and blood urea nitrogen (BUN) levels. The Glycerol treatment resulted in marked elevation of:K + (8.66±0.64mmol/l); creatinine (1.47±0.23 mg/dl);and BUN (44.39±5.78 mg/dl) and caused deranged renal functions which were significantly attenuated after soymilk treatment: K + (6.51±0.33 mmol/l); creatinine (0.88±0.005 mg/dl); and BUN (19.67±1.45 mg/dl) with[P < 0.05].Based on these results, this study demonstrates the potential beneficial effects of soy bean against glycerol-induced acute renal failure in rats.
... The improvement of renal hemodynamics which results from the supplementation of arginine could be the direct result of an increase in NO production [106]. These plant protein sources bring additional compounds into the mix that need to be considered as well, such as soy isoflavones, which might affect renal function through cell signaling actions and nitric oxide production affecting renal perfusion [107]. Soy consumption has also been associated with improvements in antioxidant status and systemic inflammation in CKD patients [107]. ...
... These plant protein sources bring additional compounds into the mix that need to be considered as well, such as soy isoflavones, which might affect renal function through cell signaling actions and nitric oxide production affecting renal perfusion [107]. Soy consumption has also been associated with improvements in antioxidant status and systemic inflammation in CKD patients [107]. Put another way, the whole "protein package" should be considered in terms of health benefits. ...
Consumer demand for plant protein-based products is high and expected to grow considerably in the next decade. Factors contributing to the rise in popularity of plant proteins include: (1) potential health benefits associated with increased intake of plant-based diets; (2) consumer concerns regarding adverse health effects of consuming diets high in animal protein (e.g., increased saturated fat); (3) increased consumer recognition of the need to improve the environmental sustainability of food production; (4) ethical issues regarding the treatment of animals; and (5) general consumer view of protein as a “positive” nutrient (more is better). While there are health and physical function benefits of diets higher in plant-based protein, the nutritional quality of plant proteins may be inferior in some respects relative to animal proteins. This review highlights the nutritional quality of plant proteins and strategies for wisely using them to meet amino acid requirements. In addition, a summary of studies evaluating the potential benefits of plant proteins for both health and physical function is provided. Finally, potential safety issues associated with increased intake of plant proteins are addressed.
... As a more alkaline alternative than animal protein sources, soy protein has been associated with beneficial factors for renal health (Anderson, 2008). Also, benefits have been reported regarding antioxidants serum levels and systemic inflammation in patients with early and late chronic kidney disease (Tomayko et al., 2015). ...
... A reduction of protein intake preserves renal function in persons with early diabetic renal disease, and the replacement of animal protein with soy protein results in lower glomerular hypertension and reduced urine albumin excretion. Specific peptides, amino acids and isoflavones are the soy components that may be responsible for these benefits (Anderson, 2008). ...
Soy consumption is a millenary habit of populations of the eastern world and has recently increased in the western world. The risks and benefits of this practice have been extensively studied, with a current fundamental need of integration of available information. The aim of this study was to carry out an integrative review on this topic, in order to consolidate the available information. Based on the main question: “What is the impact of soy consumption on human health?”, were reviewed publications classified as original articles and reviews published from 1998 to 2020 in the databases Scopus, PubMed, SciELO, Web of Science, and Cochrane Library. A total of 97 studies were selected. In the present review were described the general impact of soy on human health and its protein quality, the effects of early exposure using soy formulas, and the effects of soy consumption on breast cancer, endometrial and ovarian cancer, prostate cancer, gastrointestinal cancer, cardiovascular disease, glucose metabolism and type 2 diabetes, obesity, reproductive health, menopause, female and male osteoporosis, microbiota, immunity and immunomodulation, thyroid function, attention-deficit hyperactivity disorder, and renal function.
... Gracia et al. [28] further stated that walnuts, macadamia, almonds and cashew nuts have cholesterol-lowering properties, and a beneficial effect on the lipoproteins profile. In a controlledrandomized crossover study by Anderson [32] in 18 normo-cholesterolaemic men, results of the study indicated that diets rich in walnuts decreased total cholesterol. ...
... Vegetarians should be encouraged to consume more soy based foods since they are high biological value protein food comparable to animal products [37]. Soy foods are very important meal component for those who are still in the growing up phase (adolescents) as they are in need of the 10 essential amino acids to meet their growth spurt [32]. ...
Objective: The purpose of this study was to investigate the protein intake of vegetarians and non-vegetarians in Port Harcourt, Rivers State. Methodology: Four objectives and four research questions guided the study. A survey research design was adopted for the study. A sample size of 400 respondents was selected using Taro Yamene formula and purposive sampling techniques. The instrument used for data collection was a questionnaire tagged: Protein Intake of Vegetarians and Non-Vegetarians in Port Harcourt Questionnaire (CPIBVNVQ). The instrument was validated by three experts with a reliability coefficient of 0.56. Data obtained were analyzed using descriptive statistics (frequency, percentage) and findings were presented on tables. Results: Prevalence of vegetarianism was high in females (53%) than in males (47%). Protein intake by the vegetarians was high (97%) when compared with vegetarians who do not eat proteinous foods (3%). Among the non-vegetarians, 94% eat proteinous foods while 6% do not eat. The study also showed that protein intake is better in non-vegetarians than vegetarians. Higher percentages of non-vegetarians (84.3%) fell sick and got diagnosed of ailments as compared with 17.4% for vegetarians suggesting that the vegetarians experience enhanced immune function. Reduced saturated fat and blood cholesterol was a tool that influenced the respondents in choosing the vegetarian lifestyle with 82.5% for vegetarian and 13.8% for non-vegetarian. Conclusion: Based on the findings, it was recommended that vegetarians should be encouraged to consume more plant proteins especially soy based foods since they are high biological value protein food comparable to animal products.
... Alterations in dietary protein intake have an important role in prevention and management of several forms of kidney disease. Studies have shown that the consumption or partial substitution of soy protein for animal protein usually decreases hyper filtration in diabetic patients and may reduce urine albumin excretion (proteinuria) and reduces the risk of heart disease by lowering low density lipoprotein [8,9]. Soybeans have been used in the production of analogue yoghurt; however no study had investigated the quality of whole soybean incorporation for symbiotic yoghurts production. ...
... A clinical study conducted by Aderson [8] showed that substitution of soy protein for animal protein decreases hyper filtration in diabetic persons and may reduce urine albumin excretion (proteinuria). Hence soy flour symbiotic milk is a potential diet for diabetes. ...
The potential of milk enrichment with soybean flour was studied .Yoghourt control Sample A: 100% Milk powder (Dano)and o% wholes soyabean flour, Sample B: 90% fermented milk powder (Dano) and 10% whole soybean flour, Sample C: 80% fermented milk powder (Dano) and 20% whole soybean flour, Sample D: 70% fermented milk powder (Dano) and 30% whole soybean flour, Sample E: 60% fermented milk powder (Dano) and 40% whole soy bean flour were produced respectively. The proximate composition, physio-chemical properties and sensory evaluation were determined using standard methods .The results on proximate obtained showed increase in values for moisture (77.79-89.34) %, protein (3.06-9.23) % , fat content (1.57-3.97)% and fibre content (0.18-2.45)%. However, reversed trend was observed for ash and carbohydrate values respectively. The physiochemical analysis results obtained showed decrease in total solids (22.21-10.66)%, total solid non-fat (201.64-6.70)%, TTA (1.34-0.78)%, viscosity (10.54-0.86)Pa.s and P H with had increased values from (4.5-5.13). The sensory evaluation result revealed that there were no significant difference p>0.05 between the control and sample B in appearance but there were significance difference p<0.05 between the control and the enriched sample in terms of aroma, taste, mouthful and overall acceptability. It was observed that substituting 10% whole soybean flour with powdered milk gave a symbiotic yoghurt ranked physico-chemical and sensory characteristics values as the control yoghurts sample
... The potential renal benefits of soy have considerable public health significance because of the increasing worldwide prevalence of renal disease, which is largely a consequence of the increasing prevalence of diabetes [290]. There is preliminary evidence that soy protein places less stress on the kidneys in comparison to other high-quality proteins, which over time could reduce the risk of developing renal disease in susceptible individuals, such as those with diabetes [291,292]. More specifically, it has been proposed that replacing animal protein with soy protein leads to a decrease in hyperfiltration and glomerular hypertension, with resultant protection from diabetic nephropathy [291,293]. ...
... There is preliminary evidence that soy protein places less stress on the kidneys in comparison to other high-quality proteins, which over time could reduce the risk of developing renal disease in susceptible individuals, such as those with diabetes [291,292]. More specifically, it has been proposed that replacing animal protein with soy protein leads to a decrease in hyperfiltration and glomerular hypertension, with resultant protection from diabetic nephropathy [291,293]. ...
Soyfoods have long been recognized as sources of high-quality protein and healthful fat, but over the past 25 years these foods have been rigorously investigated for their role in chronic disease prevention and treatment. There is evidence, for example, that they reduce risk of coronary heart disease and breast and prostate cancer. In addition, soy alleviates hot flashes and may favorably affect renal function, alleviate depressive symptoms and improve skin health. Much of the focus on soyfoods is because they are uniquely-rich sources of isoflavones. Isoflavones are classified as both phytoestrogens and selective estrogen receptor modulators. Despite the many proposed benefits, the presence of isoflavones has led to concerns that soy may exert untoward effects in some individuals. However, these concerns are based primarily on animal studies, whereas the human research supports the safety and benefits of soyfoods. In support of safety is the recent conclusion of the European Food Safety Authority that isoflavones do not adversely affect the breast, thyroid or uterus of postmenopausal women. This review covers each of the major research areas involving soy focusing primarily on the clinical and epidemiologic research. Background information on Asian soy intake, isoflavones, and nutrient content is also provided.
... Lactobacillus delbrueckii, L. lactis, Streptococcus lactis, and a number of yeast are responsible for the fermentation of batter. Heterofermentative Lactic acid bacterium such as Leuconostoc mesenteroids is responsible for the sour forming, leavening action and gas production in the batter (James andAnderson, 2008 andKrishnapriya et al., 2012). Lactic acid bacteria are influence the flavor of fermented food. ...
... Lactobacillus delbrueckii, L. lactis, Streptococcus lactis, and a number of yeast are responsible for the fermentation of batter. Heterofermentative Lactic acid bacterium such as Leuconostoc mesenteroids is responsible for the sour forming, leavening action and gas production in the batter (James andAnderson, 2008 andKrishnapriya et al., 2012). Lactic acid bacteria are influence the flavor of fermented food. ...
Traditional idly fermentation involves several naturally fermenting bacteria and yeast. Fermented foods are more nutritional than the unfermented foods. Even though in the earlier times there were no technologies the nutritional quantity of food was more but now a days with the advent of many technologies, the nutritional quantity of food has gone poorer. Idly, the traditional fermented food is prepared with the composition of rice, black gram and in our work the soybeans are added for increasing the nutritional value. The probiotic organisms are the organisms are that confer health benefit on host. The probiotic bacteria Lactobacillus sp. is additionally added to enhance the nutritional content of the soybeans added batter .By the analysis of the batter it was found that increase in the nutritional value such as folic acid, proteins, iron, fiber, vitamins (b 1 ,b 2 ,b 12), and other minerals. Introduction Fermentation is the traditional process used to prepare the food, not only food but also fermentation is the process used to preservation and process of conservation (Shelver, 1996). Idly is the most preferred breakfast in South India. It consists of black gram which is main source for protein formation in the batter. Naturally, microorganisms are present in the batter which is mainly involved in the fermentation of batter. The microorganisms are responsible for the characteristic changes in the batter. Lactobacillus delbrueckii, L. lactis, Streptococcus lactis, and a number of yeast are responsible for the fermentation of batter. Heterofermentative Lactic acid bacterium such as Leuconostoc mesenteroids is responsible for the sour forming, leavening action and gas production in the batter (James and Anderson, 2008 and Krishnapriya et al., 2012). Lactic acid bacteria are influence the flavor of fermented food. Production of acid and lowering the pH forms the sourness in the batter. Most of the acid produced in the fermentation will be produced by the metabolism of sugar, sweetness will likely decreases as sourness increases (Akinniyi and Korie, 2010). Soybean seeds are known to contain different proteins showing ant nutritional and/or toxic effects such as soybean agglutins N-acetylgalactosamine-specific lectins (Adesokan et al., 2011). In this, by adding adequate amount of soya and probiotic bacteria in the batter, this increases nutritional level of the batter. To
... Many studies have reported that soya protein can retard the progression of renal failure (15) . b-Conglycinin is the major storage protein of soyabeans and is considered to be one of the bioactive components in soya protein. ...
... In the present study, b-conglycinin intervention decreased TBARS concentration and TGF-b expression and soya isoflavones also reduced oxidative and inflammatory indicators in the DN rats. Previous studies have indicated that soya protein exhibits renal protective effects in animal models subjected to various renal diseases, which may be related to the effects of its isoflavone content, such as anti-inflammatory and antioxidative effects (15) . For example, genistein down-regulated TGF-b gene expression at the transcriptional level (38) . ...
The objective of the present study was to investigate the effects of β-conglycinin and soya isoflavones on diabetic nephropathy (DN). DN was induced by an intravenous injection of streptozotocin (25 mg/kg) in spontaneously hypertensive rats. DN rats were divided into a non-diabetic group (C, control group) and three DN groups (D, DN with control diet; B, DN+control diet with one-eighth of casein replaced by β-conglycinin as the protein source; and I, DN+control diet with 0·01 % soya isoflavones). After a 4-week experimental period, we found that fasting blood sugar and plasma and kidney advanced glycation end product levels and 24 h urinary protein excretion of the B group were significantly lower than those of the D group and insulin sensitivity and nephrin expression of the B group were significantly higher than those of the D group. In addition, systolic blood pressure, angiotensin-converting enzyme activity, angiotensin II level and plasma TAG level of the B group were significantly lower than those of the D group, whereas only the levels of plasma TAG and thiobarbituric acid-reactive substances of the I group were lower than those of the D group. In conclusion, β-conglycinin may be beneficial for retarding DN progression and this effect cannot be completely explained by its isoflavone content.
... For example, emerging evidence indicates that soybeans can decrease the risk of coronary heart disease and certain cancers, such as gastrointestinal cancer and lung cancer [12][13][14][15]. Soybeans are also recognized for alleviating symptoms of menopausal hot flashes and depression, as well as having a positive impact on renal function and skin health [16,17]. Among the 36% protein content in soybeans, approximately 90% consists of two storage globulins: 11S glycinin and 7S β-conglycinin [8]. ...
... These results are in line with previous study indicated renal protective effect of CV against rhabdomyolysis induced by glycerol [27] and they explained this protection effect related to the antioxidant activity of CV, numerous studies reported the antioxidant activity of CV [28,29]. Moreover, pretreatment with soy isoflavones, also preserved the normal levels of urinary β 2 -microglobulin, urine albumin, BUN and serum creatinine compared to glycerol group and these results are in line with previous studies stated that soy milk has Reno protective in animal models of renal disease [30,31]. These protective effects may be related to the effects of soy phytochemicals on enzymes gene expression, which can increase the antioxidant activity [32]. ...
Цель. Исследовать возможный протективный эффект изофлавонов сои (GN и DZ) в сравнении с таковым карведилола (CV) на модели глицерол-индуцированного ОПП у крыс. Материалы и методы. Объектом исследования явились взрослые крысы линии Ви- стар (30 самок), контингент которых включал 5 групп. Группа 1 (6 самок) была контрольной. Каждая же из последующих четырех групп включала в себя лабораторных животных, которым накануне моделирования ОПП производилось введение ежесуточно на протяжении 14 суток: воды из расчета 8 мл/кг массы тела (группа № 2 – 6 са- мок), карведилола (CV) – 2,5 мг/кг массы тела (группа № 3 – 6 самок), изофлавона GN (5,7-dihydroxy-8-[4-hydroxyphenyl]chromen-4-one) – 21,7 мг/кг (группа № 4 – 6 самок), изофлавона DZ (4,7 Dihydroxyisoflavone) – 17,4 мг/кг (группа № 5 – 6 самок). После этого животных последних четырех групп лишали воды на 24 часа, затем им вводили гипертонический раствор глицерола (8 мл/кг массы тела в день) в течение 3 сут. внутримышечно (или ВМ) для индуцирования ОПП. На четвертые сутки животных умерщвляли, кровь отбирали на биохимический анализ, а почки подвергали гистопатологическому анализу. Результаты. В продолжение всего эксперимента не было зарегистрировано ни одного случая гибели или изменения внешнего вида животных. Увеличение массы тела было достоверно значимым во всех группах, кроме группы индуцированного ОПП. Уровень β2-миоглобина в моче, альбумина в моче, остаточного азота и креатинина в сыворотке крови был повышен в группе индуцированного ОПП по сравнению с контрольной группой и оставался в пределах нормы в группах предварительного лечения CV, GN и DZ. Результаты гистопатологического исследования почек крыс совпали с результатами биохимических исследований. Заключение. Глицерин индуцирует ОПП, а профилактическая терапия препаратами CV, GN и DZ устраняет связанные с повреждением почек неблагоприятные явления. Таким образом, и карведилол (CV), и изофлавоны сои (GN и DZ) оказывают нефро- протекторное действие, однако CV и GN обладают более выраженным защитным эффектом, чем DZ. Показано, что протеины сои могут быть полезны для выздоровления пациентов с острым повреждением почек, вызванным распадом мышечной ткани (рабдомиолизом).
Introduction. Acute kidney injury (AKI) is a thoughtful clinical problem with a high degree of morbidity and mortality. Therefore, searching for medicinal products with pronounced therapeutic and prophylactic effects in acute renal pathology appears to be relevant. Purpose. To investigate possible protective effect of soy isoflavones genistein (GN) and daidzein (DZ) compared to сarvedilol (CV) against glycerol induced AKI in rats. Materials and methods. A total of 30 adult female Wister rats were divided into five groups. Group 1 (6 rats) represented the control. Group 2 (6 rats) represented the glycerol- induced ARI model, Groups 2 (6 rats), 3 (6 rats), 4 (6 rats) and 5 (6 rats) rats were administered 8 ml/kg water, 2.5 mg/kg CV, 21.7 mg/kg GN and 17.4 mg/kg DZ respectively, orally daily for 14 days and after that animals of the last four groups were deprived from water for 24h, and then administered hypertonic solution (8 ml/kg body weight/day) IM for 3 days to induce ARI. Fourth day, the animals sacrificed, blood were collected for biochemical tests and kidneys for histopathological analysis. Results. No deaths or changes in animals appearance were reported throughout the study. Rises in body weight was significant in all groups, except AKI induced group. Urinary β2-microglobulin, urine albumin, BUN and serum creatinine were increased in the induced group compared to control and preserved normal in pretreatment groups with CV, GN and DZ. Histopathology results of rat kidneys are consistent with the biochemical results. Conclusion. Glycerol induces AKI and treatment with CV, GN and DZ reversed the adverse effects. Therefore, CV drug and soy isoflavones (GN and DZ) have a renal protective effect; however, CV and GN have more pronounced protective effect than DZ. It was shown that soya proteins might be of health values in recovering patients with acute kidney injury induced by rhabdomyolysis.
... Soybeans are enriched by unique isoflavones such as genistein and daidzein with various favorable health benefits (Liu et al. 2014b). It has been reported that consumption of a soy diet provoked notable renal protection in various animal models (Anderson 2008, Meng et al. 2017, Tomar et al. 2020. A former clinical trial revealed that short-time (less than 8 weeks) administration of soy proteins for patients with diabetes or chronic kidney disease was accompanied by less hyperfiltration and albuminuria, with subsequent improvement of renal functions (Liu et al. 2014a). ...
Acute kidney injury (AKI) is a life-threatening complication that accompanies rhabdomyolysis. Daidzein is a dietary isoflavone that has various biological activities. This study examined the therapeutic potential of daidzein and the underlying mechanisms against AKI induced by glycerol in male rats. Animals were injected once with glycerol (50%, 10 ml/kg, intramuscular) for induction of AKI and pre-treated orally with daidzein (25, 50, and 100 mg/kg) for 2 weeks. Biochemical, histopathological, immunohistopathological, and molecular parameters were assessed to evaluate the effect of daidzein. The results revealed that the model group displayed remarkable functional, molecular, and structural changes in the kidney. However, pre-administration of daidzein markedly decreased the kidney relative weight as well as the levels of urea, creatinine, K, P, kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and cystatin C. Further, daidzein lessened the rhabdomyolysis-related markers [lactate dehydrogenase (LDH) and creatine kinase (CK)]. Notably, the enhancement of the antioxidant biomarkers [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and reduced glutathione (GSH) is accompanied by a decrease in malondialdehyde (MDA) and nitric oxide (NO) levels. Moreover, upregulated gene expression levels of nuclear factor erythroid 2-related factor 2 (Nfe212) and hemeoxygenase-1 (Hmox1) were exerted by daidzein administration. Rats who received daidzein displayed markedly lower interleukin-1β (IL-1β), tumor nuclear factor-α (TNF-α), myleoperoxidase (MPO), and nuclear factor kappa B (NF-κB) levels together with higher interleukin-10 (IL-10) related to the model group. Remarkably, significant declines were noticed in the pro-apoptotic (Bax and caspase-3) and rises in antiapoptotic (Bcl-2) levels in the group that received daidzein. The renal histological screening validated the aforementioned biochemical and molecular alterations. Our findings support daidzein as a potential therapeutic approach against AKI-induced renal injury via suppression of muscle degradation, oxidative damage, cytokine release, and apoptosis.
... Profil asam amino protein kedelai berbeda dari kebanyakan protein hewani. Protein pada kedelai dapat mempengaruhi aliran darah ginjal dan laju filtrasi glomerulus penderita GGK 19 . ...
Background: Participation free radicals in biological processes have caused much damage in the human body including diseases chronic kidney failure (GGK). The number of sufferers of GGK is expected to continue to rise approximately 10 per year. One way to deal with it is to do a diet therapy through the granting of enteral formula for patients with GGK. Objective : The purpose of this study is to analyze the effect of snakehead fish, sprout soybean protein concentrate, and pumpkin flour to the physical quality, energy density, and nutritional content of enteral nutrition formulas for patients with Chronic Kidney Disease (CKD). Method:This type of research is experimental research laboratory with experimental designs "completely randomized design" using 4 levels treatment; P1, P2, P3, P4. Results: Enteral formula P4 has the best treatment than the other enteral formula products for CKD patients with 89.13 % water solubility; viscosity 136.66 cp; osmolarity of 387.17 mOsm/l; energy density 2.04 Kal/ml; carbohydrate content 57.29% of total energy; protein content 8.38% of the total energy; fat content 34.33% of energy total; water content 6.47%; ash content 1.96%; Quality protein/SAA 100%. Conclusion : Need a better packaging process so that the water content of CKD enteral formula can be stable.
... In a previous study, G. max L. induction caused no hepatic injury [53] but in current study there was mild increase in hepatic enzymes which is also similar to the previous study in which hepatic injury arise after consumption of soy protein [54]. In current study, methanolic extracts increased most of liver enzymes, which is in accordance to previous study [55]. Compared to control drug, all G. max (L.) extracts were found more potent to decrease elevated bilirubin in PCOS induced model. ...
Background: Females of reproductive age are affected by polycystic ovary syndrome (PCOS) around the globe. Conventional methods offer symptomatic relieve, with side effects so seeds of Glycine max (L.) were used in current study. Methods: Hormonal, biochemical and histopathological improvements of Letrozole (1.0 mg/kgb.w./day) induced female Sprague Dawley rats (150-200gm) were assessed after treatment with polarity based seed extracts of G.max (L.) (10 mg/kg b.w.) By keeping cyproterone acetate (1.0 mg/kg b.w.) as positive control. Results: Statistically analyzed results (p<0.0001) showed that luteinizing hormone (LH), testosterone, aspartate aminotransferase (AST) and bilirubin decreased in PCOS rats after treatment with distilled water extract (0.5±0 mlU/ml, 0.7±0.26 ng/dl, 103±18.7 IU/L, 0.8±0.1 IU/L) as compared to positive control (1.8±0.5 mlU/ml, 20.29±0.18 ng/dl, 0134.3±43.01 IU/L, 0.9±0.0mg/dl IU/L) respectively. Increase in follicle-stimulating hormone (FSH) and estradiol level by ethyl acetate extract and progesterone level by methanolic extract were significant (1.94±0.79 mlU/ml, 978±10.5pg/dl, 15.5±8.5pg/dl) as compared to positive control (2.5±1mlU/ml, 933±3.82 pg/dl, 3.3±0.68 pg/dl) respectively, while ethyl acetate extract decreased urea, creatinine and uric acid concentration (30.3±0.5mg/dl, 0.5±0.1 mg/dl, 2.6±0.7 mg/dl) as compared to control (41.3±1.5mg/dl,0.8±0.1mg/dl,4.7±0.15mg/dl) respectively, with restoration of normal ovarian stroma from typical pearl string cystic appearance and normal hepato-renal tissues in histology. Conclusion:
... 6 Whole soybean has a good potential for application in the functional food industry as it contains many components that are beneficial to health, such as fiber (which is not naturally found in yoghurt), essential fatty acids, isoflavones, proteins, oligosaccharides etc. 7 It has been reported that consumption of Soy protein decreases hyperfiltration in diabetic persons and may reduce urine albumin excretion (proteinuria). 8 Protein content of soybeans is about 4 times that of egg and 12 times that of milk 9 and contains all amino acids essential to human nutrition, which makes soy products almost equivalent to animal sources in protein quality. Soy protein is characterized by less saturated fat and no cholesterol 10 with biological value of 74, whole soybean 96 11 and protein digestibility value of 98 12 and rich in polyunsaturated fats, the iodine value ranges from 125 to 132 gI2/100 g. 13 Yoghurt is a type of dairy product produced from milk or milk products by lactic acid fermentation through the action of probiotics Streptococcus salivarius subsp. ...
... Since methionine is the initiating amino acid in eukaryotic protein synthesis (16), cellular protein synthesis cannot be initiated in methionine-deficiency, which can lead to decreased growth (17). There are many studies suggesting that soy proteins are beneficial to health, due to encompassing hypocholesterolemic, anti-carcinogenic, bone-sparing effects, hypotensive activity, and protection against metabolic diseases such as obesity or diabetes (18)(19)(20)(21)(22). However, little is known about the adverse effects of soy proteins, with the exception of allergic reactions and poor their digestibility acting as a trypsin inhibitor (21,22). ...
Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, however the exact cause of NAFLD remains unknown. Methionine, an essential amino acid, is the first limiting amino acid of soy protein, and its deficiency is suggested to cause hepatocyte damage and NAFLD. The objective of this study is to examine the changes in NAFLD susceptibility with soy protein consumption and deterioration due to prohibitin 1 (PHB1) deficiency, an important protein in hepatic mitochondrial function. In this study, liver-specific phb1 +/- mice and wild-type mice were fed a normal diet, choline-deficient diet (CDD), or soy protein diet without choline (SPD) for 16 weeks. Using hematoxylin and eosin staining, we showed that SPD attenuates symptoms of hepatocyte damage and lipid accumulation induced by CDD in mouse liver. The liver damage in mice fed the SPD was alleviated by decreasing lipogenic markers and by increasing anti-inflammatory markers. Furthermore, mRNA expression of genes involved in hepatic methionine metabolism was significantly lower in liver-specific phb1 +/- mice fed with a SPD compared with wild-type mice fed with a SPD. These data suggest a CDD can cause non-alcohol related liver damage, which can be attenuated by a SPD in wild-type mice. These phenomena were not observed in liver-specific phb1 +/- mice. It may therefore be concluded that SPD attenuates CDD-induced liver damage in wild-type mice, and that PHB1 deficiency blocks the beneficial effects of SPD against CDD-induced liver damage.
... The potential renal benefits of soybean products have considerable public health significance because of the increasing worldwide prevalence of renal disease [7]. The previous research evidence showed that replacing animal protein with soy protein contributed to a reduction in hyperfiltration and glomerular hypertension, with resultant protection from diabetic nephropathy [8,9]. Nevertheless, a meta-analysis of 12 clinical studies involving 280 patients with chronic renal disease found that dietary soy protein did not affect the glomerular filtration rate, although it significantly decreased serum creatinine, serum phosphorus, inflammation, and proteinuria in predialysis patients [10]. ...
Chronic kidney disease (CKD) is a global epidemic with an increasing prevalence worldwide. Effective preventive strategies are urgently needed. This study aimed to investigate the effect of nutraceutical components, a fermented soybean product (ImmuBalance, IMB) and an oligo-lactic acid product (LAP), on the prevention of adenine-induced CKD in mice. Female C57BL/6 mice were randomly assigned into following experimental groups: negative control; model control; and models treated with IMB at 250 or 1000 mg/kg body weight (BW), LAP at 1000 or 2000 mg/kg BW, and IMB/LAP combinations. The CKD model was established by intraperitoneal injection of adenine daily for 4 weeks, and treatments started 2 weeks before adenine injection and ended after 10 weeks. Compared with the model control, the treatments did not significantly alter the body weight or food intake. Both IMB and LAP, especially their combination, significantly inhibited tubular dilation, tubulointerstitial degeneration or atrophy, interstitial chronic inflammation and acute inflammation in the kidneys of CKD mice, and significantly decreased serum cystatin C levels. IMB or LAP significantly reversed CKD-associated increases of circulating and kidney levels of inflammatory cytokines, circulating levels of kidney injury biomarkers, and kidney levels of stem cell biomarkers, and significantly reversed CKD-associated reduction of cecum Clostridium leptum group. Our results suggest that dietary supplementation of IMB or LAP may significantly delay the development and/or progression of CKD.
... Some studies have shown that the consumption of soy protein can be used as part of the dietary strategy for the treatment of several pathological conditions, including renal disease [62][63][64][65] and elevated concentration of low-density lipoproteins (LDL)cholesterol 66,67 . In addition, the use of soy protein has been shown to attenuate the development of lipotoxicity in several organs, as described below. ...
Obesity is associated with an increase of several metabolic disorders leading to the development of diseases such as type 2 diabetes and cardiovascular disease. This is due in part to the ectopic accumulation of triglycerides in organs that are non-adipose tissues, leading to lipotoxicity. Particularly, in the liver, the accumulation of lipids, mainly of triglycerides, leads to the formation of fatty liver. The accumulation of lipids in skeletal muscle and pancreas associates with insulin resistance and a decrease in insulin secretion, respectively. In addition, it has been suggested that dysbiosis of the gut microbiota can contribute to the process of lipid accumulation in non-adipose tissues, especially in the liver. The aim of the present review is to highlight the mechanisms associated with the development of lipotoxicity, and how with the advances in nutrigenomics, it is now possible to understand the molecular mechanisms by which some nutrients can attenuate the ectopic accumulation of triglycerides in non-adipose tissues. Particularly, we emphasize research conducted on the molecular mechanisms of action of soy protein and some of its isoflavones, and how these can reduce lipotoxicity by preventing the accumulation of lipids in the liver, skeletal muscle, and pancreas, as well as their role on the gut microbiota to attenuate the development of fatty liver. Thus, nutrigenomics is opening new dietary strategies based on several functional foods that can be used to ameliorate the pathologies associated with lipotoxicity.
... Limited data suggested that soy can be beneficial on renal health [376], cognitive functions [377], immunity [378] and reproduction [379]. ...
Soy is a basic food ingredient of traditional Asian cuisine used for thousands of years. In Western countries, soybeans have been introduced about a hundred years ago and recently they are mainly used for surrogate foods production. Soy and soy foods are common nutritional solutions for vegetarians, due to their high protein content and versatility in the production of meat analogues and milk substitutes. However, there are some doubts about the potential effects on health, such as the effectiveness on cardiovascular risk reduction or, conversely, on the possible disruption of thyroid function and sexual hormones. The soy components that have stimulated the most research interest are isoflavones, which are polyphenols with estrogenic properties highly contained in soybeans. In this review, we discuss the characteristics of soy and soy foods, focusing on their nutrient content, including phytoestrogens and other bioactive substances that are noteworthy for vegetarians, the largest soy consumers in the Western countries. The safety of use will also be discussed, given the growing trend in adoption of vegetarian styles and the new soy-based foods availability.
... The bioactive phytochemicals in soybean manifested complementary effects on renal function by improving renal flow, reducing proteinuria, renal histological damage and resultantly retarding the development of kidney disease. [198][199][200][201] SI acted as an effective chemopreventive agent against KBrO 3 (potent nephrotoxic agent) mediated renal oxidative A c c e p t e d M a n u s c r i p t 16 stress and subsequent cell proliferation response in wistar rats by significant reduction in levels of tumour promoter markers, scavenging ROS, induction of anti-oxidant enzyme and detoxification through induction of phase II pathways involving enzymes such as glutathione S-transferase and quinone reductase. [202] Moreover, administration of soy protein delayed an early stage of kidney disease progression after 1st and 3rd week by reducing renal fibrosis and cyst growth in male Han:SPRD-cy rats. ...
Functional foods are the focus of attraction for well-being. The healthy living of Asians may be attributed to a diet enriched with soy isoflavones (SI) viz. genistein and daidzein which fills the gap of proteinaceous diet in vegetarians. Several factors such as administration, dosage, metabolism, ingestion of other pharmacological substances, type of estrogen receptors and presence or absence of endogenous estrogen affect the activities and bioavailability of isoflavones. Mode of therapeutic action could be either through the stimulation of estrogen receptors or by the non-involvement of estrogen receptors. Soy, owing to its isoflavones content serve as a balanced and remedial substitute in combating various lifestyle disorders like cancer prevention by interruption of the breakdown of extracellular matrix that surrounds growing vessels and tumors, lowering of lipid and blood insulin levels by regulating lipid and glucose metabolism, alleviation of menopausal symptoms and osteoprotective effects by modulating estrogen receptors, thus acting as a safer switch to hormone replacement therapy, anti-hypertensive effect which may also contribute to cardioprotective, anti-oxidative effect, regulation of cognitive functions and many others. Therefore, it could be regarded as a valuable therapeutics. However, since SI also act as endocrine disruptors, they also possess some negative effects. Concerns have been raised in relation to thyroid function abnormality. In view of above mentioned facts an attempt has been made to review the literature available on both beneficial as well as deleterious role of isoflavones, soy derived bioactive compounds.
... Clarification is still needed regarding the mechanism(s) underlying the association between the low serum bicarbonate level and RHF. It is well known that high protein intake can increase the glomerular filtration rate in human beings and that substitution of soy protein for animal protein results in less hyperfiltraton [21]. In a cross-sectional study of 2,938 CKD patients, the percentage of total protein intake from plant sources was associated with a higher serum bicarbonate level [22]. ...
Background
Lower serum bicarbonate, mainly due to the modern Western-style diet, and renal hyperfiltration (RHF) are both independently associated with higher mortality in the general population with preserved renal function. The objective of this study was to evaluate the association between serum bicarbonate and RHF.
Methods
The health data of 41,886 adults with an estimated glomerular filtration rate (eGFR) ≥60 mL/min per 1.73 m² were analyzed. The eGFR was calculated with the Chronic Kidney Disease Epidemiology Collaboration creatinine equation and RHF was defined as eGFR with adjusted residuals > sex-specific 95th percentile.
Results
The adjusted mean of eGFR was lower in the highest quintile of serum bicarbonate than in other quintiles, after adjusting for confounders. A lower percentile rank of serum bicarbonate was associated with higher odds of RHF. The odds ratio (OR) for RHF in the lowest quintile of serum bicarbonate was 1.39 (95 % confidence interval, 95 % CI, 1.11–1.75) compared to the highest, after adjusting for confounders. With subgroup analysis, the association was prominent in participants with a body mass index >25 kg/m² (OR 1.98, 95 % CI 1.32–2.95 in the lowest quintile compared to the highest), compared to those with a body mass index ≤25 kg/m² (OR 1.18, 95 % CI 0.89–1.56 in the lowest quintile compared to the highest).
Conclusions
This study observed an association between lower serum bicarbonate and higher odds of RHF and the possible differential effect of obesity in this association. It is necessary to confirm the association between lower serum bicarbonate and RHF and its causality.
... Stephenson et al. (2005) reported that 40% of new cases of renal disease are related to diabetes. While reviewing studies pertaining to the beneficial effects of soy protein consumption for renal function, Anderson (2008) concluded that the role of soy isoflavones and soy peptides in improving renal function in diabetic neuropathy should be investigated. ...
... Además del efecto sobre la DMO, las isoflavonas de la soja también han sido reportadas por su posible acción anticancerígena en tejidos de mama (10), próstata (11) y colón (12); también como mitigante de los efectos adversos de la radioterapia sobre tejidos normales (13), protector del endotelio vascular (14), promotor de la proliferación y la diferenciación de células de la dentina (15), y coadyuvante en el tratamiento de la diabetes mellitus (16) y de enfermedades renales (17). Actualmente se está estudiando su efecto preventivo en el Alzheimer (18,19). ...
... Además del efecto sobre la DMO, las isoflavonas de la soja también han sido reportadas por su posible acción anticancerígena en tejidos de mama (10), próstata (11) y colón (12); también como mitigante de los efectos adversos de la radioterapia sobre tejidos normales (13), protector del endotelio vascular (14), promotor de la proliferación y la diferenciación de células de la dentina (15), y coadyuvante en el tratamiento de la diabetes mellitus (16) y de enfermedades renales (17). Actualmente se está estudiando su efecto preventivo en el Alzheimer (18,19). ...
Las isoflavonas de la soja son metabolitos secundarios conocidos como fitoestrógenos por su similitud estructural con el 17b-estradiol. La daidzeina y la genisteina son las principales isoflavonas de la soja. Debido a su capacidad de unión a los receptores de estrógeno (RE) son consideradas moduladores selectivos de los receptores de estrógenos (MSRE). El consumo dietario de isoflavonas es relacionado con la disminución de los síntomas de la menopausia, prevención de enfermedades cardiovasculares y de otras enfermedades crónicas como la diabetes mellitus. También, las isoflavonas han sido propuestas para el tratamiento de algunos tipos de cáncer y la prevención de la osteoporosis; sin embargo, existe gran controversia sobre los posibles efectos estrogénicos en niños púberes y pre-púberes alimentados con fórmulas a base de proteína de soja. El objetivo de este trabajo es presentar una revisión sistemática de la química de las isoflavonas de la soja y sus efectos sobre la salud del hueso en adultos y niños.
... To our knowledge, our study is the first prospective study to suggest a possibly protective effect of soy foods on the risk of developing gout. The protective association between soy and gout, if true, may be mediated through the promotion of weight loss (31) and an enhanced uricosuric effect (32,33). ...
Prospective studies evaluating diet on gout risk in Asian populations are lacking. We examined the relationship between consumption of dietary protein and its major sources, and risk of gout in a Chinese population.
We used data from the Singapore Chinese Health Study, a prospective cohort with 63,257 Chinese adults aged 45-74 years at recruitment (1993-1998). Habitual diet information was collected via a validated semi-quantitative food frequency questionnaire, and physician-diagnosed gout was self-reported during two follow-up interviews up to 2010. Cox proportional hazards models were used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) with adjustment for potential confounders among 51,114 eligible study participants who were free of gout at baseline and responded to our follow-up interviews.
A total of 2,167 participants reported physician-diagnosed gout during the follow-up. The multivariate-adjusted HR (95% CI) of gout comparing extreme quartiles was 1.27 (1.12 to 1.44; p<0.001 for trend) for total protein, 1.27 (1.11 to 1.45; p<0.001 for trend) for poultry, 1.16 (1.02-1.32; p=0.006 for trend) for fish and shellfish, 0.86 (0.75 to 0.98; p=0.018 for trend) for soy food, and 0.83 (0.73 to 0.95; p=0.012 for trend) for legumes. No statistically significant associations were found with intakes of other protein sources (red meat, eggs, dairy products, grains, nuts and seeds).
Total protein intake, mainly contributed by poultry, fish and shellfish, is associated with an increased risk of gout, while dietary intakes of soy and legumes are associated with a reduced risk of gout. This article is protected by copyright. All rights reserved.
© 2015 American College of Rheumatology.
... 145 Substituting soy protein for animal protein may also be beneficial in diabetics with proteinuria but studies have not been consistent. 146 A number of alternative medicine supplements have also been studied (Table 3). Lastly, sodium restriction to 50-70 mmol daily may enhance the action of RAS inhibitors and result in a greater reduction in albuminuria in type 2 diabetics. ...
Diabetic nephropathy is a significant cause of chronic kidney disease and end-stage renal failure globally. Much research has been conducted in both basic science and clinical therapeutics, which has enhanced understanding of the pathophysiology of diabetic nephropathy and expanded the potential therapies available. This review will examine the current concepts of diabetic nephropathy management in the context of some of the basic science and pathophysiology aspects relevant to the approaches taken in novel, investigative treatment strategies.
... Although studies are small, several support the idea that plant-based diets can delay the progression of CKD, provide endothelial protection, control high blood pressure, and decrease proteinuria. [1][2][3][4][5][6][7][8][9][10] These days, our dialysis patients seldom die secondary to high potassium or uremia. Many of our patients now face the same diseases as the general population: heart disease, cancer, and strokes. ...
... Furthermore, substituting soy or vegetable protein for animal protein in the diet has been shown to reduce the risk and progression of renal disease in both type 1 and type 2 diabetes. [105][106][107][108][109][110] There are only a few intervention studies assessing the effects of a vegetarian diet in people with diabetes, and weight loss has generally been greater on the vegetarian diets, making it difficult to determine the independent effect of the diets. 111 However, greater weight loss may be one of the advantages of a vegetarian diet because even small amounts of weight loss can help in both the prevention and management of type 2 diabetes. ...
There is now a significant amount of research that demonstrates the health benefits of vegetarian and plant-based diets, which have been associated with a reduced risk of obesity, diabetes, heart disease, and some types of cancer as well as increased longevity. Vegetarian diets are typically lower in fat, particularly saturated fat, and higher in dietary fiber. They are also likely to include more whole grains, legumes, nuts, and soy protein, and together with the absence of red meat, this type of eating plan may provide many benefits for the prevention and treatment of obesity and chronic health problems, including diabetes and cardiovascular disease. Although a well-planned vegetarian or vegan diet can meet all the nutritional needs of an individual, it may be necessary to pay particular attention to some nutrients to ensure an adequate intake, particularly if the person is on a vegan diet. This article will review the evidence for the health benefits of a vegetarian diet and also discuss strategies for meeting the nutritional needs of those following a vegetarian or plant-based eating pattern.
... Substituting soy pro- tein for animal protein has been found to decrease hyperfiltration in subjects with diabetes and may reduce urine albumin excretion. 88 A small study of 8 patients with type 1 diabetes and a raised albumin excretion rate (AER) found that following a pre- dominately vegetarian diet (with a sim- ilar protein content to their usual diet) for 8 weeks led to a significant reduction in AER, which then returned to baseline after resuming their normal diet for a fur- ther 8 weeks. 89 This occurred despite no significant changes in blood glucose control or blood pressure. ...
A large body of evidence suggests that vegetarian and plant-based diets provide exceptional health benefits, including a reduced risk of obesity, diabetes, heart disease and some types of cancer, and increased longevity. Vegetarian diets are typically lower in fat, particularly saturated fat, and higher in dietary fiber. They are also likely to include more whole grains, legumes, nuts, and soy protein, which together provide micro-nutrients and protective factors at higher levels than most Western diets. In observational studies, a vegetarian or vegan diet is associated with reduced risk of development of type 2 diabetes and lower risk of complications in those with existing diabetes. Although it is often difficult to separate vegetarianism from other healthy lifestyle behaviors, this eating pattern and the absence of red meat and processed meat products may provide particular benefits in the management of diabetes and prediabetes. This article critically reviews the scientific evidence for the role of vegetarian diets in the prevention and management of diabetes.
... Consumption of soya bean and soya bean foods has been linked to many health benefits. Various studies have reported associations between soya bean consumption and reduced risk of cardiovascular disease, cancer, diabetes, bone loss and menopausal symptoms amongst others (Friedman and Brandon 2001, Hori et al. 2001, Chen et al. 2003, Zhang et al. 2003, Stephenson et al. 2005, Anderson 2008 ). These reports have fuelled the growth of soya foods in Western countries. ...
The management of allergens along the food value chain and the diagnosis of food allergic diseases continue to pose serious challenges to the food industry as well as health care professionals. Of the over 170 foods known to provoke allergic reactions, nine foods (and their derived products) are today considered to be major allergens accounting for over 90% of all food allergic reactions. These priority allergens include milk, eggs, soya beans, peanuts, tree nuts (e.g. almonds, walnuts, pecans, cashews, Brazil nuts, hazel nuts, pistachios, pine nuts, macadamia nuts, chestnuts and hickory nuts), seafood such as fish (i.e. both saltwater and freshwater finfish), crustaceans (e.g. shrimp, prawns, crab, lobster and crayfish) and molluscs (e.g. snails, oysters, clams, squid, octopus and cuttle- fish), gluten-containing cereals (i.e. wheat, rye, barley and their hybridised strains and products), sesame and mustard. Symptoms of food allergic reactions and the threshold dose required to provoke allergic reaction markedly vary among sensitised individuals. Food production practices, processing conditions and matrix effects can also modify the molecular structure of food allergens and their potential immunogenic properties which can make allergens diffi- cult to detect even when present in foods. This chapter provides an overview of the different types of food hypersensitivities including a distinction between food allergies and food intolerance, the properties of the nine priority food allergens, current approaches for the management of food allergens and a summary of some of the current methods used in food allergen detection.
Background: Acute kidney injury (AKI) is a severe, high-morbidity condition with limited effective preventative and therapeutic strategies despite advancements in understanding and treatment. Specific Background: Rhabdomyolysis-induced acute kidney injury (AKI) presents significant challenges in renal research, but soy isoflavones, particularly GN and DZ, have shown potential in mitigating oxidative stress and inflammation. Knowledge Gap: Soy isoflavones, while potentially providing renal protection, their impact on renal and hematologic parameters in glycerol-induced AKI models has not been thoroughly studied. Aims: The study evaluated the effectiveness of soy isoflavones in regulating renal and hematologic parameters in a glycerol-induced AKI rat model, assessing their potential as therapeutic agents. Results: The study involving adult female Wistar rats showed that pretreatment with glycerol or dihydroxystilbene significantly reduced urinary β2-microglobulin, albumin, BUN, and serum creatinine levels in the AKI-induced group, reversing hematological changes. Novelty: The study explores the protective effects of soy isoflavones on renal function and hematologic parameters in AKI, highlighting GN's superior efficacy over DZ. Implications: Soy isoflavones, particularly GN, may be potential preventive or therapeutic strategies for AKI caused by rhabdomyolysis, warranting further research for clinical applications. Highlights: GN and DZ reduce kidney damage in glycerol-induced AKI. GN is more effective than DZ in kidney and blood parameters. Soy isoflavones could treat or prevent AKI. Keywords: Acute kidney injury, soy isoflavones, glycerol-induced AKI, renal protection, hematologic parameters
Diabetes is a major health issue for humans, and its complications can lead to a variety of health problems. Nephropathy has been recognised since the 1930s, when Kimmelstiel and Wilson first reported the characteristic nodular glomerulosclerosis lesions in diabetic kidneys. Diabetic nephropathy (DN), commonly known as diabetic kidney disease, is a condition in which diabetics have excessive quantities of urine albumin excretion, diabetic glomerular lesions, and a reduction in their glomerular filtration rate (GFR). Type 1 diabetes (autoimmune -cell destruction and absolute insulin insufficiency), type 2 diabetes (relative insulin deficit and resistance), and others are the three forms of diabetes (eg, pancreatic disease). Diabetes nephropathy is a leading cause of chronic kidney disease and end-stage renal failure around the world. Much research has been conducted in both basic science and clinical therapies to enhance understanding of the mechanism of diabetic nephropathy and to expand the available therapeutics. Diabetic nephropathy prevention continues to rely on screening for microalbuminuria and treating hyperglycemia. However, several studies suggest that managing diabetic kidney disease is more challenging. Despite comparable hyperglycemic management, some studies suggest that the incidence of renal problems varies by patient. As a result, there has been a great deal of interest in studying the inherent renal protective effect of various antihyperglycemic drugs. The goal of this study is to provide information about the diabetic kidney disease conceptual model, pathogenesis, screening, and diagnosis. It will also address the treatment and prevention of diabetic nephropathy, with a focus on comparing the mechanisms, safety profiles, and efficacy of different antihyperglycemic medications.
A low insulin‐like growth factor 1 (IGF‐1) level is known to be associated with many disorders. Several studies have shown that soy consumption may influence IGF‐1, but the findings remain inconclusive. In this work, we conducted a systematic review and meta‐analysis to provide a more accurate estimation of the effect of soy consumption on plasma IGF‐1. A comprehensive systematic search was performed in Scopus, Embase, Web of Science, and PubMed/MEDLINE databases from inception until October 2019. Eight studies fulfilled the eligibility criteria. The pooled weighted mean difference (WMD) of the eligible studies was calculated with random‐effects approach. Overall, a significant increment in plasma IGF‐1 was observed following soy intervention (WMD: 13.5 ng/ml, 95% CI: 5.2, 21.8, I2 = 97%). Subgroup analyses demonstrated a significantly greater increase in IGF‐1, when soy was administered at a dosage of ≤40 g/day (WMD: 11.7 ng/ml, 95% CI: 10.9 to 12.6, I2 = 98%), and when the intervention duration was <12 weeks (WMD: 26.6 ng/ml, 95% CI: 9.1 to 44.1, I2 = 0.0%). In addition, soy intervention resulted in a greater increase in IGF‐1 among non‐healthy subjects (WMD: 36 ng/ml, 95% CI: 32.7 to 39.4, I2 = 84%) than healthy subjects (WMD: 9.8 ng/ml, 95% CI: 8.9 to 10.7, I2 = 90%). In conclusion, this study provided the first meta‐analytical evidence that soy intake may increase IGF‐1 levels, but the magnitude of the increase is dependent on the intervention dosage, duration, and health status of the participants.
Objective Vegetarian diets have been shown to increase the risk of certain nutritional deficiencies, such as iron. As a number of patients with chronic kidney disease (CKD) in Taiwan are lacto–ovo vegetarians, the aim of this study was to investigate the effects of different proportions and sources of protein in lacto–ovo vegetarian and omnivorous diets, as well as the influence of adequate dietary protein intake, on renal function and nutritional status of Taiwanese patients with stage 3 to stage 5 CKD.
Methods This is a cross-sectional study. In total, 100 outpatients with stage 3 to stage 5 CKD were enrolled in this study, including 40 lacto–ovo vegetarians and 60 omnivores. Subjects were divided into the lacto–ovo vegetarian group and omnivorous group based on dietary protein patterns. The indicators of renal function included estimated glomerular filtration rate (eGFR), creatinine, and blood urea nitrogen (BUN). Albumin, hemoglobin (Hb), and red blood cell count (RBC) measurements served as nutritional indicators. The levels of dietary energy and protein, as well as protein sources (plant or animal), were also analyzed.
Results The levels of serum phosphate and triglycerides were significantly lower in the lacto–ovo vegetarian group than in the omnivore group, suggesting that lacto–ovo vegetarian diets have both phosphate-lowering and lipid-lowering effects, which could reduce the development of hyperphosphatemia and dyslipidemia. However, since all groups consumed higher than the recommended amounts of protein diet intake, no significant differences were observed in other renal function indices between the two groups.
Conclusion Although a larger cohort study is necessary, the findings of this study could help patients with CKD to make healthier food choices and be used to support future medical nutritional therapies.
Dolichos sofa Linn., Glycine angustifolia Miq., Glycine gracilis Skvortsov, Glycine hispida (Moench.) Maxim., Glycine hispida var. brunnea Skvortsov, Glycine hispida var. lutea Skvortsov, Glycine soja (L.) Merr., Phaseolus max Linn. (basionym), Phaseolus sordidus Salisb., Soja angustifolia Miquel, Soja hispida Moench., Soja japonica Savi, Soja max (L.) Piper, Soja soja Karst., Soja viridis Savi.
Chronic kidney disease (CKD) is a major public health problem with significant clinical, societal, and psychosocial burdens. Nutrition therapy has been an integral part of the medical management of patients with CKD for more than a century, with the main goals of preserving kidney function and preventing complications. Nutrition abnormalities may emerge well before dialysis therapy is initiated and are associated with poor outcomes. It is therefore important to revisit nutrition management in the advanced stages of CKD to gain a broader insight into its role and effect on patient outcomes. Traditionally, nutrition recommendations have focused on the prescription of energy (calories) and macro- and micronutrients. Today, dietary modeling also focuses on the evidence for food consumption on health. This review argues that advanced non-dialysis-dependent CKD nutrition requirements to a large extent align with healthy eating guidelines for the general population and should not be based on deprivation or be unusually restrictive. The best currently available evidence for the CKD diet is likely to be derived from CKD nutrition prescriptions in conjunction with evidence underpinning national dietary guidelines and evidence of healthy dietary patterns, such as Mediterranean-style and Dietary Approaches to Stop Hypertension (DASH)-style eating. Positive messages from these dietary patterns should improve acceptance of CKD dietary interventions among patients.
The purpose of this research was to study the effect of mocaf, snakehead fish flour, and sprouts soybean protein concentrate on the physical quality, energy density, nutritional content, and nutritional quality enteral formula for CKD patients. This type of research is laboratory experiment with experimental design completely randomized design using 4 level of treatment are F-G1 (enteral nutrition devepment 1), FG-2 (enteral nutrition development 2), FG-3 (enteral nutrition development 3); FG-4 (enteral nutrition development 4). The research was implemented in May-July 2013. Enteral nutrition FG-2 is a best treatment for enteral nutrition product to CKD patients. Further research can be done using intervention for formula FG-2 in animal experiments to determine the effect of the formula in preventing renal function decline.
Scope:
The soy isoflavone, daidzein, is metabolized by gut microbiota to O-desmethylangolensin (ODMA) and/or equol. Producing equol is postulated as a contributing factor for the beneficial effects of soy.
Methods and results:
This randomized, controlled, crossover design used an untargeted metabolomic approach to assess the metabolic profile of different daidzein metabolizers. Adults (n = 17) with cardiometabolic risk factors received soy nuts or control food for four-weeks, separated by a two-week washout. No significant differences were detected pre- and post-intervention and between interventions. Examination of the ability to metabolize daidzein revealed three groups: ODMA only producers (n = 4), equol+ODMA producers (n = 8), and non-producers (n = 5). Analysis of the serum metabolome revealed non-producers could be distinguished from ODMA-only and equol+ODMA producers. Differences between these phenotypes were related to obesity and metabolic risk (methionine, asparagine, and trimethylamine) with equol+ODMA producers having lower concentrations, yet paradoxically higher pro-inflammatory cytokines. In urine, non-producers clustered with ODMA producers, and were distinct from equol+ODMA producers. Urinary metabolite profiles revealed significantly higher excretion of fumarate and 2-oxoglutarate, as well as pyroglutamate, alanine, and the gut microbial metabolite dimethylamine in equol+ODMA producers.
Conclusion:
These results emphasize that the serum and urine metabolomes are distinct based on the ability to metabolize isoflavones. This article is protected by copyright. All rights reserved.
The soy isoflavones are secondary metabolites known as phytoestrogens because of its structural similarity to 17b-estradiol. Genistein and Daidzein are the main soy isoflavones. Due their binding ability to estrogen receptors (ER) they are considered as selective estrogen receptor modulators (SERM). The dietary intake of isoflavones has been associated with decreasing menopause symptoms, prevention of cardiovascular disease and some chronic diseases such as diabetes mellitus. Also, the isoflavones have been proposed for the treatment of certain kind of cancer and osteoporosis prevention, but there is a lot of controversy about the possible estrogenic effects in pubertal and pre-pubertal children who have been fed with soy protein-based formulas. The aim of this research is to present a systematic review of the soy isoflavone chemistry and their effects on bone health in adults and children.
Studies of the effects of soy in laboratory animals routinely identify significant reductions in hypertension. Clinical studies in humans are less consistent in their documentation of blood pressure lowering effects of soy although a consensus is emerging that confirms an antihypertensive effect. The primary health benefits of soy are ascribed to soy isoflavones and soy protein. Antihypertensive mechanisms of soy isoflavones include increases in vasodilator activity and reduction in vasoconstrictor activity, inhibition of the renin-angiotensin system, antioxidant effects, and positive effects on renal function. Soy isoflavones are also known as phytoestrogens as they can activate the genomic estrogen receptor. Recent evidence indicates that isoflavones can also activate the peroxisome proliferator activated receptor (PPAR) as well as the pregnane X receptor (PXR) and that these genomic mechanisms may also be involved in the regulation of blood pressure. Soy protein has been shown to contain the bioactive peptide, lunasin, which may be involved in the antihypertensive effect of soy protein. These recent findings regarding PPAR, PXR, and lunasin, as well as reports that soy isoflavones and soy protein may exert synergistic effects on hypertension reduction, provide new excitement to the study of the antihypertensive effects of soy.
Background and objectives:
Nephrotic syndrome is a chronic disease especially common in the childhood and adolescence. Reactive oxygen species (ROS) and free radicals have significant role in the pathogenesis of nephrotic syndrome. The aim of this study was to evaluate the effect of soy protein and genistein (main isoflavone of soybean) on renal antioxidant status of nephrotic rats.
Methods:
This study was done for 8 weeks on 40 adult male Sprague-Dawley rats divided into four groups of 10 rats each. Study groups included: 1-Control, 2-Nephrotic syndrome, 3-Nephrotic syndrome+soy protein diet and 4-Nephrotic syndrome+soy protein diet+genistein. Urine protein and urine creatinine were measured. After homogenization of kidney, total antioxidant capacities (TAC), activities of catalase enzyme, the concentration of malondialdehydes (MDA) and carbolynated proteins were determined spectrophotometrically. Pathological examination was done on kidneys with light microscope. Cell viability was evaluated with MTT assay on WEHI-164 fibro sarcoma cell line. The MMP2 enzyme activity was evaluated in different concentrations of genistein.
Results:
Total antioxidant capacity was significantly increased in soy genistein. Catalase activity was significantly increased in soy and soy genistein groups. Protein carbonyl and MDA were significantly lower in soy and soy genistein groups. The scores of pathological examination showed significant improvement in soy and soy genistein groups. Genistein decreased the proliferation of the WEHI-164 fibrosarcoma cell line.
Conclusion:
It seems that soy protein decreases kidney damages in nephrotic syndrome. Adding genistein to soy protein causes improvements in antioxidant status of kidney tissue. Genistein decreases proliferation of cell.
A vegetarian diet can easily meet human dietary protein requirements as long as energy needs are met and a variety of foods are eaten. Vegetarians should obtain protein from a variety of plant sources, including legumes, soy products, grains, nuts and seeds. Eggs and dairy products also provide protein for those following a lacto-ovo-vegetarian diet. There is no need to consciously combine different plant proteins at each meal as long as a variety of foods are eaten from day to day, because the human body maintains a pool of amino acids which can be used to complement dietary protein. The consumption of plant proteins rather than animal proteins by vegetarians may contribute to their reduced risk of chronic diseases such as diabetes and heart disease.
Background/objectives:
There is a growing body of evidence to indicate that soy protein consumption may have a beneficial effect on kidney function. We performed a meta-analysis to evaluate the effects of soy protein consumption compared with animal protein consumption in patients with pre-dialysis chronic kidney disease (CKD).
Subjects/methods:
We conducted a structured electronic search of the databases PubMed, EMBASE, Cochrane Library and Chinese Biological Medicine for randomized controlled trials published up to March 2014. The outcome measures were serum creatinine (SCR), triglyceride (TG), total cholesterol (TC), calcium (Ca) and phosphorus concentrations. Weighted or standard mean differences were calculated for net changes using random-effects models.
Results:
The meta-analysis consisted of nine trials, comprising 197 subjects. Soy protein intake significantly reduced SCR and serum phosphorus concentrations. The mean difference was -6.231 μmol/l (95% confidence interval (CI): -11.109, -1.352 μmol/l) for SCR (P=0.012) and -0.804 (95% CI: -1.143, -0.464 μmol/l) for serum phosphorus (P=0.00). It also significantly reduced serum TG, with a pooled estimated change of -0.223 mmol/l (95% CI: -0.396, -0.051 mmol/l; P=0.011) after the exclusion of one trial indicated by sensitivity analyses. No statistically significant effects were observed for TC (-0.135 mmol/l (95% CI: -0.289, 0.019 mmol/l)) or Ca (0.023 mmol/l (95% CI: -0.016, 0.062 mmol/l)).
Conclusions:
The meta-analysis suggested a protective effect of soy protein consumption on SCR and serum phosphorus concentrations in pre-dialysis CKD patients. It may also have a significant effect on lowering serum TG concentrations. However, nonsignificant effects on TC and Ca were observed. Evidence was limited because of the relatively small number of available trials and subjects.
Objectives:
The aim of the study was to examine the long-term effect of commonly used whole soy foods (soy flour) and purified daidzein (one major isoflavone and the precursor of equol) on renal function among prehypertensive postmenopausal women who are also equol producers, a population most likely to benefit from soy intervention.
Design and methods:
This was a 6-month double-blind, randomized, placebo-controlled trial. Two hundred seventy eligible Chinese women were randomized to either one of the three treatments: 40 g soy flour (whole soy group), 40 g low-fat milk powder + 63 mg daidzein (daidzein group) or 40 g low-fat milk powder (placebo group) daily each for 6 months. Fasting blood and 24-h urine samples were collected at the beginning and end of trial. Serum creatinine, cystatin C, urea, angiotensin-converting enzyme, minerals and 24-h urinary creatinine and minerals were analyzed. Estimated glomerular filtration rate (eGFR) was calculated with the Cockcroft-Gault and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations.
Results:
Two hundred fifty-three subjects completed the study according to the protocol. Urinary isoflavones indicated good compliance of participants. No significant changes were observed in most of renal parameters, however, there was a less decrease in eGFRcockcroft in 6-month change (p=0.044) and %change (p=0.031) with whole soy intake relative to milk placebo. Subgroup analysis among women with lowered renal function suggested whole soy consumption tended to improve markers of renal function relative to control.
Conclusions:
Six-month consumption of whole soy tended to have a modest improvement of renal function in prehypertensive postmenopausal women with lowered renal function. Future trials in subjects with more declined renal function are necessary.
Trial registration:
The trial was registered in ClinicalTrials.gov with identifier of NCT01270737. (URL: http://clinicaltrials.gov/ct2/show/NCT01270737).
Examining the role of dietary protein and establishing intake guidelines among individuals with diabetes is complex. The 2013 American Diabetes Association (ADA) standards of care recommend an individualized approach to decision making with regard to protein intake and dietary macronutrient composition. Needs may vary based on cardiometabolic risk factors and renal function. Among individuals with impaired renal function, the ADA recommends reducing protein intake to 0.8-1.0 g/kg per day in earlier stages of chronic kidney disease (CKD), and to 0.8 g/kg per day in the later stages of CKD. Epidemiological studies suggest animal protein may increase risk of diabetes; however, few data are available to suggest how protein sources influence diabetes complications.
The book reflects the contemporary understanding of the system and the rate of proteolysis in the ways of its regulation in terms of pathology. Examined protease blood and other tissues, proteolytic systems, the mechanism of action of serine protease inhibitor system. Separately described serpins (serine protease inhibitors) and their typical representatives. Compares the properties of aprotinin (animal) and soybean trypsin inhibitor (plant). Presented its own data on the comparative study of the activity of these inhibitors and their effects on hemostasis and complement, as well as any impact of soy protein isolate on the performance of proteolysis in human serum.
Genistein, an isoflavone putative tyrosine kinase inhibitor, was used to investigate the coupling of insulin receptor tyrosine kinase activation to four metabolic effects of insulin in the isolated rat adipocyte. Genistein inhibited insulin-stimulated glucose oxidation in a concentration-dependent manner with an ID50 of 25 micrograms/ml and complete inhibition at 100 micrograms/ml. Genistein also prevented insulin's (10(-9) M) inhibition of isoproterenol-stimulated lipolysis with an ID50 of 15 micrograms/ml and a complete effect at 50 micrograms/ml. The effect of genistein (25 micrograms/ml) was not reversed by supraphysiological (10(-7) M) insulin levels. In contrast, genistein up to 100 micrograms/ml had no effect on insulin's (10(-9) M) stimulation of either pyruvate dehydrogenase or glycogen synthase activity. We determined whether genistein influenced insulin receptor beta-subunit autophosphorylation or tyrosine kinase substrate phosphorylation either in vivo or in vitro by anti-phosphotyrosine immunoblotting. Genistein at 100 micrograms/ml did not inhibit insulin's (10(-7) M) stimulation of insulin receptor tyrosine autophosphorylation or tyrosine phosphorylation of the cellular substrates pp185 and pp60. Also, genistein did not prevent insulin-stimulated autophosphorylation of partially purified human insulin receptors from NIH 3T3/HIR 3.5 cells or the phosphorylation of histones by the activated receptor tyrosine kinase. In control experiments using either NIH 3T3 fibroblasts or partially purified membranes from these cells, genistein did inhibit platelet-derived growth factor's stimulation of its receptor autophosphorylation. These findings indicate the following: (a) Genistein can inhibit certain responses to insulin without blocking insulin's stimulation of its receptor tyrosine autophosphorylation or of the receptor kinase substrate tyrosine phosphorylation. (b) In adipocytes genistein must block the stimulation of glucose oxidation and the antilipolytic effects of insulin at site(s) downstream from the insulin receptor tyrosine kinase. (c) The inhibitory effects of genistein on hormonal signal transduction cannot necessarily be attributed to inhibition of tyrosine kinase activity, unless specifically demonstrated.
Tyrosine-specific protein kinase activity of the epidermal growth factor (EGF) receptor, pp60v-src and pp110gag-fes was inhibited in vitro by an isoflavone genistein. The inhibition was competitive with respect to ATP and noncompetitive to a phosphate acceptor, histone H2B. By contrast, genistein scarcely inhibited the enzyme activities of serine- and threonine-specific protein kinases such as cAMP-dependent protein kinase, phosphorylase kinase, and the Ca2+/phospholipid-dependent enzyme protein kinase C. When the effect of genistein on the phosphorylation of the EGF receptor was examined in cultured A431 cells, EGF-stimulated serine, threonine, and tyrosine phosphorylation was decreased. Phosphoamino acid analysis of total cell proteins revealed that genistein inhibited the EGF-stimulated increase in phosphotyrosine level in A431 cells.
In laboratory animals, the consumption of soy protein, rather than animal protein, decreases serum cholesterol concentrations, but studies in humans have been inconclusive. In this meta-analysis of 38 controlled clinical trials, we examined the relation between soy protein consumption and serum lipid concentrations in humans.
We used a random-effects model to quantify the average effects of soy protein intake on serum lipids in the studies we examined and used hierarchical mixed-effects regression models to predict variation as a function of the characteristics of the studies.
In most of the studies, the intake of energy, fat, saturated fat, and cholesterol was similar when the subjects ingested control and soy-containing diets; soy protein intake averaged 47 g per day. Ingestion of soy protein was associated with the following net changes in serum lipid concentrations from the concentrations reached with the control diet: total cholesterol, a decrease of 23.2 mg per deciliter (0.60 mmol per liter); 95 percent confidence interval, 13.5 to 32.9 mg per deciliter [0.35 to 0.85 mmol per liter]), or 9.3 percent; low-density lipoprotein (LDL) cholesterol, a decrease of 21.7 mg per deciliter (0.56 mmol per liter); 95 percent confidence interval, 11.2 to 31.7 mg per deciliter [0.30 to 0.82 mmol per liter]), or 12.9 percent; and triglycerides, a decrease of 13.3 mg per deciliter (0.15 mmol per liter; 95 percent confidence interval, 0.3 to 25.7 mg per deciliter [0.003 to 0.29 mmol per liter]), or 10.5 percent. The changes in serum cholesterol and LDL cholesterol concentrations were directly related to the initial serum cholesterol concentration (P < 0.001). The ingestion of soy protein was associated with a nonsignificant 2.4 percent increase in serum concentrations of high-density lipoprotein (HDL) cholesterol.
In this meta-analysis we found that the consumption of soy protein rather than animal protein significantly decreased serum concentrations of total cholesterol, LDL cholesterol, and triglycerides without significantly affecting serum HDL cholesterol concentrations.
The effect of soy protein, soy isoflavones and saponins on paraquat (PQ)-induced oxidative stress was investigated in rats. Rats were fed experimental diets containing casein (CAS), soy protein (SPI), and casein with soy isoflavones and saponins (CAS + IS). The diets were supplemented or not with 0.025% paraquat (CAS + PQ, SPI + PQ, and CAS + IS + PQ). The protective effects of soy protein, soy isoflavones, and saponins on paraquat-induced oxidative stress were examined. Ingestion of soy protein generally mitigated the lung enlargement (P = 0.076), loss of body weight (P = 0.051) and oxidation of liver lipid (P = 0.043) and glutathione (P = 0.035) induced by paraquat, although soy isoflavones and saponins did not. To determine whether soy protein exerted its antioxidative effects by preventing paraquat absorption from digestive organs, rats were fed CAS or SPI diets and orally administered a 12.5 g/L paraquat solution. Plasma, urine, and fecal paraquat concentrations did not differ between the two groups, indicating that soy protein did not prevent paraquat absorption. The present study suggests that intake of soy protein itself, but not soy isoflavones and saponins, reduces paraquat-induced oxidative stress in rats, although this effect was not due to reduced absorption of paraquat from digestive organs.
Nephrotic syndrome (NS) is characterized by the presence of proteinuria and hyperlipidemia. However, ingestion of soy protein has a hypolipidemic effect. The present study was designed to determine whether the ingestion of a 20% soy protein diet regulates the expression of hepatic sterol regulatory element binding protein (SREBP)-1, fatty acid synthase (FAS), malic enzyme, beta-hydroxy-beta-methylglutaryl-CoA (HMG-CoA) reductase (r) and synthase (s), and LDL receptor (r), and to assess whether soy protein improves lipid and renal abnormalities in rats with chronic NS. Male Wistar rats were injected with vehicle or with puromycin aminonucleoside to induce NS and were fed either 20% casein or soy protein diets for 64 d. NS rats fed 20% soy protein had improved creatinine clearance and reduced proteinuria, hypercholesterolemia, hypertriglyceridemia, as well as VLDL-triglycerides and LDL cholesterol compared with NS rats fed the 20% casein diet. In addition, the soy protein diet decreased the incidence of glomerular sclerosis, and proinflammatory cytokines in kidney. Ingestion of the soy protein diet by control rats reduced the gene expression of SREBP-1, malic enzyme, FAS and increased HMG-CoAr, HMG-CoAs and LDLr. However, NS rats fed either casein or soy protein diets had low insulin concentrations with reductions in SREBP-1, FAS and malic enzyme expression compared with control rats fed the casein diet. NS rats fed the soy diet also had lower HMG-CoAr and LDLr mRNA levels than NS rats fed casein. In conclusion, the beneficial effects of soy protein on lipid metabolism are modulated in part by SREBP-1. However, in NS rats, the benefit may be through a direct effect of this protein on kidney rather than mediated by changes in expression of hepatic lipid metabolism genes.
The principal soy phytoestrogen genistein has an array of biological actions. It binds to estrogen receptor (ER) alpha and beta and has ER-mediated estrogenic effects. In addition, it has antiestrogenic effects as well as non-ER-mediated effects such as inhibition of tyrosine kinase. Because of its complex biological actions, the molecular mechanisms of action of genistein are poorly understood. Here we show that genistein dose-dependently increases estrogenic transcriptional activity in mesenchymal progenitor cells, but its biological effects on osteogenesis and adipogenesis are different. At low concentrations (< or =1 microm), genistein acts as estrogen, stimulating osteogenesis and inhibiting adipogenesis. At high concentrations (>1 microm), however, genistein acts as a ligand of PPARgamma, leading to up-regulation of adipogenesis and down-regulation of osteogenesis. Transfection experiments show that activation of PPARgamma by genistein at the micromolar concentrations down-regulates its estrogenic transcriptional activity, while activation of ERalpha or ERbeta by genistein down-regulates PPARgamma transcriptional activity. Genistein concurrently activates two different transcriptional factors, ERs and PPARgamma, which have opposite effects on osteogenesis or adipogenesis. As a result, the balance between activated ERs and PPARgamma determines the biological effects of genistein on osteogenesis and adipogenesis. Our findings may explain distinct effects of genistein in different tissues.
Protein restriction is used conventionally in the prevention and treatment of diabetic nephropathy. Recently, the use of soy protein instead of animal protein has been postulated as a new preventive and treatment option. The aim of this study was to determine the qualitative and quantitative effects of dietary protein on biomarkers of diabetic nephropathy in a Type 2 diabetes mellitus mouse model (BKS.cg-m +Lepr(db)/+Lepr(db) mice). Diabetic (+Lepr(db)/+Lepr(db)) and control (m+/m+) mice (n = 24/group) consumed one of four different diets ad libitum [20% casein, 20% soy protein, 12% casein or 12% soy protein (energy-based percentages)] from 35 +/- 4 d of age until termination (184-217 d of age). Blood and urine were collected throughout the study to measure biomarkers of diabetes and diabetic nephropathy. Kidney tissue was collected at the end of the study for weight. In diabetic mice, a 20% casein diet increased urinary albumin excretion to macroalbuminuric levels, whereas a 20% soy protein diet led to no major changes in urinary albumin excretion. Low protein diets (12%), independently of protein type, decreased urinary albumin excretion to low microalbuminuric levels. There were no significant differences in plasma glucose concentrations. These findings show lower urinary albumin excretion when a soy protein diet or a low casein diet is fed, suggesting a delay in the progression of diabetic nephropathy.
Heart and renal diseases are two major problems in diabetic patients. Hyperlipidemia is one of the main risk factors of cardiovascular complications in diabetes. The type of protein consumed also affects the changes in renal blood flow, glomerular resistance and renal function in these patients. Hence, this study was undertaken to show the effect of soy protein consumption on lipid profiles and kidney function of diabetic patients with nephropathy, who attended an educational university hospital as well as a private kidney disease clinic in Tehran.
This crossover randomized clinical trial was conducted on 14 patients who were free of any uncontrolled condition or other renal diseases. The patients were asked to follow a usual nephropathy diet (0.8 g/kg protein, 70% animal and 30% vegetable protein) for 7 weeks. After a washout period of 4 weeks consuming the prestudy diet, subjects were readmitted to repeat the same cycle with a similar diet containing 35% soy protein and 30% vegetable protein. Paired t-test, carryover effect and period effect were used for statistical analysis.
: There were 10 men and four women whose mean (s.d.) of weight was 70.6 (10.3) kg. Significant reductions were seen in total cholesterol (P<0.01), triglyceride (P<0.002) and LDL-c (P<0.04), urinary urea nitrogen and proteinuria (P<0.001) after soy vs animal protein consumption. There were no significant changes in HDL-c, LDL-c/HDL-c levels. We also saw a favorable effect on renal function.
Soy inclusion in the diet can modify the risk factors of heart disease and improve kidney function in these patients.
Soy protein was shown to exhibit several beneficial effects on renal function in nondiabetic patients with nephropathy, and to improve serum lipids. This study examined the effects of isolated soy protein consumption on urinary albumin excretion, serum lipids, plasma amino acids, and isoflavones in diabetic patients with nephropathy. Male patients (n = 14) with type 2 diabetes and nephropathy were followed in a crossover design for 7 mo. The study comprised two 8-wk intervention periods, placed between a 4-wk lead-in and two 4-wk washout periods. In the 2 intervention periods, 0.5 g/(kg. d) of the dietary protein was provided as either isolated soy protein (ISP) or casein, in random order. Blood and urine samples were collected at the beginning and end of each period. Data were analyzed by multiple linear regression for a repeated-measure design. ISP consumption led to changes of -9.5% in urinary albumin excretion (P < 0.0001), -0.45 in the total-to-HDL-cholesterol ratio (P < 0.05), -0.20 in the LDL-to-HDL cholesterol ratio (P < 0.05), and +4.3% in HDL cholesterol (P = 0.0040). Plasma arginine concentrations, the arginine-to-lysine ratio, and plasma isoflavone concentrations were higher after ISP consumption (P < 0.05). Urinary albumin excretion was negatively correlated with plasma total isoflavones (rho = -0.441), daidzein (rho = -0.326), and O-desmethylangolesin (rho = -0.389) (P < 0.05). The findings indicate that isolated soy protein consumption improves several markers that may be beneficial for type 2 diabetic patients with nephropathy.
Soybeans have a high-quality protein that has been consumed for approximately 5000 years in Oriental countries. The awareness that soy products are healthy has increased their consumption in Western countries. Substantial data from epidemiological surveys and nutritional interventions in humans and animals indicate that soy protein reduces serum total and low-density lipoprotein (LDL) cholesterol and triglycerides as well as hepatic cholesterol and triglycerides. This review examines the evidence on the possible mechanisms for which soy protein has beneficial effects in diabetes, obesity and some forms of chronic renal disease. Consumption of soy protein due to low methionine content reduces serum homocysteine concentration, decreasing the risk of acquiring a cardiovascular disease. On the other hand, soy protein reduces the insulin/glucagon ratio, which in turn down-regulates the expression of the hepatic transcription factor sterol regulatory element binding protein (SREBP)-1. The reduction of this factor decreases the expression of several lipogenic enzymes, decreasing in this way serum and hepatic triglycerides as well as LDL cholesterol and very LDL triglycerides in diabetes and obesity, reducing lipotoxicity in the liver. Soy protein intake also reduces hepatic lipotoxicity by maintaining the number of functional adipocytes, preventing the transfer of fatty acids to extra adipose tissues. Furthermore, soy protein isoflavones stimulate the transcription factor SREBP-2, increasing serum cholesterol clearance. The reduction of serum cholesterol and triglyceride concentrations by soy protein intake produces beneficial effects in the kidney preventing the inflammatory response, increasing the renal flow by releasing endothelial nitric oxide (NO) synthase from the caveolae, facilitating the synthesis of NO. Thus, soy protein consumption may reduce the clinical and biochemical abnormalities in diseases mediated by lipid disorders.
The Diabetes Control and Complications Trial has demonstrated that intensive diabetes treatment delays the onset and slows the progression of diabetic complications in subjects with insulin-dependent diabetes mellitus from 13 to 39 years of age. We examined whether the effects of such treatment also occurred in the subset of young diabetic subjects (13 to 17 years of age at entry) in the Diabetes Control and Complications Trial. One hundred twenty-five adolescent subjects with insulin-dependent diabetes mellitus but with no retinopathy at baseline (primary prevention cohort) and 70 adolescent subjects with mild retinopathy (secondary intervention cohort) were randomly assigned to receive either (1) intensive therapy with an external insulin pump or at least three daily insulin injections, together with frequent daily blood-glucose monitoring, or (2) conventional therapy with one or two daily insulin injections and once-daily monitoring. Subjects were followed for a mean of 7.4 years (4 to 9 years). In the primary prevention cohort, intensive therapy decreased the risk of having retinopathy by 53% (95% confidence interval: 1% to 78%; p = 0.048) in comparison with conventional therapy. In the secondary intervention cohort, intensive therapy decreased the risk of retinopathy progression by 70% (95% confidence interval: 25% to 88%; p = 0.010) and the occurrence of microalbuminuria by 55% (95% confidence interval: 3% to 79%; p = 0.042). Motor and sensory nerve conduction velocities were faster in intensively treated subjects. The major adverse event with intensive therapy was a nearly threefold increase of severe hypoglycemia. We conclude that intensive therapy effectively delays the onset and slows the progression of diabetic retinopathy and nephropathy when initiated in adolescent subjects; the benefits outweigh the increased risk of hypoglycemia that accompanies such treatment. (J PEDIATR 1994;125:177-88)
Isoflavonoids are compounds present in many legumes, but are derived in the human diet mainly from soybeans and various soybean-based food products. The major isoflavonoids occurring in soy are the glycosides of genistein and daidzein. The metabolic products of genistein metabolism in humans have not been clearly shown. The two main products of daidzein metabolism in humans appear to be equol and O-desmethylangolensin. Increasing evidence suggests that oxidative modification to low-density lipoprotein is involved in atherogenesis, and that natural antioxidants that prevent or inhibit oxidative damage to low-density lipoprotein may beneficially influence atherogenesis. In the present experiments, the effects of genistein and daidzein, and the daidzein metabolites equol and O-desmethylangolensin on Cu2+-induced oxidation of lipoproteins in serum were examined. Three concentrations of each compound (0.1 μM, 1 μM, 10 μM) were tested for antioxidant activity in six individual serum samples. All compounds tested inhibited lipoprotein oxidation. The minimum concentration for significant inhibition was 1 μM for genistein and daidzein (P < 0.05), and 0.1 μM equol and O-desmethylangolensin (P < 0.05). Equol and O-desmethylangolensin were more potent inhibitors of in vitro lipoprotein oxidation in serum than the two major dietary isoflavonoids. This study has demonstrated that soybean isoflavonoids and metabolic products of daidzein metabolism inhibit lipoprotein oxidation in vitro. Human intervention studies are needed to determine if these compounds can influence oxidation in vivo.
This study was designed to investigate the effect of protein intake on glomerular filtration rate, and to demonstrate and evaluate the functional reserve of the kidney. Normal subjects ingesting a protein diet had a significantly higher creatinine clearance than a comparable group of normal subjects ingesting a vegetarian diet. A progressive increment in protein intake in normal volunteers resulted in a significant increase in creatinine clearance. Diurnal variations in creatinine clearance were found. These daily variations correlated well with the periods of food intake. The capacity of the kidney to increase its level of function with protein intake suggests a renal function reserve. In short-term studies, the effect of a protein load on glomerular filtration rate was evaluated. Normal subjects showed an increase in glomerular filtration rate two and a half hours after protein load to a maximal glomerular filtration rate of 171.0 +/- 7.7 ml per minute. In patients with a reduced number of nephrons, renal functional reserve may be diminished or absent.
During gastrointestinal digestion or food processing of proteins, small peptides can be released and may act as regulatory compounds with hormone-like activities. Numerous biologically active peptides (bioactive peptides) have been identified. Most bioactive peptides are derived from milk and dairy products, with the most common being angiotensin converting enzyme inhibitory peptides. Soybean protein and soybean derived peptides also play an important role in soybean physiological activities, particularly those related to the prevention of chronic diseases. However, the bioactive potential of soybean derived bioactive peptides is yet to be fully appreciated. After a general introduction of approaches and advances in bioactive peptides from food sources, this review focuses on bioactive peptides derived from soybean proteins and their physiological properties. Technological approaches to generate bioactive peptides, their isolation, purification, characterization, and quantification, and further application in food and drug design are also presented. Safety concerns, such as potential toxicity, allergenicity, and sensory aspect of these peptides are likewise discussed.
Soy hydrolysate and the soy-fermented foods, natto and tempeh, were dephosphorylated, deglycosylated and digested with a variety of endoproteases (pronase, trypsin, Glu C protease, plasma proteases and kidney membrane proteases) to generate oligopeptides. The peptides were purified and characterized. They demonstrated a range of biological activities – angiotensin converting enzyme (ACE) inhibitory, anti-thrombotic, surface tension and antioxidant properties. The biologically active peptides were mostly derived from glycinin, a highly expressed soy protein, and were found mainly in the pronase, kidney membrane proteases and plasma proteases digests of the fermented foods. The proteases of lower specificity produced more oligopeptides and a higher percentage of bioactive peptides than the proteases of higher specificity, namely trypsin and Glu C. A peptide with ACE inhibitory activity was found in the pronase digest of natto, which also produced a peptide with surface active properties. The kidney membrane hydrolysate of natto contained an ACE inhibitor, in addition to a peptide with anti-thrombotic activity bearing homology to hirutonin, a previously described synthetic thrombin inhibitor [DiMaio, Gibbs, Lefebvre, & Munn, 1992, J. Med. Chem. 35, 3331]. Synthetic analogs were also evaluated as substrates for some inhibitors.
We undertook a study to determine whether soy protein feeding would ameliorate renal injury in the Han:SPRD-cy rat model of polycystic kidney disease (PKD). Male offspring of Han:SPRD-cy heterozygotes received isocaloric diets based on 20% casein or 20% heat-treated soy protein at weaning ad libitum for 8 wk. Soy-fed animals demonstrated lower serum creatinine (66 vs. 125 mumol/l; P = 0.002), lower urinary ammonium excretion (0.080 vs. 0.173 mmol/kg; P = 0.01), reduced renal cysts (0.98 vs. 4.92 ml/kg body wt, P < 0.0001), renal fibrosis (0.79 vs. 1.4 ml/kg; P = 0.016), macrophage infiltration, renal tubular cell proliferation, and apoptosis. Proton nuclear magnetic resonance (1H-NMR) studies of urine demonstrated that soy diet was associated with increased losses of citric acid cycle organic anions. 1H-NMR of perchloric acid-extracted tissue found that levels of succinate were not depleted in soy-fed animals, despite increased urinary losses. Soy-fed animals had marked elevation of tissue betaine (P < 0.001), with reduced taurine and cholines, compared with casein-fed animals (P < 0.001). Soy feeding dramatically reduces both tubular and interstitial pathology in the Han:SPRD-cy rat model of PKD, through mechanisms that remain to be determined.
Several studies have suggested that dietary protein quality may be an important determinant in the natural history of renal disease. We have therefore studied the effects of a predominantly vegetarian diet in eight patients with Type 1 diabetes mellitus and an albumin excretion rate (AER) in excess of 30 micrograms min-1. The AER was measured after an 8-week run-in period on the patient's usual diet, and again after 8 weeks of a predominantly vegetarian diet in which the proportion of vegetable protein was supplemented in order to minimize the reduction in total dietary protein intake. The median fractional albumin clearance fell during the study from an initial value of 188 x 10(-+) (range 58-810 x 10(-4)) at the end of the run-in period to 87 x 10(-4) (23-829 x 10(-4)) at the end of the period on low animal protein diet (difference 79 x 10(-4) (95% Cl 9-149 x 10(-4)), p less than 0.05). The AER then returned to values similar to those obtained at the beginning of the study after a further 8 weeks in those patients returning to their usual diet. No significant changes in blood glucose control or in arterial pressure were observed. A predominantly vegetarian diet may therefore have important beneficial effects on diabetic nephropathy without the need for a heavily restricted total protein intake.
The influence of replacing dietary casein with soy protein on longevity and age-related pathologic lesions of male Fischer 344 rats was investigated. Caloric intake and body weights were similar for rats on the two diets. Rats on the soy protein-containing diet had a median length of life of 844 days compared to 730 days for those on the casein-containing diet (p less than .002), and the ages of the 10th percentile survivors were 937 and 857 days, respectively (p less than .02). The progression of chronic nephropathy was markedly retarded by replacing casein with soy protein. Only 7% of the rats dying spontaneously on the soy protein-containing diet exhibited end-stage chronic nephropathy compared to 41% of the rats on the casein-containing diet. Clearly, the soy protein-containing diet enables ad libitum fed male Fischer 344 rats to be used as a model for aging research without the occurrence of renal failure as a major confounding problem.
Dietary protein restriction is known to be beneficial in the preservation of renal function when renal mass is reduced. This study investigates the effects of two different dietary proteins, casein and soya, upon renal function in normal rats and rats subjected to subtotal nephrectomy. The diets were isocaloric, with identical sodium, potassium and phosphorus contents. Normal rats ingesting a 24% soya protein diet demonstrate lower effective renal plasma flow rates and lower glomerular filtration rates than rats ingesting a 24% casein diet. Experimental animals were subjected to a unilateral nephrectomy and contralateral partial renal infarction and were fed either casein or soya, at 24 or 12% levels, for 3 months. Those animals ingesting the soya diets demonstrated improved survival (p less than 0.05), less proteinuria (p less than 0.02), less renal hypertrophy (p less than 0.005) and less renal histological damage. The nature of the dietary protein appears to influence both normal renal function and the progression of experimentally induced renal disease.
To study the influence of preceding dietary protein intake on the renal response to a protein meal we examined renal hemodynamic and excretory responses to a meat meal in six normal human subjects either taking their normal-protein diet (NPD, 75 +/- 5 g/day) or after 3 wk of a low-protein diet (LPD, 43 +/- 3 g/day; P less than 0.005). Glomerular filtration rate (GFR) was lower on LPD than on NPD (107 +/- 7 vs. 124 +/- 5 ml X min-1 X 1.73 M-2, respectively; P less than 0.01), as was renal plasma flow (RPF) (NPD, 666 +/- 44; LPD, 605 +/- 43 ml X min-1 X 1.73 M-2; P less than 0.05). Filtration fraction (FF) was not different (NPD, 0.19 +/- 0.01; LPD, 0.18 +/- 0.01). Urinary excretion of albumin was also lower after LPD than NPD (2.1 +/- 0.5 vs. 4.2 +/- 0.8 micrograms/min; P less than 0.05). After an 80-g protein meat meal, GFR rose to a ceiling significantly higher on NPD than on LPD (132 +/- 4.8 vs. 120 +/- 5.2 ml X min-1 X 1.73 M-2; P less than 0.02), even though the percent changes were greater on LPD than on NPD (12.7 +/- 3.3 vs. 6.6 +/- 1.5%, respectively; P less than 0.05). There was a rise in RPF that was entirely attributable to a fall in renal vascular resistance, and FF did not change. On both diets, oral protein loading produced a 200-300% increase in the urinary excretion and fractional clearance of albumin and IgG, but failed to alter that of beta 2-microglobulin.(ABSTRACT TRUNCATED AT 250 WORDS)
Rats fed a semipurified diet containing casein developed higher levels of circulating triglycerides and cholesterol than animals fed a soy protein-containing diet. The increased serum lipid levels in non-fasted rats were associated largely with the d less than 1.006 g/ml lipoprotein particles (e.g. chylomicrons or very low density-like lipoproteins). In addition, casein-fed rats exhibited higher levels of circulating insulin and depressed hepatic 7 alpha-hydroxylase levels compared to soy-fed rats. Supplementation of the casein diet with arginine, to give an arginine/lysine ratio comparable to that in the soy diet, resulted in a reduction of d less than 1.006 g/ml lipids, a reduction in serum insulin levels and an elevation in hepatic 7 alpha-hydroxylase activity. Supplementation of the soy diet with lysine also resulted in modification of these parameters toward those observed with casein diets, albeit the effects were less dramatic. The results suggest that the hyperlipidemia associated with feeding casein-based diet is associated with decreased rates of clearance of chylomicron-like lipoproteins and their component triglycerides and cholesterol. Furthermore, this is largely prevented by addition of arginine to diets containing casein as the sole protein source.
In this review the authors have dealt with three basic questions that have vexed renal physiologist and nephrologists for decades: Why are human beings endowed with far more nephron units than are required to maintain external balance for a variety of solutes and water? Why do progressive declines in renal blood flow and glomerular filtration rates and progressive glomerular sclerosis occur after the third decade of life? Why is renal disease inexorably progressive? Insight into all three questions become readily apparent when consideration is given to the possibility of a fundamental mismatch between the evolutionary design characteristics of the human kidney and the functional burden imposed by modern ad libitum eating habits. Sustained rather than intermittent excesses of protein (and perhaps other solutes) in the diet impose similarly sustained increases in renal blood flow and glomerular filtration rates, which require that the 'reserve' glomeruli of the outer cortex be in use more or less continuously. Consequently, time-averaged pressures and flows in outer glomeruli contribute to unrelenting 'intrarenal hypertension' and predispose even healthy people to progressive glomerular sclerosis and deterioration of renal function. The biologic price of this adaptation to ad libitum feeding is acceptable in the absence of diabetes, acquired renal disease, or surgical loss of renal mass. But the more pronounced elevations in glomerular pressures and flows associated with these latter conditions may accelerate the development of glomerular sclerosis, leading to more rapid loss of renal function. Unfortunately, the current treatments for chronic renal insufficiency, including efforts to control systemic hypertension, urinary-tract infection, and secondary hyperparathyroidism, do little to interrupt the hemodynamic mechanisms of progressive renal failure. It is to be hoped that additional therapies aimed at preventing excessive glomerular pressures and flows will be introduced in an effort to check the relentless progression of clinical renal disease. An obvious first step, might be a reduction of protein intake, implemented early in the course of intrinsic renal disease. Rigid metabolic control achieved by continuous insulin infusion or other means and instituted early in the course of juvenile-onset diabetes, could likewise prove effective in preventing glomerulopathy in this high-risk population. Clearly, resolution of these and the many other issues raised in this article will come only from more reseach.
We have previously shown beneficial effects of dietary protein restriction on transforming growth factor beta (TGF-beta) expression and glomerular matrix accumulation in experimental glomerulonephritis. We hypothesized that these effects result from restriction of dietary L-arginine intake. Arginine is a precursor for three pathways, the products of which are involved in tissue injury and repair: nitric oxide, an effector molecule in inflammatory and immunological tissue injury; polyamines, which are required for DNA synthesis and cell growth; and proline, which is required for collagen production. Rats were fed six isocaloric diets differing in L-arginine and/or total protein content, starting immediately after induction of glomerulonephritis by injection of an antibody reactive to glomerular mesangial cells. Mesangial cell lysis and monocyte/macrophage infiltration did not differ with diet. However, restriction of dietary L-arginine intake, even when total protein intake was normal, resulted in decreased proteinuria, decreased expression of TGF-beta 1 mRNA and TGF-beta 1 protein, and decreased production and deposition of matrix components. L-Arginine, but not D-arginine, supplementation to low protein diets reversed these effects. These results implicate arginine as a key component in the beneficial effects of low protein diet.
The scarce literature on dietary manipulation of dyslipidemia in patients with nephrotic syndrome and in patients with chronic renal insufficiency is reviewed. Our favorable personal experience in both clinical conditions is illustrated as well. A special low-protein soy diet given for 2 or 4 months partially corrected hypercholesterolemia in nephrotic patients, and a low-protein diet also low in cholesterol and rich in polyunsaturated fatty acids corrected hypertriglyceridemia and hypercholesterolemia in patients with progressive renal damage. The soy diet had an additional favorable effect on proteinuria of nephrotic patients that might have been a direct consequence of the partial correction of the hypercholesterolemia. The addition of 5 g/d of fish oil to the soy diet did not modify the effects of the soy diet on proteinuria nor was it able to correct the hypertriglyceridemia of nephrotic patients. Dietary intervention should be the first-line treatment for the dyslipidemia of these renal diseases, since it can be used for long periods of time and is devoid of side effects so long as good nutritional status is maintained.
The effects of feeding a soy protein isolate or genistein, an isoflavonoid present in soy protein, on cyst development were examined in the DBA/2FG-pcy (pcy) mouse, an accepted animal model of polycystic kidney disease, before the appearance of clinical symptoms. In study 1, 60-day-old male pcy mice were evenly divided into two groups and fed semipurified diets, based on casein or a soy protein isolate (15 g protein/100 g diet) for 90 days. In study 2, the animals were fed a casein-based diet (25 g casein/100 g diet) with or without genistein (0.05 g/100 g diet) for 60 days. In study 1, total kidney weight and kidney weight relative to body weight were significantly reduced (by 24% to 25%) in the animals fed the soy protein-based diet, relative to the casein-fed group, as was kidney water content (by 38%). In addition, mean cyst volume, as measured by morphometry, were lower (by 25%) in kidneys from the soy protein-fed group. No differences were found between these two groups with respect to final body weight, plasma creatinine, and protein content; however, plasma urea values were significantly lower in the soy protein-fed animals. Genistein supplementation of a casein-based diet in study 2 did not reduce the renal enlargement and cyst development associated with progression of polycystic kidney disease. These results suggest that soy protein is effective in retarding cyst development in the pcy mouse and that this beneficial effect may be unrelated to its genistein content.
For > 150 y, clinicians and investigators have observed that high protein intakes accelerate the progression of renal disease and that low protein intakes have beneficial effects. Some studies suggest that the effects of soy-protein intake resemble those of a low-protein diet. The Brenner hypothesis suggests that high protein intakes by diabetic individuals create hyperfiltration and glomerular hypertension eventuating in renal damage. On the basis of the available evidence, we are proposing the soy-protein hypothesis, which states that substituting soy protein for animal protein in diabetes patients results in less hyperfiltration and glomerular hypertension and, therefore, resultant protection from diabetic nephropathy. Furthermore, substituting soy protein for animal protein should have therapeutic value in diabetic nephropathy with resultant slowing of deterioration of renal function and decreasing proteinuria. The preliminary results of the study of 8 type 2 diabetes patients with obesity, hypertension, and proteinuria are reported. Under the conditions of the study, providing soy protein as half of the daily protein intake had no distinct effects on renal function or proteinuria in these subjects. Soy-protein intake was associated with a significant reduction in serum cholesterol and triacylglycerol concentrations. Further studies are required to critically examine the effects of soy-protein intake on the renal function of diabetes patients.
The effects of dietary soy protein compared to casein were examined in male and female CD1-pcy/pcy (pcy) mice with polycystic kidney disease. Animals 10 wk of age were fed purified diets containing either soy protein isolate or casein given at a level of 17.4 or 6% protein. After 13 wk on the diets, body weights and serum concentrations of albumin and protein indicated that protein nutrition was adequate on all diets. Overall, animals fed soy protein versus casein had 28% lower (P = 0.0037) relative kidney weights (g/100 g body wt), 37% lower (P = 0.0089) cyst scores (% cyst area x relative kidney weight), and 25% less (P = 0.0144) kidney water (g). Dietary protein reduction resulted in 30% lower (P = 0.0010) relative kidney weights, 25% lower (P = 0.0327) cyst scores, and 35% less (P = 0.0001) kidney water. Analysis of interactions between main effects revealed that the effects of soy protein on kidney size were significant only in females, and that effects of soy protein on cyst score were significant only in animals on the low protein diets. In addition, differences in kidney weights and cyst score due to protein reduction were significant in animals fed soy protein, but not in those fed casein as the protein source. These results show that both dietary protein source and level significantly affect polycystic kidney disease in pcy animals, with the effects of dietary soy protein being most pronounced in female animals fed the low protein diets and the effects of protein reduction being most pronounced in animals fed soy protein-based diets.
Modification of polycystic kidney disease and fatty acid status by soy protein diet.
Previous studies have demonstrated that soy protein can slow progression of renal injury in the Han:SPRD-cy rat. We undertook a study to establish whether this benefit was independent of any nutritional deprivation, and whether or not it was associated with changes in polyunsaturated fatty acid status that have been previously linked to the anti-inflammatory or antineoplastic potential of soy diets.
Male Han:SPRD-cy rats were pair fed a 20% casein or 20% soy protein diet for six weeks from weaning. Tissue was harvested for analysis of cystic change, cell proliferation, macrophage infiltration, and fibrosis. Renal and hepatic tissues were also harvested for lipid analysis using gas chromatography.
Animals thrived on both diets. Soy protein feeding was associated with reduced cystic change (4.3 vs. 7.0 mL/kg, P < 0.0001), epithelial cell proliferation (15.7 vs. 21.0 cells/mm epithelium, P < 0.0001), macrophage infiltration (25.3 vs. 43.5 cells/high-power field, P < 0.0001), and fibrosis (0.6 vs. 1.07 mL/kg, P < 0.0001). The soy diet prevented a significant elevation in serum creatinine in diseased versus normal animals. Soy feeding was associated with higher renal and hepatic linoleic acid content and higher hepatic alpha-linolenic acid, but lower hepatic arachidonic acid content.
Isocaloric soy protein feeding ameliorates both epithelial and interstitial changes in the Han:SPRD-cy rat independent of a hypocholesterolemic effect. The histologic benefit is associated with changes in polyunsaturated fatty acid metabolism that may influence both inflammatory and proliferative pathways.
Objective: The dietary phytoestrogens genistein and daidzein have been shown to relax agonist-preconstricted arteries in vitro; the mechanisms of relaxation remain incompletely understood. This study aimed to determine whether the relaxation of phenylephrine (PE)-constricted rat aorta and main pulmonary artery by genistein and daidzein was endothelium-dependent. Methods: Effects of endothelial-denudation, and pretreatment with with 100 μM l-NG-nitroarginine methyl ester (l-NAME) and/or 10 μM indomethacin on relaxation of PE (1 μM)-preconstricted contractures by genistein (1–100 μM) and daidzein (3–100 μM) were assessed by measuring isometric force development by rat arterial rings. The effect of l-NAME on relaxation to 17β-estradiol (10 μM) was also measured in aorta. Results and conclusions: Genistein and daidzein caused concentration-dependent relaxation of aorta rings preconstricted with PE (1 μM). The IC50 values were 5.7 μM (n=8, 95% confidence limits 4.3–7.7 μM) and 36.7 μM (n=12, 95% confidence limits 25.7–44.1 μM), respectively. Removal of the endothelium and pretreatment with l-NAME (100 μM) significantly inhibited relaxation at 3, 10 and 30 μM genistein and 10 and 30 μM daidzein. The contracture evoked in rat aorta by depolarization with 75 mM K⁺ solution was similarly relaxed by genistein in a partially endothelium-dependent manner. 17β-Estradiol (10 μM) caused a 48.7±5.0% (n=11) relaxation of the PE contracture, which was significantly reduced to 25.1±5.3% (n=7) by l-NAME. Relaxations brought about by 17β-estradiol, genistein, and daidzein were not significantly affected by the genomic estrogen receptor antagonist ICI 182,780 (10 μM). Similar endothelium-dependent effects of genistein were observed in the main pulmonary artery. The results show that the relaxation of these rat arteries by concentrations of genistein and daidzein which overlap those present in human plasma after ingestion of soybean-containing meals is largely endothelium dependent
Dietary soy protein compared with casein retards disease progression in a gender-specific manner in the pcy mouse. In this model of polycystic kidney disease (PKD), kidney insulin-like growth factor-I (IGF-I) levels are elevated. The present study examined the gender-specific effects of soy protein feeding on disease and IGF-I in Han:SPRD-cy rats.
Normal (+/+) and affected (cy/+) weanling male and female Han:SPRD-cy rats were given either casein- or soy protein-based diets for six weeks. Renal size, water content, cyst size and IGF-I, serum creatinine, urea and IGF-I, and creatinine clearance were determined.
Soy protein-fed cy/+ animals had lower kidney weight, water content and cyst size, lower serum urea and creatinine, and higher creatinine clearance. In cy/+ females, dietary soy protein resulted in normalized serum creatinine and creatinine clearance. Kidney IGF-I levels (ng/kidney) were 32 to 76% higher in cy/+ compared with +/+ groups (P < 0.001). Soy protein feeding resulted in lower kidney IGF-I in cy/+ males (1123 vs. 1496 ng/kidney, P < 0.001) and cy/+ females (816 vs. 943 ng/kidney, P < 0.05). In males, soy protein feeding resulted in lower serum IGF-I concentrations in +/+ (1439 vs. 1708 ng/mL, P < 0.05) and in cy/+ (1483 vs. 2073 ng/mL, P < 0.001) animals.
Dietary soy protein compared with casein delays the progression of disease in male and female Han:SPRD-cy rats. Overall, IGF-I was lower in +/+ animals, in females, and in animals consuming the soy protein diet, supporting a role for IGF-I in the pathogenesis of disease in the Han:SPRD-cy rat and an ameliorating role for dietary soy protein.
This study was done to evaluate the effects of soy protein hydrolyzate with bound phospholipids (c-SPHP), on the serum cholesterol levels in hypercholesterolemic subjects over a three-month period. Subjects were Taiwanese adult male volunteers whose serum total cholesterol levels were above 220 mg/dl. Twenty-one subjects were divided into three groups randomly, and each group was given c-SPHP zero, 3, or 6 g per day. Test diets were orally administered in a powdered drink form that contained c-SPHP or casein hydrolyzate (placebo). The subjects were given the test diet four times daily. The study consisted of a two-week pre-feeding period, a three-month feeding period, followed by a two-week post-feeding period. After 3 months of c-SPHP administration, 3 g per day, serum total cholesterol decreased significantly from the initial level (15.0%, p<0.01) and compared with the placebo group (p<0.05). Furthermore, LDL-cholesterol decreased significantly (27.7%, p<0.01) and the LDL/HDL ratio also decreased significantly (47.4%, p<0.01) from the initial levels. These effects of c-SPHP were dose-dependent. This study suggests that c-SPHP has remarkable improving effects on the serum cholesterol levels in hypercholesterolemic subjects.
Hypertension, hyperlipidemia, hyperfiltration, hyperinsulinemia, glomerular hypertrophy, and ultimately glomerular injury and renal failure are associated with obesity in the Zucker rat. Evidence from other laboratories suggests that soy protein might offer renal protection.
At five weeks of age obese rats were placed on diets containing either soy or casein as a protein source and studied until 24 weeks of age. At six weeks of age and every four weeks thereafter, 24-hour urine collections were obtained along with measurements of systolic blood pressure (tail cuff) and blood from the tail vein. At the end of the study the kidneys were fixed and sectioned for histology.
Both groups gained weight and developed systemic hypertension and hyperinsulinemia at the same rate. Glomerular filtration rate (creatinine clearance) also was similar between groups throughout the study and both groups developed glomerular hypertrophy to the same extent. The development of hypertriglyceridemia was actually accelerated in the soy-fed rats compared to the casein-fed animals. The soy diet, however, virtually completely prevented the development of hypercholesterolemia, primarily low-density lipoprotein (LDL) and/or very low-density lipoprotein (VLDL) cholesterol, and slowed the development of proteinuria and glomerular injury.
The data suggest that an important determinant of the protective effects of soy was related to the prevention of hypercholesterolemia in this model. Other unmeasured differences between groups, such as differences in glomerular capillary blood pressure or the effects of the antioxidant properties of soy components also may have contributed to the protective effects of soy.
Progression to renal parenchymal damage and end-stage renal disease, which seems to be largely independent of the initial insult, is the final common pathway for chronic, proteinuric nephropathies in animals and humans. The key event is enhanced glomerular capillary pressure; this impairs glomerular permeability to proteins and permits excessive amounts of proteins to reach the lumen of the proximal tubule. The secondary process of reabsorption of filtered proteins can contribute to renal interstitial injury by activating intracellular events, including upregulation of the genes encoding vasoactive and inflammatory mediators. Both interstitial inflammation and progression of disease can be controlled by such drugs as angiotensin-converting enzyme inhibitors, which strengthen the glomerular permeability barrier to proteins and thereby limit proteinuria and filtered protein-dependent inflammatory signals. Clinical data strongly suggest that remission can now be achieved in some patients with chronic renal disease. Because of the current lag time between starting treatment and remission, however, a substantial proportion of patients still progress to end-stage renal disease before renal function begins to stabilize. A multimodal approach that centers on reducing or removing all risk factors associate