Article

Cholesterol-Lowering Effects of Maitake (Grifola frondosa) Fiber, Shiitake (Lentinus edodes) Fiber, and Enokitake (Flammulina velutipes) Fiber in Rats

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Abstract

The effects of mushroom fibers on serum cholesterol and hepatic low-density lipoprotein (LDL) receptor mRNA in rats were investigated. Rats were fed a cholesterol-free diet with 50 g/kg cellulose powder (CP), 50 g/kg maitake (Grifola frondosa) fiber (MAF), 50 g/kg shiitake (Lentinus edodes) fiber (SF), or 50 g/kg enokitake (Flammulina velutipes) fiber (EF) for 4 weeks. There were no significant differences in the body weight, food intake, liver weight, cecum weight, and cecum pH among the groups. Cecal acetic acid, butyric acid, and total short-chain fatty acid (SCFA) concentrations in the SF and EF groups were significantly higher than those in the other groups. The serum total cholesterol concentration in the CP group was significantly higher than that in the MAF and EF groups. The very LDL (VLDL) + intermediate-density lipoprotein (IDL) + LDL-cholesterol concentration in the CP group was significantly higher than that in the MAF, SF, and EF groups, whereas the high-density lipoprotein (HDL)-cholesterol concentration in the EF group was significantly lower than that in the other groups at the end of the 4-week feeding period. The hepatic LDL receptor mRNA level in the EF group was significantly higher than that in the CP group. The fecal cholesterol excretion in the MAF, SF, and EF groups was significantly higher than that in the CP group. The results of this study demonstrate that MAF and EF lowered the serum total cholesterol level by enhancement of fecal cholesterol excretion, and in particular, by enhancement of hepatic LDL receptor mRNA in EF group.

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... Many mushroom species have been reported to induce hypocholesterolemic effects on laboratory rodents and F. velutipes is no exception. 34,36,37 As expected, the present study reproduced these findings with decreased plasma total and HDL-cholesterol concentrations (12-17%) at 9 g/kg/d of F. velutipes consumption. The influence on LDL-cholesterol reached significance at 6 g/kg/d. ...
... The influence on LDL-cholesterol reached significance at 6 g/kg/d. As proposed by Fukushima et al., 36 these effects could be transmitted through enhanced cholesterol excretion in feces and via elevated LDL-receptor mRNA levels in the liver. In addition to fiber, 36 lovastatin present in F. velutipes is one potential agent responsible for the cholesterollowering effects. ...
... As proposed by Fukushima et al., 36 these effects could be transmitted through enhanced cholesterol excretion in feces and via elevated LDL-receptor mRNA levels in the liver. In addition to fiber, 36 lovastatin present in F. velutipes is one potential agent responsible for the cholesterollowering effects. 38 While the hypocholesterolemic effect is clear and potentially beneficial in hyperlipidemic patients, the possibility of side effects needs to be assessed in more detail before the use of this species in health-promotion can be recommended without any caution. ...
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Rhabdomyolysis (destruction of striated muscle) is a novel form of mushroom poisoning in Europe and Asia indicated by increased circulating creatine kinase levels. Particular wild fungi have also been reported to induce elevated creatine kinase activities in mice. Flammulina velutipes (enokitake or winter mushroom) is one of the most actively cultivated mushroom species globally. As it is marketed as a medicinal mushroom and functional food, it is important to examine whether it could induce potentially harmful health effects similar to some previously studied edible fungi. The present study examined the effects of F. velutipes consumption on the plasma clinical chemistry, hematology, and organ histology of laboratory mice. Wild F. velutipes were dried, pulverized, mixed with a regular laboratory rodent diet, and fed to the animals at 0, 3, 6, or 9 g/kg body mass/day for five days ( n = 6/group). F. velutipes consumption caused increased activities of plasma creatine kinase and the MB-fraction of creatine kinase at 6–9 g/kg/d, indicating potentially deleterious effects on both skeletal and cardiac muscle. The plasma total and high-density lipoprotein cholesterol concentrations (at 9 g/kg/d) and white blood cell and lymphocyte counts (at 6–9 g/kg/d) decreased. Although the cholesterol-lowering properties of F. velutipes can be beneficial, the previously unexamined, potentially hazardous side effects of mushroom consumption (myo- and cardiotoxicity) should be thoroughly investigated before recommending this mushroom species as a health-promoting food item. Impact statement This work is important to the field of functional foods, as it provides novel information about the potential myo- and cardiotoxic properties of an edible mushroom, Flammulina velutipes. The results are useful and of importance because F. velutipes is an actively cultivated mushroom and marketed as a health-promoting food item. The findings contribute to the understanding of the complexity of the balance between the beneficial and potentially harmful effects of mushroom consumption.
... ACE inhibitors have been reported to diminish mortality in patients with hypertension [85]. Recently, investigators have described that Pleurotus ostreatus [86], P. cystidiosus [85], P. cornucopiae [87], Auricularia auricula-judae [88], Ganoderma leucocontextum [65], Grifola frondosa [89], Agaricus bisporus [30] and Leucopaxillus tricolor [29] are all ACE inhibitors that decrease hypertension. Wild mushrooms in Nepal that also have ACE inhibitor activities were tested by Bang et al. [90]. ...
... High-fat diet in rats-TC, LDL, body weight, food intake, liver weight, cecum weight, cecum pH, Cecal acetic acid, butyric acid, and total SCFA Fibers [89] High-fat diet in male hamsters-TG, TC, LDL, total lipids, phospholipids, LDL/HDL ratio Dietary fiber, polysaccharide, and mycosterol, [125] Medicinal Fomes fomentarius STZ-induced diabetic rats-plasma glucose, TG, TC, ALT, AST Exo-biopolymers [89] Medicinal ...
... High-fat diet in rats-TC, LDL, body weight, food intake, liver weight, cecum weight, cecum pH, Cecal acetic acid, butyric acid, and total SCFA Fibers [89] High-fat diet in male hamsters-TG, TC, LDL, total lipids, phospholipids, LDL/HDL ratio Dietary fiber, polysaccharide, and mycosterol, [125] Medicinal Fomes fomentarius STZ-induced diabetic rats-plasma glucose, TG, TC, ALT, AST Exo-biopolymers [89] Medicinal ...
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Obesity is a group of metabolic disorders caused by multiple factors, including heredity, diet, lifestyle, societal determinants, environment, and infectious agents, which can all lead to the enhancement of storage body fat. Excess visceral fat mass in adipose tissue generate several metabolic disorders, including cardiovascular diseases with chronic inflammation based pathophysiology. The objective of the current review is to summarize the cellular mechanisms of obesity that attenuate by antioxidant potentials of medicinal and edible mushrooms. Studies have showed that mushrooms potentially have antioxidant capacities, which increase the antioxidant defense systems in cells. They boost anti-inflammatory actions and thereby protect against obesity-related hypertension and dyslipidemia. The practice of regular consumption of mushrooms is effective in the treatment of metabolic syndrome, including obesity, and thus could be a good candidate for use in future pharmaceutical or nutraceutical applications.
... It accounts for approximately 22% of the total global mushroom production, second to Agaricus bisporus. Shiitake mushrooms are rich in nutrients such as essential amino acids, vitamins (B 1 , B 2 , C, and D), minerals, dietary fibers, and β-glucan [2][3][4][5]. Compared to other widely cultivated mushrooms, shiitake mushrooms contain higher levels of macronutrients (except for proteins), sugars, tocopherols, and polyunsaturated fatty acids (FAs) but lower levels of saturated FAs [6]. ...
... Compared to other widely cultivated mushrooms, shiitake mushrooms contain higher levels of macronutrients (except for proteins), sugars, tocopherols, and polyunsaturated fatty acids (FAs) but lower levels of saturated FAs [6]. Furthermore, shiitake mushrooms possess anticancer, antitumor, antimicrobial, anti-inflammatory, and hypercholesterolemic activities [2,7,8]. ...
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Shiitake mushroom (Lentinula edodes) is commonly consumed worldwide and is cultivated in many farms in Korea using Chinese substrates owing to a lack of knowledge on how to prepare sawdust-based substrate blocks (bag cultivation). Consequently, issues related to the origin of the Korean or Chinese substrate used in shiitake mushrooms produced using bag cultivation have been reported. Here, we investigated differences in fatty acids (FAs) and stable isotope ratios (SIRs) in shiitake mushrooms cultivated using Korean and Chinese substrates under similar conditions (strain, temperature, humidity, etc.) and depending on the harvesting cycle. The total FA level decreased significantly by 5.49 mg∙g−1 as the harvesting cycle increased (p < 0.0001); however, no differences were found in FAs between shiitake mushrooms cultivated using Korean and Chinese substrates. Linoleic acid was the most abundant FA, accounting for 77–81% of the total FAs during four harvesting cycles. Moreover, the SIRs differed significantly between the Korean and Chinese substrates, and the harvesting cycles resulted in smaller maximum differences in SIR values compared to those of the cultivation substrate origins. Our findings contribute to the identification of the geographical origin of shiitake mushrooms and may have potential applications in international shiitake-mushroom markets.
... The fruiting bodies and liquid culture mycelium of this mushroom is known to contain effective antitumor and immunomodulating polysaccharide in different fractions. Other medicinal uses of this mushroom (Table 5) include, antiviral, anti HIV, cardiovascular, hepatoprotective, blood pressure regulation, control of diabetes, reduction of cholesterol, treatment of chronic fatigue syndrome (CFS), and antioxidant activity (Adachi et al. 1988;Kubo et al. 1994;Kabir et al. 1987;Kubo and Nanba 1997;Mizuno and Zhuang 1995;Nanba 1993;Fukushima et al. 2001). ...
... Moreover, consumption of whole G. frondosa fruiting body and the water-soluble extract also led to a decrease in blood pressure in Zuker fatty rats, a diabetes rat model (Talpur et al. 2002a, b). Fukushima et al. (2001) demonstrated that when rats were fed a cholesterol-free diet with 50 g/kg G. frondosa fiber for 4 weeks, the serum total cholesterol level of the animals lowered significantly. In genetically diabetic mice, oral administration of 20% whole mushroom maitake (G. ...
Preprint
Maitake (Grifola frondosa) is a basidiomycete fungus belonging to the Polyporaceae family, due to its medicinal properties, it has been used in Eastern cultures for thousands of years. Fruit body and liquid-cultured mycelium of this mushroom have been reported to contain useful antitumor and immunomodulating polysaccharides from various fractions. These polysaccharides have been identified as many types of glucans (β-(1→3)-, β-(1→6). It contains a polysaccharide compound beta-glucan which is not found in other types of mushroom. It is reported to help strengthen the body's natural immune system and improve general health. D-Fraction, MD fraction and extracts with whole maitake powder have shown particular promises as immunomodulating agents and as an adjunct to cancer and HIV therapy. They are also beneficial for the treatment of hyperlipidemia, hypertension, hepatitis, cardiovascular disease, as well as demonstrate hepatoprotective, antidiabetic, antioxidant, antiviral and anti-inflammatory properties. Present review focuses on the pharmacological and medical aspects of G. frondosa. Abstract Maitake (Grifola frondosa) is a Basidiomycete fungus belonging to the Polyporaceae
... Levels of VLDL-cholesterol, total cholesterol, triglycerides, intermediate-density lipoprotein (IDL), and LDL-cholesterol concentrations were reduced. The studies suggested these effects were attributable to Maitake's ability to increase the excretion of total fecal cholesterol and bile acids [221][222][223]. ...
... From the scientific literature findings [161,165,182,186,223], the main mechanisms proposed for the cholesterol-lowering properties of β-glucans appear to be: ...
Article
Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Factors increasing the risks for CVD development are related to obesity, diabetes, high blood cholesterol, high blood pressure and lifestyle. CVD risk factors may be treated with appropriate drugs, but prolonged can use cause undesirable side-effects. Among the natural products used in complementary and alternative medicines, are the β-ᴅ-glucans; biopolymers found in foods (cereals, mushrooms), and can easily be produced by microbial fermentation. Independent of source, β-glucans of the mixed-linked types [(1,3)(1,6)-β-ᴅ-glucans - fungal, and (1,3)(1,4)-β-ᴅ-glucans - cereal] have widely been studied because of their biological activities, and have demonstrated cardiovascular protective effects. In this review, we discuss the roles of β-ᴅ-glucans in various pathophysiological conditions that lead to CVDs including obesity, dyslipidemia, hyperglycemia, oxidative stress, hypertension and atherosclerosis. The -glucans from all of the sources cited demonstrated potential hypoglycemic, hypocholesterolemic and anti-obesogenicity activities, reduced hypertension and ameliorated the atherosclerosis condition. More recently, -glucans are recognized as possessing prebiotic properties that modulate the gut microbiome and impact on the health benefits including cardiovascular. Overall, all the studies investigated unequivocally demonstrated the dietary benefits of consuming β-glucans regardless of source, thus constituting a promising panaceutical approach to reduce CVD risk factors.
... Other than proteins, shiitake contain high levels of macronutrients, and are also high in sugars, tocopherols and polyunsaturated fatty acid (PUFA) levels and low in saturated fatty acid (SFA) content (Reis et al., 2012). Counted among their medicinal attributes are antitumor (Minato et al., 1999), antioxidant (Choi et al., 2006), antiviral (Rincão et al., 2012), antibacterial (Hatvani, 2001) and cholesterol-lowering (Fukushima et al., 2001) activities. ...
Article
The study assessed the changes in digestibility of some agricultural wastes such as chickpea straw (CPS), corn stalk (CS), alfalfa hay (AH) and sunflower head residue (SFH) during the spawn running period and fruitbody production of Lentinula edodes (Berk.) Pegler (shiitake) to better understand the nutritional needs of this mushroom species. In addition, the effects of these wastes on some productivity features of shiitake cultivated under laboratory conditions were evaluated. Oak awdust (OS) was used as a control substrate. The substrates were analyzed for nitrogen (N), cellulose, hemicellulose and lignin content at three different growth stages. Morever, the effect of agro-wastes on spawn run time, time to first primordia initiation, time to first harvest, yield, biological efficiency (BE) and average mushroom weight were evaluated during the cultivation cycle. Among the five substrates, the SFH exhibited maximum productivity, followed by CPS (233.7 g/kg and 228.1 g/ kg, respectively). No correlation was found between the shiitake yield and the N or lignocellulosic content of the growing substrates. On the other hand, the shiitake consumed hemicellulose during the spawn running period, whereas the consumption of cellulose and lignin occured during the pinheading and fruiting formation stages. The hemicellulose, cellulose and lignin contents in the spent substrate were 36.5-51.9%, 5.3-27.0% and 24.0-36.8% lower, respectively, than in the initial substrates, while the N content in the mushroom substrate was increased by 10.3% (CS)−97.1% (OS) after shiitake cultivation. In conclusion, shiitake mushrooms had a preference for substrates containing a moderate amount of N, hemicellulose and lignin, and having a low cel-lulose:lignin ratio. Morever, the chemical composition of the growing substrates changed during the life cycle of the mushroom and the protein content increased with time, while the amount of lignocellulosic content in the substrates was reduced, making it more digestible.
... In addition to their effects on the immune system, dietary mushrooms have been demonstrated to improve insulin resistance in diabetes [20,21] and to have cholesterol-lowering [22], antiatherogenic [23], anti-hypertensive [24], inflammatory bowel disease-inhibitory [25], and antiallergic [26] effects. The general impact of this extensive body of research is that Maitake is widely accepted to have physiological effects promoting the maintenance and improvement of health. ...
Article
Background: The prevention of influenza virus infection is a critical public health challenge.Thus new, safe, and effective strategies are needed to reduce the risk of infection. Maitake mushrooms (Grifola frondosa) are popular in Asia for their flavor and immune-stimulating properties. In this study, we examined whether the dietary consumption of Maitake was effective in boosting the potency of influenza virus vaccination.Methods: We set up a double-blind, placebo-controlled clinical trial (n=50 subjects for Maitake consumption; n=50 for placebo) and analyzed hemagglutination inhibition (HI) antibody titers in response to trivalent influenza vaccine (type A H1N1, H3N2, and type B BX-51B) for a 12-week period of daily Maitake intake (6.825g), beginning 4 weeks before and continuing 8 weeks after vaccination. We also evaluated the efficacy of Maitake for suppression of common cold symptoms by questionnaire.Results: We found that continuous Maitake intake raised HI titers against influenza type A virus H1N1 and type B virus, and significantly increased the seroconversion rate for older adults (>60 years of age). Additionally, severe cold symptoms including rhinorrhea and headache were significantly improved by Maitake intake.Conclusion: In this clinical trial, we demonstrated that Maitake intake enhanced antibody production in response to influenza vaccination while simultaneously suppressing multiple common cold symptoms. The current results suggest that Maitake may activate both innate and adaptive immune responses for the prevention of virus infection. In conclusion, we expect that Maitake intake potentiates host defense systems and has a protective effect against influenza virus and other pathogenic viruses and bacteria.Keywords: clinical trial, Grifola frondosa, influenza, Maitake, vaccine
... Flammulina filiformis (previously known as Asian F. velutipes) is one of the most popular mushrooms due to its good quality, low price and high nutrition [1][2][3]. It has been found that F. filiformis can reduce the serum total cholesterol level [4]. F. filiformis contains various beneficial components such as protein, amino acids and vitamins. ...
Article
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Lysine content is considered an important indicator of the quality of Flammulina filiformis. In this study, chitosan was used to improve lysine content of F. filiformis. Optimal design conditions were obtained using central combination design (CCD): treatment concentration was 14.61 μg/mL, treatment time was 52.90 h, and the theoretical value of lysine content was 30.95 mg/g. We used Basic Local Alignment Search Tool Protein (BLASTP) to search the F. filiformis genome database using known AATs in the NCBI database. There were 11 members of AAT in F. filiformis. The expression levels of AAT3 and AAT4 genes increased significantly with chitosan treatment. Subsequently, AAT3 and AAT4 silencing strains were constructed using RNAi technology. The lysine content of the wild-type (WT) strain treated with chitosan increased by 26.41%. Compared with the chitosan-induced WT strain, chitosan-induced lysine content decreased by approximately 24.87% in the AAT3 silencing strain, and chitosan-induced lysine content in the AAT4 silencing strain increased by approximately 13.55%. The results indicate that AAT3 and AAT4 are involved in the regulation of the biosynthesis of lysine induced by chitosan in F. filiformis. AAT3 may participate in the absorption of lysine, and AAT4 may be involved in the excretion of lysine with chitosan treatment.
... Lentinula edodes (Berk.) Pegler (shiitake) mushrooms contain many bioactive components such as antitumor polysaccharides (Zhang et al., 2010), antioxidant and antimicrobial substances (Kitzberger et al., 2007), antibacterial and antifungal compounds (Hearst et al., 2017), and cholesterol-lowering active ingredients (Fukushima et al.,2001). In addition, the extract of Hericium erinaceus (lion's mane mushroom) has been reported to exhibit antihyperglycemic (Chaiyasut and Sivamaruthi, 2017), anti-inflammatory (Mori et al., 2015), and anti-obesity activity (Hiraki et al., 2017), as well as neurological support (Spelman et al.,2017). ...
... Lentinula edodes (Berk.) Pegler (shiitake) mushrooms contain many bioactive components such as antitumor polysaccharides (Zhang et al., 2010), antioxidant and antimicrobial substances (Kitzberger et al., 2007), antibacterial and antifungal compounds (Hearst et al., 2017), and cholesterol-lowering active ingredients (Fukushima et al.,2001). In addition, the extract of Hericium erinaceus (lion's mane mushroom) has been reported to exhibit antihyperglycemic (Chaiyasut and Sivamaruthi, 2017), anti-inflammatory (Mori et al., 2015), and anti-obesity activity (Hiraki et al., 2017), as well as neurological support (Spelman et al.,2017). ...
Article
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Objective: This research investigated that the use of four selected agro-waste materials rich in phenolic content on cultivation of Hericium erinaceus and Lentinula edodes mushrooms. Material and Method: For this purpose, these wastes were comparatively evaluated regarding their suitability for mycelial growth, yield and biological efficiency (BE), of these mushroom species. The oak sawdust (OS) basal medium was mixed with 20% grape pomace (GP), green walnut hull (GWH), olive press cake (OPC), and tea waste (TW) for the production of these species in factorial experiments based on a completely randomised design with ten replications. Results: For both H. erinaceus and L. edodes, the shortest spawn running time (22.4 and 45.4 days, respectively) and the highest yield (225.0 g kg-1 and 282.9 g kg-1 , respectively) were found using GP. The BE of H. erinaceus and L. edodes were varied between 15.2-64.3% and 36.0-70.7% , respectively. Conclusion: GP, TW and OPC were seen as promising alternative substrates for the cultivation of these species. Moreover, for the effective utilisation and profitable disposal of green walnut hulls, further research is needed. to test their performance for the cultivation of other mushroom species. ÖZ Amaç: Bu çalışmada fenolik içeriği yüksek olan dört farklı tarımsal atığın Hericium erinaceus and Lentinula edodes mantarlarının üretiminde kullanımı araştırılmıştır. Materyal ve Metot: Bu amaçla, bu atıkların bahsedilen mantar türlerinin misel gelişimleri, verim ve biyolojik etkinlikleri (BE) karşılaştırmalı olarak değerlendirilmiştir. Meşe talaşı (OS) ana material olarak kullanılmış ve bu ortama %20 oranında üzüm posası (GP), yeşil ceviz kabuğu (GWH), zeytin pirinası (OPC) ve çay atıkları eklenerek mantar üretiminde kullanılmıştır. Denemeler 10 tekerrürlü olarak tesadüf parselleri deneme desenine göre planlanmıştır. Bulgular: Hem H. erinaceus hemde L. edodes'de en kısa misel gelişim süresi (22.4 ve 45.4 gün, sırasıyla) ve en yüksek verim (225.0 g kg-1 and 282.9 g kg-1 ,sırasıyla) OS ve GP kombinasyonlarında gözlenmiştir. H. erinaceus ve L. edodes mantarlarının BE'leri ise sırası ile %15.2-64.3 ve %36.0-70.7 arasında değişmiştir. Sonuçlar: Bu mantar türlerinin üretiminde GP, TW ve OPC alternatif katkı materyali olarak kullanılabilirler. Fakat mantar üretiminde yeşil ceviz kabuğundan etkili ve karlı bir şekilde yararlanabilmemiz için ek çalışmalar yapılması gerekmektedir.
... Flammulina velutipes serves as an excellent fibrous source that exhibit effects of cholesterollowering [41], antioxidant, immunomodulatory, anti-inflammatory and anti-tumor. Previous studies indicated that the polysaccharides, oligosaccharides and extracts prepared from fruiting FV body showed strong antioxidant activities [42][43][44]. ...
Article
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This study was conducted to evaluate the effects of dietary FVS supplementation on growth performance, nutrient digestibility, biochemical profile of serum and fecal short chain fatty acids (SCFAs) production in weaned piglets. In Exp.1, 150 weaned pigs (initial body weight: 6.89 ± 1.17 kg) were allotted to five dietary treatments. The treatment diets included a basal diet and four experimental diets supplemented with 2.5%, 5.0%, 7.5% and 10.0% FVS respectively. The animal trial lasted for 28 days. In Exp.2, 72 piglets (initial body weight: 8.20 ± 1.67 kg) were allotted to three dietary treatments. The treatment diets included a basal diet and two experimental diets supplemented with 1.5% and 3.0% FVS, respectively. The animal trial lasted for 56 days. The results showed that pigs fed dietary FVS with 3% or lower inclusion levels had no significant difference (p > 0.10) on growth performance compared with pigs fed the control diet during day 1–28 and day 1–56. Dietary FVS supplementation decreased the apparent total tract digestibility (ATTD) of nutrients on day 28, day 35 and day 56, but no significant changes (p > 0.05) of nutrient digestibility were observed on day 14. Although piglets fed diets with higher levels of FVS showed impaired growth performance and ATTD of nutrients, dietary FVS supplementation improved the fecal SCFA production, antioxidant capacity, interleukin-2 and growth hormone levels in serum, and reduced the harmful low-density lipoprotein levels in serum on day 56. In conclusion, as a promising alternative fibrous ingredient, FVS could be supplemented in diets of weaned piglets with a proportion under 3%.
... For example, when obese mice were administered mukitake mushroom Panellus serotinus , there was a significant reduction in hepatic lipids, partly due to a decrease in hepatic lipogenic enzyme activity and enhancement in carnitine palmitoyltransferase activity, the latter of which is responsible for fatty acid oxidation 11,12 . Enokitake Flammulina velutipes has been shown to alleviate hyperlipidemia, likely through enhanced gene expression of hepatic low-density lipoprotein receptor in rats 13 . Feeding rats a diet of 4 shiitake mushroom Lentinus edodes significantly stimulated energy expenditure 14 . ...
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Accumulation of abdominal fat triggers metabolic syndrome, which is a cluster of metabolic abnormalities, such as dyslipidemia, glucose intolerance, insulin resistance or hyperinsulinemia, and hypertension, that leads to the development of diabetes and cardiovascular disease. Mushrooms have been used as a foodstuff and folk medicine worldwide. Among these mushrooms, Sparassis crispa (SC) is a relatively newly cultivated edible and medicinal mushroom, which has been reported to have anti-diabetic and anti-hypertensive properties. However, little is known about the anti-obesity and anti-hyperlipidemic properties of SC. In the present study, we investigated the effects of dietary SC on lipid metabolism and energy expenditure in Sprague-Dawley rats with diet-induced obesity and diabetes, and conducted respiratory gas analysis to determine how energy metabolism is altered by SC. After feeding periods of 3 and 7 weeks, dietary SC had significantly reduced hepatic triacylglycerol and cholesterol contents in a dose-dependent manner. These changes were attributable to suppression of fatty acid and cholesterol synthesis in the liver and increased insulin sensitivity in the body. In addition, after a feeding period of 6 weeks, dietary SC significantly increased energy expenditure through carbohydrate oxidation, reducing abdominal fat mass after 7 weeks. In conclusion, our results indicate that in addition to the previously reported anti-diabetic and anti-hypertensive activities, dietary SC exhibits anti-obesity and anti-hyperlipidemic activities that help protect against metabolic syndrome.
... This value is comparable to that obtained by According to Lee et al. (1994) and Aboua (1995), the variation in the lipid content of snail meat powder is due to its living environment and its diet. This low fat content of snail meat powder could be useful in dietary supplementation for people who are interested in calorie restriction (Chang, 1996;Fukushima et al., 2001;De Román, 2006). This low level of lipids in snail meat is a major asset in the fight against certain diseases such as cardiovascular diseases (Babalola et al., 2009). ...
... Shiitake mushrooms (SM) are nutrient-dense. In Asia, these mushrooms are thought to have special medicinal properties with respect to several diseases, including diabetes, anemia, various forms of cancer, and oral health [11][12][13][14][15][16]. The way in which the mushrooms are prepared can play a role in the nutrient retention. ...
Article
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Increasing consumer desire for functional food ingredients, including such products as shiitake mushroom (Lentinus edodes P.) powder (SM), demands that the sensory impact of such ingredients be tested in an appropriate food system. Pork patties are a common food in many Asian countries. Pork patties in this study were prepared with and without SM, an ingredient that is gaining popularity around the world. A lexicon for describing the texture and flavor of cooked pork patties, with and without 0.5% sodium tripolyphosphate (STP), a typical additive to meat, and with varying amounts of SM (0% to 6%) was developed by a highly trained panel to compare sensory properties for each type of patty. The attributes evaluated were juiciness, toughness, rubberiness, mealiness, pork identity (pork ID), meatiness, mushroom, onion, garlic, black pepper, heat/burn, soapy, chemical, animal hair, fatty, salty, sour, bitter, slick, and astringent. An addition of 0.5% STP produced more intense ratings for soapy, salty, sour, and astringent attributes. Without STP, patties containing shiitake mushroom powder had a more mealy consistency but more pork ID than they did with STP.
... Our study shows that dietary intake of a variety of mushrooms is effective in preventing obesity by suppressing visceral fat accumulation. Similarly, many studies have reported that the dietary fiber contained in mushrooms has an anti-obesity effect [8,35,36]. Mushrooms are known to contain a large amount of dietary fiber [37], and the mushroom mixture used in this study contained 5.20% water-soluble dietary fiber and 30.5% insoluble dietary fiber ( Table 2). The dietary fiber contained in mushrooms is glucan, lignin, pectin and chitin [38,39]. ...
Article
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A lot of Japanese people are generally known for having a healthy diet, and consume a variety of mushrooms daily. Many studies have reported anti-obesity effects of mushrooms, but few have investigated the effects of consuming a variety of edible mushroom types together in realistic quantities. In this study, we investigated whether supplementation with a variety of mushroom types affects visceral fat accumulation and gut microbiota in mice. The most popular mushroom varieties in Japan were lyophilized and mixed according to their local production ratios. C57BL/6J mice were fed a normal diet, high-fat (HF) diet, HF with 0.5% mushroom mixture (equivalent to 100 g mushrooms/day in humans) or HF with 3% mushroom mixture (equivalent to 600 g mushrooms/day in humans) for 4 weeks. The mice were then sacrificed, and blood samples, tissue samples and feces were collected. Our results show that mushroom intake suppressed visceral fat accumulation and increased the relative abundance of some short chain fatty acid- and lactic acid-producing gut bacteria. These findings suggest that mushroom intake is an effective strategy for obesity prevention.
... The edible mushrooms in a natural hypocholesterolemic and antisclerotic diet is often prescribed in Oriental medicine (Sun et al., 1984). Dietary fiber (nonstarch polysaccharides, mainly β-glucans) has also been suggested to be an important hypocholesterolemic component in mushrooms, fibers A. bisporus (button mushroom) can dramatically enhance the hepatic LDL receptor messenger RNA (mRNA), causing the diminution of the serum TC (Fukushima et al., 2000(Fukushima et al., , 2001. β-glucans extracts of cholesterol a fat by formation of an inclusion complex with β-glucans. ...
... 8,9 Our previous studies reveal that dietary fibers and polyphenolic compounds present in different foods can preferentially modulate gut microbial ecology in diabetic and obese rat models. 10,11 Although previous studies have shown cholesterol-lowering effects of L. edodes, 12 no connection has been established between the microbiome composition and lipid profile in L. edodes-supplemented rats. Therefore, the present study was designed to assess changes in the gut microbiome of hypercholesterolemic rats supplemented with L. edodes. ...
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Recent interest in diet-induced modulation of the gut microbiome has led to research on the impact that dietary fibers can have on host health. Lentinus edodes mushroom–derived fibers may act as an appropriate substrate for gut microbe digestion and metabolism. The metabolites that gut microbes excrete can modulate host energy balance, gut absorption, appetite, and lipid metabolism. In the present study, we explored the dynamics of the gut microbiome of hypercholesterolemic rats supplemented with L. edodes. Wistar rats were offered a chow maintenance diet (CMD; CON group) or the same CMD ration with cholesterol (1.5% w/w) and cholic acid (0.5% w/w) added to induce hypercholesterolemia (day 1 to day 24). Hypercholesterolemic rats were subsequently offered either the same cholesterol–cholic acid diet (HC-CON group) or were supplemented with L. edodes (5% w/w; LE group) for 42 days (day 25 to day 66). At the end of the experiment, serum triglycerides, total cholesterol, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol concentrations were determined. Colon digesta were subjected to DNA extraction and subsequent 16S rRNA gene sequencing. Raw sequences were quality filtered and statistically analyzed using QIIME and LEfSe tools. Triglyceride concentrations were lower (P = 0.002) in the LE group than in the CON and HC-CON groups. Total cholesterol and LDL cholesterol concentrations were slightly decreased, whereas HDL cholesterol concentrations were increased by L. edodes supplementation compared with the HC-CON group. The gut microbiome of the LE group had higher species richness characterized by increased abundance of Clostridium and Bacteroides spp. Linear discriminant analysis identified bacterial clades that were statistically different among treatment groups. In conclusion, manipulation of gut microbiota through the administration of L. edodes could manage dyslipidemia.
... Meanwhile, the weight of the extirpated liver was also 60-70% lower than that of the control group, and the corresponding cholesterol excretion ratio in feces increased by 1.8 times with G. frondosa treatment, further demonstrating that G. frondosa treatment helped improve lipid metabolism and inhibit increases in liver lipid and serum lipid after the ingestion of high-fat feed [88]. Similar results were obtained by Fukushima and coworkers, who showed that serum total cholesterol concentrations and very-low-density lipoprotein (VLDL) levels in rats fed with 50 g/kg G. frondosa were lowered compared with those of the control group (50 g/kg cellulose powder), and the fecal cholesterol excretion was significantly higher compared with the control group [89]. ...
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Grifola frondosa (G. frondosa), generally known as hen-of-the-woods or maitake in Japanese and hui-shu-hua in Chinese, is an edible mushroom with both nutritional and medicinal properties. This review provides an up-to-date and comprehensive summary of research findings on its bioactive constituents, potential health benefits and major structural characteristics. Since the discovery of the D-fraction more than three decades ago, many other polysaccharides, including β-glucans and heteroglycans, have been extracted from the G. frondosa fruiting body and fungal mycelium, which have shown significant antitumor and immunomodulatory activities. Another class of bioactive macromolecules in G. frondosa is composed of proteins and glycoproteins, which have shown antitumor, immunomodulation, antioxidant and other activities. A number of small organic molecules such as sterols and phenolic compounds have also been isolated from the fungus and have shown various bioactivities. It can be concluded that the G. frondosa mushroom provides a diverse array of bioactive molecules that are potentially valuable for nutraceutical and pharmaceutical applications. More investigation is needed to establish the structure–bioactivity relationship of G. frondosa and to elucidate the mechanisms of action behind its various bioactive and pharmacological effects.
... Tambi?n se reconocen en Flammulina velutipes propiedades ben?ficas para la reducci?n de la presi?n sangu?nea, asociada a los altos niveles de potasio y la baja concentraci?n de sodio encontrada en todos los hongos en general (Akin- dahunsi y Oyetayo, 2006); en la reducci?n del nivel de colesterol (Fukushima et al., 2001), relacionada con el compuesto eritadenina, como antibi?tico natural, debido a la presencia de sesquiterpenos de tipo curarin (Ishikawa et al., 2001), como antiviral y antimic?tico ). ...
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Este libro tiene como finalidad introducir al lector en la biología de los hongos, la diversidad de las especies y en las aplicaciones tecnológicas en la industria, en especial del hongo comestible Flammulina velutipes. Este es un tipo de hongo muy popular en Asia, cultivado y consumido en el resto del mundo pero que aún no ha sido desarrollado en Argentina, lo cual podría representar una interesante innovación a nivel comercial en el mercado local. Los autores presentan aquí una guía para el cultivo de la especie en la cual detallan cada uno de los pasos necesarios para su producción y los problemas asociados que pueden aparecer.
... Production of L. edodes has increased faster than any other mushroom, accounting for about 25% of global edible fungus production [3,4]. L. edodes is valuable as food and medicine, rich in essential amino acids, dietary fiber, vitamins, and minerals but low in calories and fat [5][6][7][8][9]. Its bioactive compounds, including polysaccharides, terpenoids, steroids, phenols, nucleotides, and glycoprotein derivatives [10], may reduce the risk of hypertension, hypercholesterolemia, diabetes mellitus, and cancer [10,11]. ...
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Lentinula edodes (shiitake) is a popular nutritious edible mushroom with a desirable aroma and flavor. Traditional cultivation of L. edodes on beds of logs has been replaced by cultivation on sawdust, but the effects of cultivation changes on L. edodes mushrooms have not been well characterized. We determined the metabolic profile, bioactive compounds, and antioxidant capacity in L. edodes grown on log or sawdust substrates. Metabolic profiles of L. edodes extracts were determined by 1H nuclear magnetic resonance (NMR) and ultra-performance liquid chromatography to quadrupole time-of-flight mass spectrometry. Principal component analysis score plots from 1H NMR analysis showed clear differences between samples. Concentrations of primary metabolites, especially amino acids, generally decreased in L. edodes grown on logs compared to sawdust. Phenolic compounds showed variations in concentration depending on the cultivation method. Bioactive compounds and their antioxidant capacity were analyzed spectrophotometrically. L. edodes cultivated on logs had high concentrations of bioactive compounds with strong antioxidant capacity compared to L. edodes cultivated on sawdust. Thus, the concentration of primary metabolites was high in L. edodes grown on sawdust, which produces a high growth rate. In contrast, log-cultivated L. edodes, which were similar to wild mushrooms, had high levels of bioactive compounds and high antioxidant capacity. This information is useful for determining optimal cultivation conditions for nutritional and medicinal uses of L. edodes mushrooms.
... In rat experiments, fungal metabolites grifolin (2-trans,trans-farnesyl-5-methylresorcinol) and neogrifolin (4-trans,trans-farnesyl-5-methylresorcinol), isolated from Polyporus confluens (ningyotake) (Sugiyama et al., 1992), as well as chrysin from P. ostreatus, have been shown to lower cholesterol (Anandhi et al., 2012). G. frondosa and F. velutipes have also been reported to exert a hypocholesterolemic effect in rats (Fukushima, 2001). Some triterpenes from G. lucidum (ganoderic acid and its derivatives) are able to inhibit the biosynthesis of choles terol (Komoda et al., 1989). ...
... It has been proven that the polysaccharide extract of Pleurotus pulmonarius delays the progression of hepatocellular carcinoma [2]; polysaccharide from Pholiota nameko has anti-inflammatory properties in rodents [3]; Agaricus bisporus inhibits prostate tumor growth in mice [4]; Pleurotus eryngii, Grifola frondosa, and Hypsizygus marmoreus protect apolipoproteinE deficient mice from development of atherosclerosis [5]. Simultaneously, edible mushrooms are regarded as an important dietary supplement for people interested in calorie restriction, because of the low amount of fat, cholesterol, and calories in their bodies and high concentration of fiber [1,[6][7][8]. The therapeutic action of mushrooms is attributed to the presence of bioactive compounds such as vitamins, polysaccharides, and secondary metabolites in their fruiting bodies. ...
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Tricholoma equestre was rich in carbohydrates (88.03g 100-1 g-1 dw), followed by proteins (5.65 g 100-1 g-1 dw), ash (4.57 g 100-1 g-1 dw) and fat (1.75 g 100-1 g-1 dw). Moisture (88.31%) and Energy (390.49 kcal 100-1 g-1 dw) were also calculated. The concentrations of trace elements : Fe (12.85 ± 0.68 mg kg-1), Zn (8.63 ± 0.19 mg kg-1), Cu (1.16 ± 0.14 mg kg-1) and Mn (0.85 ± 0.13 mg kg-1), were assayed. Trace elements content of samples indicated that the Batak mountain was an ecologically pure region in Bulgaria, and therefore the mushrooms collected from this location could be consumed without any risk for human health. According to this study, the edible wild mushroom Tricholoma equestre could be used in human nutrition due to its good properties.
... Shiitake are also rich in vitamins B2, B12, D2 [2], and micro-and macro-elements (K, P, Mg, Ca, Zn, Cu, Mn, Se, and Fe) [4][5][6]. They are low in cholesterol and total fat but contain a high proportion of unsaturated fatty acids [7]. ...
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Shiitake mushrooms have been highly regarded as possessing enormous nutritive and medicinal values. No clinical studies have yet investigated the effect of shitake supplementation on the health of horses. The aim of this study was to evaluate the effect of shiitake mushroom supplementation on the morphological and biochemical blood properties in horses. A total of 17 adult horses were divided into two groups: supplemented and control. The supplemented group was fed 60 g of shiitake mushrooms per day for 5 months. Blood samples were collected in five sessions. Blood morphological analysis showed higher levels of lymphocytes in session 3 and monocytes in session 4 in the supplemented group. In addition, basophils, hemoglobin, and hematocrit were elevated compared to the control group. Biochemical analysis showed that the shiitake mushrooms affected a large number of parameters. In particular, alkaline phosphatase was found to be the most sensitive to shitake mushroom supplementation, for which the statistical differences were significant for sessions 2, 4, and 5. Furthermore, calcium was found to be affected by supplementation only in session 4, and gamma-glutamyl transferase in session 2. In addition, the bilirubin and glucose levels were lower in the supplemented group, and the albumin/globulin ratio was higher compared to the control group. The differences between the supplement and the control group in various sessions suggest that shiitake mushrooms are a beneficial nutritional supplement for horses.
... Similarly, L. edodes spores have caused hypersensitivity pneumonitis in a mushroom worker [35]. L. edodes also displays cholesterol-lowering properties [36] indicating that, again, the balance of beneficial and potentially hazardous effects of a species has to be taken into consideration when assessing its suitability for consumption. Hitherto, the causative agents of these effects often remain to be determined, and scientists have reached contradictory conclusions on edibility, especially regarding T. equestre [15,37]. ...
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Mushroom poisonings remain a significant cause of emergency medicine. While there are well-known species, such as Amanita phalloides, causing life-threatening poisonings, there is also accumulating evidence of poisonings related to species that have been considered edible and are traditionally consumed. In particular, the Tricholoma equestre group was reported to cause myotoxicity. In addition, particular wild mushrooms that are traditionally consumed especially in Asia and Eastern Europe have been subject to suspicion due to possible mutagenicity. Hitherto, the causative agents of these effects often remain to be determined, and toxicity studies have yielded contradictory results. Due to this, there is no consensus about the safety of these species. The issue is further complicated by difficulties in species identification and other possible sources of toxicity, such as microbiological contamination during storage, leading to sometimes opposite conclusions about the edibility of a species. This review focuses on existing data about these types of mushroom poisonings, including the still sparse knowledge about the causative chemical agents. In addition, the aim is to initiate a meta-discussion about the issue and to give some suggestions about how to approach the situation from the viewpoint of the collector, the researcher, and the practicing physician.
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Oyster mushroom (Pleurotus ostreatus) is the most commonly grown mushroom species after white button mushroom (Agaricus bisporus) inTurkey. The cultivation of Pleurotus spp. dates back to 1980’s in the country. The cultivation of white button mushrom has also become quite common in the same years. Although Oyster mushroom is easier to grow than white button mushroom, the cultivation of this mushroom has not attracted the attentionof the growers hence not grown widely. This mushroom species does not require laborsome work such as compost preparation and can be easily grown on oak, ash and poplar stumps and agricultural waste products rich in cellulose and lignin. Furthermore, wastes of Oyster mushroom cultivation can be used in animal feeding and agricultural production. In addition to these properties, the mushroom is an important food and raw material source in human nutrition and health as it has significant nutritional and medicinal values. The interest in Oyster mushroom cultivation has increased noticeably in recent years in the country. However, as in white button mushroom, the mushroom spawn which is the most important input of oyster mushroom production is obtained from foreign sources. Up to date, there has not been any native isolates or cultures of both mushroom species that were identified and commercialized for spawn production in the country. Importation of mushroom spawn produced from isolates originated or developed in other countries put aheavy economic burden on the growers and the country. In this study,mushroom spawn was produced from a native isolate of P. ostreatus, and the growth potential and yield of the isolate were evaluated by inoculating the spawn onto wheat straw compost. This is a pioneer research to produce mushroom spawn domesticallyand to reduce the dependence on foreign spawn supply.
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In this study, protease, α‐amylase and 5‰ β‐glucanase enzymolysis in combination with high‐pressure homogenisation were used for the preparation of polysaccharide‐based nanoparticles from Flammulina velutipes stipes, respectively, named FNP‐1, FNP‐2 and FNP‐3, and the nanoparticles were subsequently characterised. The FNP size distribution ranged from 50 nm to 300 nm, among which FNP‐2 and FNP‐3 were smaller than FNP‐1, based on the SEM images. GC‐MS results showed that these particles were mainly composed of glucose and glucosamine. The FNP dispersions at 1 wt% behaved as non‐Newtonian, shear‐thinning fluids, and the FNP‐3 dispersion presented superior viscoelasticity. With an increasing degree of enzymolysis, the thermal stability of the FNPs decreased. In addition, these particles presented various cation‐exchange properties. Therefore, the Flammulina velutipes polysaccharide‐based nanoparticles obtained from this study can be potentially used as a promising functional food ingredient in the food industry. The preparation process, SEM images, X‐ray diffraction, thermal and rheological properties of three F. velutipes polysaccharide nanoparticles.
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Purpose: To investigate the mechanism implicated in the effect of an insoluble fiber (obtained from carob pod) rich in polyphenols (IFCP) in lipid metabolism in the liver. Methods: Male New Zealand rabbits were fed with the following diets for 8 weeks: control diet (CT group), dyslipidemic diet supplemented with 0.5% cholesterol + 14% coconut oil (DL group) and dyslipidemic diet containing 0.5% cholesterol + 14% coconut oil plus 3% IFCP (DL + IFCP group). Results: Dyslipidemic diet with IFCP was able to reduce development of mixed dyslipidemia, liver relative weight and collagen I protein expression compared to DL rabbits. Analyses of the main enzymes implicated in cholesterol and triglycerides metabolism revealed that IFCP increased hepatic concentration of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase) and cytochrome P450, family 7, subfamily a, polypeptide 1C (CYP7A1) (82.34, 114.42%, respectively) as well as protein expression of LDL receptor (42.48%) in DL rabbits. Importantly, IFCP also increased hepatic lipase (HL) levels (91.43%) and decreased glycerol phosphate acyltransferase (GPAT) and sterol regulatory element-binding protein 1C (SREBP1c) liver expression levels (20.38 and 41.20%, respectively). Finally, sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α) hepatic expression increased in DL + IFCP group compared with DL (159.81 and 48.00%, respectively). Conclusions: These findings show that IFCP is able to abrogate the deleterious effects of hepatic dyslipidemia by modulating SIRT1 and PGC-1α pathways.
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Maitake mushroom (Grifola frondosa [Dicks.] Gray) is generally cultured using the sawdust of broadleaf trees. The maitake strain Gf433 has high production efficiency, with high-quality of fruiting bodies even when 30% of the birch sawdust on the basal substrate is replaced with conifer sawdust. We performed metabolome analysis to investigate the effect of different cultivation components on the metabolism of Gf433 and Mori52 by performing CE–MS on their fruiting bodies in different cultivation conditions to quantify the levels of amino acids, organic acids, and phosphorylated organic acids. We found that amino acid and organic acid content in Gf433 were not affected by the kind of sawdust. However, Gf433 contained more organic acids and less amino acids than Mori52, and Gf433 also contained more chitin compared with Mori52. We believe that these differences in the metabolome contents of the two strains are related to the high production efficiency of Gf433.
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This study compared the quality and drying characteristics of dried king oyster mushroom (Pleurotus eryngii), shiitake mushroom (Lentinus edodes GNA01) and maitake mushroom (Grifola frondosa) slices obtained by sundrying, hot-air drying (40, 50, 60?), low-temperature vacuum drying (20, 25, 30?), heat-pump dehumidifying drying (30, 40, 50?), and freeze drying. The quality changes investigted included color, browning degree, hardness, general components, ß-glucan. Color changes in king oyster mushroom during freeze drying were less than that between control (raw) and treated mushrooms. Compared with other drying methods, low-temperature vacuum drying of shiitake mushroom resulted in less color changes. Browning degree differed significantly between the different drying methods. As temperature increased, low-temperature vacuum drying resulted in decreased browning while heat-pump dehumidifying drying resulted in increased browning. In king oyster mushroom, hardness increased with temperature under hot-air drying, low-temperature vacuum drying and heat-pump dehumidifying drying. In shiitake mushroom, hardness increased with increasing temperature under hot-air drying and heat-pump dehumidifying drying. ß-glucan content after drying was found to be between 28.29 and 39.39% in king oyster mushroom, 23.05 and 29.48% in shiitake mushroom and 16.10 and 24.51% in maitake mushroom. Copyright © The Korean Society of Food Preservation. All rights reserved.
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Pollution of the environment with inorganic and organic substances is one of the main problems in the world. For this reason, it is necessary to conduct researches for effective methods of biodegradation of xenobiotics, including drugs whose unmetabolized forms are introduced into the environment, especially into water. One possible solution to this problem may be the use of white rot fungi, such as Lentinula edodes. This is an edible species used in medicine because of its beneficial anti-cancer, hypocholesterolemic, hypotensive, hypoglycemic and antioxidant effects. Due to the fact that the mycelium of L. edodes produces enzymes with oxidizing properties that can degrade xenobiotics. The aim of the work was verification if in vitro cultures of L. edodes can be used for bioremediation of non-steroidal, anti-inflammatory drug: piroxicam. For this purpose, the in vitro culture of L. edodes was derived and the mycelial cultures of this species enriched with piroxicam were analyzed. The biodegradation pathway of piroxicam by L. edodes mycelium was carried out by the UPLC/MS/MS method. The degradation process of piroxicam was found to affect primarily the linker between the thiazine and the piperidine ring, leading to its oxidation and cleavage. Additionally, oxidation of the benzothiazine moiety was observed, leading to hydroxylation and oxidation of the phenyl ring as well as oxidation of the thiazine ring leading to partial or complete removal of the sulfonamide moiety. It seems that the degradation process led finally to 2-hydroxybenozquinone, which may be further oxidized to inorganic compounds. What’s more, concentration of piroxicam in in vitro cultures of L. edodes was not correlated with effectiveness of biodegradation of this compound – on each experimental series, the level of degradation was the same. The results confirm the possibility of using the investigated L. edodes mycelium for remediation of piroxicam.
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Chapter
Shiitake mushroom (Lentinula edodes (Berk.) Sing.) is widely cultivated in China, Japan, Korea and many other Asian countries. It is one of the most extensively grown and consumed edible fungi in the world, with an exceptional high agricultural yield. Taxonomically, L. edodes belongs to the phylum Basideomycotina and family Agaricaceae. It is broadly distributed in the wild, mainly in the subtropical to temperate regions of the northern hemisphere. Due to its excellent taste qualities, high nutritional value, and medicinal properties, L. edodes is of great importance for the food industry and has medicinal applications. Various active medical ingredients such as lentinan, lentin, lectin and eritadenin, have been isolated from L. edodes culture media, fruiting bodies or mycelium. Enzymes, such as laccase, produced by L. edodes, have potential for industrial applications related to paper production (biopulping), residue treatment and improvement in the digestibility of animal rations. Like for other edible fungi cultivation, the raw materials for shiitake mushroom cultivation mostly constitute agricultural waste such as sawdust, straw and cottonseed husk. Moreover, the waste from the shiitake mushroom cultivation itself can be further used as a bio-organic fertilizer, greatly contributing to the process of crop rotation. Due to the changing natural environment along with the continuous improvement of living standards, mushroom cultivation is facing constant challenges. In order to obtain shiitake mushroom strains adapted to different climatic conditions, different cultivation methods and processing practices, breeders continuously screen for new shiitake varieties implementing diverse methods. In this chapter, we present an overview of the origin, distribution, taxonomic position, genetic characteristics, cultivation patterns and history of shiitake mushroom breeding by traditional and modern breeding methods in China.
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Increased consumption of high-calorie foods leads to obesity usually associated with metabolic disorders including diabetes, hyperglycemia, and dyslipidemia. Ganoderma applanatum is a nonedible mushroom traditionally used in West Cameroon for the treatment of many diseases including hypertension, diabetes, and hepatitis. This study was designed to investigate the antidyslipidemic potential of water-soluble polysaccharides of G. applanatum in MACAPOS-2- (maize, cassava, palm oil, and sugar) induced obese rats. For this purpose, obesity was induced on 6–8-week-old male Wistar rats with a local high-fat diet for four months. G. applanatum polysaccharides (GAPs) obtained by hot water extraction were orally administered to obese rats for two months at different dose levels (50, 100, and 150 mg/kg bodyweight), and its potential was investigated on food consumption, bodyweight gain, serum, and tissue lipids parameters. GAP extract increased the bodyweight gain by raising the food intake of obese rats. Furthermore, the administration of GAP extract at different dose levels significantly decreased the total cholesterol, triglyceride, low-density lipoprotein cholesterol levels, and the atherogenic index from 50 to 150 mg/kg bodyweight. Conversely, GAP extract improved the high-density lipoprotein cholesterol level in obese rats compared with untreated rats after two months’ study period. These results indicated that GAP extract may be considered as a novel bioactive compound against dyslipidemia and its associated complications.
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Impaired lipid profile is defined as abnormal plasma levels of low-density lipoprotein, triglycerides, and total cholesterol. This disease state is associated with the development and progression of various disorders, such as diabetes mellitus, cardiovascular diseases, and acute myocardial infarction. Globally, all of these disorders are related to a significant rate of death. Therefore, finding a suitable approach for the prevention and treatment of lipid profile-related disorders is in the spotlight. Recently, herbal therapy has been considered a promising therapeutic approach for the treatment of hyperlipidemia or its related disorders due to its safety and efficacy. Hereby, we address the potential benefits of some of these herbal compounds on different aspects of lipid profile and its abnormalities with a special focus on their underlying mechanisms. Using herbal products, such as teas and mushrooms, or their derivatives, Rosmarinus officinalis Linn, Curcuma longa, Green tea, Lippia triphylla, Lippia citriodora, Plantago asiatica L, Vine tea, and Grifola frondosa have been proved to exert several therapeutic impacts on lipid profile and its related disorders, and we would provide a brief review on them in this literature. K E Y W O R D S lipid profile, lipid metabolism, Herbal medicines, cholesterol lowering
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The Lentinus edodes species, known as shiitake, has a history of extensive use in many cuisines in several East Asian countries owing to its unique and pleasant flavor and texture. As international food trade increases, reliable discrimination of geographical origin is becoming increasingly crucial in Korea to identify cheaper imported Chinese shiitake. Herein, stable isotope ratios (i.e., δ¹³C, δ¹⁵N, δ¹⁸O, and δ³⁴S) were measured with a stable isotope ratio mass spectrometer, and a geographical discrimination method using orthogonal projection to latent structure-discriminant analysis was developed. The externally validated discrimination method showed excellent predictability (Q²cum = 0.881) and illustrated that δ¹⁸O and δ¹⁵N were important isotope markers for the geographical discrimination of dried shiitake slices. This study extends the knowledge of geographical differences between China and Korea evidenced by the shiitake isotope signatures, thereby contributing to potential geographical authentication with broader applications for international shiitake markets.
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The shiitake culinary-medicinal mushroom Lentinus edodes (=Lentinula edodes) has been used as a nutritional complement. This study evaluated, through reprotox tests, the consumption of L. edodes in pregnant rats, considering it as a functional food. Pregnant rats were daily exposed to L. edodes before implantation (LeB)-from 1 to 19 days of gestation, and after implantation (LeA)-from 9 to 19 days of gestation, compared with controls. On the 20th day of gestation, cesarean sections were performed. Blood was collected and hematological parameters (hemoglobin, hematocrit, white and red blood cells and platelets) were analyzed. Moreover, albumin, calcium, creatine kinase, alkaline phosphatase, transferases, creatinine, urea, triglycerides, cholesterol, lipase, glucose, and insulin were assessed in serum. Organs were collected and weighed, and the fetuses were analyzed morphologically by body measurements. The consumption of L. edodes reduced triglycerides levels and there were no changes in maternal weight, biochemical and hematological parameters, organ weight, and reproductive capacity. There were no morphological changes in the fetuses' body measurements, suggesting possible safety in ingestion of mushroom. Reprotox tests used to evaluate the daily consumption of L. edodes points out potentiality as a functional food, suggesting safety during the gestational period.
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We applied a vacuum microwave drying (VMD) process to shiitake mushrooms under different pressure conditions below 20 kPa, and investigated drying time, hardness and rehydration characteristics, extracted guanylic acid, color, and sensory evaluation. The samples were subjected to different microwave treatments at different levels of power (25 W/g dry matter, 50 W/g dry matter, and 75 W/g dry matter) and absolute pressures (3 kPa, 10 kPa, and 20 kPa). VMD reduced drying time by approximately 13 to 70 times compared with hot air drying (HAD). Decreasing the pressure tended to soften the rehydrated samples, whereas the amount of guanylic acid extracted from samples treated at 20 kPa was the largest. The sensory evaluation score of VMD-treated shiitake mushrooms was larger than HAD-treated mushrooms. Collectively, these results suggest that VMD is more suitable and useful than HAD in producing high quality dried shiitake mushrooms.
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Effects of physical and nutritional conditions for the mycelial growth of edible wild strains of Flammulina velutipes were evaluated. Among the strains highest and lowest mycelial growth was found at the temperature of 25 ºC and 15 ºC. This mushroom has a broad pH range for its mycelial growth and development and mostly favorable growth was observed at pH 6. In case of culture media, results indicated that Lilly, glucose tryptone, yeast-malt extract, Hamada and potato dextrose agar were the favorable and Hoppkins and Czapek dox were the unfavorable culture media for the mycelial growth. Fructose was the best and lactose was the less effective carbon sources for the mycelial growth. The most suitable nitrogen sources were ammonium acetate, alanine, glycine, calcium nitrate and potassium nitrate, while less effective sources were histidine, arginine and ammonium acetate for the mycelial growth of Flammulina velutipes.
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A supercritical extraction plant (with a 6 L extraction cell) was successfully used to obtain ergosterol-enriched extracts from Lentinula edodes (40 ºC, 225 bar, 1-5h, 20 L/h recirculated CO2). Ergosterol (ERG) and the SFE extract (SFE) with the highest ergosterol concentration were also microemulsified and submitted to in vitro digestion to study their ability to displace cholesterol from dietary mixed micelles (DMMs). ERG was also mixed with a β-glucan-enriched (33.5%) extract (BGE) from L. edodes to investigate synergies. Results indicated that they all (including BGE without ERG) could reduce cholesterol levels in DMMs. However, when ERG and SFE were administrated to mice simultaneously with a hypercholesterolemic diet, no significant differences in serum cholesterol levels were detected compared to control. Only when BGE was administrated to another mice model after the hypercholesterolemia was previously induced, significant reduction of cholesterol was noticed.
Chapter
The health benefits of mushrooms find their place in the ancient texts of Greek, Roman, Chinese, and in Ayurveda. Exploration and validation of the history and ethnic knowledge of the use of mushrooms have been a basis for a number of novel bioactive agents which may serve as leads for drug discovery. Mushrooms are significantly nutritious since they are low in fat and calories, whereas they are rich in protein including essential amino acids and dietary fiber. They are also a good source of various vitamins and trace elements. Mushrooms are documented for their health-promoting and pharmacological activities like antioxidant, antidiabetic, anticancer, immunomodulating, anti-allergic, anticholesterolemic, cardiovascular protector, and hepatoprotective effects and antimicrobial benefits such as antibacterial, antiviral, antifungal, and antiparasitic. This chapter includes medicinal and health-promoting effects of different mushrooms.
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Partial substitution of wheat flour with Flammulina velutipes powder (FVP) or soluble polysaccharide (SPFV) at different addition levels, and the effects of which on the rheological and microstructural properties of dough were investigated. FVP significantly (P < 0.05) increased the water absorption but decreased the development time and stability of dough significantly (P < 0.05). Furthermore, it was capable of providing a weaker extension and harder dough with the increasing of FVP addition levels. FVP increased the storage (G′) and loss (G″) moduli, while the tan δ decreased with the increasing of FVP addition levels. However, SPFV addition had inconsistent viscoelastic results with that of FVP addition. The microstructure of dough showed that the continuity of gluten networks had been disrupted by FVP and SPFV at a higher addition level. This research could provide a foundation for the application of FVP in wheat-flour foods, and FVP addition levels of 2.5% to 5.0% are recommended.
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This study was designed to investigate the effects of dietary fenugreek seed extract (FSE) supplementation on egg production, egg quality, blood profiles, cecal microflora, and excreta noxious gas emission in laying hens. A total of 384 laying hens (26-weeks old, Hyline-brown) were fed three different levels of FSE (0, 0.05, and 0.1%) in a corn-soybean diet for 6 weeks. The inclusion of FSE in the laying hen diet did not affect egg production, feed intake, or feed conversion among treatments; however, egg weight, eggshell breaking strength, eggshell thickness, and yolk color increased in FSE-fed groups (linear, P<0.05). Supplemental FSE decreased the serum total cholesterol concentration, whereas the HDL-cholesterol concentration increased in the FSE fed-groups (linear, P<0.05). FSE led to an increase in cecal Lactobacillus number (linear, P<0.05), and a decrease in Escherichia coli number (quadratic, P<0.05) and excreta ammonia gas emission (linear, P<0.05). These results suggest that the addition of FSE does not increase egg production, but may affect egg quality, serum total- and HDL-cholesterol concentration, and cecal microflora. FSE also decreased ammonia gas emission in laying hen excreta.
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Dietary fiber is plant-derived material that is resistant to digestion by human alimentary enzymes. Fiber may be divided into two broad chemical classes: 1) non-alpha-glucan polysaccharides (cellulose, hemicelluloses, and pectins) and 2) lignins. Dietary fiber behaves within the gastrointestinal tract as a polymer matrix with variable physicochemical properties including susceptibility to bacterial fermentation, water-holding capacity, cation-exchange, and adsorptive functions. These properties determine physiological actions of fiber and are dependent on the physical and chemical composition of the fiber. Fiber undergoes compositional changes as a consequence of bacterial enzymatic action in the colon. Dietary fiber is of clinical significance in certain disorders of colonic function and in glucose and lipid metabolism. Dietary fiber increases stool bulk by acting as a vehicle for fecal water and by increasing fecal bacterial volume. Use of fiber in the treatment of constipation and uncomplicated diverticular disease is well established. By increasing stool bulk, fiber also reduces the fecal concentration of bile acids and other substances. Certain types of fiber decrease the rate of glucose absorption and attenuate postprandial rises in blood glucose and insulin. Plasma cholesterol levels are reduced by mucilaginous forms of fiber. This effect appears to be mediated in part by an increase in fecal acidic sterol excretion.
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A new method of total RNA isolation by a single extraction with an acid guanidinium thiocyanate-phenol-chloroform mixture is described. The method provides a pure preparation of undegraded RNA in high yield and can be completed within 4 h. It is particularly useful for processing large numbers of samples and for isolation of RNA from minute quantities of cells or tissue samples.
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Plasma cholesterol concentration is reduced by feeding some dietary fibers but the mechanism is not fully understood. We examined whether cecal fermentation products are involved in lowering plasma cholesterol by feeding rats a highly fermentable sugar-beet fiber (SBF) in four separate experiments. These were designed to investigate the effects on plasma cholesterol of oral ingestion of fermentation products on plasma cholesterol, the effects of the products in comparison with that of a short-chain fatty acid (SCFA) mixture, effects of individual SCFA and effects of alteration of energy and nitrogen ratio in the diet by the addition of the SCFA mixture. Cecal contents of rats were cultured with SBF by using a jar fermenter under anaerobic conditions, and the supernatant from the culture medium, containing fermentation products of SBF, was collected and freeze-dried before feeding to rats. Yield of fermentation products as dry weight from the fiber was 80-90%. In rats fed a diet containing fermentation products (80 g/kg diet), plasma cholesterol concentrations were lower than in rats of the fiber-free group 3, 7 and 14 d after feeding the test diet. Major SCFA in the fermentation products were sodium salts of acetic, propionic and butyric acids. Plasma cholesterol concentration in rats fed the diet containing a mixture of equal amounts of the three SCFA salts (66 g/kg diet) as the fermentation products diet was also lower than that in the fiber-free group and was not different from those in rats fed SBF (100 g/kg diet) and the fermentation products. In rats fed an acetate-containing diet but not in rats fed diets without acetate, plasma cholesterol was significantly lower than in the fiber-free group. In conclusion, absorption of SCFA from cecal fermentation products lowers plasma cholesterol. Acetate, and not propionate, may be responsible for lowering plasma cholesterol concentration.
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Through the use of a quantitative solution hybridization assay with 32P-labeled cDNA probes, we found that mevinolin, an inhibitor of cholesterol synthesis, elevates the level of mRNA for the low density lipoprotein receptor in livers of hamsters and rabbits. In hamsters the maximal effect (3-fold increase) occurred at 0.1% mevinolin in the diet for 10 days. The same dose produced a maximal induction (10-fold) of mRNA levels for 3-hydroxy-3-methylglutaryl CoA reductase, the rate-limiting enzyme of cholesterol synthesis, and a maximal decrease (80%) in plasma cholesterol. The drug lowered the level of all cholesterol-carrying lipoproteins in plasma. In normal rabbits, mevinolin produced a 90% reduction in plasma low density lipoprotein-cholesterol levels, which was associated with a 2.5-fold increase in low density lipoprotein receptor mRNA levels. A similar induction of receptor mRNA occurred in livers of Watanabe-heritable hyperlipidemic rabbits, although the plasma cholesterol was not reduced to normal, presumably because the receptors produced by the mutant mRNA function poorly. These data are consistent with the hypothesis that mevinolin and other inhibitors of 3-hydroxy-3-methylglutaryl CoA reductase lower plasma cholesterol levels in part by stimulating production of mRNA for the low density lipoprotein receptor in liver.
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Rats were fed a cholesterol-free diet with no added fiber (fiber-free) or with 15 g/100 g beet fiber or 5 g/100 g cholestyramine for 14 d. Final plasma total cholesterol concentrations were significantly lower in rats fed beet fiber than in those fed fiber-free or cholestyramine diets. This difference was due mainly to lower HDL cholesterol concentrations. The group fed beet fiber also tended (P < 0.1) to have lower apolipoprotein A-I concentration in plasma. Northern blot analysis revealed that the relative concentrations of jejunal apolipoprotein A-I and A-IV mRNA were the same in all groups, whereas ileal apolipoprotein A-I and A-IV mRNA levels were significantly lower in rats fed beet fiber or cholestyramine than in those fed the fiber-free diet. Hepatic apolipoprotein E mRNA concentrations were the same in all groups, but apolipoprotein A-I mRNA levels were significantly lower in rats fed beet fiber than in those fed the other diets. Apolipoprotein A-IV mRNA tended (P < 0.1) to be lower in rats fed the beet fiber diet. These data suggest that the hypocholesterolemic effect of dietary beet fiber is associated with diminished expression of the hepatic apolipoprotein A-I gene.
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Fermentable energy in insoluble dietary fibre (DF) sources was evaluated by in vivo and in vitro methods using rats. Test diets contained 50 and 100 g maize husk or organic-acid-treated maize husk/kg diet. Soluble fractions were removed from both the DF sources by washing. The acid treatment increased digestibility by a microbial hemicellulase from 12.7% to 32.6%. The fermentability of DF was evaluated by measurement of the production rate of short-chain fatty acids (SCFA) in a short-term in vitro incubation of the caecal contents of rats fed on test diets for 22 d. The production rates of the major SCFA, acetic, propionic and butyric acids, were increased by feeding both DF sources, and these production rates in the acid-treated DF group were significantly higher than those in the untreated DF group. The production rate of a minor SCFA, isovaleric acid, was decreased by feeding both diets. The production rate of total SCFA in rats given the acid-treated maize husk was 32.6% higher than that in rats given the untreated maize husk. The fermentable energy in DF was estimated in vivo by subtracting the faecal excretion of DF energy from ingested DF energy. The fermentable energy in DF was increased by the acid treatment (32.5% in maize husk and 63.4% in acid-treated maize husk), which agreed with the SCFA production rate predicted in the caecum. These results indicate that a short-term incubation of caecal contents is a useful method for evaluation of the fermentability of DF sources, and that acid treatment can increase the fermentability of an insoluble DF source.
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The aim of this study was to evaluate the influence of dietary propionic acid and bile acid excretion on the hypocholesterolemic effect of fibers. For this purpose, rats were adapted to a diet containing 10 g inulin, 10 g beta-cyclodextrin, or 2.5 g calcium propionate per 100 g diet. Both the inulin and beta-cyclodextrin diets elicited high propionic acid fermentations in the cecum (approximately 45% of total short-chain fatty acids) with relatively low molar proportions of acetic and butyric acids. In rats fed the three experimental diets, 5-7 mumol/min of propionic acid was absorbed in the portal vein, and propionic acid was entirely metabolized by the liver. Plasma cholesterol was more effectively depressed by the beta-cyclodextrin diet than by the inulin diet; the propionic acid-supplemented diet was ineffective in this respect. The inulin diet slightly increased fecal bile acid excretion, compared with the control diet, whereas beta-cyclodextrin markedly enhanced (1.8-fold) bile acid excretion. Microsomal hydroxymethylglutaryl-CoA (HMG-CoA) reductase activity was slightly depressed in rats fed the propionic acid-supplemented diet, whereas it was enhanced by the beta-cyclodextrin diet in parallel to the activity of cholesterol 7 alpha-hydroxylase. The present data suggest that absorption and further hepatic metabolism of large amounts of propionic acid are not sufficient to counteract the induction of HMG-CoA reductase resulting from bile acid fecal losses. The rise of these losses plays a major role in the hypocholesterolemic effect of beta-cyclodextrin.
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The aim of this study was to determine the effects of fiber feeding on short-chain fatty acid (SCFA) production in laboratory rats and in an in vitro fermentation model using fecal inocula from rats adapted to a high fiber diet. In addition, the effect of fiber intake on endogenous sterol synthesis was evaluated. Twenty male Sprague-Dawley rats were divided into four groups and fed a control or 30% fiber diet (cellulose, pectin or pea fiber) for 4 wk. In vitro fermentation was compared with measurements of cecal SCFA content of fiber-adapted rats. Sterol synthesis in isolated hepatocytes was determined in groups of five to seven rats fed 15% dietary fiber for 4 wk. Cellulose was poorly fermented in both the in vitro and in vivo experiments. Pectin fermentation produced high levels of propionate, whereas pea fiber was associated with notable butyrate production. Adaptation to pectin produced seven times more SCFA in rat cecal contents (515 +/- 78 mumol) in comparison to a fiber-free diet (70.6 +/- 4.9 mumol), with similar results observed in vitro. Sterol synthesis in hepatocytes of rats fed pectin was significantly greater than in those of control or cellulose-fed rats. Despite significantly higher rates of SCFA production in pectin-fed rats, cholesterol synthesis was not inhibited, suggesting that SCFA are not the cholesterol-lowering factor of highly fermentable fiber sources.
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Psyllium, a source of dietary fiber rich in soluble components results in lower serum cholesterol concentration in several species. Suggested mechanisms for the hypocholesterolemic effect include a greater excretion of fecal bile acids and total steroids, and up-regulation of bile acid biosynthesis. The activity of cholesterol 7alpha-hydroxylase (7alphaOHase), the rate limiting enzyme in bile acid biosynthesis, is higher in rats fed 5% psyllium. Whether this higher activity corresponds to an increase in mRNA levels has not been determined. Four groups of 10 rats were fed a semipurified diet containing 5% cellulose (CEL; control), 5% cellulose plus 1% cholic acid (CCA), 5% cellulose plus 2% cholestyramine (CHY) or 5% psyllium hydrocolloid (PSY) for 3 wk. Liver cholesterol concentration, fecal bile acid and total steroid excretion, 7alphaOHase activity and 7alphaOHase mRNA levels were measured. Liver cholesterol content in rats fed CCA was significantly higher than in all other groups. Rats fed CHY and PSY had significantly lower liver cholesterol content than those fed CEL. Total fecal steroid and bile acid excretions were significantly greater in rats fed CCA, CHY and PSY than in those fed CEL. Activities and mRNA levels of 7alphaOHase in rats fed CHY and PSY were significantly higher than in rats fed CEL or CCA. These data indicate that feeding psyllium to rats increases fecal bile acid and total steroid excretion as well as 7alphaOHase activity and 7alphaOHase mRNA levels.
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We previously showed that plasma cholesterol levels decreased following ingestion of a short-chain fatty acid (SCFA) mixture composed of sodium salts of acetic, propionic, and butyric acids simulating cecal fermentation products of sugar-beet fiber (SBF). In the present study, we investigated whether hepatic and small intestinal cholesterol synthesis is involved in the cholesterol-lowering effects of SCFA and SBF. In vitro (expt. 1) and in vivo (expt. 2) cholesterol synthesis rates and the diurnal pattern of SCFA concentrations in portal plasma (expt. 3) were studied in three separate experiments in rats fed diets containing the SCFA mixture, SBF (100 g/kg diet), or the fiber-free control diet. Cholesterol synthesis was measured using 3H2O as a tracer. The in vitro rate of cholesterol synthesis, measured using liver slices, was greater in the SBF group, but not in the SCFA group, than in the fiber-free control group. In contrast, the hepatic cholesterol synthesis rate in vivo was lower in the SCFA group, but not in the SBF group, than in the control group. The mucosal cholesterol synthesis rate for the whole small intestine was <50% of the hepatic rate. The rate in the proximal region was slightly but significantly lower in the SCFA group, and was significantly higher in the SBF group than in the fiber-free group. The rate in the distal small intestines was also significantly greater in the SBF group than in the fiber-free group. Plasma total cholesterol concentrations were lower in the SCFA and SBF groups than in the fiber-free group in both experiments 2 and 3. Diurnal changes in portal SCFA and cholesterol levels were studied in the experiment 3. SCFA concentrations increased rapidly after the start of feeding the SCFA diet, and changes in plasma cholesterol were the reciprocal of those observed in SCFA. These results show that a decrease in hepatic cholesterol synthesis rate mainly contributes to the lowering of plasma cholesterol in rats fed the SCFA mixture diet. Changes in portal SCFA and cholesterol concentrations support this conclusion. In SBF-fed rats, SCFA produced by cecal fermentation are possibly involved in lowering plasma cholesterol levels by negating the counteractive induction of hepatic cholesterol synthesis caused by an increase in bile acid excretion.
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A method for isolation and quantification of fecal bile acids is described which allows sterol balance studies to be made in man or in small laboratory animals without requiring the use of radioisotopes in vivo. Bile acids are purified by column and thin-layer chromatography, converted to the trimethylsilyl ethers of their methyl esters, and quantified by GLC with detection by hydrogen flame ionization. Recoveries are complete when internal standard corrections are applied, with an error <±3%. The claim that the final fecal bile acid fraction accounts for all the bile acids and nothing but bile acids is validated in several ways. The sensitivity is such that fecal aliquots containing as little as 50 μg of mixed bile acids can be analyzed accurately, but the procedure lends itself well to preparative scale work for more definitive study of individual bile acids. After oral administration of cholic-24-C¹⁴ and chenodeoxycholic-24-C¹⁴ acids to one patient, 98% of the administered radioactivity was excreted in the bile acid fraction of the fecal extracts over a period of 38 days, and 2% in the urine. This experiment indicated the stability of bile acid structure during intestinal transit and provided additional evidence for the completeness of the described method of determining fecal bile acids.
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The aim of this study was to evaluate the influence of dietary propionic acid and bile acid excretion on the hypocholesterolemic effect of fibers. For this purpose, rats were adapted to a diet containing 10 g inulin, 10 g β-cyclodextrin, or 2.5 g calcium propionate per 100 g diet. Both the inulin and β-cyclodextrin diets elicited high propionic acid fermentations in the cecum (∼45% of total short-chain fatty acids) with relatively low molar proportions of acetic and butyric acids. In rats fed the three experimental diets, 5–7 µmol/min of propionic acid was absorbed in the portal vein, and propionic acid was entirely metabolized by the liver. Plasma cholesterol was more effectively depressed by the β-cyclodextrin diet than by the inulin diet; the propionic acid-supplemented diet was ineffective in this respect. The inulin diet slightly increased fecal bile acid excretion, compared with the control diet, whereas β-cyclodextrin markedly enhanced (1.8-fold) bile acid excretion. Microsomal hydroxymethylglutaryl-CoA (HMG-CoA) reductase activity was slightly depressed in rats fed the propionic acid-supplemented diet, whereas it was enhanced by the β-cyclodextrin diet in parallel to the activity of cholesterol 7α-hydroxylase. The present data suggest that absorption and further hepatic metabolism of large amounts of propionic acid are not sufficient to counteract the induction of HMG-CoA reductase resulting from bile acid fecal losses. The rise of these losses plays a major role in the hypocholesterolemic effect of β-cyclodextrin.
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Plasma cholesterol concentration is reduced by feeding some dietary fibers and mushroom fruit body, but the mechanism is not fully understood. We examined the effects of mushroom (Agaricus bisporus) fiber and sugar beet fiber on serum cholesterol and hepatic LDL receptor mRNA in rats. Rats were fed a cholesterol-free diet with 50 g/kg cellulose powder (CP), 50 g/kg mushroom (Agaricus bisporus) fiber (MSF) or 50 g/kg sugar beet fiber (BF) for 4 wk. There were no significant differences in the body weight, food intake and cecum weight among the groups. The relative liver weight in the CP group was significantly greater than that in the MSF and BF groups. The cecal pH in the CP and MSF groups was significantly higher than that in the BF group. Cecal acetic acid, butyric acid and total short-chain fatty acid (SCFA) concentrations in the BF group were significantly higher than those in the other groups. The serum total cholesterol, VLDL + intermediate density lipoprotein (IDL) + IDL cholesterol concentrations in the CP group were significantly greater than those in the MSF and BF groups. The HDL cholesterol concentration in the MSF group was significantly lower than that in the CP group. The hepatic LDL receptor mRNA level in the MSF and BF groups was significantly higher than that in the CP group. The results of this study demonstrate that mushroom fiber and sugar beet fiber lowered the serum total cholesterol level by enhancement of the hepatic LDL receptor mRNA.
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In addition to HMG-CoA reductase, another HMG-CoA utilizing enzyme is present in the Mt fraction of sweet potato root tissue and its activity interferes with the assay to HMG-CoA reductase activity.
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Two mechanisms have been proposed for the hypocholesterolaemic effects of dietary oat bran, i.e. acceleration of cholesterol catabolism or inhibition of cholesterol biosynthesis. The latter is proposed to occur via propionate formed through large bowel microbial fermentation of fibre. We have examined both of these mechanisms in rats fed dietary oat bran and have found that faecal bile acid and neutral sterol excretion was enhanced compared with animals fed cellulose. In contrast, concentrations of propionate in the hepatic portal vein, although raised by dietary oat bran, were less than 2% of those at which inhibition of hepatic cholesterogenesis has been observed in vitro. When hepatic cholesterol synthesis was measured with 3H2O, it was increased in oat branfed rats. Therefore, it appears most likely that the hypocholesterolaemic effects of this cereal fibre preparation can be explained by increased faecal steroid excretion and not through inhibition of cholesterogenesis by volatile fatty acids of large bowel origin.
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The mevalonate pathway produces isoprenoids that are vital for diverse cellular functions, ranging from cholesterol synthesis to growth control. Several mechanisms for feedback regulation of low-density-lipoprotein receptors and of two enzymes involved in mevalonate biosynthesis ensure the production of sufficient mevalonate for several end-products. Manipulation of this regulatory system could be useful in treating certain forms of cancer as well as heart disease.
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The effects of propionate, a product of intestinal fiber fermentation, on fatty acid and sterol synthesis were studied in isolated rat hepatocytes. Fatty acid synthesis, as measured by tritium incorporation from 3H2O, was inhibited in the presence of 1 mmol/L propionate with no substrate additions or additions of acetate, butyrate, lactate or oleate. Incorporation of [1-14C]acetate into fatty acids was also inhibited in the presence of propionate. Although propionate markedly depressed [1-14C]acetate incorporation into sterols in hepatocyte preparations, tritium incorporation from 3H2O into sterols was not inhibited, indicating that overall sterol synthesis was not affected. Thus, in vitro, the effect of propionate on lipid metabolism is apparently limited to inhibition of de novo fatty acid synthesis.
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The activity of the microsomal 3-hydroxy-3-methylglutaryl-coenzyme A reductase was assayed with a procedure based on the extraction of the product mevalonolactone in a benzene phase. Diamide is an uncompetitive inhibitor of the reaction, while coenzyme A disulfide and tetraethylthiouram disulfide act as non-competitive inhibitors. Diamide inhibition cooperatively increases with the inhibitor concentration. HMG produces a decrease in enzyme activity that combines with that of coenzyme A disulfide. Both CoASH and coenzyme A esters strongly inhibit the reductase activity. Three new synthetic compounds with either thio-ether or thio-ester groups also show inhibitory effect on the enzyme activity.
Article
Dietary fiber is plant-derived material that is resistant to digestion by human alimentary enzymes. Fiber may be divided into two broad chemical classes: 1) non-alpha-glucan polysaccharides (cellulose, hemicelluloses, and pectins) and 2) lignins. Dietary fiber behaves within the gastrointestinal tract as a polymer matrix with variable physicochemical properties including susceptibility to bacterial fermentation, water-holding capacity, cation-exchange, and adsorptive functions. These properties determine physiological actions of fiber and are dependent on the physical and chemical composition of the fiber. Fiber undergoes compositional changes as a consequence of bacterial enzymatic action in the colon. Dietary fiber is of clinical significance in certain disorders of colonic function and in glucose and lipid metabolism. Dietary fiber increases stool bulk by acting as a vehicle for fecal water and by increasing fecal bacterial volume. Use of fiber in the treatment of constipation and uncomplicated diverticular disease is well established. By increasing stool bulk, fiber also reduces the fecal concentration of bile acids and other substances. Certain types of fiber decrease the rate of glucose absorption and attenuate postprandial rises in blood glucose and insulin. Plasma cholesterol levels are reduced by mucilaginous forms of fiber. This effect appears to be mediated in part by an increase in fecal acidic sterol excretion.
Article
The effects of propionate on serum and liver lipid concentrations were studied in cholesterol-fed rats. Both serum and liver cholesterol levels were significantly lower in rats fed the cholesterol-propionate diet than in rats fed the cholesterol diet without propionate. Liver triglyceride levels were also significantly lower in the propionate-treated group. Serum triglyceride concentrations were not influenced by the propionate feeding. Propionate intake was not associated with histologic changes in liver tissue. This study indicates that 0.5% sodium propionate-supplemented diets slightly but significantly reduced cholesterol accumulation in both serum and liver of cholesterol-fed rats. Thus propionate, a metabolic product of fiber fermentation, may mediate some of the hypocholesterolemic effects of certain soluble plant fibers.
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The effects of the flower lipid-saccharide complex and unsaponifiable matter (1 g/kg of diet) from the sunflower on liver lipid metabolism and intestinal flora was studied in rats given cholesterol-enriched diets. After six weeks of feeding, the microsomal cholesterol concentration in the liver had been significantly reduced with the sunflower diet. The ratio of cholesterol/phospholipid was also reduced by the sunflower diet. The 3-hydroxy-3-methylglutaryl coenzyme A reductase activity of the sunflower groups was significantly lower than that of the control group. There was no significant difference in the cholesterol 7 alpha-hydroxylase activity, although this tended to increase with dietary sunflower consumption. The number of Bacillus in the cecum flora was significantly higher in the lipid-saccharide complex group than in the other groups, while Bifidobacterium and Eubacterium in the cecum flora was significantly higher in the unsaponifiable matter group when compared to the control group. These results suggest that the lipid-saccharide complex and unsaponifiable matter in the sunflower are related to liver cholesterol synthesis and intestinal flora.
Article
The effect of different polysaccharides fermented in the large intestine and liable to lower plasma cholesterol was investigated in rats. Male rats were assigned to one of five treatment groups: control diet or a diet containing pectin, guar gum, gum arabic or beta-cyclodextrin. The four compounds were effectively fermented, yielding cecal short-chain fatty acids (SCFA) concentrations in the range of 130 to 170 mmol/L. Relative to controls, the cecal concentration of propionate was significantly higher in rats fed all fibers, especially those fed guar gum (+190%) or beta-cyclodextrin (+385%). All the fermented carbohydrates elicited a significant cholesterol-lowering effect, which was most potent in rats fed guar gum or beta-cyclodextrin, the two fibers that also significantly depressed plasma triglycerides. These two carbohydrates significantly lowered LDL and HDL1 cholesterol, triglyceride-rich lipoprotein triglycerides and apolipoprotein E levels. Apolipoprotein B was lowered only by beta-cyclodextrin. The microsomal activities of hydroxymethylglutaryl (HMG) CoA reductase and of cholesterol 7 alpha-hydroxylase were markedly elevated in rats fed guar gum or beta-cyclodextrin and, to a lesser extent, in those fed pectin compared with controls. Increased bile acid excretion seems to be essential in the cholesterol-lowering effect of soluble fibers and related compounds. This effect is connected to induction of HMG CoA reductase and lowering concentrations of apolipoprotein E-containing particles.
Article
Plasma cholesterol concentrations were significantly lower in rats fed a cholesterol-free diet containing white wheat flour than those fed the diet with whole wheat or wheat bran. Concentrations of total bile acids and neutral sterols in cecal digesta were significantly higher in rats fed wheat flour than in those fed whole wheat, wheat pollard or wheat bran. Digesta bile acids and neutral sterol pools correlated negatively with plasma cholesterol, indicating that excretion was regulating plasma concentration. Total cecal volatile fatty acid (VFA) concentrations were unaffected by diet but cecal propionate was higher and butyrate lower in rats fed wheat flour than in those fed whole wheat. Cecal digesta butyrate concentrations correlated negatively with the cholesterol metabolite, coprostanol, and with secondary bile acids. Cecal propionate correlated negatively with plasma cholesterol concentration, but butyrate correlated equally positively, suggesting these VFA were indicators rather than regulators of altered cecal steroid metabolism. Effects of white wheat flour on steroid metabolism and cecal VFA resemble those of oat bran and support the observation that wheat flour might be hypocholesterolemic in humans.
Article
Amylase-resistant starch (RS) represents a substrate for the bacterial flora of the colon, and the question arises as whether RS shares with soluble fibers common mechanisms for their lipid-lowering effects. It is uncertain whether a cholesterol-lowering effect depends basically on an enhanced rate of steroid excretion or whether colonic fermentations also play a role in this effect. In the present study, the effect of RS (25% raw potato starch), of a steroid sequestrant (0.8% cholestyramine), or both were compared on bile acid excretion and lipid metabolism in rats fed semipurified diets. RS diets led to a marked rise in cecal size and the cecal pool of short-chain fatty acids (SCFA), as well as SCFA absorption; cholestyramine did not noticeably affect cecal fermentation. Whereas cholestyramine was particularly effective at enhancing bile acid excretion, RS was more effective in lowering plasma cholesterol (-32%) and triglycerides (-29%). The activity of 3-hydroxy-3-methylglutaryl-CoA reductase was increased fivefold by cholestyramine and twofold by RS. This induction in rats fed RS diets was concomittant to a depressed fatty acid synthase activity. In rats fed the RS diet, there was a lower concentration of cholesterol in all lipoprotein fractions, especially the (d = 1.040-1.080) fraction high-density lipoprotein (HDL1), while those fed cholestyramine had only a significant reduction of HDL1 cholesterol. In contrast to cholestyramine, RS also depressed the concentration of triglycerides in the triglyceride-rich lipoprotein fraction.(ABSTRACT TRUNCATED AT 250 WORDS)
Article
The effect of the diet containing 5% of powdered oyster mushroom (Pleurotus ostreatus) or an equivalent amount of mushroom ethanolic extract on cholesterol content in serum and liver, on its distribution in lipoproteins, absorption and turnover was studied in male Wistar rats (initial body weight about 70 g) fed a diet with 0.3% cholesterol. 12 weeks of feeding with whole oyster mushroom or mushroom extract reduced cholesterol level in serum by 52 and 33%, respectively. However, cholesterol content in liver was reduced only by whole oyster mushroom (by 20%). Diminished serum cholesterol level was mediated in 60% by reduction of cholesterol in very-low-density lipoproteins. Both whole oyster mushroom and mushroom extract increased the concentration of cholesterol in high-density lipoproteins. Consuming whole oyster mushroom decreased cholesterol absorption (estimated by dual-isotope plasma ratio method) by nearly 16% while no significant effect of mushroom extract could be demonstrated. Feeding the diet containing whole oyster mushroom or its extract reduced the half-times of decay curve of cholesterol-4-14C by 29 and 35%, respectively and reciprocally increased the fractional catabolic rate of plasma cholesterol.
Article
Experimental rat models (5-week-old Sprague-Dawley rats) with hyperlipemia were prepared by feeding high-cholesterol feed containing sodium cholate and casein as a protein source. Dried maitake (Grifola frondosa) powder was mixed with the basic high-cholesterol feed and the serum lipids were periodically measured. Values of cholesterol, triglyceride and phospholipid in serum of rats in the maitake-feed group were suppressed by 0.3-0.8 times those in animals fed the basic feed, the latter values being close to those in rats given normal feed. The value of high density lipoprotein (HDL)-cholesterol in serum which is generally reduced by the ingestion of high-cholesterol feed remained the level it was at the beginning of the experiment. Weights of extirpated liver and epididymal fat-pads were significantly less (0.6-0.7 times) than those in the basic feed group, indicating that maitake inhibits lipid accumulation in the body. Liver lipids were also measured and the values were found to be decreased by maitake administration as true of serum lipid, suggesting maitake has an anti-liver lipid activity. Measurement of the amount of total cholesterol and bile acid in feces showed, the ratio of cholesterol-excretion had increased 1.8 times and bile acid-excretion 3 fold by maitake treatment. From these results, it is believed that maitake helps to improve the lipid metabolism as it inhibits both liver lipid and serum lipid which are increased by the ingestion of high-fat feed.
Article
The effect of the fruiting body and mycelium of Volvariella volvacea (straw mushroom) on the concentrations of plasma lipids, liver cholesterol, fecal neutral sterol and bile acid excretions was investigated in male Golden Syrian hamsters. The hamsters were fed a purified hypercholesterolemic diet (0.1% cholesterol, 10% fat) for 4 wk to elevate plasma lipid concentrations. Twelve hamsters with elevated plasma total cholesterol were randomly assigned to each treatment group: control (5% cellulose), mushroom fruiting body (5%) and mushroom mycelium (5%). After 4 wk of mushroom diet consumption, the plasma total cholesterol, HDL cholesterol, and combined VLDL + LDL cholesterol concentrations (mmol/L) were significantly lower than control in the group fed the fruiting body-diet (40, 38 and 43%, respectively) (P < 0.05). The liver cholesterol levels were significantly lower in both the mushroom fruiting body- and the mycelium-fed groups (28 and 21% in terms of concentration; 39 and 30% in terms of total content, respectively) (P < 0.05) than that in the control group. Fecal neutral sterol excretion in the mushroom fruiting body- and mycelium-fed groups was significantly higher (81 and 74%, respectively) (P < 0.05) than that in the control group. Although no significant differences (P > 0.05) in the excretion of fecal bile acids were observed among groups fed the mushroom diets and the control diet, the mushroom fruiting body diet-fed hamsters apparently had less bacterial degradation of cholic acid as indicated by a significantly greater proportion (P < 0.05) of fecal cholic acid than in controls. They also had a significantly lower proportion of fecal deoxycholic acid (P < 0.05). This study suggests that the fruiting body of the straw mushroom lowers elevated plasma cholesterol in hypercholesterolemic hamsters, whereas the mycelium does not.
Article
Plasma cholesterol concentration is reduced by feeding some dietary fibers and mushroom fruit body, but the mechanism is not fully understood. We examined the effects of mushroom (Agaricus bisporus) fiber and sugar beet fiber on serum cholesterol and hepatic LDL receptor mRNA in rats. Rats were fed a cholesterol-free diet with 50 g/kg cellulose powder (CP), 50 g/kg mushroom (Agaricus bisporus) fiber (MSF) or 50 g/kg sugar beet fiber (BF) for 4 wk. There were no significant differences in the body weight, food intake and cecum weight among the groups. The relative liver weight in the CP group was significantly greater than that in the MSF and BF groups. The cecal pH in the CP and MSF groups was significantly higher than that in the BF group. Cecal acetic acid, butyric acid and total short-chain fatty acid (SCFA) concentrations in the BF group were significantly higher than those in the other groups. The serum total cholesterol, VLDL + intermediate density lipoprotein (IDL) + LDL cholesterol concentrations in the CP group were significantly greater than those in the MSF and BF groups. The HDL cholesterol concentration in the MSF group was significantly lower than that in the CP group. The hepatic LDL receptor mRNA level in the MSF and BF groups was significantly higher than that in the CP group. The results of this study demonstrate that mushroom fiber and sugar beet fiber lowered the serum total cholesterol level by enhancement of the hepatic LDL receptor mRNA.
  • American Institute of Nutrition
Report of the American Institute of Nutrition ad hoc committee on standards for nutritional studies