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Hibiscus Sabdariffa extract reduces serum cholesterol in men and women
Abstract
Hibiscus sabdariffa Linne (Malvaceae), a plant long used as a soft drink and medical herb in Taiwan, has been found to reduce blood lipids in animals. To investigate the cholesterol-lowering potential of H. sabdariffa extract (HSE) in human subjects, a clinical study was conducted using an oral preparation of HSE capsules. The study consisted of 42 volunteers who were observed over a period of 4 weeks. The volunteers ranged from 18 to 75 years old with a cholesterol level of 175 to 327 mg/dL. Subjects were randomly assigned to 3 groups: group I (1 capsule of HSE during each meal), group II (2 capsules), and group III (3 capsules). Serum cholesterol levels were determined at baseline before the study commenced and at 2 and 4 weeks of the treatment period. In general, taking HSE led to a significant decrease in serum cholesterol level in subjects from groups I and II after 4 weeks. After HSE had been administered for 2 weeks, serum cholesterol levels were found to be lower in all groups (P < .05 for groups I-III) compared with baseline values by 7.8% to 8.2%. A similar response was observed, a reduction in serum cholesterol level by 8.3% to 14.4%, after 4 weeks of taking the supplement. It is important to note that the serum cholesterol level for 71% of group II volunteers was significantly lowered with a mean reduction of 12% (P < .05). We conclude that a dosage of 2 capsules of HSE (with a meal) for 1 month can significantly lower the serum cholesterol level. The observation of lowered serum cholesterol in these subjects suggests that HSE may be effective in hypercholesterolemic patients.
... Nonetheless, most biological properties of HS are attributed to the presence of diverse bioactive compounds/secondary metabolites such as phenolic acids, flavonoids, anthocyanins, and organic acids [33,34] (Figure 1), as well as to their bioaccessibility in the gastrointestinal tract [35] and bioconversion during colonic fermentation [36]. Table 1 lists some phytochemical screening of HS calyxes. ...
... Pharmaceuticals 2022, 15, x FOR PEER REVIEW 3 of 36 In this context, the interest in research on HS health benefits has significantly increased globally due to the potential of medicinal uses to prevent or control NCDs [8,[30][31][32]. Nonetheless, most biological properties of HS are attributed to the presence of diverse bioactive compounds/secondary metabolites such as phenolic acids, flavonoids, anthocyanins, and organic acids [33,34] (Figure 1), as well as to their bioaccessibility in the gastrointestinal tract [35] and bioconversion during colonic fermentation [36]. Table 1 lists some phytochemical screening of HS calyxes. ...
... It is characterized by an imbalance of lipids mainly due to elevated lipids (cholesterol and triglycerides) and reduced high-density lipoprotein (HDL) levels in the blood, and it is commonly treated with pharmacological drugs [120,121]. The lipid-lowering effects of calyx extracts, capsules, tea, and beverages from HS have been investigated in recent years [9,19,20,22,33,102,117,[120][121][122][123][124][125][126], as shown in Table 4. In healthy subjects without modification in their dietary habits, Tazoho et al. [121] demonstrated that HS tea consumption twice a day (500 mL in the morning and 500 mL in the afternoon, containing 35 g of HS powder/L) for 14 days effectively reduced the total cholesterol (from 134 to 101.7 mg/dL) and low-density lipoprotein (LDL, from 84.70 to 37.97 mg/dL) levels with an increase in HDL (from 32.05 to 42.14 mg/dL) levels. ...
Hibiscus sabdariffa Linn. Malvaceae (HS) is characterized by its edible calyxes. The HS calyxes are widely used for cosmetic, food, and medicinal applications. According to ethnobotanical evidence, decoction, infusion, or maceration extracts from HS calyxes have been used in folk medicine to treat many ailments. Moreover, several in vitro and in vivo studies have demonstrated the pharmacological properties and potential human health benefits of HS consumption. On the other hand, the evaluation of the physiological effects and health benefits of HS in clinical studies is most challenging. Therefore, this narrative review summarizes and discusses the physiological effects and health benefits of HS calyxes reported in clinical trials. Preparations obtained from HS calyxes (extracts, infusions, decoction, teas, beverages, capsules, and pills) are used as non-pharmacological therapies to prevent/control diverse chronic non-communicable diseases. The most-reported HS health benefits are its antihypertensive, antidyslipidemic, hypoglycemic, body fat mass reduction, nephroprotective, antianemic, antioxidant, anti-inflammatory, and anti-xerostomic activities; these effects are associated with the phytochemicals found in HS. Moreover, no adverse effects were reported during the clinical trials. However, clinical studies exhibited some limitations; thus, further studies are required to validate the clinical efficacy of HS in large-scale studies with higher doses and a good experimental design
... Additionally, the phenolic components and flavonoids in the hibiscus calyces extract give it antioxidative qualities (Afiune et al., 2017). Earlier studies have found that Hibiscus Sabdariffa extract consumed for a month reduces cholesterol levels dramatically (Lin et al., 2007) and also enhances metabolism and lower blood pressure (Joven et al., 2014). ...
... Many student athletes may be aware of the negative consequences of energy drinks, such as headaches, elevated heart rates, and stomachaches, yet they nevertheless tend to drink them, ignoring their adverse effects (Seifert et al., 2013). Because of their well-documented health and therapeutic benefits, natural supplements like pomegranate, watermelon, ginger, and hibiscus juice have gained much popularity in the sports world (Lin et al., 2007;Seifert et al., 2013;Tarazona-Diaz et al., 2013). ...
Background: Sport training places significant demand on athletes, motivating them to seek strategies to enhance performance and maintain competitiveness. The use of ergogenic aids has become prevalent in sport, although not without potential risks. Hibiscus-ginger juice, rich in vitamins and minerals, has been suggested to improve metabolism, aid in post-exercise recovery, reduce inflammation, and enhance athletic performance. Aims: This study aimed to investigate the effect of hibiscus ginger juice supplementation on aerobic power and blood lactate levels in athletes. Methods: A pretest-posttest experimental design was employed, involving 28 university athletes aged 20 – 37 years. Participants were randomly assigned to a treatment group receiving 500 mL of hibiscus-ginger juice daily after training for 24 days, or a control group. Physiological measures of blood lactate levels and aerobic power were assessed on three separate occasions during the study period. Results: Mixed model ANOVA showed no significant differences in blood lactate levels (p = .502) or aerobic power (p = .117). Daily consumption of 500 mL of hibiscus-ginger juice for 24 days did not significantly alter aerobic power or blood lactate levels of athletes. Conclusion: The findings suggest that consuming hibiscus-ginger juice may not provide a performance advantage for athletes compared to those who do not. Keywords: Acute supplementation, aerobic power, blood lactate level, hibiscus-ginger juice, university athletes.
... It is also used for the extraction of blood viscosity by reducing systolic and diastolic blood pressure. It is used to calm the contractions in the muscles of the uterus, stomach, intestines, pain and antispasmodic pain, as well as the pain of the chest Pectoral and is an antidote to tapeworms and cylindrical [27]. As well as containing anthocyanin, which acts as an antioxidant because of its possession of phenols [28]. ...
... Lin et al. [27] found that the use of sepals extracts resulted in lowering blood cholesterol (8.3-14.4%) after 1 month of study on a sample of 42 people at a rate of three times a day. ...
Medicinal plants and plants occupy a major place in the world’s agricultural and industrial production as the main source of pharmaceutical drugs or as a source of active substances that are used in the preparation of medicine. The Roselle plant Hibiscus sabdariffa L.(Malvaceae Family) is known in Arabic as “karkade” and “Roselle”. The continental regions of Africa and Asia are the original home of the Roselle. The months of March and April and proceeds to reap the fruits during the months of October to the end of December. Recent researches and studies have pointed to the use of Roselle plant in the medical, food and industrial fields. It is used in the manufacture of jellies and jams. The syrup is added to some medical preparations. It is refreshing, moisturizing, and helps digestion. It is also a useful drink in the cases of bile. It causes urination and acts as an antifungal agent. and is used in the treatment of high blood pressure, It is also used in cancer treatment.
... Several studies have shown that H. sabdariffa extracts have anti-inflammatory activity [7,8] and reduce blood levels of total cholesterol, LDL-cholesterol and blood glucose [9], reduce the risk of developing atherosclerosis [8] and reduce blood pressure [10]. Other studies have suggested that H. sabdariffa extract confers vascular protection due to the direct effects of its polyphenol content on endothelial cells [11][12][13]. ...
... Several studies have shown that H. sabdariffa extracts have anti-inflammatory activity [7,8] and reduce blood levels of total cholesterol, LDL-cholesterol and blood glucose [9], reduce the risk of developing atherosclerosis [8] and reduce blood pressure [10]. Other studies have suggested that H. sabdariffa extract confers vascular protection due to the direct effects of its polyphenol content on endothelial cells [11][12][13]. ...
Hibiscus sabdariffa L. is a worldwide component for tea and beverages, being a natural source of anthocyanins, which are associated with cardiovascular activities. To investigate this relationship, we explored different methods of aqueous extraction on the anthocyanin content and antioxidant activity of H. sabdariffa L. calyx extract (HSCE). Pharmacological effects via platelet aggregation, calcium mobilization, cyclic nucleotide levels, vasodilator-stimulated phosphoprotein Ser157 and Ser239, and on the vasomotor response of aortic rings isolated from mice are studied herewith. We found that the application of ultrasonic turbolization, 20 min, combined with acidified water was significantly more effective in the extraction process, providing extracts with the highest levels of anthocyanins (8.73 and 9.63 mg/100 g) and higher antioxidant activity (6.66 and 6.78 μM trolox/g of sample). HSCE significantly inhibited (100–1000 μg/mL) arachidonic acid-induced platelet aggregation, reduced calcium mobilization, and increased cAMP and cGMP levels with VASPSer157 and VASPSer239 phosphorylation. Vasorelaxation reduction was confirmed by the aortic rings and endothelium assays treated with nitric oxide synthase inhibitors, soluble guanylyl cyclase (sGC) oxidizing agent, or Ca²⁺-activated K⁺ channel inhibitor. The increasing of cGMP levels could be understood considering the sGC stimulation by HSCE compounds in the specific stimulus domain, which allows an understanding of the observed antiplatelet and vasorelaxant properties of H. sabdariffa L. calyx extract.
... Over the last few years, several experimental studies have revealed biological and pharmacological properties of polyphenols compounds, especially their anti-inflammatory activity, antiviral and cytotoxic activity [27,28]. The fact that most medicinal plants is a well-documented, are enriched with polyphenol compounds that have excellent antioxidant properties [29,30]. It is clear that calyces of Roselle possess good phytoconstituents that will be helpful in future for the cure of different types of diseases. ...
... We noted that anthocyanins are the majority compound with 17.53 mg/g and represent 61.55% of the three compounds, followed by the phenols with 6.90 mg/g (24.23%) and finally flavonoids with 4.05 mg/g (14.22%). These results are close to those of Lin et al. [29] because they have a similarity in the relative amounts of chemical constituents (anthocyanins, phenols, flavonoids) in the different extracts. The differences are probably due to the discrepancy between geographical areas and to climatic conditions [31]. ...
... In Malaysia the extracted oil from Hibiscus Sabdariffa was used for making scrubs and soaps. However, most of the seeds are disposed of by the product's manufactures [24] . ...
... It is made by dried calyx of Roselle. It is found to be in red colour and it tastes like berries [24] . ...
Nowadays beverages are consumed which has high bioactive compound. Both cocoa and Hibiscus-flower extract have high antioxidant effect and their combined effect increases the free radical scavenging potentials of the beverages. Hibiscus Sabdariffa has various effect such as Anti-hypertensive effect, Anti-oxidant effect, Diuretic effect, Anti-spasmodic effect etc. The dried flower extract is used to prepare various Tea, Syrup, Jams-jellies and beverages. The phytochemicals studies have found that it contains alkaloids, tannins, saponins, glycosides, phenols and flavonoids. Daily intake of Hibiscus tea, an amount readily incorporated into diet, effectively lowered BP in mild hypertensive adults and has anti-oxidative properties. Nutritionally, Hibiscus Sabdariffa contain vitamin c (ascorbic acid). The extracts of Hibiscus Sabdariffa are used for the treatment of various ailments such as high blood pressure, liver disease and fever. It shows antihypercholesterolaemic, antinociceptive and antipyretic in rats and rabbits but not anti-inflammatory activities. On smooth muscles (in vitro) the effect of calyx extract is variable, it mainly obstructs the tone of isolated muscles. In healthy person, the intake of Hibiscus Sabdariffa has led to remarkable drop of uric acid, citrate, tartrate, calcium, sodium, potassium, phosphate, and urinary concentration of creatinine but not oxalate.
... Las antocianinas son un grupo de constituyentes ampliamente distribuidos en el reino vegetal, que le brindan colores rojo-naranja a azul-violeta a muchas flores y frutas, que han demostrado en estudios epidemiológicos reducir el riesgo de enfermedades cardíacas coronarias y enfermedades crónicas (Wang et al., 2007). Los efectos fisiológicos positivos de estos pigmentos vegetales están relacionados con su actividad antioxidante potente, demostrado en varios estudios in vitro e in vivo, sin embargo se ha demostrado en estudios farmacocinéticos en humanos que la baja absorción sistémica de estos compuestos limita su potencial farmacológico (Wallace, 2011). ...
... En un estudio clínico aleatorizado con entrecruzamiento divididos en 2 periodos de 14 días (Lin et al., 2007), se evaluó el potencial en reducir el colesterol sérico de En un estudio aleatorizado y controlado con dieta (Gurrola-Díaz et al., 2010), se evaluó por 31 días el efecto de una cápsula de 100 mg de extracto acuoso en polvo equivalente a 19.24 mg de antocianinas, en el colesterol total, triglicéridos, colesterol HDL, urea, creatinina, alanina aminotransferasa (ALT), aspartato aminotransferasa (AST), glucosa y resistencia a insulina (triglicéridos/colesterol HDL), en 18 sujetos con síndrome metabólico y 26 sin síndrome metabólico (grupos experimental y control, respectivamente), subdividiendo cada grupo en 3 tratamientos: únicamente dieta, únicamente el extracto, y dieta combinada con el extracto. Los sujetos con síndrome metabólico tratados únicamente con el extracto redujeron significativamente la glucosa y los niveles de colesterol total, aumentaron los niveles de colesterol HDL, y mejoraron la tasa de resistencia a insulina. ...
The pharmacological potential of Hibiscus sabdariffa L. calyxes extracts in metabolic disorders such as hypertension, dyslipidemia and hyperuricemia has been demonstrated in vitro, in vivo and in clinical trials, showing a close relationship with the chemical stability, in the extraction and storage of bioactive compounds and their behavior in biological compartments. The extracts of its calyces are characterized by a low degree of toxicity, with an LD50 in rats above 5000 mg / kg. In view of its pharmacological properties and its high security reported, extracts and isolated compounds (anthocyanins and protocatechuic acid) could be a source of therapeutically useful products. This review examines the evidence of bioactive compounds, the factors that influence their pharmacological potential and therapeutic effectiveness and safety of H. sabdariffa demonstrated in vivo and in clinical trials.
... The calyces were dried and pulverised with mortar and pestle. About 210 g of powder was extracted in 1400 ml of distilled water at 95 o C for two hours (Lin et al., 2007). The extracted powder was filtered (Whatman no. 1 filter paper) and concentrated at a temperature of 40 o C (Ibrahim et al., 2017) using hot air ovum (Hospibrand, USA). ...
... The extracted powder was filtered (Whatman no. 1 filter paper) and concentrated at a temperature of 40 o C (Ibrahim et al., 2017) using hot air ovum (Hospibrand, USA). The residual powder extracts were recovered and preserved at 4 o c till use (Ali et al., 2003;Lin et al., 2007), and a yield of 55% was obtained. ...
Summary: The hyperglycaemia of diabetes mellitus (DM) induces oxidative stress which damages the tissues. Glibenclamide, an oral hypoglycaemic drug used in the treatment of DM has associated side effects. Natural products are considered safe in the treatment of chronic diseases. Hibiscus sabdariffa (HS) is a plant that has demonstrated antidiabetic activity. We aimed to determine the potential benefits of co-administration of HS and glibenclamide in ameliorating oxidative stress in streptozotocin (STZ)-induced diabetic rats. A total of 25 male albino Wistar rats were divided randomly into five groups: control (Non-DM), diabetic (DM), diabetic treated with 600μg/kg BW of glibenclamide (DM + GLIB), diabetic treated with 500mg/kg BW of HS (DM + HS), diabetic treated with both 600μg/kg BW of glibenclamide and 500mg/kg BW of HS (DM + GLIB + HS). The interventions were administered for a period of 28 days. The Non-DM rats were significantly heavier (p<0.01) compared to rats in the other treatment groups. Glibenclamide or HS alone and in combination, significantly lowered (p < 0.001) the final fasting blood glucose concentration of the rats in the respective treatment groups. HS and a combination of HS+ GLIB resulted in increased (p<0.05) serum activity of catalase, glutathione peroxidase and superoxide dismutase compared to the DM untreated rats. The serum level of malondialdehyde was significantly lowered (p=0.000) in rats that received a combination of HS + GLIB compared to the DM untreated rats. Co-administration of HS + GLIB showed beneficial regeneration of islet-cells in the pancreas. Co-administration of HS + GLIB appears to be more beneficial in the treatment of DM and associated oxidative stress than when given as single agents. Thus, a case for their incorporation as a combined therapy for DM should be considered.
... polyphenols (Prenesti et al., 2007;Tzu-Li Lin et al.,2007); a rich source of dietary fiber, vitamins, minerals and bioactive compounds such as organic acids, i.e. malic, tartaric, citric, and hibiscic, and phytosterols (Gonzalez et al., 2012). The phenolics present in the plant consist mainly of anthocyanins like delphinidin-3-glucoside, sambubioside, and cyanidin-3sambubioside mostly contribute to their antioxidant properties (Aurelio et al., 2007;Wong et al., 2002). ...
Roselle (Hibiscus sabdariffa L.) contains significant amount of anthocyanins and Vitamin C, however, these nutrients are heat sensitive and are easily degraded during heat processing. This study assessed the influence of drying methods on the physicochemical properties of roselle powders. The 80:20(extract:maltodextrin) liquid feed formulation produced the best quality spray-dried powder. Optimum parameters for spray-drying was established at inlet temperature, Ti = 173+ 1°C, outlet temperature, T0 = 73 +1°C, feed rate(R) of 10 rpm and air pressure (P) of 1.5 – 2.0 bars. Presoaking conditions anddrying methods significantly influenced the antioxidant components of the roselle extract powder. At higher water temperatures (50C° and 100°C), higher losses of anthocyanin and Vitamin C were recorded. Likewise, similar changes were observed in the oven – dried (45°C, 24h) roselle powder. Spray – dried powder had lower Aw, moisture, protein, ash and fiber contents than the oven –dried powder. This study suggested that spray –drying protects the essential nutrients anthocyanin and Vitamin C, however, degrades the proximate composition of roselle powder.
... Analizaron la efectividad antipirética del extracto acuoso, teniendo como resultado una disminución de fiebre provocada por levaduras (ratones y ratas). Tzu et al. (2007) Analizaron la reducción del nivel de colesterol en humanos, a través del suministro oral de extracto de jamaica liofilizado. Carvajal et al. (2006) Identificaron que reduce el daño celular, además de inhibir elementos carcinogénicos en el hígado, cavidad oral, colon, tejido glandular del estómago y en la vesícula. ...
Actualmente, en México existe la tendencia hacia un mayor consumo de productos naturales que beneficien la salud y a largo plazo no produzcan efectos negativos, por lo cual, el objetivo de esta investigación es evaluar si los principales extractos y subproductos de la flor de jamaica se pueden considerar estratégicos, en función de sus propiedades, impacto en la salud, cadena de valor, pues México es uno de los 10 principales productores a nivel mundial. Para esto, se utilizó el siguiente método: a) se recopilaron y analizaron investigaciones sobre la flor de jamaica y beneficios al ser humano; b) se analizó la información con la herramienta Delphi; c) se desarrolló un dendrograma para categorizar la relevancia en su uso, y, d) se determinaron las condiciones y potencial de la cadena de valor de los procesos que integran su cadena de suministro. Los resultados muestran que no presenta actividad tóxica o mutagénica y que tiene un gran impacto en 3 vertientes: medicina alternativa, como desinfectante y complemento alimenticio. Se encontró que su cadena de valor es incipiente, pero con potencial en: regiones de siembra, centros de investigación y vinculación con el sector industrial para su aprovechamiento, cobertura de comercialización y venta.
... The plant contains a diverse array of bioactive components, including flavonoids, polyphenols, anthocyanins, and organic acids, which have been shown to possess immunomodulatory properties [18,19]. ...
Medicinal plants have chemical and phytochemical characteristics that have shown them to be promising therapeutic tools to reduce morbidity and mortality in various diseases. In the current context of the COVID-19 pandemic, the scientific community faces challenges in the search for new therapies. In this sense, the potential of the Hibiscus sabdariffa species in preventing the binding of the SARS-CoV-2 virus to the Angiotensin-Converting Enzyme 2 (ACE2) receptor has been investigated, which could attenuate the complications associated with the disease. With the objective of evaluating a therapeutic alternative to strengthen the immune response against COVID-19, a randomized controlled clinical trial was carried out in a sample of patients diagnosed with COVID-19 in Barranquilla, Atlántico. The results obtained revealed significant differences both in the recovery of the cases in comparison with the controls, and in the incidence of infection between both groups. These findings support the suggestion that Hibiscus sabdariffa could be a promising alternative to mitigate the effects of COVID-19. Taking these results into account, the importance of continuing to investigate and deepen the therapeutic potential of medicinal plants, such as Hibiscus sabdariffa, is highlighted in the context of the current pandemic. These scientific advances could provide additional and complementary options for the management of this disease.
... However, unlike our study, published studies have focused on its therapeutic uses in treating various metabolic dysregulations and clinical conditions [83], not on its preventative potential or its association with these disorders. The data from human trials support hibiscus's use in moderating BP [84,85] and blood lipids [86]. A recent review of animal studies and clinical trials to assess hibiscus's effectiveness for treating MetS biomarkers improved blood glucose, TC, HDL-C, TG, and BP [87]. ...
(1) Introduction: given the high prevalence of metabolic syndrome (MetS) in Saudi Arabia, especially in Jeddah, this study aims to understand the dietary and lifestyle-related risk factors among Jeddah’s non-diabetic adults. (2) Material and Methods: Employing a cross-sectional design, non-diabetic adults were sourced from public healthcare centers. Demographics, lifestyle, and dietary habits were surveyed. Blood pressure, anthropometrics, and fasting blood samples measuring plasma glucose, serum triglycerides, and HDL cholesterol were collected. The age cut-off for MetS was ascertained using the receiver operating characteristic curve. Variables influencing MetS were evaluated using univariate logistic regression, and consequential factors underwent multivariate analysis, adjusted for age and sex. (3) Results: Among 1339 participants, 16% had MetS, with age being the strongest predictor (p < 0.001). The optimal age cut-off was 32 years. For those <32, elevated BP in men and waist circumference (WC) in women were most prevalent. For those >32, elevated WC was dominant in both sexes. Univariate logistic regression revealed that higher income and education correlated with lower MetS prevalence, while marriage and smoking were risk factors. Adjusting for age and sex, only very high income had a significant low-risk association (p = 0.034). (4) Conclusion: MetS is notable in the studied group, with age as the pivotal predictor. High income reduces MetS risk, while marital status and smoking could increase it. Since this was a cross-sectional study, cohort studies are needed to validate our findings.
... The study by Lin et al. investigated the impact of three concentrations of HSE on human cholesterol levels, which ranged from 175 to 327 mg/dL, over a duration of four weeks. The administered capsules contained 500 mg of prestandardized HSE, consisting of anthocyanins (20.1 mg), flavonoids (10 mg), and polyphenols (14 mg) [38]. Different daily doses of HSE were examined, with participants divided into three groups: 1.5 g, 3 g, and 4.5 g. ...
Hibiscus sabdariffa (HS), commonly known as Roselle, has a rich history of traditional uses and is recognized for its diverse pharmacological properties, including antihypertensive, anti-inflammatory, antimicrobial, and more. This comprehensive review synthesizes the existing literature on the health benefits associated with the consumption of HS or its ingredients. Key areas of focus include metabolic health, blood sugar, and lipid regulation, wherein studies have reported varying effects on parameters such as fasting blood glucose, insulin sensitivity, and lipid profiles. Furthermore, Roselle exhibits anti-inflammatory properties, as evidenced by its impact on inflammatory markers such as MCP-1 and TNF-α. Additionally, HS extracts have shown notable antibacterial efficacy against various strains, with a potential role in urinary tract infection management. Studies also suggest potential benefits for renal function, with improvements in markers such as blood urea nitrogen and creatinine levels. In this article, we aim to review the existing literature on the health benefits of HS.
... Some authors have described H. sabdariffa plant as a multipurpose plant and its leaves and calyces are used in the preparation of soft drinks/ infusions, jams, vegetables and ethnomedicine to treat various diseases in Africa and Mexico (Pattanittum et al., 2010;Odigie et al., 2003). Extracts from the leaves and calyces have been used as traditional medicine to treat cancer, hypertension, diabetes mellitus, liver damage and kidney stones (Lin et al., 2007;Prasongwatana et al., 2008). The calyces and leaf extracts have a high concentration of antioxidants in the form of phenolic acids/polyphenols, vitamin C, and flavonoids, mainly anthocyanins resulting in high natural antioxidant activity (Josiah et al., 2010;Ortega & Beltran, 2014;Julian et al., 2009). ...
The extraction efficiency of aqueous and 80 % methanolic solvent systems on phytochemicals and antioxidant capacity from two varieties of Roselle (Hibiscus sabdariffa var.) was evaluated for ethno-medicinal and nutritional purposes. Phytochemical screening revealed the presence of tannins, phenols, saponins, flavonoids, cardiac glycosides and carbohydrates from both extractions. Methanolic extracts had high (P < 0.05) total phenolic compound in both red and dark red calyx H. sabdariffa, compared to aqueous extracts which ranged from 17.97 ± 0.08–258.06 ± 0.17 for dark red calyx leaf and methanolic red calyx calyces respectively. However, the study showed that red calyx H. sabdariffa had high (P < 0.05) concentration of total phenolic content compared to dark red calyx H. sabdariffa irrespective of the effect of solvent systems. In this study, aqueous extracts exhibited higher TAC than methanolic extracts but aqueous dark red calyx H. sabdariffa had high (P < 0.05) TAC compared to red calyx H. sabdariffa extracts. In methanol, red calyx H. sabdariffa exhibited high (P < 0.05) TAC compared to dark red calyx sabdariffa extracts. Anthocyanins content was high (P < 0.05) in methanol compared to aqueous extracts which ranged from 4.1562 ± 0.0742–315.460 ± 0.428 for aqueous dark red calyx fruit and dark red calyx calyces respectively. The type and polarity of solvent had a significant effect on both the quality and quantity of the extracts, phytochemicals and antioxidants of the extracts from the two H. sabdariffa varieties. The study revealed that methanolic extracts had high antioxidants, phytochemicals and anthocyanins compared to aqueous extracts. Therefore consumption and use of H. sabdariffa extracts could improve human health by either reducing or delaying the development of cell degenerative diseases like cancer and diabetes mellitus.
... Some authors have described H. sabdariffa plant as a multipurpose plant and its leaves and calyces are used in the preparation of soft drinks/ infusions, jams, vegetables and ethnomedicine to treat various diseases in Africa and Mexico (Pattanittum et al., 2010;Odigie et al., 2003). Extracts from the leaves and calyces have been used as traditional medicine to treat cancer, hypertension, diabetes mellitus, liver damage and kidney stones (Lin et al., 2007;Prasongwatana et al., 2008). The calyces and leaf extracts have a high concentration of antioxidants in the form of phenolic acids/polyphenols, vitamin C, and flavonoids, mainly anthocyanins resulting in high natural antioxidant activity (Josiah et al., 2010;Ortega & Beltran, 2014;Julian et al., 2009). ...
... The brilliant red color and good flavor make it a precious food product (Tsai et al., 2002). Roselle include anthocyanins, flavonoids and polyphenols (Lin et al., 2007). Hibiscus sabdariffa L. exhibited in vitro antibacterial activities against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Micrococcus luteus, Clostridium sporogenes, Bacillus stearothermophilus, Bacillus cereus, Serratia mascences and Pseudomonas fluorescence (Abdel-Shafi et al., 2019). ...
Purpose
Natural dyeing has existed in human life from past to present. Although it lost its importance after the industrial revolution, it has started to make again a name for itself today with the increase in environmental awareness. The purpose of this study is to investigate whether the Hibiscus sabdariffa L. can be used in the coloring of woolen fabrics and as a natural antibacterial agent for these fabrics.
Design/methodology/approach
Within the scope of the study, it was investigated whether the antibacterial activity of the Hibiscus sabdariffa L. can be transferred to woolen fabrics. In the study, woolen fabric samples were dyed with and without mordant with the help of Hibiscus sabdariffa L. extract. After the dyed fabric samples were washed and dried, their color values were measured, and antibacterial effect tests (against Staphylococcus aureus – Escherichia coli ), washing and rubbing fastness tests were carried out. In addition to these, scanning electron microscopy images of dyed fabric samples were taken and Fourier transform infrared microspectroscopy analyzes were also performed.
Findings
As a result of the study, it has been determined that the antibacterial activity of the Hibiscus sabdariffa L. can be transferred to woolen fabrics without the use of any chemicals.
Originality/value
Natural antibacterial agent for woolen fabrics was obtained within the scope of the study without the use of chemicals.
... This is why we decided to focus on HS, due to its well-documented high polyphenol content and its widespread use in traditional medicine. Studies developed by Alarcon-Aguilar et al. [11] and Lin et al. [12] have shown that the polyphenol concentration in HS is considerably higher than in other plants. Therefore, the scientific interest in HS has increased due to its potential use in the treatment of metabolic syndrome [13,14]. ...
Metabolic syndrome is a complex and multifactorial disorder associated with increased risk of cardiovascular disease and type 2 diabetes, exacerbated by a sedentary lifestyle and situations such as the COVID-19 pandemic. Recent studies have shown that consumption of fruits and vegetables high in polyphenols has a protective effect, reducing cardiovascular risk. Hibiscus sabdariffa (HS) in combination with other plant extracts has recently attracted scientists’ attention due to its potential use in the treatment of metabolic syndrome. This systematic review and meta-analysis examines the effects of HS in combination with other plant extracts on the prevention of metabolic syndrome, exploring their synergistic effects and potential as therapeutic agents. For this purpose, a systematic search of randomized clinical trials (RCTs) was conducted in four different databases and the data obtained were then used for a meta-analysis. Initially, the titles and abstracts of 1368 studies were read. From these, 16 studies were examined closely for their eligibility, and finally, seven RCTs with 332 participants were included in both the meta-analysis and the qualitative analysis. Our results show that HS in combination with other plant extracts improved anthropometric parameters, blood pressure, and lipid profile (low density lipoprotein cholesterol and total cholesterol) compared to a placebo control group. It is important to note that although this meta-analysis suggests that HS in combination with other plant extracts may have a beneficial effect on cardiovascular parameters, further research is needed to determine the optimal dose and intake duration.
... The aim of the present study was to investigate the effect of Zygophyllum gaetulum (Zygophyllaceae) lyophilized aqueous extract on erythrocytes lipid peroxidation and antioxidant status as well as on paraoxonase 1 (PON 1) activity in rats fed a high-cholesterol diet. High cholesterol diet is regarded as a crucial factor in the development of hypercholesterolemia, atherosclerosis and ischemic heart disease 27,28 . After 4-week of treatment with Zygophyllum gaetulum extract, plasma total cholesterol and non-HDL cholesterol concentrations decreased significantly. ...
Currently, herbal medicines are experiencing a resurgence of interest and their popularity is increasing in developing and developed countries due to their natural origin and minor side effects. This study aimed to investigate the effects of a lyophilized aqueous extract of Zygophyllum gaetulum (Zg) on erythrocytes lipid peroxidation and paraoxonase 1 (PON 1) activity in rats fed a high-cholesterol diet. Twelve hypercholesterolemic male Wistar rats (cholesterolemia value > 3mmol/L) weighing 176±5g were divided into two groups fed a high cholesterol diet (1% cholesterol+0.5% cholic acid) supplemented (HC-Zg) or not (HC) with Zg aqueous extract (1%), for 4 weeks. In the HC-Zg group compared with the HC group, plasma total cholesterol (TC) and non-HDL cholesterol levels were respectively 1.5-and 2.2-fold lower, whereas HDL-cholesterol was 2-fold higher. Atherogenic indexes, TC/HDL-C and TC-HDL-C/HDL-C wererespectively decreased by 71% and 66%. In erythrocytes, thiobarbituric acid reactive substances (TBARS) concentrations tended to decrease but not significantly. The activities of superoxide dismutase (SOD) and catalase (CAT) were increased by 42% and 38%, respectively, while those of glutathione peroxidase (GSH-Px) and glutathione reductase (GSSH-Red) showed no significant difference. Moreover, reduced glutathione content (GSH) was similar in both groups. Plasma PON 1 activity was 1.5-fold higher in the hypercholesterolemic group treated with Zg compared with the untreated group. In conclusion, in the hypercholesterolemic rat, the treatment with Z. gaetulum extract induced a cholesterol-lowering effect but didn't improve erythrocytes lipid peroxidation despite stimulation of antioxidant enzymes activities. Moreover, Zg extract increased plasma PON 1 activity suggesting a possible lipoprotein protection from oxidation.
... No obstante, sus costos de producción son bajos en comparación con otros cultivos, lo cual hace viable su implementación y desarrollo en la producción agrícola del país (Caamal et al., 2020). Se han realizado estudios en jamaica sobre su producción y concentración de antocianinas en los cálices debido a que presenta propiedades medicinales, reduciendo el colesterol y la presión arterial (Herrera et al., 2004;Lin et al., 2007;Apáez-Barrios et al., 2018b). ...
El objetivo de la investigación fue evaluar el vigor en el cultivo de jamaica (Hibiscus sabdariffa L.) utilizando rizobacterias de Pseudomonas fluorences bajo condiciones de estrés ocasionado por sulfato de cobre (CuSO4), como una alternativa para la fitorremediación de suelos contaminados con aguas residuales. El experimento se realizó en las instalaciones del Colegio de Postgraduados, Campus Montecillo, México. Se utilizaron semillas de dos variedades de jamaica (var. Criolla y var. Araña) inoculadas con células de seis cepas bacterianas (M83, M67, M88, L168, M82_A y M82_C), las cuales fueron sembradas y cultivadas en un invernadero para determinar: longitud del tallo (LT), longitud de la raíz (LR), biomasa seca de la raíz (BSR), contenido de clorofila (CCL), número de hojas (NH), diámetro del tallo (DT) y volumen radical (VR). El diseño experimental implementado fue de bloques completamente al azar con un arreglo factorial (4 x 2 x 2 x 2). Las concentraciones de CuSO4 utilizadas en la siembra fueron 10-2 de concentración molar (M) para la var. Criolla y 10-6 M para la var. Araña. El tipo de suelo fue determinante porque causó diferencias significativas en la mayoría de las variables evaluadas, excepto en la LR, BSR y VR. La inoculación con cepas bacterianas causó inhibición en el crecimiento del DT en la var. Araña a los 80 días después de la siembra (dds). Las cepas que promovieron el crecimiento vegetal de las plantas de jamaica fueron la M83, M67 y M82 utilizadas en ambas variedades. Se concluye que las plantas de jamaica no presentaron efectos negativos debido a la condición de estrés causada por CuSO4. De manera general, la variedad que tuvo una mayor tolerancia al CuSO4 fue la var. Criolla, por lo cual, se puede considerar como una alternativa para la fitorremediación de suelos contaminados con aguas residuales.
... Even though the possible mechanism(s) of action of Roselle extract is not investigated, daily consumption of an aqueous Roselle extract resulted in a decrease in systolic and diastolic blood pressure [34]. A clinical trial by Lin et al. [35] on Hibiscus showed cholesterol reduction by 8.3% to 14.4% after just one month. A total of 42 subjects were randomized to 3 groups for the study, conducted in Taiwan. ...
The Gambia, 'The smiling Coast' of Africa, is a strip of low lying country located between latitudes 13 o 00 ' and 13 o 50 ' N and longitudes 16 o 50 ' and 13 o 45 ' W, with a total land boundary of 740 km, and dense population of 1,857,181. The two distinct climates are the rainy and dry seasons. The dry season which lasts from October till May is characterized by dry dusty wind; while the wet season lasts from June till early October, with total annual rainfall that varies from the coastline inwards. Based on the rainfall pattern, the three major agroecological zones include Sahelian, Sudan-Sahelian and Sudan-Guinean which favour the cultivation of some cash crops, food crops, and herbal plants. Foods, in the form of liquid or solid, are sources of nutrition and medicine for good health; malnutrition, or poison. Foods and nutrition are essential for maintaining good health and preventing disease. Not only is malnutrition prevalent in The Gambia, but most of the populace also seemed unaware of the content, quality, composition, the nutritive, or medicinal value of the foods consumed. In this review, the chemical, medicinal, and nutritive values of some commonly consumed or traditional foods and drinks and the names of some herbal plants and their uses in The Gambia are reported.
... It has been suggested that the polyphenols, anthocyanins, and other bioactive compounds found in roselle calyces (Hibiscus sabdariffa) may contribute to lipid-lowering and inhibition of LDL-C oxidation through its antioxidant activity or other mechanisms [40]. A human trial conducted by Lin et al. [41] revealed that taking one or two capsules of roselle extract reduced TC by 11-15% after 4 weeks of supplementation; however, there were no reports for LDL-C, HDL-C, and TG. In a recent meta-analysis of 9 clinical trials, the efficacy of roselle supplementation in regulating cholesterol levels in patients with metabolic syndrome and related diseases showed a reduction in total cholesterol, LDL-C, and HDL-C but not TG [42]. ...
Oxidative stress and inflammation play key roles in the pathophysiology in the pathophysiology of dyslipidemia, which are positive risks that increase atherosclerosis leading to important healthcare problems. Therefore, we aimed to study the antioxidant, anti-inflammatory, and lipid-lowering effects of jelly drink containing polyphenol-rich roselle calyces extract and passion fruit juice with pulp concentrate (RP jelly drink) in comparison to a placebo jelly drink for 8 weeks. Forty-three adults with dyslipidemia were randomly assigned into two groups: the RP jelly drink group and the placebo group. Glucose, total cholesterol (TC) triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), oxidative stress biomarkers, inflammatory parameters, and monocyte chemotactic protein-1 (MCP-1) were measured with fasting blood samples at baseline, 4 weeks and 8 weeks of intervention. Results showed a significant decrease in LDL-C and TG, respectively, after 8 weeks of RP jelly drink consumption (LDL-C: 107.63 ± 22.98 m g / d L ; TG: 109.79 ± 38.83 m g / d L ) compared to baseline measurements (LDL-C: 128.43 ± 32.74 m g / d L ; TG: 132.33 ± 75.11 m g / d L ). These may be possible due to reduced inflammation and improvements in oxidative stress, as demonstrated by the reduction of tumor necrosis factor- (TNF-) α and malondialdehyde (MDA), and the enhancement of glutathione (GSH) after consuming the RP jelly drink for 8 weeks. However, no significant differences of treatment on glucose, total cholesterol, MCP-1, interleukin-6, and interleukin-10 were observed. In conclusion, daily consumption of RP jelly drink for 8 weeks resulted in significant improvement in lipid profiles in subjects with dyslipidemia. However, more research is needed to assess its nutritional and functional potential.
... The serum cholesterol level for 71% of group II volunteers was significantly lowered with a mean reduction of 12% (P < . 05) (239) . ...
Plants are a valuable source of a wide range of secondary metabolites, which are used as pharmaceuticals, agrochemicals, flavours, fragrances, colours, biopesticides and food additives. In the current review, PubMed, Web Science, Science Direct, Researchgate, Academia. edu and Scopus were searched to determinethe medicinal plantswhich pass the clinical trials with documented efficacy and safety.
... Over the last few years, several experimental studies have revealed biological and pharmacological properties of polyphenols compounds, especially their anti-inflammatory activity, antiviral and cytotoxic activity [9]. The fact that most medicinal plants is a well-documented, are enriched with polyphenol compounds that have excellent antioxidant properties [10,11]. ...
This research was conducted during the 2018 and 2019 seasons, and the aim of the research was to study the effect of each of the different drying methods (drying in the shade, direct sunlight, electric ovens, and solar dryer) and the different storage periods (0, 2, 4 and 6 months) on the quality of Roselle (Hibiscus sabdariffa L.) for both variety cultivars Sabhia 17 Dark and Sabhia 17 Light. The results showed that the method of drying in the shade gave the best results for most of the characterizes studied for both varieties of the both seasons, and the results for the different storage times did not differ significantly between them, especially the calyxes content of the two varieties of TPC, DPPH% and TFC. On the other hand the chemical composition data of roselle observed about the light variety is rich in ascorbic acid, TFC and TPC, while the dark variety is rich in the total anthocyanin content (490 mg / 100g DWS).
... Histologically, it was reported that exposure for 10 weeks to doses of a 0.5-1% w/w diet of H. sabdariffa aqueous extract resulted in decreased fat cell formation and the inhibition of blood vessel calcification, as well as serum total cholesterol, LDL, and triglyceride levels. According to a study conducted among hyper-cholesterolemic patients, two capsules of Roselle extract (1g), given three times a day (for a total of 3g/day), could significantly lower serum cholesterol [72].While another study confirmed that the ethanolic extract from the leaves of Roselle exhibit hypo-lipidemiceffect [73]. Subjects with metabolic syndrome that received the ethanolic extract of Roselle had significantly reduced glucose, total cholesterol and low density lipoprotein, while increasing high density lipoprotein [74]. ...
Hibiscus sabdariffa Linn., commonly known as Roselle, is a very popular medicinal plant throughout the world. Besides its use in the preparation of various kinds of delicaciessuch as jams, puddings, cakes, the plant is widely used in various traditional systems of medicine. This article aims to provide a comprehensive review on the traditional use, pharmacognostical characterization, nutritional and phytochemical composition, and pharmacological properties of Roselle plant. A search forpublications made in last ten years was retrieved from the following specialized electronic databases: Elsevier Science Direct, Springer Link, and NCBI. The results of different articles availablesuggest that the plant is rich in potent bioactive constituents havinga range of pharmacological activity supportingits traditional claims. Although marketed formulations/infusions of Roselle are available but further studies should be carried out to evaluate the toxicological profile and therapeutic efficacy of H. sabdariffa on humans.
... The serum cholesterol level for 71% of group II volunteers was significantly lowered with a mean reduction of 12% (P < .05) (168) . ...
Hyperlipidemia refers to elevated levels of lipids and cholesterol in the blood. It plays an important role in the development of atherosclerosis, the main cause of death in the world. Medicinal plants can lower blood lipids by many mechanisms included inhibition of the expression of fatty acid synthase, decreasing free fatty acid release, inhibition of HMG-CoA reductase, increasing the fecal excretion of fat and cholesterol, inhibition of the activity of pancreatic lipase and inhibition of cholesterol absorption. The current review will highlight the hypolipidemic effects of medicinal plants as promising effective and safe therapies.
... Previous studies showed that 450 g of roselle extract was administered 3 times per day over 4 weeks 49 , and 500 g of fresh calyxes were administered once daily as a treatment for hypercholesterolemic subjects 50 . The duration times of these previous studies ranged from 15 to 90 days for the administration roselle extract 51,52 . ...
Non-alcoholic fatty liver disease (NAFLD) has become a major world-wide health problem and is characterized by lipid accumulation in the liver induced by high fat diet (HFD) consumption. It is usually associated with inflammation, oxidative stress, and insulin resistance. Roselle extract (Hibiscus sabdariffa) is an herb which is used in traditional medicine. However, further study is necessary to represent the mechanism of NAFLD and find new preventive strategies. This study aims to investigate the protective effects of roselle extract on NAFLD rat models. Male Sprague–Dawley rats (n = 35) were divided into 5 groups, control, HFD, HFD + Simvastatin (HFD + SIM), HFD + 250 mg/kg BW, and HFD + 500 mg/kg BW of roselle extract (HFD + R250 and HFD + R500, respectively). The results showed that roselle extract reduced hepatic lipid contents, de novo lipogenesis enzymes, microsomal triglyceride transfer protein, inflammatory cytokines, malondialdehyde, and increased antioxidant properties, transporter related with lipoprotein uptake, and insulin signal proteins. Comparing to SIM, the HFD + R500 group exhibited the greater benefit in terms of anti-hepatic steatosis, antioxidant properties, and an ability to improve insulin resistance. This study demonstrates that roselle extract improved antioxidant properties and attenuated hepatic steatosis, liver inflammation, oxidative stress, and insulin resistance in HFD-induced NAFLD in rats, which could be used for NAFLD prevention.
... De vermeende cholesterolverlagende eigenschap van hibiscusthee zag er echter wat meer belovender uit in sommige oudere onderzoeken aangezien daarin werd gesuggereerd dat een cholesterolverlaging van maar liefst 8 [%] zou kunnen optreden bij het drinken van 2 (twee) kopjes per dag over de tijd van 1 (één) maand aan onderzoek [9], echter toen alle onderzoeken werden samengevoegd, waren de resultaten min of meer een wassen neus, hetgeen leidde tot de conclusie dat het beschikbare bewijs uit gerandomiseerde controleonderzoeken niet ondersteunt dat hibiscus het vermogen heeft om serumlipiden significant te verlagen [10]. Dit kan zo zijn omdat slechts ongeveer 50 [%] van de mensen lijkt te reageert op het drinken van het equivalent van 2 (twee) tot 5 (vijf) kopjes per dag, hoewel degenen die er wel op reageren kunnen mogelijk een respectabele daling van ongeveer 12 procent in serumcholesterol niveau krijgen [11], maar er gaat echter niets boven de 30 [%] LDL-cholesteroldaling die een mens binnen enkele weken zou kunnen krijgen na het eten van een voldoende gezond plantaardig dieet [12]. Hibiscus zou dus kunnen werken voor het verlagen van het cholesterolgehalte, maar de gegevens zijn niet veelbelovend in de zin dat het niet zou kunnen werken voor die andere ongeveer 50 [%] van de menselijke dieren. ...
The dried petals of the hibiscus flower may help as nutrition for the cardiovascular system, potentially as nutrition against cancer and may help as nutrition for the immune system. Article: Hibiscus [Sources below] The relatively often reddish colored dried petals of the flowers of the in the relatively warm temperate mediterranean, subtropical and tropical areas of the world growing hibiscus shrub plant genus (also called "flor de Jamaica" in the country Mexico, "sorrel" in the Caribbean areas, "roselle" in many parts of the world, also "rose mallow", "hardy hibiscus", "rose of Sharon" which name is more specifically used to describe the not in the same family related hypericum calycinum, "ibískos", "ἰβίσκος", "rose of Althea" more specifically used for the garden hibiscus hibiscus syriacus and "tropical hibiscus") containing about 200 plant species, e.g., the hibiscus blossom sabdariffa Sudan, which genus is categorizable in the mallow malvaceae plant family (also called "kaasjeskruidfamilie", "malvaceae sensu lato" and "malvaceae sensu") often used in tea (e.g. hibiscus tea also called "sour tea" because it has acids in it like citric acid [2] or (inclusive or) as the zing in red zinger tea) or (inclusive or) even higher in nutrients using the whole flower parts as high antioxidant smoothie fruit punches (as you can in the following proportions soak 1 (one) handful of bulk dried organic hibiscus flowers cold brewing overnight and then blend with 1 (one) knuckle of fresh ginger, 1 (one) teaspoon of amla powder, 3 (three) tablespoons of date syrup or (exclusive or) blend in some dates, 1 (one) handful of fresh dark leavy green mint leaves and some lemon juice to make a drink just to drink throughout the day which is cold storable in the fridge) are possible usable as: >it may be useful as nutrition for the immune system since a study showed that consumption of an aqueous hibiscus extract like tea has impact on systemic antioxidant potential in relatively healthy human animal being subjects thus shown that the antioxidant phytonutrients in hibiscus are effectively absorbed in human animal bodies having bioavailable in the bloodstream. If you take people and have
... Our result is similar to those reported by Aguirre-García et al (2019). In addition, Lin et al (2007) observed that H. sabdariffa can decrease serum cholesterol levels in human. ...
The objective of the study conducted here was to investigate effect of Hibiscus sabdariffa extract on the body weight, complete blood count (CBC), liver function, and lipid profile in rabbits. A total of 20 local male rabbits were randomly divided into four experimental groups, including five rabbits in each group: (i) control; (ii) starvation; (iii) H. sabdariffa extract; and (iv) H. sabdariffa extract and starvation. Blood samples were collected directly from the heart at the end of the experiment (day 28) and used for complete blood count and estimation of cholesterol, triglycerides, ALT, and AST. Aorta and liver sections were histopathologically examined. Results indicated that the Body weight at the end of the study was significantly decreased in starvation, extract, and starvation and extract groups, compared to the beginning of the study for each group. There was no difference in the body weight between groups at the end of the study. Rabbits in the extract group showed significant increase in lymphocytes, RBC, hemoglobin, and platelets, compared to those in control and in starvation groups. ALT activity significantly increased in starvation, extract, and starvation and extract groups, compared to those in control group. AST activity significantly increased in both extract and starvation and extract group, compared to those in control and starvation groups. Cholesterol and triglycerides decreased in starvation, extract, and starvation and extract groups, compared to those in control group. Histopathological sections indicated simple changes in aorta layers in starvation group rabbits including few number foam cells in tunica media. Liver sections from starvation group rabbits showed coagulative necrosis of hepatocytes, hyperplasia of bile duct endothelia, dilation and congestion of central veins. In extract group there was dilation of central veins, vacuolar degeneration of the hepatocytes, infiltration of inflammatory cells and hepatic artery congestion. Similar changes were revealed in liver sections from starvation and extract group. In conclusion, aqueous H. sabdariffa can decrease the body weight as alternative to the starvation, decrease blood cholesterol and triglycerides, and increase the immunity; however, daily consumption can have impact on the liver.
... 48 Several studies have indicated that HS extracts can reduce the levels of TG, Tc, LDLc, and LDLc/HDLc in humans and animal models. 49 The aqueous extract of HS lowered Tc better than simvastatin and improved antihyperlipidemic activity when co-administered at low doses in an animal model. 50 Research results have also revealed that patients should avoid the simultaneous usage of a HS herbal beverage and hydrochlorothiazide (HCT) diuretics to control hypertension. ...
High blood pressure is the main risk factor for cardiovascular disease and should be controlled primarily by changes in lifestyle, such as regular exercise, a low-salt diet, and weight loss in overweight or obesity. If lifestyle changes are not enough, many types of medications can be used to control high blood pressure; however, side effects constitute one of the most critical limitations of conventional medicines associated with high blood pressure. For this reason, the use of traditional and herbal medicines has been welcomed by the public for many years. Sour tea (Hibiscus sabdariffa) is one of the most suitable herbal medicines for hypertension. According to research results, sour tea has the same effect as conventional medicines without serious side effects. The present study introduces sour tea as a suitable herbal medicine for high blood pressure to provide readers of this article with a comprehensive understanding of the medicinal properties of sour tea for the treatment of hypertension and its effects on several other common diseases, including cancer.
... In Nigeria, the dried red roselle calyces are processed into a clean non-alcoholic beverage recognized as Zobo, which is a frequent drink among the low and middle-income people. Research of Hibiscus sabdariffa has extended beyond everyday consumption as a nutritive drink or tea to its consumption for the lowering of serum cholesterol (Lin et al., 2007), antihypertensive effect (AbdelRahman & Shayoub, 2016), antioxidant activity and antigenotic power (Pozos et al., 2020). The extract of Hibiscus sabdariffa has also been reported to possess antiviral, anticancer, immunological, antidiabetic, and antioxidant effects making it a promising plant for therapeutic use (Al-Snafi, 2018). ...
Consumers expect greater functionality from food and beverage products. Celebrated for a range of health benefits, polyphenols have been linked to a preventive role for chronic diseases and viral infections and have the ability to relieve oxidative stress. A drink made with roselle calyces (Hibiscus sabdariffa) and sweet basil leaves (Ocimum basilicum L) may provide therapeutic or preventive effects against chronic and infectious diseases. Damage caused by oxidative stress may be alleviated by the polyphenols found in roselle calyces and sweet basil leaves. The roselle-basil samples at different blend ratio were analysed for pH, total soluble solids, total titratable acidity, vitamin C, lycopene, total phenolic contents, antioxidant properties, and storage stability at different temperature (4 and 29°C). The incorporation of sweet basil leaves to roselle calyces slightly decreased the vitamin C and lycopene content of the processed drink but increased the total carotenoid and antioxidant activities (ABTS and ORAC) of the drink. The radical scavenging properties of the processed drink increased with the addition of the dried sweet basil leaves and samples kept at a higher temperature of 29°C showed a rise in antioxidant activities compared to samples stored at 4°C. The increase in the free radical scavenging power of the drinks show that the roselle-basil drink may serve as health drink and addition of sweet basil leaves up to 5% may be suitable to produce roselle-basil drink.
Hibiscus sabdariffa has been used as food, herbal drinks, and flavoring ingredients in the food and pharmaceutical industries. This study aims to explain the botany, utilization and bioactivity of H. sabdariffa. This research was carried out using library research, especially from Google Scholar, using the keywords H. sabdariffa, H. sabdariffa bioactivity, and H. sabdariffa use. The H. sabdariffa is a species belonging Malvaceae, which easy found in the yard and has been cultivated. The traditional medicine, H. sabdariffa is used to treat digestive disorders, liver disease, fever, hypercholesterolemia, hypertension, obesity, prevention/treatment of cancer, cardiovascular and gout. The use of H. sabdariffa as a traditional medicine is related to its bioactivity such as antioxidant, diuretics, anti-microbial, anti-hypercholesterolemia, anti-diabetes mellitus, anti-hypertension, anti-cancer. and hepatoprotective. The bioactivity of H. sabdariffa is related to secondary metabolites, especially the anthocyanins delphinidin-3-O-sambubioside and cyanidin-3-O-sambubioside. H. sabdariffa has great potential to be developed as a nutraceutical to treat hypertension and diabetes mellitus.
This study is based on the cultivation and scope of Hibiscus species, namely,Hibiscus rosa-Sinensis and Hibiscus sabdariffa.The objective wasto find out the history of the production of Hibiscus, usage in different centuries, the most suitable regions for cultivation in India, various nutritive content, different health-related properties and benefits,new products that had been introduced, and abstract on what future may hold for the flowers.The study contains information on the antimicrobial, antioxidant, anti-cancerous properties along with several benefitslike hypolipidemic effect, blood pressure-lowering effect, anti-diabetic activity, effect on lipid metabolism, antihypertensive effect,etc on the concerned flower.We have looked intothe limitation of the flower, the need forurgent preservation methods to extend the shelf life of the product.As per our findings roselle leaves are used for their, antimicrobial, emollient, antipyretic, diuretic, anti-helminthic, sedative properties and as a soothing cough remedy
The biocompatible metal-organic framework [Zn4(GA)4(H2O)4] · 4H2O (H2GA = glutamic acid) was used as a container for anthocyanins from Hibiscus sabdariffa in composite films based on kappa-carrageenan and hydroxypropyl methylcellulose. The obtained composite materials showed high antioxidant activity and ability to undergo pH-induced color change upon reactions with gaseous products of pathogen development and, hence, possess the potential for practical application as functional materials for food packaging.
Hibiscus sabdariffa It is a member of the Malvaceae family and is often referred to as "red sorrel" or "roselle.These are the kind of plants that are used for a long time in Taiwan as a herbal remedy and soft drink that decreases animal blood cholesterol levels.[10] acetaminophen, a popular over-the- counter antipyretic-analgesic, is frequently used orally with water or other liquids at any time of day. A sweetened water extract of the dried calyx of Hibiscus Sabdariffa is called zobo drink[11].The COVID-19 pandemic and a sedentary lifestyle can exacerbate metabolic syndrome, a complex and multifaceted illness linked to an increased risk of heart disease and type 2 diabetes. Eating foods that are high in polyphenols has been demonstrated in recent research to have a preventive impact, lowering the risk of cardiovascular illness. Because of its potential to treat metabolic syndrome, scientists have recently focused on Hibiscus sabdariffa (HS) in conjunction with other plant extracts. The effects of HS in conjunction with additional plant extracts on the prevention of metabolic syndrome are investigated in this systematic review and meta-analysis, along with their potential as therapeutic agents and synergistic effects.[12].Infusion of Hibiscus sabdariffa (H. sabdariffa) is a very popular drink in many parts of the world. Its phytochemical composition is associated to antioxidant, hypotensive, and antiatherosclerotic effects. However, the molecular mechanisms involved in these processes are not well known. The aim of this review was to report the scientific evidence supporting that regular use of H. sabdariffa decreases oxidative stress, atherosclerosis, lipid profile, and blood pressure. Further more no unfavorable incidents or adverse effects were documented.[13] Keywords- Hibiscus Sabdariffa, cardiovascula
Roselle, Hibiscus sabdariffa L. (family Malvaceae) is one of the most important and popular medicinal plants. Roselle is native from India to Malaysia, where it is commonly cultivated, and must have been carried at an early date to Africa. It is known as karkadeh in Asia, Pundi palle in South Asia, isapa in Africa Florida Cranberry in America. Recent researches & studies shown that the use of Roselle plant in medical, food & industrial fields also. It is used in cold &warm drinks, jams & jellies. Its use as emollient, laxative, antioxidant, nutritive, antihypertensive, antifungal agent. Rosella helps in digestion, refreshing, moisturizing & used in treatment of cancer
Nos últimos anos, têm crescido a preocupação por uma alimentação de qualidade e natural. Estudos mostram que algumas plantas do gênero Hibiscus possuem propriedades antioxidantes e devido a essas propriedades, podem ser estudadas como um possível agente antioxidante natural e alternativo para alimentos. O presente trabalho teve como objetivo estudar o potencial antioxidante de extratos das flores de H. sabdariffa utilizando diferentes técnicas de extração, além de realizar sua incorporação em nanopartículas de gelatina. As nanopartículas foram sintetizadas pelo método de dessolvatação em dois passos e caracterizadas quanto a sua morfologia, potencial zeta, distribuição de tamanho e eficiência de encapsulamento.
A espécie Hibiscus sabdariffa possui rica composição de compostos bioativos. Os estudosfarmacobotânicos e fitoquímicos desse vegetal têm contribuído para a compreensão de seusmecanismos de ação e para o desenvolvimento de novos produtos naturais com aplicações namedicina e na indústria farmacêutica. Dessa forma o objetivo foi investigar os efeitos dosombreamento no cultivo do Hibiscus sabdariffa no bioma Mata Atlântica, com foco nafarmacobotânica e na fitoquímica. A abordagem envolveu a identificação das substânciaspresentes por meio de análises histoquímicas. A pesquisa foi desenvolvida na Universidade doOeste de Santa Catarina. Após 45 dias da semeadura, foram transferidas quinze mudas para cadaambiente: 1- pleno sol, 2-sombreamento 50% e 3-sombreamento arbóreo nativo. Após as plantasatingirem a idade adulta foram analisadas as estruturas morfológicas, anatômicas, percentual demassa seca e a composição química da sépala e das folhas. Os testes histoquímicos foramaplicados para cristais de oxalato de cálcio, compostos fenólicos, antocianina, compostoslipofílicos, testes para identificação de saponina e taninos. Foi possível constatar que emambientes ensolarados a espécie apresentou melhor crescimento vegetativo. Independente dosombreamento, a espécie possui compostos lipofílicos e fenólicos, bem como a presença desaponinas. Porém, verificou-se níveis maiores de saponina no limbo foliar quando comparado asépalas florais. Com relação aos taninos, não foi observado em nenhum dos tratamentos.Conclui-se que, o Hibiscus sabdariffa L. é uma espécie de ambientes quentes e não toleraconsórcio com espécies arbóreas, pois apresenta maior produtividade em ambientes de pleno sol.
La Hibiscus sabdariffa L., también conocida como flor de jamaica, es una planta que pertenece a la familia de las Malvaceae. En los últimos años, se han estudiado sus propiedades bioactivas atribuidas principalmen-te a una variedad de sustancias químicas presentes, entre las cuales destacan las antocianinas, un grupo de antioxidantes pertenecientes a los polifenoles, una famila de compuestos con gran capacidad para neutralizar especies reactivas de oxígeno y disminuir el daño oxidativo celular. Este último se relaciona con enfermedades crónicas, incluído el cáncer, el cual representa una de las primeras causas de muerte a nivel mundial. Así mismo, un área activa de investigación relacionada con alternativas terapuéticas contra el cáncer es el estudio de las antocianinas por su capacidad para disminuir viabilidad, proliferación y angio-génesis en células malignas.
Sour Tea is an herb that is widely used today. In the past, the plant was used to treat a wide range of disorders, including kidney and bladder stones, sexual stimulants, disinfectants, and reduced complications of diabetes and hypertension. So far, numerous human and animal studies have been conducted on the effect of sour tea on blood lipid profile. This article is based on the findings from PubMed, Scopus, ISI and Google Scholar databases. In this review study, studies on the effects of sour tea on blood lipid profile have been investigated. According to more studies in this field, this substance can probably improve blood lipid patterns, especially in diabetics. Sour tea also plays an important role in reducing the blood lipid profiles due to its antioxidant activity and the activity of antioxidant enzymes.
Cardiovascular disease (CVD) is the one of major global health issues with approximately 30% of the mortality reported in the mid-income population. Low-density lipoprotein (LDL) plays a crucial role in development of CVD. High LDL along with others forms a plaque and blocks arteries, resulting in CVD. The present chapter deals with the mechanism of receptor-mediated endocytosis of LDL and its management by drugs such as statins and PCSK9 inhibitors along with dietary supplementation for health improvements.
Diabetes mellitus is a chronic metabolic disorder due to insulin function insufficiency. This study aimed to test the effectiveness of flower extract of roselle (Hibiscus sabdariffa L.) extract in producing antidiabetic compounds. The inhibition of roselle flower extract on the alpha- glucosidase enzyme was carried out in vitro. Molecular docking was also carried out to bind ligands derived from roselle flower extract's secondary metabolites to the alpha-glucosidase and alpha-amylase enzymes. Based on molecular docking, models have negative binding energies suggesting those ligands make a complex to the site receptor. Kaemferol-3-O-rutinoside and tiliroside become the most stable complex based on the lowest energy score of –9.5 and –8.1 kcal/mol for alpha-amylase and alpha-glucosidase, respectively. The highest antidiabetic activity was obtained at a 100 ppm roselle flower ethanol extract and distilled water with an inhibition value of 100.00 and 99.25%, respectively. The alpha-amylase inhibiting test, using a concentration of 2.5 mg/mL, had an inhibitory activity of 41.77%. The in vitro assessment was conducted using the meta-analysis. The meta-analysis study showed that roselle flower extract could reduce glucose levels in fasting rats better than negative controls (diabetic rats) by 61% than those not given the roselle flower extract.
Background
The conventional treatments for hypercholesterolemia are too atomistic to effectively handle the condition. A phytotherapy which is rich in bioactive compounds could be a more effective approach. This study highlights plants prescribed against high cholesterol by herbalists in Casablanca, Morocco, and investigates their clinical effectiveness through a literature review.
Methods
An ethnopharmacological survey was conducted on 127 herbalists. The socio-demographic profile of the respondents, vernacular plant names, parts used, preparation methods, routes of administration and posology were recorded. The data was analyzed using the Citation Number, Use Value, Family Use Value and Choice Value indices. The literature review of the plants subject to clinical trials was conducted by probing ScienceDirect, Springer and PubMed.
Results
A total of 33 plant species distributed over 19 families were identified. The most represented families were Apiaceae, Fabaceae, Asteraceae and Lamiaceae. The most prescribed species were Linum usitatissimum, Coriandrum sativum, Avena sativa, Olea europea, Allium sativum, Juglans regia, Glycine max, Curcuma longa, Foeniculum vulgare and Rosmarinus officinalis. Flax and coriander had the highest Use Value. The literature review on hypercholesterolemia clinical trials revealed 15 common species related to this survey.
Conclusion
To treat hypercholesterolemia, herbalists emphasized 10 relevant plants: Linum usitatissimum, Coriandrum sativum, Avena sativa, Olea Europea, Allium sativum, Juglans regia, Glycine max and Rosmarinus officinalis. Some clinical trials have also shown these plant species to be effective cholesterol-lowering plants. This agreement between herbalists and clinical trials reflects the ability of the Moroccan traditional pharmacopoeia to meet the population health needs. However, serious attention should be given toward the toxicity of plants.
This is an overview of plant use for medicinal applications, a practice from old civilizations still used around the world. According to WHO, nearly 80% of people use herbal medicine plant extracts as their primary health solution. Ethnobotany emerges as a research field to document and understand the traditional knowledge about plants and their roles in society. Diseases like diabetes, hypertension, hypercholesterolemia, and cancer are the predominant challenges to global health, chronic diseases accounting for two-thirds of deaths worldwide. This document discusses ethnobotanical studies on many medicinal plants affecting these diseases.
Context:
Hibiscus sabdariffa (hibiscus) has been proposed to affect cardiovascular risk factors.
Objective:
To review the evidence for the effectiveness of hibiscus in modulating cardiovascular disease risk markers, compared with pharmacologic, nutritional, or placebo treatments.
Data sources:
A systematic search of the Web of Science, Cochrane, Ovid (MEDLINE, Embase, AMED), and Scopus databases identified reports published up to June 2021 on randomized controlled trials using hibiscus as an intervention for lipid profiles, blood pressure (BP), and fasting plasma glucose levels in adult populations.
Data extraction:
Seventeen chronic trials were included. Quantitative data were examined using a random effects meta-analysis and meta-regression with trial sequential analysis to account for type I and type II errors.
Data analysis:
Hibiscus exerted stronger effects on systolic BP (-7.10 mmHg [95%CI, -13.00, -1.20]; I2 = 95%; P = 0.02) than placebo, with the magnitude of reduction greatest in those with elevated BP at baseline. Hibiscus induced reductions to BP similar to that resulting from medication (systolic BP reduction, 2.13 mmHg [95%CI, -2.81, 7.06], I2 = 91%, P = 0.40; diastolic BP reduction, 1.10 mmHg [95%CI, -1.55, 3.74], I2 = 91%, P = 0.42). Hibiscus also significantly lowered levels of low-density lipoprotein compared with other teas and placebo (-6.76 mg/dL [95%CI, -13.45, -0.07]; I2 = 64%; P = 0.05).
Conclusions:
Regular consumption of hibiscus could confer reduced cardiovascular disease risk. More studies are warranted to establish an effective dose response and treatment duration.
Systematic review registration:
PROSPERO registration no. CRD42020167295.
In order to obtain better productivity and a good level of secondary metabolites for cultivating plants with organic residues, it is necessary to define the method of application and the best combination considering plant density. Our objective was to study the influence of the plant arrangement and methods of application of poultry manure in the soil over agroeconomic performance and the antioxidant activity of the hibiscus. Treatments in the field consisted of two plant arrangements (single or double rows, both with 0.50 meters between plants) and four methods of application of poultry manure to the soil [incorporating (10 t ha-1), mulching (10 t ha-1), mulching (5 t ha-1) + incorporating (5 t ha-1) and a control—no poultry manure] and, in the laboratory, antioxidant activity in relation to the treatments in the field and preparation methods (maceration or infusion). Treatments were arranged in randomized blocks of 2 × 4 with four replicates. The greatest production of dried calyx (0.68 t ha-1) and of capsules (1.32 t ha-1), the greatest number of fruits (2.10 million ha-1) and the greatest net income (R$ 36,115.42) resulted of plants cultivated in single rows with the poultry manure covering the crops. The antioxidant activity of the hibiscus calyces showed no variation in relation with field treatments or with the method of preparation. Cultivation in single rows covered with poultry manure is adequate for the hibiscus plant.
This study discusses the effectiveness of methanolic extract and fractions (butanol, ethyl acetate, and n-hexane) of H. sabdariffa Linn fruit towards antidiabetic activities (in vitro). In order to test the efficacy, toxicity and insulin secretion capacity of rat pancreatic β-cell lines (BRIN-BD11) were tested with the methanolic extract and fractions. The outcomes showed that both the extract and the fractions demonstrated significantly lower levels of cytotoxic activities. Furthermore, the methanolic extract and fractions displayed varied sensitivity levels towards insulin release after an incubation period of 30 min. The methanolic extract, at a concentration of 300 µg/mL, significantly stimulated secretion of insulin by 2.85-fold (p<0.001). In addition, butanol, ethyl acetate, and n-hexane fractions revealed a gradual increase in insulin secretion. The stimulated insulin secretion for these fractions had been recorded at 2-fold (p<0.01), 2.67-fold, and 2.31-fold (p<0.001), respectively, at the highest concentrations. The methanolic extract and fractions also appeared to stimulate secretion of insulin with all modulators present, for example, potassium chloride (KCl), insulin secretion inhibitor (verapamil and diazoxide), as well as insulin secretagogue (tolbutamide and isobutylmethylxanthine (IBMX)). These results indicate that H. sabdariffa Linn fruit methanolic extract and fractions could indeed be beneficial for future development of antidiabetic drugs.
Roselle (Hibiscus sabdariffa L.) belongs to the genus Hibiscus under the tribe Hibisceae of the family Malvaceae. The genus Hibiscus contains more than 300 species that are grown throughout the tropical and subtropical regions of the world. Several species of Hibiscus are economically important, as they provide food, fiber, and medicine. Other species are valuable, as they have esthetic value. Indian sorrel or roselle (H. sabdariffa L.) is cultivated for use as a vegetable and/ or to make drinks and jams. On the other hand, kenaf (Hibiscus cannabinus) is cultivated and extensively used for making fiber. Over the past few decades, two Hibiscus species (namely, roselle and kenaf) have been researched to evaluate them as new crops in different countries. Indian sorrel is an annual or perennial plant. It is cultivated for many useful purposes such as edible calyx, leaves, and seeds or fibers and paper pulp.
Two field experiments were carried out at experimental farm of Faculty of Agriculture, Zagazig University, Egypt, during the two summer consecutive seasons of 2018 and 2019. To study the impact of sowing dates and some amino acids on the roselle (Hibiscus sabdariffa L.) yield in terms of number of fruits per plant, dry sepal’s yield per plant and per feddan as well as its chemical constituents in terms of total chlorophyll (SPAD) and anthocyanin (mg/100g as dry weight) contents. A split-plot experiment was carried out in the field based on a randomized complete block design with three replications. The main plot was four sowing dates (15th April, 1st May, 15th May and 1st June) and the sub-plot was five amino acids treatments (tap water as control, tyrosine and glutamine acids each at 100 or 200 ppm concentrations). The results showed that the early in sowing from June1 to April 15 increased fruit number per plant, dry sepals yield per plant (g) and per feddan (kg) as well as total chlorophyll content and anthocyanin content. Also, all the values of the studied parameters were significantly increased when the roselle plants sprayed with glutamine acid at 200 ppm compared to control. In final, planting roselle seeds in 15th April and sprayed with 200 ppm glutamine four times per season manifests to enhance yield and is adequate for fulfilling the highest anthocyanin contents in sepals of roselle under Sharkia Governorate conditions.
Considering the high prevalence of hypertension, its debilitating end organ damage, and the side effects of chemical drugs used for its treatment, we conducted this experimental study to evaluate the effect of sour tea (Hibiscus sabdariffa) on essential hypertension. For this purpose, 31 and 23 patients with moderate essential hypertension were randomly assigned to an experimental and control group, respectively. Patients with secondary hypertension or those consuming more than two drugs were excluded from the study. Systolic and diastolic blood pressures were measured before and 15 days after the intervention. In the experimental group, 45% of the patients were male and 55% were female, and the mean age was 52.6 +/- 7.9 years. In the control group, 30% of the patients were male, 70% were female, and the mean age of the patients was 51.5 +/- 10.1 years. Statistical findings showed an 11.2% lowering of the systolic blood pressure and a 10.7% decrease of diastolic pressure in the experimental group 12 days after beginning the treatment, as compared with the first day. The difference between the systolic blood pressures of the two groups was significant, as was the difference of the diastolic pressures of the two groups. Three days after stopping the treatment, systolic blood pressure was elevated by 7.9%, and diastolic pressure was elevated by 5.6% in the experimental and control groups. This difference between the two groups was also significant. This study proves the public belief and the results of in vitro studies concerning the effects of sour tea on lowering high blood pressure. More extensive studies on this subject are needed.
In view of the continuing need for effective anticancer agents, and the association of diet with reduced cancer risk, edible plants are increasingly being considered as sources of anticancer drugs. Hibiscus sabdariffa Linne (Malvaceae), an attractive plant believed to be native to Africa, is cultivated in the Sudan and Eastern Taiwan. Polyphenols had been demonstrated previously to possess antioxidative and antitumor promoting effects. In this study, investigations were conducted to examine the mechanism of the anticancer activity of H. sabdariffa L., Hibiscus polyphenol-rich extracts (HPE). Using HPLC assay, HPE was demonstrated to contain various polyphenols. HPE induced cell death of eight kinds of cell lines in a concentration-dependent manner. Among them human gastric carcinoma (AGS) cells were the most susceptible to HPE (0.95 mg/mL HPE inhibited its growth by 50%). Our results revealed that AGS cells underwent DNA fragmentation, and had an increase in the distribution of hypodiploid phase (apoptotic peak, 52.36%) after a 24-h treatment with HPE (2.0 mg/mL). This effect of HPE in AGS cells might be mediated via p53 signaling and p38 MAPK/FasL cascade pathway, as demonstrated by an increase in the phosphorylation of p53 and the usage of a specific p38 inhibitor, SB203580. Thus, our data present the first evidence of HPE as an apoptosis inducer in AGS cells and these findings may open interesting perspectives to the strategy in human gastric cancer treatment.
As an anti-metabolite, Azathioprine inhibits the de novo and salvage pathways of purine synthesis. Intraperitoneal injection of this drug results in not only lymphocyte suppression but also toxicity to bone marrow, gastrointestinal tract, and liver. This Azathioprine-induced hepatotoxicity was found to be associated with oxidative damage. Plants with antioxidative properties have been traditionally used to prevent diseases associated with free radicals. In this report, we used water extracts of three herbal plants that have been commonly used for treating many illnesses (Hibiscus sabdariffa, Rosmarinus officinalis and Salvia officinalis). Here we show their novel hepatoprotective effects against Azathioprine-induced hepatotoxicity in rats. Typically, administration of Azathioprine induces oxidative stress through depleting the activities of antioxidants and elevating the level of malonialdehyde in liver. This escalates levels of alanine aminotransferase, and aspartate aminotranferase in serum. Pretreatment with any of the three herbal plants used in this investigation proved to have a protective effect against Azathioprine-induced hepatotoxicity. Animals pretreated with water extracts from any of the three herbs under investigation not only failed to show necrosis of the liver after azathioprine administration, but also retained livers that, for the most part, were histologically normal. In addition, these herbs blocked the induced elevated levels of alanine aminotransferase and aspartate aminotranferase in serum. The Azathioprine-induced oxidative stress was relieved to varying degrees by the examined herbal extracts. This effect was evident through reducing malonialdehyde levels and releasing the inhibitory effect of Azathioprine on the activities of glutathione, catalase and superoxide dismutase. To our knowledge, this report is the first that shows hepatoprotective effects of Hibiscus, Rosmarinus and Salvia species against Azathioprine-induced acute liver damage.
The scientific basis for the statement that plants and their active constituents play an important role in the prevention of chronic and degenerative diseases is continously advancing. The object of the present study was to evaluate the effect of Hibiscus sabdariffa L. dried calyx ethanolic extract on the serum lipid profile of Sprague-Dawley rats. The rats were fed during 4 weeks with either a basal diet, containing high cholesterol (1%), cholic acid (0.25%), lard oil (10%), or a supplemental diet with H. sabdariffa extract at 5%, 10%, and 15% levels (SD(5), SD(10), SD(15)). Weight gain and faeces dry weight were both very significantly less (p <or= 0.01) in SD(10) and SD(15) groups as compared to the control group, as was food efficiency in SD(15). In the case of SD(10), food efficiency was only significantly lower (p <or= 0.05). Faeces dry weight in SD(5) however, was the only one found to be significantly higher (p <or= 0.05). Triacylglycerols and LDL levels were both significantly less (p <or= 0.05) in all groups (SD(5), SD(10), and SD(15)) as compared to the control. For total lipids, SD(10) and SD(15) showed significantly lower levels (p <or= 0.05), whereas very significant differences (p <or= 0.01) were observed in the case of SD(5). All groups had lower cholesterol levels compared to controls; however, only the SD(5) group was statistically significant (p <or= 0.05). No significant results were found in any group in the cases of either phospholipid or HDL levels. A hypothesis of hibiscus acid racemization, (+)-HCA to (-)-HCA, mediated by intestinal flora enzymes possibly explains the significant triacylglycerol decrease in all experimental groups. VLDL, the precursor of LDL, is composed predominantly of triacylglycerols, suggesting that the significant decrease in LDL is related to observed triacylglycerol synthesis inhibition. Five percent H. sabdariffa extract addition showed the best results in the reduction of serum lipids under study conditions.
Hibiscus sabdariffa L extract (HSE) is an aqueous extract of Hibiscus sabdariffa L flowers that is used as a local soft drink and medical herb in Taiwan. Oxidation of low-density lipoprotein (LDL) has been shown to increase the incidence of atherosclerosis. In this study, we determined the antioxidative activity of HSE on LDL oxidation by examining relative electrophoretic mobilities (REM) and thiobarbituric acid-reactive substances (TBARS). The data revealed an inhibitory effect of HSE on Cu2+-mediated REM and TBARS. HSE exhibited a remarkable ability to reduce cholesterol degradation and ApoB fragmentation. Overall, HSE showed a high potency to inhibit the production of oxidized LDL induced by copper and, specifically, to reduce serum triglycerides in high-fructose diet (HFD) fed rats and serum cholesterol in high-cholesterol diet (HCD) fed animals. The levels of LDL and the ratio of LDL-cholesterol (LDL-C) to HDL-cholesterol (HDL-C) were reduced by HSE in both hyperlipidaemia models. Based on these findings, we suggest that HSE may be used to inhibit LDL oxidation and to prevent various types of hyperlipidaemia in HFD- or HCD-fed rats. Copyright © 2004 Society of Chemical Industry
Flavonoid content of mulberry leaves of 19 varieties of species, determined spectrophotometrically in terms of rutin equivalent, varied from 11.7 to 26.6 mg g−1 in spring leaves and 9.84 to 29.6 mg g−1 in autumn leaves. Fresh leaves gave more extract than air-dried or oven-dried ones. HPLC showed that mulberry leaves contain at least four flavonoids, two of which are rutin and quercetin. The percentage superoxide ion scavenged by extracts of mulberry leaves, mulberry tender leaves, mulberry branches and mulberry bark were 46.5, 55.5, 67.5 and 85·5%, respectively, at a concentration of 5 μg ml−1. The scavenging effects of most mulberry extracts were greater than those of rutin (52.0%).
Hibiscus protocatechuic acid (PCA), a phenolic compound isolated from the dried flower of Hibiscus sabdariffa L. (Malvaceae), demonstrated antioxidant and antitumor promotion effects in our previous study. In the present study, Hibiscus PCA was found to inhibit the survival of human promyelocytic leukemia HL-60 cells in a concentration- and time-dependent manner. The study revealed that HL-60 cells underwent internucleosomal DNA fragmentation and morphological changes characteristic of apoptosis after a 9-hr treatment with Hibiscus PCA (2 mM). Flow cytometric analysis of the DNA content of cells treated with PCA for 12 hr showed that the cells were distributed mainly in the hypodiploid phase (apoptotic peak, 46.7%), less in the G1 (34.2%) and S phase (14.0%), and few in the G2/M phase (5.1%). Moreover, PCA treatment caused an increase in the level of hypophosphorylated retinoblastoma (RB; 180% of control at the 6-hr time point) and, on the contrary, a decline in hyperphosphorylated RB. A rapid loss of RB was observed when the treatment period was extended. Further studies showed that Hibiscus PCA application reduced Bcl-2 protein expression to 47%, and increased Bax protein expression to 181% after 1.5 hr as compared with time 0. Overexpression of Bcl-2 in HL-60 cells delayed the occurrence of Hibiscus PCA-induced apoptosis. These data suggest that Hibiscus PCA is an apoptosis inducer in human leukemia cells, and that RB phosphorylation and Bcl-2 protein may play a crucial role in the early stage.
Some patients with familial hypercholesterolemia (FHC, type II) are highly responsive to the cholesterol-lowering effect of clofibrate, while others are not only resistant to this effect but may even show an increase in plasma beta-lipoproteins. In an attempt to find an explanation for these striking differences, we have studied the pharmacokinetics of clofibrate in FHC patients at both extremes of responsiveness. The results disclosed several major differences between the two groups. Plasma clofibric acid (CPIB) measured during the chronic administration of the drug was significantly higher in the responders than in the non-responders, whether all patients in each group or only those with tendon xanthomas were considered. Plasma CPIB concentrations were negatively correlated with body weight in the responders but not in CPIB-resistant patients. They were also inversely proportional to decreases in plasma beta-lipoprotein cholesterol after chronic clofibrate administration in the responsive group, but directly proportional to increases in the non-responders. Increasing the dose of clofibrate from 2 to 3 g/day in CPIB-resistant patients always resulted in an increase in plasma CPIB levels, but this was followed in some patients by a decrease and in others by an increase in plasma beta-lipoprotein cholesterol concentrations, so that the overall effect was not statistically significant. The half-life of plasma CPIB was measured over 48 h after a single 1-g dose of clofibrate in patients who had not received this drug for at least 3 weeks. Half-life was significantly longer in the responsive patients. In addition, the bioavailability and the rate of absorption of clofibrate tended to be higher in this group than in the resistant patients. We suspect that both groups differ not only in the metabolic handling of clofibrate but also in some aspect of their beta-lipoprotein cholesterol metabolism.
In a randomized, double-blind five-year trial, we tested the efficacy of simultaneously elevating serum levels of high-density lipoprotein (HDL) cholesterol and lowering levels of non-HDL cholesterol with gemfibrozil in reducing the risk of coronary heart disease in 4081 asymptomatic middle-aged men (40 to 55 years of age) with primary dyslipidemia (non-HDL cholesterol greater than or equal to 200 mg per deciliter [5.2 mmol per liter] in two consecutive pretreatment measurements). One group (2051 men) received 600 mg of gemfibrozil twice daily, and the other (2030 men) received placebo. Gemfibrozil caused a marked increase in HDL cholesterol and persistent reductions in serum levels of total, low-density lipoprotein (LDL), and non-HDL cholesterol and triglycerides. There were minimal changes in serum lipid levels in the placebo group. The cumulative rate of cardiac end points at five years was 27.3 per 1,000 in the gemfibrozil group and 41.4 per 1,000 in the placebo group--a reduction of 34.0 percent in the incidence of coronary heart disease (95 percent confidence interval, 8.2 to 52.6; P less than 0.02; two-tailed test). The decline in incidence in the gemfibrozil group became evident in the second year and continued throughout the study. There was no difference between the groups in the total death rate, nor did the treatment influence the cancer rates. The results are in accord with two previous trials with different pharmacologic agents and indicate that modification of lipoprotein levels with gemfibrozil reduces the incidence of coronary heart disease in men with dyslipidemia.
In a multicentric general-practice-study 2504 hyperlipoproteinemic patients were treated with etofibrate retard for 4 weeks. The drug was administered once daily in the evening. A highly significant decrease of the mean values of cholesterol around 18.4% and 27.6% resp., and of the mean triglycerides between 31.3% and 16.5% resp. were observed. The atherogenic index was reduced by 28%. The simultaneous, highly significant reduction of blood glucose and of uric acid levels as well as of blood pressure showed the comprising effects of etofibrate retard against the atherosclerosis and its risk factors. The excellent tolerance of the drug was stated by more than 99% of the patients treated.
Apolipoprotein (apo) E-deficient mice develop atherosclerotic lesions that contain epitopes formed during the oxidative modification of lipoproteins, and they demonstrate high titers of circulating autoantibodies against such epitopes, suggesting that this murine strain may provide a model to investigate the atherogenic mechanisms of oxidized lipoproteins (Palinski et al, Arterioscler Thromb. 1994; 14:605-616). To test the hypothesis that lipoprotein oxidation contributes to lesion formation in apoE-deficient mice, we studied the effect of the antioxidant N,N'-diphenyl 1,4-phenylenediamine (DPPD) in mice fed a high-fat diet containing 0.15% cholesterol. Animals were divided into two subgroups matched for sex and plasma cholesterol levels, and DPPD (0.5% wt/wt) was added to the diet of one subgroup. Throughout the 6 months of intervention, DPPD treatment had no significant effect on plasma cholesterol. Plasma levels of DPPD at the end of the experiment were 33.1 mumol/L. As judged by resistance to loss of polyunsaturated fatty acids, lipoproteins (d < 1.019 g/mL) from DPPD-treated animals showed greater resistance to copper-induced oxidation than lipoproteins from control animals. In addition, there was a greater than twofold prolongation of the lag time in the formation of conjugated dienes in the LDL and IDL fractions of DPPD-treated mice. Atherosclerosis was significantly reduced, by 36% in the DPPD-treated mice (14.0 +/- 4.53% of aortic surface area versus 21.9 +/- 11.6%; n = 32; P < .02). These results are consistent with the hypothesis that lipoprotein oxidation contributes to atherogenesis in apoE-deficient mice. However, further studies with other antioxidants are needed to validate this hypothesis.
Patients with cardiovascular risk factors often have combined hyperlipidaemia which can be effectively treated with fibrate drugs. Resins can be added when further cholesterol reduction is necessary. In this clinical study, after an initial 4-week placebo prephase, 40 high-risk patients with combined hyperlipidaemia were treated with 2 x 500 mg etofibrate per day for five months to reduce blood lipids according to the intervention guidelines. Low-dose cholestyramine was added when further cholesterol reduction was needed. In 23 patients it was found that total cholesterol and LDL cholesterol could be significantly and sufficiently reduced by 30% (p < 0.05), and by 28.8% (p < 0.05) with etofibrate therapy alone. Additional cholestyramine treatment was necessary in 17 patients, resulting in significant total reductions of 37.6% (p < 0.05) in total cholesterol and 36.7% (p < 0.05) in LDL cholesterol by 4 g cholestyramine per day. Triglyceride reductions (22.8% and 25.0%) and fibrinogen reductions (11.2% and 13.4%) were similar in both treatment groups, showing no influence of the addition of cholestyramine. Tolerance and safety data revealed no negative effects for either treatment. Thus etofibrate, either alone or in combination with low-dose cholestyramine, proved to be an effective and well-tolerated therapeutic regime in combined hyperlipidaemia.
No attention has been paid to anthocyanin pigments from the viewpoint of inhibitors of lipid peroxidation and scavengers of active oxygen radicals; therefore, we investigated the antioxidative, radical scavenging, and inhibitory effects on lipid peroxidation by UV light irradiation of three anthocyanin pigments, pelargonidin 3-O-beta-D-glucoside (P3G), cyanidin 3-O-beta-D-glucoside (C3G), and delphinidin 3-O-beta-D-glucoside (D3G), isolated from the Phaseolus vulgaris L. seed coat, and their aglycons, pelargonidin chloride (Pel), cyanidin chloride (Cy), and delphinidin chloride (Del). All pigments had strong antioxidative activity in a liposomal system and reduced the formation of malondialdehyde by UVB irradiation. On the other hand, the extent of antioxidative activity in a rat liver microsomal system and the scavenging effect of hydroxyl radicals (-OH) and superoxide anion radicals (O2-) were influenced by their own structures.
In this review of the scientific literature on the relationship between vegetable and fruit consumption and risk of cancer, results from 206 human epidemiologic studies and 22 animal studies are summarized. The evidence for a protective effect of greater vegetable and fruit consumption is consistent for cancers of the stomach, esophagus, lung, oral cavity and pharynx, endometrium, pancreas, and colon. The types of vegetables or fruit that most often appear to be protective against cancer are raw vegetables, followed by allium vegetables, carrots, green vegetables, cruciferous vegetables, and tomatoes. Substances present in vegetables and fruit that may help protect against cancer, and their mechanisms, are also briefly reviewed; these include dithiolthiones, isothiocyanates, indole-3-carbinol, allium compounds, isoflavones, protease inhibitors, saponins, phytosterols, inositol hexaphosphate, vitamin C, D-limonene, lutein, folic acid, beta carotene, lycopene, selenium, vitamin E, flavonoids, and dietary fiber. Current US vegetable and fruit intake, which averages about 3.4 servings per day, is discussed, as are possible noncancer-related effects of increased vegetable and fruit consumption, including benefits against cardiovascular disease, diabetes, stroke, obesity, diverticulosis, and cataracts. Suggestions for dietitians to use in counseling persons toward increasing vegetable and fruit intake are presented.
The aqueous extracts of Acacia nilotica and Hibiscus sabdariffa were tested for anti-inflammatory, analgesic and antipyretic activities in animal models. Acacia nilotica extract had an inhibitory effect on carrageenan induced paw edema and yeast-induced pyrexia in rats. It also produced a significant increase in the hot plate reaction time in mice. Hibiscus sabdariffa extract had no effect on paw edema but had an inhibitory effect on yeast induced pyrexia and a significant effect on the hot plate reaction time. Among the phytoconstituents found in both plants, flavanoids, polysaccharides and organic acids may be mainly responsible for their pharmacological activities.
1. Recent studies (4S, CARE, WOSCOPS) with the HMG CoA reductase inhibitors have shown that reductions of total cholesterol and LDL cholesterol reduce the risk for a new fatal or non-fatal cardiac event by approximately 30-35%, providing LDL is decreased by 25-35%. 2. Preliminary data also suggest that achieved LDL levels around 3.2 mmol/L results in no greater reduction in new events than when LDL is lowered even further. 3. There is considerable debate, nonetheless, as to whether these reduction in cardiovascular events are entirely a consequence of LDL reduction or whether the lipid-modifying agents have effects on lipoprotein structure, endothelial cell function, clotting and haemorrheological pathways. 4. The study results achieved with statins have obscured the role of fibrates as useful agents for reducing cardiovascular disease. Fibrates have a different mode of action to stains by reducing triglyceride-rich lipoprotein precursors and favourably altering LDL and HDL composition. 5. The practising clinician needs to consider the lipoprotein phenotype and to choose whether the ideal treatment is stain alone, fibrate alone or perhaps a combination.
Dried flower extracts of Hibiscus sabdariffa L., a local soft drink material and medical herb, was found to possess antioxidant activity in the present study. In the preliminary studies, antioxidant potential of three fractions of the ethanol crude extract (HS-C: chloroform-soluble fraction; HS-E: ethyl acetate soluble fraction; HS-R: residual fraction) obtained from the dried flowers of Hibiscus sabdariffa L. were evaluated by their capacity of quenching 1,1 -diphenyl-2-picrylhydrazyl (DPPH) free radical and inhibiting xanthine oxidase (XO) activity. HS-E showed the greatest capacity of scavenging free radical (EC50=0.017mg/ml), and HS-C showed the strongest inhibitory effect on XO activity (EC5o=0.742 mg/ml). Furthermore, antioxidant bioactivities of these crude extracts were investigated using a model of tert-butyl hydroperoxide (t-BHP)-induced oxidative damage in rat primary hepatocytes. All fractions were found to inhibit significantly the unscheduled DNA synthesis (UDS) induced by t-BHP at a concentration of 0.20 mg/ml. HS-C and HS-E also decreased the leakage of lactate dehydrogenase (LDH) and the formation of malondialdehyde (MDA) induced by t-BHP (1.5 mM) considerably at a concentration of 0.10 and 0.20 mg/ml in the rat primary hepatocyte cultures. These results indicated that the dried flower extracts (HS-C and HS-E) of H. sabdariffa L. protect rat hepatocytes from t-BHP-induced cytotoxicity and genotoxicity by different mechanisms.
Hibiscus protocatechuic acid (PCA), a phenolic acid isolated from Hibiscus sabdariffa L., was evaluated for its ability to inhibit the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced promotion in skin tumors of female CD-1 mice. Topical application of PCA (5, 10 or 20 micromol) 5 min prior to TPA (15 nmol) treatment twice weekly for 20 weeks to mice which were initiated with benzo[a]pyrene (B[a]P) inhibited the incidence of tumors in mice to 81.3, 62.5 and 56.3%, respectively, while all mice in the TPA-treated group developed tumors. The average number of tumors in mice pretreated with PCA was 2-4 and that of mice treated only with TPA was 6.6. The protection effects of PCA were also presented by its significant suppression on the TPA-induced hyperplasia in the skin and edema of mouse ears by 65 and 73% at doses of 10 and 20 micromol, respectively. When it was applied to the dorsal surface of CD-1 mice before TPA application, PCA (5, 10 or 20 micromol) inhibited the induction of epidermal ornithine decarboxylase (ODC) activity by 5 nmol TPA and myeloperoxidase (MPO) activity by 6.5 nmol TPA. The same doses of PCA also reduced the formation of hydrogen peroxide in the mouse skin to an inhibition of 61, 84 and 89%, respectively, when compared with that of the TPA-treated group. These results indicate that PCA possesses potential as a cancer chemopreventive agent against tumor promotion.
Oxidized low density lipoprotein (LDL) promotes atherogenesis. Although pharmacological antioxidants such as probucol inhibit both LDL oxidation and atherosclerosis in hyperlipidemic animals, the effects of natural antioxidants such as vitamin E are inconclusive. To further determine the effects of supplemental dietary antioxidants in vivo, we evaluated whether combined dietary antioxidants (0.1% vitamin E, 0.5% beta-carotene, and 0.05% vitamin C) inhibit LDL oxidation and fatty streak lesion development in homozygous LDL receptor-null (LDLR-/-) mice fed a high-fat, high-cholesterol diet. An additional group of mice were fed black tea, which has been shown to inhibit LDL oxidation in vitro. After receiving a high-fat, high-cholesterol diet for 8 weeks, the combined antioxidant-supplemented (antioxidant) group (n=18), tea group (n=19), and control group (n=17) had equivalent plasma cholesterol levels. LDL oxidation, as measured by the lag phase of conjugated diene formation, was markedly inhibited in the antioxidant group compared with the tea or control groups [mean lag phases=143+/-7 (antioxidant), 100+/-5 (tea), and 84+/-4 (control) minutes; P<0.0001 antioxidant versus tea or control]. The cross-sectional surface area of fatty streak lesions in the aortic sinus was reduced by 60% in the antioxidant group compared with both the tea and control groups (P<0.0001 antioxidant versus tea or control). There was no difference in lesion area between tea and control groups. Although both LDL oxidation and atherosclerosis were significantly inhibited in the antioxidant group, no correlation between lag phase values and lesion size was observed among individual animals. Furthermore, black tea did not inhibit fatty streak development in LDLR-/- mice. These data suggest that combined natural dietary antioxidants inhibit both LDL oxidation and atherogenesis in animals with elevated LDL but that inhibition of LDL oxidation alone may not prevent the development of atherosclerosis.
Polyphenols constitute one of the most numerous and ubiquitous groups of plant metabolites and are an integral part of both human and animal diets. Ranging from simple phenolic molecules to highly polymerized compounds with molecular weights of greater than 30,000 Da, the occurrence of this complex group of substances in plant foods is extremely variable. Polyphenols traditionally have been considered antinutrients by animal nutritionists, because of the adverse effect of tannins, one type of polyphenol, on protein digestibility. However, recent interest in food phenolics has increased greatly, owing to their antioxidant capacity (free radical scavenging and metal chelating activities) and their possible beneficial implications in human health, such as in the treatment and prevention of cancer, cardiovascular disease, and other pathologies. Much of the literature refers to a single group of plant phenolics, the flavonoids. This review offers an overview of the nutritional effects of the main groups of polyphenolic compounds, including their metabolism, effects on nutrient bioavailability, and antioxidant activity, as well as a brief description of the chemistry of polyphenols and their occurrence in plant foods.
Introduction: The prevalence and human health consequences of deficient and inadequate vitamin D status were assessed. Materials and methods: The assessment was performed through an evaluation of the extensive existing relevant scientific literature. A scientific literature search was conducted on MEDLINE (National Library of Medicine, Bethesda, MD, USA) for relevant articles regarding the prevalence and human health consequences of deficient and inadequate vitamin D status published prior to November, 2014. Additional publications were identified from references provided in original papers. Results: Several thousand relevant scientific publications were identified, examined, and evaluated. Of this pool of potential data, the information provided by 348 publications was incorporated into this assessment. Conclusions: Vitamin D deficiency and inadequacy are rampant worldwide. The many physiological functions that rely upon vitamin D justify a reassessment of the definition of vitamin D deficiency that reflects the true importance of this endocrinologically active vitamin to human health. The continuing preventable gobal epidemic of suboptimal vitamin D status challenges the relevance of current attitudes toward dietary supplementation with this critical nutrient.
The LD(50) of roselle calyx extract and its effect on blood pressure were determined. The LD(50) was found to be above 5000 mg kg(-1). Roselle calyx infusion was found to lower significantly (p<0.05) both systolic and diastolic pressure in spontaneously hypertensive and normotensive Wistar-Kyoto rats at tested doses of 500 and 1000 mg kg(-1) body weight. The reduction in blood pressure in both groups was positively correlated with weight. Continuous consumption of the infusion at 1000 mg kg(-1) was discovered to lead to sudden death in spontaneously hypertensive rats but not in Wistar-Kyoto rats. Water intake was not significantly different (p>0.05) in the control groups of the two strains of rats used, neither was there a significant difference in their urine output. The water intake in the treated spontaneously hypertensive and normotensive rats was not different from the corresponding control groups. However the urine output of the treated spontaneously hypertensive rats was significantly higher. A significant decrease in serum creatinine, cholesterol, and glucose in the treated rats compared with the control as well as a significant increase in serum uric acid was observed. The serum proteins (albumin and total protein) in the treated rats when compared with the control groups was not changed significantly.
Epidemiologic data support the association between high intake of vegetables and fruits and low risk of chronic disease. There are several biologically plausible reasons why consumption of vegetables and fruit might slow or prevent the onset of chronic diseases. Vegetables and fruit are rich sources of a variety of nutrients, including vitamins, trace minerals, and dietary fiber, and many other classes of biologically active compounds. These phytochemicals can have complementary and overlapping mechanisms of action, including modulation of detoxification enzymes, stimulation of the immune system, reduction of platelet aggregation, modulation of cholesterol synthesis and hormone metabolism, reduction of blood pressure, and antioxidant, antibacterial, and antiviral effects. Although these effects have been examined primarily in animal and cell-culture models, experimental dietary studies in humans have also shown the capacity of vegetables and fruit and their constituents to modulate some of these potential disease-preventive mechanisms. The human studies have relied on intermediate endpoints related to disease risk. Design methodologies used include multiple-arm trials, randomized crossover studies, and more compromised designs such as nonrandomized crossovers and pre- and posttreatment analyses. Length of treatment ranged from a single dose to years depending on the mechanism of interest. Stringency of dietary control varied from addition of supplements to a habitual diet to provision of all food for the duration of a treatment. Rigorously conducted experimental dietary studies in humans are an important link between population- and laboratory-based research.
The 80% ethanol extract of roselle (Hibiscus sabdariffa Linn.), a medicinal plant in Thailand, was examined for antimutagenic and chemopreventive activity in a colon carcinogenesis model. It reduced about 60-90% of the mutagenicity induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and other heterocyclic amines 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline(MelQ),2-amino-3, 8-dimethylimidazo[4,5-f]quinoxaline(MelQx),3-amino-1,4-dimet hyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2),2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1),2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), at a concentration of 12.5 mg/plate in the Salmonella mutation assay. The extract showed no mutagenicity and no antibacterial activity below this dose. Mutagenicity of methylazoxymethanol (MAM) acetate, which, like PhIP, is a colon carcinogen,was also efficiently inhibited by the roselle extract. To investigate chemoprevention by roselle in a colon carcinogenesis model, we examined the inhibitory effects of the roselle extract in F344 rats in which aberrant crypt focus (ACF) formation was induced by azoxymethane (AOM) and PhIP. In the initiation stage, the number of AOM-induced ACF in the colon was significantly decreased by roselle (17-25%) compared with that in rats treated with AOM alone. The amount of O6-methylguanine in the colonic mucosa tended to be decreased in the roselle-treated rats. The number of PhIP-induced ACF was also significantly decreased by roselle treatment (22%) at a concentration of 1.0 g/kg body weight in the initiation stage. However, in the post-initiation stage of AOM-induced ACF formation, roselle increased the number of ACF, especially the number of foci which had more than three crypts/focus. These results indicate that roselle has antimutagenic activity against MAM acetate and heterocyclic amines and that it decreases the number of AOM- and PhIP-induced ACF in the initiation stage, although it rather increased the number of ACF in the post-initiation stage.
The epidemiologic data do not support a strong role for vitamin C in reducing risk of coronary disease. The evidence supporting a protective effect for the family of dietary carotenoids is stronger, but any important protective effect attributable to the specific supplementation of beta-carotene can be excluded. Conversely, results from observational and experimental studies consistently support an effect of vitamin E supplementation on reducing risk of coronary heart disease. The evidence suggests that the major effect, if any, is found at supplemental intake levels at or greater than 100 IU/d. If confirmed in further trials, the net benefit of vitamin E supplementation among populations with existing coronary disease may be substantial, although the current available evidence is insufficient to warrant a change in public policy recommendations.
1. There has been considerable recent interest in the possibility that increased intake of dietary anti-oxidants may protect against cardiovascular disease. This is partly due to the knowledge that oxidative events in vivo may play a role in the pathogenesis of atherosclerosis.
2. While dietary anti-oxidants, such as vitamins E and C, have received considerable attention in this regard, relatively little is known about a similar anti-oxidant role for plant-derived polyphenolic compounds, such as the flavonoids and phenolic acids. A review of the distribution, bioavailability and biological activity of these compounds suggests that they may have a physiological role as anti-oxidants.
3. Human trials on the anti-oxidant effects of beverages rich in polyphenolics, such as red wine, fruit juice or tea, have been limited and results are, at present, inconclusive. This is due, in part, to poor methodologies available to measure oxidative damage in vivo.
4. There is a sound rationale for considering polyphenolics as important contributors to the dietary anti-oxidant intake derived from fruits and vegetables. However, continuing research is needed using appropriate biomarkers of oxidant damage in vivo before these compounds can be conclusively considered as dietary anti-oxidants with nutritional benefit.
Hibiscus anthocyanins (HAs), a group of natural pigments occurring in the dried flowers of Hibiscus sabdariffa L., which is a local soft drink material and medical herb, were studied for antioxidant bioactivity. The preliminary study showed that HAs were able to quench the free radicals of 1,1-diphenyl-2-picrylhydrazyl. This antioxidant bioactivitiy was further evaluated using the model of tert-butyl hydroperoxide (t-BHP)-induced cytotoxicity in rat primary hepatocytes and hepatotoxicity in rats. The results demonstrated that HAs, at the concentrations of 0.10 and 0.20 mg/ml, significantly decreased the leakage of lactate dehydrogenase and the formation of malondialdehyde induced by a 30-min treatment of t-BHP (1.5 mM). The in vivo investigation showed that the oral pretreatment of HAs (100 and 200 mg/kg) for 5 days before a single dose of t-BHP (0.2 mmol/kg, ip) significantly lowered the serum levels of hepatic enzyme markers (alanine and aspartate aminotransferase) and reduced oxidative liver damage. The histopathological evaluation of the liver revealed that Hibiscus pigments reduced the incidence of liver lesions including inflammatory, leucocyte infiltration, and necrosis induced by t-BHP in rats. Based on the results described above, we speculate that Hibiscus pigments may play a role in the prevention of oxidative damage in living systems.
The polyphenolic, flavonoid, and caffeine compositions of four commercial tea bag products (typical of those used in the UK, US, continental Europe, and the Middle East) and beverages prepared from them under a range of typical consumer use conditions have been studied. Leaf composition was determined by extraction with aqueous methanol: the absolute compositions of all four products were remarkably similar in terms of most phenolic compounds. The flavonoids comprised the major proportion (93-94%) of the total phenolics estimated by the Folin-Ciocalteu method. At brew times up to 2 min the composition of the brew solids was for each product practically independent of brew time, with flavonoids again comprising the major proportion (86-88%) of the total phenolics. The efficiency of extraction in brewing of total phenolics, total flavonoids, catechins, and theaflavins was up to 35-55% of the total available in the leaf, whereas the flavonol and flavone glycosides and caffeine were more efficiently extracted (up to 55-90%). The contribution of tea to the UK adult average total dietary intake of flavonols and flavones was calculated to be up to 80% depending on brewing conditions.
Epidemiological studies, and some clinical trials, demonstrate that a proper diet reduces the rate of occurrence of cardiovascular disorders. Several in vitro studies suggest that some components of plant foods, most of which sharing a phenolic structure, are endowed with interesting 'pharmacological activities'. This article reviews the evidence that links a high dietary intake of phytochemicals from various sources with a reduced incidence of coronary heart disease.