Toxicological investigation of aqueous-methanolic extract of the calyces of Hibiscus sabdariffa L

Antiapoptotic and antioxidant capacity of phytochemicals from Roselle (Hibiscus sabdariffa) and their potential effects on monosodium glutamate-induced testicular damage in rat

Monosodium glutamate (MSG), common flavor enhancer and feed additive, causes male reproductive dysfunction. However, Roselle tea, popular Hibiscus sabdariffa (HS) beverage, has a controversial effectiveness on male fertility. Therefore, the current study aimed to investigate either the adverse effect of aqueous HS extract (HSE) on the testicle or its potential ameliorative role including some stress markers, biochemical and immunohistochemical expressions in rats subjected to MSG. Here, the animals were divided into four groups that were given distilled water, HSE, MSG, and HSE + MSG respectively via gavage. After 6 weeks from the beginning of experiment, blood samples were collected for hormonal analysis. Additionally, testicular specimens were excised and processed for oxidative/antioxidant parameters determination, histological examination, and immunohistochemical evaluation of Bax and PCNA positive spermatogenic cells. Preliminary phytochemical analyses as well as antioxidant capacity of the HSE were tested. Our results revealed a strong inhibitory activity of the HSE phytochemical constituents against DPPH radical. MSG group revealed a significant decrease of testosterone, LH, FSH, and antioxidant parameters with elevated MDA compared with control and HSE groups. Additionally, an alteration of the testicular histo-architecture was observed among MSG group along with increased Bax and decreased PCNA positive cells. Meanwhile, the HSE showed a potent protective effect against testicular damage as well as oxidative stress induced by MSG. On the whole, our findings provide evidence that HSE can ameliorate MSG-induced testicular toxicity via induction of cell proliferation along with reduction of oxidative stress and cellular apoptosis in adult rat that attributed to the antioxidant and antiapoptotic effects of its phytochemical constituents.

A Snapshot on Food Allergies: A Case Study on Edible Flowers

This perspective study addresses the main causes of adverse reactions to foods in humans, by taking into account the main allergic reactions that may occur as a result of food ingestion, as well the main allergens present in food and how their allergenicity change as a result of food preparation. In addition, European legislation on food labeling and novel foods was taken into account. The case study of this perspective is on the potential allergenicity of edible flowers as well as evidence of phytochemistry and toxic compounds and the risk associated with their ingestion. Regarding edible flowers, a key issue to address is if they are safe to consume or not. In the framework of the project “Innovative activities for the development of the cross-border supply chain of the edible flower” (ANTEA), we considered 62 different species and varieties of edible flowers. The results obtained by consulting two databases on allergens, COMPRISE and Allergen Nomenclature, marked two alerts for two species of edible flowers selected in the project. Moreover, based on edible flower consumption, about ten grams per serving, and on their protein content, we can also state that the risk of allergic reactions due to edible flower ingestion is very low.

Toxicity assessment of sub-acute and sub-chronic oral administration and diuretic potential of aqueous extract of Hibiscus sabdariffa calyces

Background

Food and herbal usage of Hibiscus sabdariffa (HS) is attaining improved global relevance and acceptance without recourse to its potential toxic effects. This study investigated the safety profile of acute, sub-acute, sub-chronic administrations and diuretic potential of aqueous extract of Hibiscus sabdariffa calyces (AEHSC).

Method

Acute oral toxicity, sub-acute and sub-chronic toxicity as well as diuretic studies were carried out on HS. A total of 20 Wistar rats were used for each toxicity study and assigned into four groups of five rats. The extract was administered as a single daily dose of 125, 250 and 500 mg/kg body weight (bwt) for 28 and 90 days respectively. To evaluate diuretic activity, 25 rats were divided into five groups of five rats and administered normal saline, hydrochlorothiazide 10 mg/kg, AEHSC 67.5, 125 and 250 mg/kg via the oral route. Urine sample was collected after 18 h, volume measured and concentration of electrolytes analyzed. The hematological and biochemical parameters were evaluated as well as the histopathology of kidney and liver.

Results

The acute oral toxicity was found to be >2000 mg/kg. AEHSC did not alter concentration of WBC, MCV, MCHC, lymphocyte as well as total and direct bilirubin in the sub-acute study. However, AEHSC significantly (p < 0.05) increased total protein, albumin, globulin, Na⁺, Cl⁻, HCO₃^- and platelet levels, while levels of uric acid, creatinine, K⁺, RBC, Hb, total cholesterol, triglycerides, LDL-C, HDL-C and atherogenic index were decreased significantly (p < 0.05). In the sub-chronic study, AEHSC significantly (p < 0.05) increased the levels of globulin, urea, creatinine, MCH and atherogenic index. The concentrations of uric acid, WBC, platelets and HDL-C were significantly (p < 0.05) decreased. In both the sub-acute and sub-chronic studies, activities of ALP, ALT, AST, GGT and LDH in selected organs were altered without significant increase (P < 0.05) in activity of these enzymes in the serum. The AEHSC at all the doses showed remarkable diuretic activity during 18 h period comparable to hydrochlorothiazide. The extract also showed a non-dose-dependent increase in excretion of electrolytes. Histological analysis of sections of the liver and kidney for both sub-acute and sub-chronic studies showed normal histology comparable to the control group.

Conclusion

This study revealed AEHSC has some toxic effects in rats on sub-chronic administration. In addition, the extracts produced a significant diuretic activity. Hence, prolonged oral consumption of the extract may not be recommended.

Effects of Hibiscus sabdariffa calyces on spatial memory and hippocampal expression of BDNF in ovariectomized rats

Ovarian hypofunction is characterized by decay in brain-derived neurotrophic factor (BDNF), a neurotrophin associated with cognitive and memory function. Hormone replacement therapy is the most common treatment to counteract the negative effects of ovarian insufficiency; however, this therapy may increase the odds of endometrial cancer, blood clots, stroke, and breast cancer. Therefore, a safer alternative to synthetic estrogens is needed. One possible candidate may be phytoestrogens. Hibiscus sabdariffa L. (Malvaceae) is a source of natural food colorants; the calyces and leaves of the plant are consumed in drinks and culinary preparations and are recognized for several health benefits related to their high content of anthocyanins. In the present study, we used an ovariectomized rat model to assess the phytoestrogenic effect of H. sabdariffa, and evaluated spatial memory and BDNF expression. Ninety-day-old female Wistar rats were randomly separated into six groups. Rats from four groups were ovariectomized and injected with a physiological dose of estradiol, or given, in drinking water, an extract prepared from calyces of H. sabdariffa at doses of 50 or 100 mg/kg body weight. Both Intact and Sham groups were included as controls. At day 42, short- and long-term memories were assessed by the Barnes maze test, and hippocampal BDNF expression was evaluated by RT-qPCR and Western blot. Ovariectomy significantly decreased memory performance and BDNF expression, compared with controls. However, administration of H. sabdariffa extract reversed the negative effect of ovariectomy on short- and long-term memory parameters and BDNF expression. A stronger effect was observed at a lower dose of the extract. In conclusion, the extract from H. sabdariffa acted as a phytoestrogen in ovariectomized rats, improving spatial memory performance and hippocampal BDNF expression. Based on these promising results, further clinical experimentation is recommended to study the benefits of H. sabdariffa as an alternative hormonal therapy in patients with ovarian hypofunction.

Comparison Among Garlic, Berberine, Resveratrol,Hibiscus sabdariffa, GenusZizyphus, Hesperidin, Red Beetroot,Catha edulis,Portulaca oleracea, and Mulberry Leaves in the Treatment of Hypertension and Type 2 DM: A Comprehensive Review

Diabetes mellitus (DM) and hypertension are 2 of the most prevalent diseases with poor impact on health status worldwide. In most cases, they coexist with other metabolic disorders as well as cardiac, micro- and macrovascular complications. Many plants are known for their hypotensive, cardioprotective, and/or antidiabetic activities. Their active ingredients either identified and isolated or still utilized as herbal preparations of certain plant parts. The use of medicinal plants comprises the main basis for most of the traditional medicine (TM) systems and procedures. As conventional medicines seem insufficient to control such progressive diseases, herbal agents from TM could be used as adjuvant with good impact on disease control and progression as well as other concomitant health conditions. The aim of this study is to compare the efficacy of 10 different herbal medicines of botanical origin or herbal preparations in the management of hypertension and its cardiovascular complications and type 2 DM along with various coexisting health disorders. These herbal medicines are garlic, berberine, resveratrol, Hibiscus sabdariffa, Zizyphus ( oxyphylla, mucronate, jujube, rugosa), hesperidin, red beetroot, Catha edulis, mulberry leaves, and Portulaca oleracea.

Organic Acids from Roselle (Hibiscus sabdariffa L.)-A Brief Review of Its Pharmacological Effects

Roselle (Hibiscus sabdariffa L.), also known as jamaica in Spanish, is a perennial plant that grows in tropical and subtropical regions, including China, Egypt, Indonesia, Mexico, Nigeria, Thailand, and Saudi Arabia. It has a long history of uses, mainly focused on culinary, botanical, floral, cosmetic, and medicinal uses. The latter being of great impact due to the diuretic, choleretic, analgesic, antitussive, antihypertensive, antimicrobial, immunomodulatory, hepatoprotective, antioxidant, and anti-cancer effects. These therapeutic properties have been attributed to the bioactive compounds of the plant, mainly phenolic acids, flavonoids, anthocyanins, and organic acids (citric, hydroxycitric, hibiscus, tartaric, malic, and ascorbic). Most literature reviews and meta-analyses on the therapeutic potential of Hibiscus sabdariffa L. (Hs) compounds have not adequately addressed the contributions of its organic acids present in the Hs extracts. This review compiles information from published research (in vitro, in vivo, and clinical studies) on demonstrated pharmacological properties of organic acids found in Hs. The intent is to encourage and aid researchers to expand their studies on the pharmacologic and therapeutic effects of Hs to include assessments of the organic acid components.

Potential Application of Tetrapleura tetraptera and Hibiscus sabdariffa (Malvaceae) in Designing Highly Flavoured and Bioactive Pito with Functional Properties

Sorghum beer (pito) is an indigenous alcoholic beverage peculiar to northern Ghana and parts of other West African countries. It is overwhelmed with calories, essential amino acids (such as lysine, etc.), B-group vitamins, and minerals. In recent years, there has been a growing demand for highly flavoured yet functional pito in Ghana; however, the local producers lack the prerequisite scientific expertise in designing such products. We propose the utilization of Tetrapleura tetraptera (TT) and Hibiscus sabdariffa (HS) as cheap and readily available materials in designing functional flavoured pito. The addition of TT and HS would not alter the fermentation profile but rather augment the starter with nutrients, thus improving the fermentation performance and shelf life of the final pito. In vitro and in vivo studies provide substantive evidence of antioxidant, nephro- and hepato-protective, renal/diuretic effect, anticholesterol, antidiabetic, and antihypertensive effects among others of the TT and HS, hence enriching the pito with health-promoting factors and consequently boosting the health of the consumer. Herein, we summarise the phytochemical, biological, pharmacological, and toxicological aspects of TT and HS as well as the technology involved in brewing the novel bioactive-flavoured pito. In addition, we also report the incidence of heavy metal in conventional pito.

Beneficial Effects of Natural Bioactive Compounds from Hibiscus sabdariffa L. on Obesity

Obesity is a condition associated with the accumulation of excess fat in the body, energy imbalance, lipogenesis, etc., which increases adipose tissue mass through adipogenesis and poses a health risk. Its prevalence has become an economic burden to the health care system and the world at large. One of the alternatives to tackling obesity involves the use of bioactive compounds. We critically examined the effects of Hibiscus sabdariffa extract (HSE) on various parameters associated with the development of obesity such as; the effect of HSE on body weight, the effect of HSE on lipid accumulation, cholesterol metabolism and plasma parameters, the inhibitory effect of HSE on pancreatic lipase, and the effect of HSE on adipocyte differentiation/adipogenesis. This review has gathered reports on the various anti-obesity effects of H. sabdariffa bioactive compounds in cell and animal models, as well as in humans. Available toxicology information on the consumption of H. sabdariffa revealed that its toxicity is dose-dependent and may cause an adverse effect when administered over a long period of time. Reports have shown that H. sabdariffa derived bioactive compounds are potent in the treatment of obesity with an evident reduction in body weight, inhibition of lipid accumulation and suppression of adipogenesis through the PPARγ pathway and other transcriptional factors.

Metabolaid® Combination of Lemon Verbena and Hibiscus Flower Extract Prevents High-Fat Diet-Induced Obesity through AMP-Activated Protein Kinase Activation

Lemon verbena (Lippia citriodora) has been used as a food spice, cosmetic, and in traditional medicine formulations to treat asthma and diabetes in South America and Southern Europe. Hibiscus flower (Hibiscus sabdariffa L.) is used in traditional Chinese medicine in the form of a tea to treat hypertension and inflammation. In the present study, we examined the synergistic effects of a formula of Metabolaid^® (MetA), a combination of lemon verbena and hibiscus-flower extracts, on obesity and its complications in high-fat-diet (HFD)-induced obese mice. The results showed that MetA decreased body weight, white adipose tissue (WAT), and liver weight. Additionally, serum and hepatic lipid profiles, glucose levels, glucose tolerance, and cold-induced thermogenesis were significantly improved. Appetite-regulating hormones adiponectin and leptin were significantly increased and decreased, respectively, while the inflammatory-related factors tumor necrosis factor (TNF)-α and interleukin (IL)-6 were downregulated by MetA. Adipogenesis-activating gene expression was decreased, while increased thermogenesis-inducing genes were upregulated in the WAT, correlating with increased phosphorylation of AMPK and fatty-acid oxidation in the liver. Taken together, these results suggest that MetA decreased obesity and its complications in HFD mice. Therefore, this formula may be a candidate for the prevention and treatment of obesity and its complications.

Regeneration of plantlets through somatic embryogenesis from root derived calli of Hibiscus sabdariffa L. (Roselle) and assessment of genetic stability by flow cytometry and ISSR analysis

Induction of somatic embryogenesis and complete plantlet regeneration from callus culture of Hibiscus sabdariffa L. var. HS4288 has been made. Leaf and root explants were cultured on Murashige and Skoog (MS) and Driver–Kuniyuki Walnut (DKW) basal media supplemented with different concentrations of synthetic auxins and cytokinins. Root explants on DKW medium supplemented with 2.26μM 2, 4-Dichlorophenoxyacetic acid (2, 4-D) and 4.65μM kinetin (KIN) induced highest percentage (70%) of embryogenic calli. Average number of globular embryos per root derived callus produced within 6 weeks of culture initiation on MS media with different plant growth regulators (PGRs) ranged from 2.27±0.12 to 8.80±0.17 and that of cotyledonary embryos ranged from 0.00 to 2.53±0.20. On DKW medium comparatively more globular embryos (2.70±0.15 to 14.53±0.23) and cotyledonary embryos (0.00 to 8.90±0.17) were produced than that of MS medium. Regeneration of complete plantlets was highest (76.67%) when embryogenic calli with mature somatic embryos were grown on DKW medium containing 2.32μM KIN and 2.22μM 6-Benzyladenine (BA). Plants were primarily hardened in humidity, temperature and light controlled chamber and finally in a greenhouse showed 70% survival ability. Different stages of somatic embryogenesis process in the root derived embryogenic calli were elaborated in detail by morphological, histological and SEM study. The data were statistically analyzed by Duncan Multiple range test (p ≤ 0.05) and Principal component analysis (PCA). Flow cytometry and Inter-simple sequence repeats (ISSR) marker analysis confirmed that there was no genetic variation within the regenerated plants.

A review on phytochemistry and therapeutic uses of Hibiscus sabdariffa L

Hibiscus sabdariffa L. (roselle) belonging to the Malvaceae family is widely grown in many countries. This plant is often used in the traditional medicine being rich in phytochemicals like polyphenols especially anthocyanins, polysaccharides and organic acids thus having enormous prospective in modern therapeutic uses. The study aimed to review and document all the available evidence and information about the calyces of Hibiscus sabdariffa (roselle) with the special focus on their nutritional composition, bioactive constituents and therapeutic uses. The electronic database was searched up to 2017, using keywords Hibiscus sabdariffa, chemical constituents of roselle, therapeutic uses of roselle. Journals, books and conference proceedings were also searched. The review provides valuable information about the nutraceutical component of Hibiscus sabdariffa L. and their utilization for curing various degenerative diseases like hypertension, hyperlipidemia, cancer and other inflammatory diseases of liver and kidney. Their toxicological effects have also been discussed from a safety point of view. Most studies supported and provided the scientific basis for the statement that Hibiscus sabdariffa and their active constituents play an important role in the prevention of chronic and degenerative diseases that are associated with oxidative stress. Our study suggests, that good research is needed, to establish a potential strategy that can balance the pharmacological and toxic effects of roselle and standardized fingerprint of Hibiscus sabdariffa is required internationally for quality control.

Antibacterial activities of medicinal plants used in Mexican traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

We provide an extensive summary of the in vitro antibacterial properties of medicinal plants popularly used in Mexico to treat infections, and we discuss the ethnomedical information that has been published for these species.

MATERIALS AND METHODS

We carried out a bibliographic investigation by analyzing local and international peer-reviewed papers selected by consulting internationally accepted scientific databases from 1995 to 2014. We provide specific information about the evaluated plant parts, the type of extracts, the tested bacterial strains, and the inhibitory concentrations for each one of the species. We recorded the ethnomedical information for the active species, as well as their popular names and local distribution. Information about the plant compounds that has been identified is included in the manuscript. This review also incorporates an extensive summary of the available toxicological reports on the recorded species, as well as the worldwide registries of plant patents used for treating bacterial infections. In addition, we provide a list with the top plant species with antibacterial activities in this review RESULTS: We documented the in vitro antibacterial activities of 343 plant species pertaining to 92 botanical families against 72 bacterial species, focusing particularly on Staphylococcus aureus, Mycobacterium tuberculosis, Escherichia coli and Pseudomonas aeruginosa. The plant families Asteraceae, Fabaceae, Lamiaceae and Euphorbiaceae included the largest number of active species. Information related to popular uses reveals that the majority of the plants, in addition to treating infections, are used to treat other conditions. The distribution of Mexican plants extended from those that were reported to grow in just one state to those that grow in all 32 Mexican states. From 75 plant species, 225 compounds were identified. Out of the total plant species, only 140 (40.57%) had at least one report about their toxic effects. From 1994 to July 2014 a total of 11,836 worldwide antibacterial patents prepared from different sources were recorded; only 36 antibacterial patents from plants were registered over the same time period. We offered some insights on the most important findings regarding the antibacterial effects, current state of the art, and research perspectives of top plant species with antibacterial activities in vitro.

CONCLUSIONS

Studies of the antibacterial in vitro activity of medicinal plants popularly used in Mexico to treat infections indicate that both the selection of plant material and the investigation methodologies vary. Standardized experimental procedures as well as in vivo pharmacokinetic studies to document the effectiveness of plant extracts and compounds are necessary. This review presents extensive information about the medicinal plants possessing antibacterial activity that has been scientifically studied and are popularly used in Mexico. We anticipate that this review will be of use for future studies because it constitutes a valuable information tool for selecting the most significant plants and their potential antibacterial properties.

Phytochemical Content, Health Benefits, and Toxicology of Common Edible Flowers: A Review (2000-2015)

Edible flowers contain numerous phytochemicals which contribute to their health benefits, and consumption of edible flowers has increased significantly in recent years. While many researchers have been conducted, no literature review of the health benefits of common edible flowers and their phytochemicals has been compiled. This review aimed to present the findings of research conducted from 2000 to 2015 on the species, traditional application, phytochemicals, health benefits, and the toxicology of common edible flowers. It was found in 15 species of common edible flowers that four flavonols, three flavones, four flavanols, three anthocyanins, three phenolic acids and their derivatives were common phytochemicals and they contributed to the health benefits such as anti-oxidant, anti-inflammatory, anti-cancer, anti-obesity, and neuroprotective effect. Toxicology studies have been conducted to evaluate the safety of common edible flowers and provide information on their dosages and usages.

Antimutagenic Effect of Hibiscus sabdariffa L. Aqueous Extract on Rats Treated with Monosodium Glutamate

Hibiscus sabdariffa L. is a plant of the Malvaceae family, commonly known as roselle. H. sabdariffa is known to contain antioxidant, cholesterol-lowering, antiobesity, insulin resistance reduction, antihypertensive, and skin cancer chemopreventive properties. This study evaluated the effects of H. sabdariffa aqueous extract against cyclophosphamide (CPA, 25 mg/Kg) induced damage to DNA in male Wistar rats by micronucleus test. Samples of H. sabdariffa calyx were obtained in the municipality of Barra do Garças, Mato Grosso, Brazil. The aqueous extract was prepared by infusion and each animal received a daily dose of 400 mg/Kg by gavage for 15 consecutive days of treatment. The presence of anthocyanins was confirmed by ferric chloride test and phenolic compounds using high-performance liquid chromatography, with emphasis on the identification of rutin. The animals were sacrificed by deepening of anaesthesia to obtain bone marrow and determination of the frequency of micronucleated polychromatic erythrocytes. The group treated with the aqueous extract of H. sabdariffa revealed a 91% reduction in micronucleus frequency when compared with the positive control group. Under the conditions tested, H. sabdariffa L. presented a protective effect to CPA-induced damage to DNA of the treated animals, and it is a potential candidate as a chemopreventive agent against carcinogenesis.

Antioxidant activity and protective effects of cocoa and kola nut mistletoe ( Globimetula cupulata ) against ischemia/reperfusion injury in Langendorff-perfused rat hearts

Protection against cardiomyocyte damage following ischemia/reperfusion (I/R) injury is highly desirable in patients with ischemic heart disease. Hydromethanol extracts of Globimetula cupulata (mistletoe) growing on cocoa (CGCE) and kola nut (KGCE) trees were assessed for antioxidant content and cardioprotective potential against I/R. Graded concentrations (1–50 μg/mL) of CGCE or KGCE were tested on Langendorff-perfused rat hearts to evaluate the effects on the flow rate, heart rate, and force of cardiac contraction, while another set of hearts were subjected to biochemical analyses. Both extracts showed good antioxidant content and activity, but KGCE (EC₅₀: 24.8±1.8 μg/mL) showed higher hydroxyl radical scavenging activity than CGCE (70.2±4.5 μg/mL). Both extracts at 3 μg/mL reversed (p < 0.001) membrane peroxidation and the significant decrease in nitrite level, coronary flow rate, and superoxide dismutase and catalase activity caused by the I/R cycle. It is concluded that G. cupulata protects against ischemia–reperfusion injury in rat hearts via augmenting endogenous antioxidants and significant restoration of altered hemodynamic parameters.

Safety assessment of Hibiscus sabdariffa after maternal exposure on male reproductive parameters in rats

CONTEXT

Hibiscus sabdariffa L. (Malvaceae) is a species widely used in folk medicine for the treatment of some disorders.

OBJECTIVE

This study evaluated the effects of H. sabdariffa (HS) on the development of the male reproductive tract in rats following in utero exposure.

MATERIALS AND METHODS

Pregnant rats received 250 or 500 mg/kg of HS extract or vehicle from gestational day 12 until day 21 of lactation.

RESULTS AND DISCUSSION

Both doses of HS increased the body weight of male offspring at weaning, without compromising the puberty onset parameters. At puberty, there was a significant increase in the vas deferens absolute weight and a significant reduction in the relative weight of kidney at higher dose. These animals also presented a significant reduction in the sperm number in the caput/corpus of epididymis after exposure to both doses and a reduction in the sperm number in the cauda epididymis for the lower dose. At adulthood, the highest dose significantly reduced the sperm production in relation to controls and both doses provoked a reduction in the relative sperm number in the epididymis without affecting the sperm morphology.

CONCLUSION

These findings demonstrated that maternal exposure to H. sabdariffa can adversely influence the male reproductive system in rats.

Parkia biglobosa improves mitochondrial functioning and protects against neurotoxic agents in rat brain hippocampal slices

OBJECTIVE

Methanolic leaf extracts of Parkia biglobosa, PBE, and one of its major polyphenolic constituents, catechin, were investigated for their protective effects against neurotoxicity induced by different agents on rat brain hippocampal slices and isolated mitochondria.

METHODS

Hippocampal slices were preincubated with PBE (25, 50, 100, or 200 µg/mL) or catechin (1, 5, or 10 µg/mL) for 30 min followed by further incubation with 300 µM H2O2, 300 µM SNP, or 200 µM PbCl2 for 1 h. Effects of PBE and catechin on SNP- or CaCl2-induced brain mitochondrial ROS formation and mitochondrial membrane potential (ΔΨm) were also determined.

RESULTS

PBE and catechin decreased basal ROS generation in slices and blunted the prooxidant effects of neurotoxicants on membrane lipid peroxidation and nonprotein thiol contents. PBE rescued hippocampal cellular viability from SNP damage and caused a significant boost in hippocampus Na(+), K(+)-ATPase activity but with no effect on the acetylcholinesterase activity. Both PBE and catechin also mitigated SNP- or CaCl2-dependent mitochondrial ROS generation. Measurement by safranine fluorescence however showed that the mild depolarization of the ΔΨm by PBE was independent of catechin.

CONCLUSION

The results suggest that the neuroprotective effect of PBE is dependent on its constituent antioxidants and mild mitochondrial depolarization propensity.

Toxicity studies of the water extract from the calyces of Hibiscus sabdariffa L. in rats

Acute and chronic toxicities of the water extract from calyces of Hibiscus sabdariffa were studied in male and female rats. After 14 days of a single oral administration of test substance 5,000 mg/kg body weight, measurement of the body and organ weights, necropsy and health monitoring were performed. No signs and differences of the weights or behaviour compared to the control rats were observed. The results indicated that the single oral administration of H. sabdariffa extract in the amount of 5,000 mg/kg body weight does not produce acute toxicity. The chronic toxicity was determined by oral feeding both male and female rats daily with the extract at the doses of 50, 100, and 200 mg/kg body weight for 270 days. The examinations of signs, animal behaviour and health monitoring showed no defects in the test groups compared to the control groups. Both test and control groups (day 270th) and satellite group (day 298th) were analysed by measuring their final body and organ weights, taking necropsy, and examining haematology, blood clinical chemistry, and microanatomy. Results showed no differences from the control groups. Overall, our study demonstrated that an oral administration of H. sabdariffa extract at the doses of 50, 100 and 200 mg/kg body weight for 270 days does not cause chronic toxicity in rat.

Effect of extract of Hibiscus on the ultrastructure of the testis in adult mice

Hibiscus sabdariffa extract is a popular beverage in many tropical and sub-tropical countries. Although, Hibiscus tea is known for its medicinal effects for thousands of years, scientific evidence of its systemic safety is very limited. The current study aimed to assess the potential adverse effects of H. sabdariffa extract on sperm morphology and testicular ultrastructure of albino mice. Thirty adult male albino mice were divided into three equal groups and were given: (a) distilled water, (b) cold Hibiscus aqueous extract, and (c) boiled Hibiscus aqueous extract. Hibiscus extract was administered orally daily for 4 weeks in a dose of 200 mg/kg body weight/mouse. Twenty-four hours after the last treatment, mice were decapitated and the testes and epididymides were excised and processed for transmission electron microscopy to assess ultrastructural and sperm abnormalities. The results clearly demonstrate that aqueous extracts from dried calyx of H. sabdariffa, either cold or boiled, alter normal sperm morphology and testicular ultrastructure and adversely influence the male reproductive fertility in albino mice. The current data suggest that Hibiscus extract should be consumed with caution, and reasonable estimates of the human risk associated with its consumption should be provided.

Determination of antimicrobial activity of sorrel (Hibiscus sabdariffa) on Escherichia coli O157:H7 isolated from food, veterinary, and clinical samples

The use of medicinal plants as natural antimicrobial agents is gaining popularity. Sorrel (Hibiscus sabdariffa) is widely used for the treatment of diseases. The objective of this study was to investigate the antimicrobial activity of sorrel on Escherichia coli O157:H7 isolates from food, veterinary, and clinical samples. Phenolics of the calyces were extracted from 10 g of ground, freeze-dried samples using 100 mL of 80% aqueous methanol. Concentrations of 10%, 5%, and 2.5% methanol extract of sorrel were investigated for its antimicrobial activity. Inhibition zones were indicated by a lack of microbial growth due to inhibitory concentrations of sorrel diffused into semisolid culture medium beneath the sorrel-impregnated disk. The results of this experiment showed that the most potent sorrel concentration was 10%, then 5%, and finally 2.5%. The overall mean zone of inhibition for the sorrel extract was 12.66 mm for 10%, 10.75 mm for 5%, and 8.9 mm for 2.5%. The highest inhibition zones (11.16 mm) were observed in veterinary samples, and the lowest (10.57 mm) in the food samples. There were significant (P<.05) differences among mean zones of inhibition found in the food, veterinary, and clinical sources. Based on the source of samples and concentration of sorrel extract, the lowest mean inhibition was 7.00±0.04 mm from clinical samples, and the highest was 15.37±0.61 mm from a food source. These findings indicated that sorrel was effective at all levels in inhibiting E. coli O157:H7; thus it possesses antimicrobial activity and hold great promise as an antimicrobial agent.

The effect of hibiscus sabdariffa on lipid profile, creatinine, and serum electrolytes: a randomized clinical trial

Background. Hibiscus Sabdariffa L. (HS), a member of malvaceae family, is a medicinal plant with a worldwide fame. Its effect on reducing serum lipids is mentioned in several studies. The purpose of this study was to assess the efficacy of this plant in reducing the serum's lipids in hypertensive patients. Materials and Methods. Ninety hypertensive patients were randomly assigned to receive Hibiscus Sabdariffa (HS) tea or black tea for 15 days. The patients were asked to drink the tea within 20 minutes following its preparation. This process had to be repeated two times, daily. Patient's FBS and lipid profile were collected at the first visit day (day 0) and on the day 30. Results. There was no significant differences between pre and post experiment values within the two groups. An upward trend in total cholesterol, HDL, and LDL cholesterol was evident in both groups. The increase in total and HDL cholesterol in both groups relative to their initial values were significant. Conclusion. Hibiscus Sabdariffa is probably a safe medicinal plant. No significant harmful changes in cholesterol, triglyceride, BUN, serum creatinine, Na and K levels were observed within 15 days after the discontinuation of the medication.

Effects of Hibiscus sabdariffa extract powder and preventive treatment (diet) on the lipid profiles of patients with metabolic syndrome (MeSy)

Insulin resistance, obesity, hypertension, and dyslipidemia are strongly associated with metabolic syndrome (MeSy), which is considered to be a reversible clinical stage before its evolution to coronary heart disease and diabetes. Currently, the antihypertensive and hypolipidemic properties of aqueous Hibiscus sabdariffa extracts (HSE) have been demonstrated in clinical trials and in vivo experiments. The aim of the present study was to evaluate the effects of a Hibiscus sabdariffa extract powder (HSEP) and a recognized preventive treatment (diet) on the lipid profiles of individuals with and without MeSy according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria. The protocol was a follow-up study carried out in a factorial, randomized design (T1=preventive treatment comprises Diet, T2=HSEP, T3=HSEP+preventive treatment (Diet) X MeSy, non-MeSy individuals). A total daily dose of 100 mg HSEP was orally administered in capsules for one month. The preventive treatment (diet) was selected according to NCEP-ATP III recommendations and adjusted individually. Total cholesterol, LDL-c, HDL-c, VLDL-c, triglycerides, glucose, urea, creatinine, AST, and ALT levels in the blood were determined in all individuals pre- and post-treatment. The MeSy patients treated with HSEP had significantly reduced glucose and total cholesterol levels, increased HDL-c levels, and an improved TAG/HDL-c ratio, a marker of insulin resistance (t-test p<0.05). Additionally, a triglyceride-lowering effect was observed in MeSy patients treated with HSEP plus diet, and in individuals without MeSy treated with HSEP. Significant differences in total cholesterol, HDL-c, and the TAG/HDL-c ratio were found when the means of absolute differences among treatments were compared (ANOVA p<0.02). Therefore, in addition to the well documented hypotensive effects of Hibiscus sabdariffa, we suggest the use of HSEP in individuals with dyslipidemia associated with MeSy.

Effect of the temperature on the spray drying of Roselle extracts (Hibiscus sabdariffa L.)

The effect of the drying temperature on the volatile components and sensory acceptance of the Roselle (Hibiscus sabdariffa) extract in powder was investigated. The Roselle extraction was carried out by maceration with 7 L of 30% ethanol (v/v), 560 g of fresh Roselle calyces for 168 h. The Roselle extracts were spray dried at different temperatures 150, 160, 170, 180, 190, 200 and 210 degrees C, giving different outlet values about yield and final moisture. The volatile compounds in Roselle extract and dried samples were performed using needles of solid phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS HP-5890). Twenty volatile compounds were identified in the extracts among them terpenoids, esters, hydrocarbons and aldehydes. Fourteen volatile compounds were identified in the powder sample, but only ten were present in the Roselle extract. This indicates that some compounds were lost and some others were generated due to a degradation process. An acceptability sensory analysis showed that the best powder sample was the Roselle extract dehydrated using temperature between 190 degrees C and 200 degrees C (p<0.05). There was not statistically significant difference in the pH of Roselle extracts ranging from 3.4 to 3.9. It was concluded that the spray drying temperature of the Roselle extracts has an effect on the volatile compounds losses.

Effect of Hibiscus sabdariffa on obesity in MSG mice

The aim of the present investigation was determine whether a standardized Hibiscus sabdariffa calyces aqueous extract has an effect on body weight in an obese animal model induced by the administration of monosodium glutamate. Hibiscus sabdariffa aqueous extract, containing 33.64 mg of total anthocyanins per each 120 mg of extract, was orally administered (120 mg/kg/day) for 60 days to healthy and obese mice, and body weight gain, food and liquid intake, aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, and triglycerides levels were measured. Hibiscus sabdariffa administration significantly reduced body weight gain in obese mice and increased liquid intake in healthy and obese mice. ALT levels were significantly increased on the 15th and 45th days in obese mice, but AST levels did not show significant changes. Mortality was not observed in the Hibiscus sabdariffa treated groups. Triglycerides and cholesterol levels showed non-significant reductions in animals treated with Hibiscus sabdariffa. Our data confirm the anti-obesity effect of Hibiscus sabdariffa reported by the Mexican population.

Plants popularly used for loosing weight purposes in Porto Alegre, South Brazil

In this study, 14 herbalists (herb sellers) were interviewed about popular use of plants with weight loss purpose in Porto Alegre, a South Brazil city. For all identified species, scientific data were reviewed aiming to establish a correlation between popular use and biological properties. Seventy-eight samples were reported as having weigh loss properties. These samples come from 23 species and Asteraceae encompasses the greatest number of representatives. The greatest number of herbalist's citations was Baccharis articulata. The majority of plants have traditional use in Brazil but none is explicitly cited for loosing weight purposes. The pharmacological data are mainly from animal and in vitro studies and do not straight related to obesity. Only Ilex paraguariensis presents clinical data of efficacy in the treatment of obesity. Seven species present pre-clinical data that indicate a potential role in the control of certain conditions which are associated with obesity, such as hyperlipidemia (Campomanesia xanthocarpa, Cuphea carthagenensis, Cynara scolymus, Hibiscus sabdariffa, Ilex paraguariensis) and high levels of blood glucose (Achyrocline satureioides, Baccharis trimera, Campomanesia xanthocarpa). In conclusion, scientific data found are insufficient to guarantee the efficacy and safety of these plants for treating obesity. However, some of them present activities which could be useful to treat certain obesity comorbidities and deserve further studies.

Ethnomedicines used in Trinidad and Tobago for urinary problems and diabetes mellitus

BACKGROUND

This paper is based on ethnobotanical interviews conducted from 1996-2000 in Trinidad and Tobago with thirty male and female respondents.

METHODS

A non-experimental validation was conducted on the plants used for urinary problems and diabetes mellitus: This is a preliminary step to establish that the plants used are safe or effective, to help direct clinical trials, and to inform Caribbean physicians of the plants' known properties to avoid counter-prescribing.

RESULTS

The following plants are used to treat diabetes: Antigonon leptopus, Bidens alba, Bidens pilosa, Bixa orellana, Bontia daphnoides, Carica papaya, Catharanthus roseus, Cocos nucifera, Gomphrena globosa, Laportea aestuans, Momordica charantia, Morus alba, Phyllanthus urinaria and Spiranthes acaulis. Apium graviolens is used as a heart tonic and for low blood pressure. Bixa orellana, Bontia daphnoides, Cuscuta americana and Gomphrena globosa are used for jaundice. The following plants are used for hypertension: Aloe vera, Annona muricata, Artocarpus altilis, Bixa orellana, Bidens alba, Bidens pilosa, Bonta daphnoides, Carica papaya, Cecropia peltata, Citrus paradisi, Cola nitida, Crescentia cujete, Gomphrena globosa, Hibiscus sabdariffa, Kalanchoe pinnata, Morus alba, Nopalea cochinellifera, Ocimum campechianum, Passiflora quadrangularis, Persea americana and Tamarindus indicus. The plants used for kidney problems are Theobroma cacao, Chamaesyce hirta, Flemingia strobilifera, Peperomia rotundifolia, Petiveria alliacea, Nopalea cochinellifera, Apium graveolens, Cynodon dactylon, Eleusine indica, Gomphrena globosa, Pityrogramma calomelanos and Vetiveria zizanioides. Plants are also used for gall stones and for cooling.

CONCLUSION

Chamaesyce hirta, Cissus verticillata, Kalanchoe pinnata, Peperomia spp., Portulaca oleraceae, Scoparia dulcis, and Zea mays have sufficient evidence to support their traditional use for urinary problems, "cooling" and high cholesterol. Eggplant extract as a hypocholesterolemic agent has some support but needs more study. The plants used for hypertension, jaundice and diabetes that may be safe and justify more formal evaluation are Annona squamosa, Aloe vera, Apium graveolens, Bidens alba, Carica papaya, Catharanthus roseus, Cecropia peltata, Citrus paradisi, Hibsicus sabdariffa, Momordica charantia, Morus alba, Persea americana, Phyllanthus urinaria, Tamarindus indicus and Tournefortia hirsutissima. Several of the plants are used for more than one condition and further trials should take this into account.

Determination of some toxic and essential metal ions in medicinal and edible plants from Mali

Plants are used in different ways in Mali, among those as medicine and as food. The monitoring of metals in the plants is of great importance for protecting the public from the hazards of possible toxic effects and also for informing the population about the nutritional value of the plants. The concentrations of some toxic and essential metal ions were surveyed in seven medicinal and edible plants from Mali. Dry ashing of the plant material and subsequent use of atomic absorption spectrophotometry were the analytical methodologies used. Iron, manganese, and zinc were found in high concentrations in some of the plants, i.e., 1.4 and 1.5 mg/g iron in Cuminum cyminum and Bombax costatum, respectively, 243 microg/g manganese in Hibiscus sabdariffa, and 62.8 and 67.1 microg/g zinc in Spilanthes oleracaea and B. costatum, respectively, whereas cobalt and cadmium were not detected in any of the plant material studied. The other ions detected, Cr, Ni, Pb, and Cu, were present in minor amounts, in the ranges of 2.2-17.2 microg/g for Cr, 1.6-8.1 microg/g for Ni, 0.7-5.2 microg/g for Pb, and 2.4-17.1 microg/g for Cu. From a toxicological point of view, none of these plants would be harmful for the user by taking in the plant material in the traditional manner, which is preparing an infusion of the plant using amounts not adding up to those necessary to reach a harmful level of the metal ions detected. The plants B. costatum and C. cyminum could be of interest as sources for iron for humans in the case of too low of a level of hemoglobin.

Phytochemical, pharmacological and toxicological aspects ofHibiscus sabdariffa L.: a review

This article reviews the reported phytochemical, pharmacological and toxicological properties of Hibiscus sabdariffa L. (English: roselle, red sorrel; Arabic: karkade), the calyces of which are used in many parts of the world to make cold and hot drinks. Nutritionally, these contain ascorbic acid (vitamin C). In folk medicine, the calyx extracts are used for the treatment of several complaints, including high blood pressure, liver diseases and fever. The pharmacological actions of the calyx extracts include strong in vitro and in vivo antioxidant activity. In rats and rabbits, the extract showed antihypercholesterolaemic, antinociceptive and antipyretic, but not antiinflammatory activities. In rat and man a strong antihypertensive action has been demonstrated. The effects of the calyx extracts on smooth muscles in vitro are variable, but they mostly inhibit the tone of the isolated muscles. In healthy men, consumption of H. sabdariffa has resulted in significant decreases in the urinary concentrations of creatinine, uric acid, citrate, tartrate, calcium, sodium, potassium and phosphate, but not oxalate. Oil extracted from the plant's seeds has been shown to have an inhibitory effect on some bacteria and fungi in vitro. The plant extracts are characterized by a very low degree of toxicity. The LD50 of H. sabdariffa calyx extract in rats was found to be above 5000 mg/kg. A single report has suggested that excessive doses for relatively long periods could have a deleterious effect on the testes of rats. In view of its reported nutritional and pharmacological properties and relative safety, H. sabdariffa and compounds isolated from it (for example, anthocyanins and Hibiscus protocatechuic acid) could be a source of therapeutically useful products.