Effect of Bridelia ferruginea Benth (Euphorbiaceae) ethyl acetate and acetone fractions on insulin resistance in fructose drinking mice

Bridelia ferruginea inhibits key carbohydrate digesting enzyme and intestinal glucose absorption and modulates glucose metabolism in diabetic rats

The antidiabetic potentials of the dichloromethene, ethyl acetate, butanol and aqueous fractions of Bridelia ferruginea leaves were investigated using in vitro, ex vivo and in vivo models. In vitro and ex vivo antidiabetic activities revealed the butanol (BFBF) to be the most active of the fractions, and thus selected for in vivo study. Diabetes was induced using the fructose-streptozotocin model. Treatments with BFBF significantly reduced blood glucose level and improved glucose tolerance, serum insulin level and sensitivity as well as suppressed hyperlipidaemia and serum nephropathy markers. Histopathological analysis revealed the ability of BFBF to protect and regenerate pancreatic β-cells. BFBF significantly elevated glutathione level, catalase and superoxide dismutase activities, while depleting MDA level in serums and kidney of diabetic rats. Phenols, steroids, terpenoids, aliphatic and aromatic compounds were identified in the fractions following GC-MS analysis. Overall, results from this study propose that BFBF possess potent antidiabetic activity.

Antidiabetic activity of aqueous stem bark extract of Annickia polycarpa in alloxan-induced diabetic mice

Background and aim

There is a growing need to develop new drugs for type II diabetes mellitus (DM) from plant sources due to the high cost and adverse side effects of current drug therapies. To this end, the antidiabetic activity of aqueous stem-bark extract of A. polycarpa (APE) in alloxan-induced diabetic ICR mice was investigated.

Experimental procedure

The effect of APE (20, 100 and 500 mg/kg), glibenclamide and metformin as positive controls, were determined over 4 weeks on fasting blood glucose (FBG). An oral glucose tolerance test (OGTT) was also conducted. The effects of these treatments on the morphology of the pancreas were assessed. In addition, phytochemical constituents and antioxidant properties of APE were determined.

Results and conclusion

APE, like glibenclamide and metformin, showed significant hypoglycaemic effect. The OGTT supported the hypoglycaemic effect. The destroyed pancreatic beta-cells in diabetic control mice were restored to normal by APE or drug treatment. APE showed antioxidant activity by scavenging DPPH free radicals; this may be due to the presence of phenolic compounds, particularly flavonoids. Thus, APE may act by restoring pancreatic beta-cell integrity through mopping of reactive oxygen species (ROS) associated with the diabetic state, and thereby improving pancreatic function and consequently, the lowering of FBG levels. These findings provide ample evidence to validate the traditional use of A. polycarpa in the management of DM.

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Aqueous stem bark extract of A. polycarpa (APE) possesses significant antidiabetic activity.

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APE has the ability to cause the regeneration of beta cells of the pancreas.

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APE’s possess antioxidant activity and may scavenge ROS, thus help in overcoming advanced complications of DM.

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Alkaloids and phenolics (flavonoids) detected may be responsible for the hypoglycaemic and antioxidant activity of APE.

In vitro effects of tannin and extracts of Bridelia ferruginea and Mitragyna inermis on the exsheathment of infective larvae of Haemonchuscontortus

Bridelia ferruginea (Euphorbiaceae) and Mitragyna inermis (Rubiaceae) are two plants of the beninese pharmacopeia used in vivo for the control of gastrointestinal nematodes (GINs) in small ruminants. The objective of the present study is to explore the mechanism of bioactive compounds involved in the action of these two plants on the third-stage infective larvae (L3s) of Haemonchus contortus. Thus, sheathed L3s of H. contortus were incubated with acetone extracts of B. ferruginea and M. inermis at concentrations of 0, 150, 300, 600 and 1200 µg/mL for 3 h at 25°C. The L3s were then washed and artificially submitted to exsheathment in the presence of sodium hypochlorite solution. The role of tannins was verified by adding a tannin inhibitor, polyvinyl polypyrrolidone (PVPP), to the acetone extracts of these two plants for 2 h at 25°C. Acetone extracts from B. ferruginea and M. inermis inhibited the exsheathment of H. contortus larvae (p < 0.001) and this inhibitory effect was dose-dependent for M. inermis at the concentrations tested. Treatment of B. ferruginea and M. inermis extracts with PVPP was associated with a partial restoration of the exsheathment kinetics of H. contortus larvae (p < 0.001), confirming the predominant role of tannins but also the residual role of other secondary metabolites. These in vitro results suggest that these plants are endowed with anthelmintic (AHs) properties and therefore likely to be used as alternatives to synthetic molecules.

Dietary fructose as a risk factor for non-alcoholic fatty liver disease (NAFLD)

Glucose is a major energy source for the entire body, while fructose metabolism occurs mainly in the liver. Fructose consumption has increased over the last decade globally and is suspected to contribute to the increased incidence of non-alcoholic fatty liver disease (NAFLD). NAFLD is a manifestation of metabolic syndrome affecting about one-third of the population worldwide and has progressive pathological potential for liver cirrhosis and cancer through non-alcoholic steatohepatitis (NASH). Here we have reviewed the possible contribution of fructose to the pathophysiology of NAFLD. We critically summarize the current findings about several regulators, and their potential mechanisms, that have been studied in humans and animal models in response to fructose exposure. A novel hypothesis on fructose-dependent perturbation of liver regeneration and metabolism is advanced. Fructose intake could affect inflammatory and metabolic processes, liver function, gut microbiota, and portal endotoxin influx. The role of the brain in controlling fructose ingestion and the subsequent development of NAFLD is highlighted. Although the importance for fructose (over)consumption for NAFLD in humans is still debated and comprehensive intervention studies are invited, understanding of how fructose intake can favor these pathological processes is crucial for the development of appropriate noninvasive diagnostic and therapeutic approaches to detect and treat these metabolic effects. Still, lifestyle modification, to lessen the consumption of fructose-containing products, and physical exercise are major measures against NAFLD. Finally, promising drugs against fructose-induced insulin resistance and hepatic dysfunction that are emerging from studies in rodents are reviewed, but need further validation in human patients.

An ethnobotanical survey of antidiabetic plants used by Hausa-Fulani tribes in Sokoto, Northwest Nigeria

ETHNOPHARMACOLOGICAL RELEVANCE

Sokoto is known for its diverse traditional medicinal wealth and international market of traditional medicines in Africa. However, information of the folk knowledge, especially for the treatment of diabetes, is not documented.

AIM OF THE STUDY

This survey identified and documented the information on traditional medicinal plants used by Hausa-Fulani community of Sokoto for the treatment of diabetes.

MATERIALS AND METHOD

Demographic data and information about the medicinal plants were collected via administration of semi-structured oral questionnaires. Willing herbal medical practitioners/traditional healers were interviewed. The medicinal plants mentioned by herbalists were collected and authenticated by a taxonomist and the voucher specimens were preserved.

RESULTS

Fifty one informants across the state divulged information on traditional medicinal plants and practices used in diabetes and revealed 54 species, belonging to 33 families, with Cassia sieberiana being cited the most (19 times) and ranked first (39%). Azadirachta indica, Ficus exasperata and Schwenckia americana ranked second (15%), each cited 8 times.

CONCLUSION

The survey documented the rich wealth of knowledge and usage of plants for the treatment of diabetes in Sokoto. The paper will not only serve as a source of information but will also help to make the knowledge accessible for further drug screening and development, and at the same time underlines the need for biodiversity conservation of this traditional wealth.