An overview of anti-diabetic plants used in Gabon: Pharmacology and Toxicology

© 2017 Elsevier B.V. All rights reserved.Ethnopharmacological relevance: The management of diabetes mellitus management in African communities, especially in Gabon, is not well established as more than 60% of population rely on traditional treatments as primary healthcare. The aim of this review was to collect and present the scientific evidence for the use of medicinal plants that are in currect by Gabonese traditional healers to manage diabetes or hyperglycaemia based here on the pharmacological and toxicological profiles of plants with anti-diabetic activity. There are presented in order to promote their therapeutic value, ensure a safer use by population and provide some bases for further study on high potential plants reviewed. Materials and methods: Ethnobotanical studies were sourced using databases such as Online Wiley library, Pubmed, Google Scholar, PROTA, books and unpublished data including Ph.D. and Master thesis, African and Asian journals. Keywords including ‘Diabetes’ ‘Gabon’ ‘Toxicity’ ‘Constituents’ ‘hyperglycaemia’ were used. Results: A total of 69 plants currently used in Gabon with potential anti-diabetic activity have been identified in the literature, all of which have been used in in vivo or in vitro studies. Most of the plants have been studied in human or animal models for their ability to reduce blood glucose, stimulate insulin secretion or inhibit carbohydrates enzymes. Active substances have been identified in 12 out of 69 plants outlined in this review, these include Allium cepa and Tabernanthe iboga. Only eight plants have their active substances tested for anti-diabetic activity and are suitables for further investigation. Toxicological data is scarce and is dose-related to the functional parameters of major organs such as kidney and liver. Conclusion: An in-depth understanding on the pharmacology and toxicology of Gabonese anti-diabetic plants is lacking yet there is a great scope for new treatments. With further research, the use of Gabonese anti-diabetic plants is important to ensure the safety of the diabetic patients in Gabon.Peer reviewedFinal Accepted Versio

Effects of Melissa officinalis L. extract on the skin tissues of hyperlipidemic rats

In this study, the effects of Melissa officinalis L. on hyperlipidemic rats were investigated biochemically. The animals were fed a lipogenic diet consisting of 2 % cholesterol, 20 % sunflower oil and 0.5 % cholic acid added to normal chow and were given 3 % ethanol for 42 d. The extract was given gavage technique to rats a dose of 2 g/kg everyday for 28 d, after 14 d, experimental animals done hyperlipidemia. In hyperlipidemic groups, a reduction of the skin glutathione level (GSH), skin superoxide dismutase (SOD) activity and serum catalase (CAT), paraoxonase (PON) activity and an increase in serum cholesterol, total lipid, triglycerides and uric acid, gamma-glutamyl transferase activity (GGT) and skin cholesterol, total lipid, lipid peroxidation (LPO), nonenzymatic glycosylation (NEG) and skin CAT, lactate dehydrogenase (LDH), glutathione peroxidase (GP,) and myeloperoxidase (MPO) activity were observed. Treatment with Melissa officinalis L. extract reversed these effects. Present results show that Melissa officinalis L. extract has a protective effect against skin tissue damage as result of hyperlipidemia, in addition to hypolipidemic effect

Effect of glurenorm on immunohistochemical changes in pancreatic β cells of rats in experimental diabetes

268-271Immunohistochemical localization of islets of Langerhans of streptozotocin (65 mg/kg, ip) induced diabetic + glurenorm (10 mg/kg, po) treated female albino rats revealed increase in number of β cells and insulin immunoreactivity of β cells. The results suggest that glurenorm can cause the stimulation of β cells of endocrine pancreas in diabetic rats

Protective effects of glurenorm (gliquidone) treatment on the liver injury of experimental diabetes

Oxidative stress plays an important role in chronic complications of diabetes mellitus, and hence the regulation of free radicals is essential in the treatment of diabetes. The aim of the current study is to investigate the effect of glurenorm (10 mg/kg) on liver tissue in experimental diabetes. Diabetes was induced by intraperitoneal injection of 65 mg/kg streptozotocin. Glurenorm was administered to one diabetic and one control group separately, from days 14 to 42. On day 42, cardiac blood samples and liver tissue were taken from each rat. In diabetic rats, blood glucose, serum alkaline phosphatase and serum amino transferase activities, serum uric acid, serum sodium and potassium levels, liver nonenzymatic glycosylation, and lipid peroxidation increased, whereas body weight and liver glutathione levels decreased. The diabetic group given glurenorm blood glucose, serum alkaline phosphatase and aminotransferase activities, serum uric acid, sodium and potassium, liver nonenzymatic glycosylation, and lipid peroxidation levels decreased, and liver glutathione levels increased. As a result of all the biochemical findings obtained, it was concluded that glurenorm has a protective effect on damage of liver of streptozotocin-induced diabetes in rats

Effects of parsley (Petroselinum crispum) extract and glibornuride on the kidney of streptozotocin-induced diabetic rats

The purpose of this study was to investigate the effect of parsley (Petroselinum crispum) extract and compare the effects with a hypoglycemic agent glibornuride on the kidney as histological and biochemical in normal and streptozotocin-induced diabetic rats. The parsley extract was administered by gavage technique to rats a dose of 2 g/kg daily for 28 d; 14 d after experimental animals were made diabetic. 5 mg/kg glibornuride were given by same method, 14 d after the experimental animals were made diabetic, to one of the diabetic group and also one of the control group, daily for 28 d. The kidney tissues were examined histologically, blood glucose, serum urea and creatinine levels were determined, spectrophotometrically. The distinct degenerative changes were observed in the kidney tissue of streptozotocin-induced rats. On the other hand, the injury to kidney tissue was minimal or absent in diabetic group given parsley extract. The damage of kidney tissue was minimal in streptozotocin-induced group given glibornuride. Blood glucose, serum urea and creatinine levels significantly increased in diabetic groups. Administration of parsley extracts and glibornuride significantly reduced blood glucose, serum urea and creatinine levels in diabetic groups. According to these results, it is concluded that parsley extract is more effective in comparison to glibornuride in the protection of kidney tissue from the damage of streptozotocin-induced diabetic rats

Combined effects of vitamin C, vitamin E, and sodium selenate supplementation on absolute ethanol-induced injury in various organs of rats

In this study, the effect of combination of vitamin C (ascorbic acid), vitamin E (alpha-tocopherol), and selenium (sodium selenate) on ethanol-induced liver and intestine injury in rats was investigated. The ethanol-induced injury was produced by the administration of 1 ml of absolute ethanol to each rats. Animals received vitamin C (250 mg/ kg), vitamin E (250 mg/ kg), and sodium selenate (Se) (0.5 mg/ kg) for 3 days; 1 h after the final antioxidant administration, they were sacrificed. Lipid peroxidation and glutathione levels, catalase (CAT), lactate dehydrogenase (LDH), superoxide dismutase (SOD), and glutathione peroxidase (GP(x)) activities were determined in liver and intestine tissues. Myeloperoxidase (MPO), aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP),gamma-glutamyltransferase (GGT) were determined in liver tissue. Also, CAT activity, urea, creatinine, uric acid, and total lipid levels were determined in serum samples. In the ethanol group, serum urea, creatinine, uric acid, and total lipid levels; liver and intestine LDH; liver MPO, AST, ALP, ALT, and GGT activities; and liver and intestine LPO levels increased, whereas serum CAT activity, liver and intestine GSH levels, and CAT, SOD, and GPx activities decreased. On the other hand, treatment with vitamin C, vitamin E, and Se reversed these effects. As a result of these findings, we can say that the combination of vitamin C, vitamin E, and selenium has a protective effect on ethanol-induced changes in lipid peroxidation, glutathione levels, and antioxidant enzyme activities in liver and intestine tissues, and in some serum parameters of rats

The morphological and biochemical effects of glibornuride on rat liver in experimental diabetes

Glibornuride is a sulphonylurea derivative used as an oral hypoglycaemic drug in diabetics. The aim of this study was to examine the histological, ultrastructural and biochemical effects of glibornuride in streptozotocin (STZ)-treated rats. The animals were rendered diabetic by intraperitoneal injection of 65 mg/kg STZ. Fourteen days later, glibornuride was given at 5 mg/kg by gavage, daily for 28 days, to one STZ-diabetic and one control group. In the STZ-diabetic group, remarkable degenerative changes were observed. On the other hand, in the STZ-diabetic group given glibornuride, the degenerative changes decreased. In the STZ-diabetic group, blood glucose levels, serum aspartate transaminase activity, and total lipid levels increased, whereas the blood glutathione levels decreased. In contrast, in the STZ-diabetic group given glibornuride blood glucose levels, serum aspartate transaminase activity and total lipid levels decreased and blood glutathione levels increased. Significant changes in total protein levels in the serum were not observed in any group. As a conclusion, we can say that glibornuride has a protective effect against the hepatotoxicity produced by STZ-diabetes