HYPOGLYCEMIC, HYPOLIPIDEMIC AND HEPATOPROTECTIVE EFFECTS OF Polyscias fulva ETHANOLIC BARK EXTRACT IN DIABETIC RATS

Abstract

Diabetes Mellitus (DM) has been on the alarming rise worldwide and medicinal plants may play a role in its treatment including Polyscias fulva (P. fulva) stem bark that is presumed to have anti-diabetic activity but not documented. Efforts to produce synthetic drugs for treating DM is costly with side effects. Therefore, this study examined the effects of crude ethanolic bark extract of P. fulva on diabetic rats to elucidate its antidiabetic potential. General qualitative phytochemicals were analyzed in the extract then male albino rats were randomized into five groups (five rats each) which were 1; normal rats, 2; diabetic-induced untreated rats, 3 and 4; diabetic-induced rats on 200 and 400mg/kg bwt/day of extract, respectively and 5 was diabetic-induced rats on metformin at 100mg/kg bwt/day. The rats received oral treatments daily for 21 days and on normal chow and water ad libitum. Fasting blood glucose levels and body weights were determined weekly. After 21 days, animals were sacrificed, blood collected and liver tissues preserved for histopathology and malonedialdehyde (MDA) assays. Serum analysis of lipid profile, liver biomarker enzymes (Alkaline Phosphatase (ALP), Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) and proteins (Total proteins-TP, albumin-ALB & globulins-GLB) were performed. Data was expressed as mean ± SEM and statistical analysis done using Student t-test and ANOVA with p<0.05. P. fulva extract showed the presence of tannins, anthraquinones, terpenoids, saponins, flavonoids and steroids and absence of alkaloids. Also, the study showed that P. fulva had significant hypoglycemic and hypolipidemic effects in the diabetic rats compared to diabetic untreated rats. Additionally, serum levels of ALP, ALT and AST were significantly lowered in extract-treated diabetic rats while TP and ALB were significantly elevated in the extract treated diabetic rats compared to diabetic untreated rats. The levels of MDA in liver tissues was significantly elevated in diabetic untreated rats compared to normal control rats while the P. fulva extract treated rats had significantly lowered levels compared to diabetic untreated group. Results on liver histopathology showed normal hepatocytes in the normal control group but the diabetic untreated group showed liver pathological changes. Upon treatment with P. fulva extract at 400mg/kg bwt/day, the pathological changes were reversed in the hepatocytes. In conclusion, the phytochemical– rich extract of P. fulva showed hypoglycemic, hypolipidemic, and hepatoprotective effects in streptozotocin (STZ) induced diabetic rats. This study provides insights into the potential of P. fulva as an alternative medicine in management of DM.