ABSTRACT
Objective: This study evaluated acute and sub-acute toxicities in rodents and microbial purity of a polyherbal formulation, Bobwell® popular among the natives for the management of diabetes mellitus (DM). It was prepared with unspecified quantities of the following plant materials viz. Gongronema latifolium. Garcinia kola, Vernonia amgydalina, Sphenocentrum jollyanum and Kigelia africana leaves. Materials and Methods: Microbial purity was evaluated on some bacterial and fungal organisms using appropriate diagnostic media. Toxicity of the polyherbal preparation was evaluated in Swiss albino mice by administering to the animals graded oral doses of the lyophilized preparation in the ranges of 1.0 to 20.0 g/kg body weight (bwt) and observed for changes. Wistar rats were also fed with different doses of the lyophilized formulation for 30 days and the effects on the biochemical profiles and haematological parameters were evaluated. Results: The purity evaluation test revealed presence of some bacterial organisms with the load within officially acceptable limits except Escherichia coli having a load of 1.50x102 cfu/ml while no fungal organisms were observed. The median acute toxicity value (LD50) of the polyherbal medicine was determined to be 15.2 g/kg bwt. There was significant increase (P ≤0.05) in the body weight of the animals treated with the highest dose of the formulation compared to the control. The biochemical parameters showed marked decrease in the plasma glucose level compared to the control. Increase in creatinine level was observed only in the animals that received the highest dose of the formulation while aspartate aminotransferase (AST) decreased significantly. On the other hand, alanine aminotransferase (ALT) exhibited significant increased (P ≤0.05) at the highest dose. The photomicrograph of hepatic tissue showed focal necro-inflammation around the portal hepatics. There was marked increase in the haemoglobin level and in the red blood cell (RBC) count at the highest doses. There was also significant increase in white blood cells (WBC). Conclusion: The high LD50 value indicated that the polyherbal preparations could be safe for use but its safety was negated by high presence of E coli load. Although the formulation showed good hypoglycaemic activity and beneficial effects on cardiovascular risk factors, at the highest dose, the formulation exhibited deleterious effect on the hepatic tissue.
ABSTRACT
Objective: To study toxicity, anti-diabetic and cardiovascular effects of hydro-ethanolic extracts of Parinari curatellifolia seed extract and Aristolochia vogelii roots extract and (1:1) mixture of the above two extracts. Materials and Methods: Twenty Wister strain albino rats were randomly assigned to four groups; A, B, C and D with each consisting of five animals received extracts as follows: Group I, P. curatellifolia and A. vogelli mixture (1:1) (500 mg/kg bwt); Group II, A. vogelli (500 mg/kg bwt); Group III, P. curatellifolia seed extract (500 mg/kg bwt); Group IV, 0.5 ml (2% w/v) acacia solution and served as control. After 30 min, the animals were each administered orally with 40% (w/v) glucose at a dose of 1ml /100 g bwt. Blood glucose levels were then monitored at 30, 60, and 120 min. intervals and reported as the average glucose level of each group. Another set of twenty five rats (diabetic rats) were randomly distributed into five groups of five animals each while the additional sixth group was the positive control consisting of five normal rats. Treatments were as follows: Group I, diabetic treated with A. vogelli at a dose of 500 mg/kg bwt; Group II, diabetic treated with P. curatellifolia at a dose of 500 mg/kg bwt; Group III, diabetic treated with glibenclamide 600μg /kg bwt; Group IV, diabetic treated with mixture of Parinari curatellifolia and A. vogelli (1:1) (500 mg/kg bwt); Group V, diabetic untreated (control negative) while group VI was the positive control. Results: A significant reduction in postprandial sugar level was observed after 30 min in all treatments. The extracts individually and in combined form also showed effective decrease in plasma glucose levels on the diabetic rats. There were significant reductions (p<0.05) in low density lipoprotein (LDL)-cholesterol levels and significant increase (p<0.05) in high density lipoprotein (HDL)–cholesterol in the treated diabetic group compared to the negative control. Furthermore, significant reductions in aspartate aminotransferases (AST) and alanine aminotransferases (ALT) levels were observed in the treated diabetic animals compared to the untreated. Also significant reduction in the creatinine and increase in the protein levels respectively were observed in the treated diabetic groups. Conclusion: The results showed that the respective extracts and the extract mixture had both good hypoglycaemic activity and beneficial effects on cardiovascular risk factors.