Therapeutic Effects of the Anti-diabetic Polyherbal Drug Diawell in Combination with Metformin on Liver and Lipid Parameters in Type 2 Diabetic Rats
Authors: Briggs O. N. , Nwachuku E. O. , Brown H. , Elechi-Amadi K. N. 
Published: October 2019

Type 2 diabetes is one of the most important diseases worldwide. It affects several organ systems including the liver and lipid metabolism. Many herbal formulations have shown anti-diabetic potential, however, their safety and efficacy remain a debate in the medical community.
Aim: This study evaluates the therapeutic effects of the anti-diabetic polyherbal drug diawell in combination with metformin on liver enzyme and lipid profile in type 2 diabetic rats.
Methodology: A total of 35 male Wistar albino rats weighing between 120-220 g were used for this study. The rats were placed on high fat diet, and diabetes was induced by a single intraperitoneal injection of freshly prepared streptozotocin (STZ) (45 mg/kg body wt). Fasting plasma glucose (FPG) was determined using the glucose oxidase method. Total Cholesterol (TC), Triglyceride (TG) and High density lipoprotein cholesterol (HDL-C) were determined using enzymatic methods. Low density lipoprotein cholesterol (LDL-C) was calculated using the Friedewald equation. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined using Reitman-Frankel method, while alkaline phosphatase (ALP) was determined using the colorimetric phenolphthalein method. Liver sections were stained using haematoxylin and eosin (H&E) staining technique, and phytochemical analysis was also done on the herbal tablet.
Results: The results show no significant differences in mean TC levels in all groups. TG level was significantly higher in the diabetic control when compared to the negative control. There were no significant differences in TG levels in the metformin group, and diawell group when compared to the diabetic control. TG levels in the combination group (metformin + diawell) was significantly lower versus the diabetic control, and showed no significant difference compared to the negative control. HDL-C was significantly higher in the negative control when compared to the diabetic control and the treatment groups. There were no significant differences in HDL-C levels in all the treatment groups, when compared to the diabetic control. LDL-C levels were significantly lower in the negative control compared to the diabetic control and treatment groups. There were no significant differences in LDL-C levels in all the treatment groups, when compared to the diabetic control. The diabetic control had significantly higher ALT, AST and ALP levels compared to the negative control and treatment groups. All the treatment groups showed no significant differences in ALT and AST levels compared to the negative control. Liver sections of the negative control showed normal histoarchitecture. The diabetic control showed inflammation and fatty deposition. The treatment groups showed a nearly normal histoarchitecture, with fatty deposits.
Conclusion: High fat diet in combination with 45 mg/kg of STZ produced significant diabetes in the Wistar rats with dyslipidaemia and elevated liver enzyme levels. Metformin and the polyherbal tablet diawell had no impact on the lipid levels as it did not correct the dyslipidaema, however, the treatments showed hepatoprotective potentials and restored liver enzyme levels to normal. Lipid lowering drugs should be included in the management of type 2 diabetes, and there should be proper evaluation of anti-diabetic herbal products.