Changes in Biochemical Components of Obesity in Wistar Rats Fed Mentha Piperita-Supplemented High-Fat Diet

Abstract

The research is designed to assess changes in biochemical components of obesity in Wistar rats fed peppermint-supplemented high-fat diet. Twenty (20) female Wistar rats of about 117.88±10.82g were divided into four (4) groups of five (5) rats each and randomly assigned to the formulated diets. The groups had similar average weights. Groups A and B were fed standard diet and High-fat diet respectively, while groups C and D were respectively fed 4% peppermint-supplemented standard diet and 4% peppermint-supplemented high-fat diet. The changes in weight and blood glucose level were monitored on weekly basis. At the end of six (6) weeks of the experiment, organ to body weight ratio, serum insulin level and HOMA-IR were determined. Markers of hepatic functions (transaminases, total bilirubin, albumin, globulin, conjugated bilirubin and total protein), markers of renal functions (electrolyte concentrations, urea and creatinine), serum activities of antioxidant enzymes (catalase, glutathione peroxidase, reduced glutathione and superoxide dismutase) and serum concentrations of malondialdehyde (MDA) were also determined. No significant (p≤0.05) differences were observed among the groups in weight gain, organ to body weight ratio, blood glucose levels, activities of antioxidant enzymes and serum MDA concentrations. The group fed 4% peppermint-supplemented high-fat diet had significantly (p≤0.05) higher activities of ALT, AST, total cholesterol and low-density lipoprotein cholesterol but significantly (p≤0.05) lower high-density lipoprotein cholesterol when compared with the group fed standard diet or high-fat diet. Serum creatinine and bicarbonate were significantly (p≤0.05) lower in the group fed 4% peppermint-supplemented high-fat diet compared with the group fed the standard diet. It is therefore concluded that including peppermint leaf powder in the diet for a period of 6 weeks may not have a significant impact on the body weight, organ development and glucose utilisation. However, it is important to note that consumption of high-fat diet supplemented with peppermint might lead to dyslipidemia, liver and kidney dysfunctions without altering oxidative balance in Wistar rats.