The effects of different levels of peppermint alcoholic extract on body-weight gain and blood biochemical parameters of adult male Wistar rats

INTRODUCTION Peppermint is an efficient medicinal plant for the treatment of diseases, and it also can be used to produce raw materials in the pharmaceutical industry. The purpose of the current study was to evaluate the effects of various levels of peppermint alcoholic extract on body-weight gain and blood biochemical parameters in adult male Wistar rats. METHODS This experiment was conducted using a completely randomized design (CRD). Fifty adult, healthy, male Wistar rats (ages of 2.5-3 months; weights of 190-210 g) were allocated randomly into five groups. T1 was the control group in which the rats received 0.3 ml of distilled water). Groups T2, T3, T4, and T5 received 75, 150, 300, and 600 mg/kg of peppermint extract, respectively. The rats received daily pretreatment by oral gavages for 21 days. We recorded body weights at the beginning and at the end of the study to determine the changes in the body weights. Blood samples were collected for the measurement of glucose, cholesterol, triglycerides, HDL, LDL, albumin, globulin, and total protein. Statistical analysis of the data was done by SAS software. The data statistically analyzed using one-way analysis of variance (ANOVA), which was conducted through Dennett's multiple comparison post-test. RESULTS The results indicated that the rats treated with peppermint gained more weight (p < 0.05) and also decreased the serum concentrations of triglycerides, total cholesterol, LDL, and glucose in T3, T4 and T5 than the other groups (p < 0.05). CONCLUSION Peppermint extract had a positive effect on body-weight gain and some blood parameters in adult male Wistar rats. The findings showed that peppermint is a crucial substance at high temperature, and future research should be focused on determining the details of the mechanisms involved in producing the observed effects of peppermint extract.