Introduction : Momordica charantia (karela) has been used for alleviating the damaging effects of metabolic disorders in Indian traditional medicine. In this study, we aimed to study the effects of karela extracts on serum glucose, ‌lipid and malondialdehyde (MDA) levels in streptozotocin-diabetic rats.

  Methodology : In this study, 40 male rats were divided into four groups. The control group received a normal diet, and diabetes was induced in the other three groups, using streptozotocin. One week after diabetes induction, the first and second groups were fed a normal diet. The third and fourth groups received karela leaf extracts (100 and 200 mg/kg) for 6 weeks via gavage. Serum glucose, lipoprotein, and MDA levels were evaluated in the groups. One-way analysis of variance (ANOVA) and Tukey’s test were performed for data analysis.

  Results : Serum glucose level was significantly higher in the diabetic and karela-treated diabetic groups during the sixth week of intervention, compared to the previous week in other words, treatment with karela extracts significantly reduced serum glucose level (P<0.05). Administration of different doses of karela extracts decreased MDA level, compared to the non-treated diabetic group. Serum HDL level also significantly increased in the karela-treated group, compared to the non-treated diabetic group (P<0.05) however, the extracts had no significant impacts on other serum lipids.

  Conclusion : The results indicated that karela leaf extracts may be effective for the treatment of diabetes in rats. This effect can be due to the presence of flavonoids and antioxidant compounds in this plant.