Momordica charantia fruits are used as a vegetable in many countries. From time immemorial, it has also been used for management of diabetes in the Ayurvedic and Chinese systems of medicine. Information regarding the standardization of this vegetable for its usage as an antidiabetic drug is scanty. There are many reports on its effects on glucose and lipid levels in diabetic animals and some in clinical trials. Reports regarding its mechanism of action are limited. So in the present review all the information is considered to produce some concrete findings on the mechanism behind its hypoglycemic and hypolipidemic effects. Studies have shown that M. charantia repairs damaged β-cells, increases insulin levels, and also enhance the sensitivity of insulin. It inhibits the absorption of glucose by inhibiting glucosidase and also suppresses the activity of disaccharidases in the intestine. It stimulates the synthesis and release of thyroid hormones and adiponectin and enhances the activity of AMP-activated protein kinase (AMPK). Effects of M. charantia like transport of glucose in the cells, transport of fatty acids in the mitochondria, modulation of insulin secretion, and elevation of levels of uncoupling proteins in adipose and skeletal muscles are similar to those of AMPK and thyroxine. Therefore it is proposed that effects of M. charantia on carbohydrate and fat metabolism are through thyroxine and AMPK.

In the present study, inhibitory effect of the methanol extract of Raphanus sativus root on lipid peroxidation has been carried out in normal rats. Graded doses of methanol extract of root of the plant (40, 80 and 120 mg kg−1 body weight) were administered orally for 15 days to experimental treated rats. Distilled water was administered to experimental control rats. At the end of experiment, rats were killed by decapitation after ether anesthesia. Blood and liver were collected to measure thiobarbituric acid reactive substance, reduced glutathione and activity of catalase. Results indicated that the extract of R. sativus root reduced the levels of thiobarbituric acid reactive substance significantly in all experimental treated groups (P < 0.05) as compared to the experimental control group. It also increased the levels of reduced glutathione and increased the activity of catalase. In vitro experiments with the liver of experimental control and experimental treated rats were also carried out against cumene hydroperoxide induced lipid peroxidation. The extract inhibited in vitro cumene hydroperoxide induced lipid peroxidation. R. sativus inhibits lipid peroxidation in vivo and in vitro. It provides protection by strengthening the antioxidants like glutathione and catalase. Inclusion of this plant in every day diet would be beneficial.

In this study, the methanol extract of Momordica charantia fruit extract was administered to diabetic rats to assess the long term effect of the extract on the lipid profile and the oral glucose tolerance test. Treatment for 30 days showed a significant decrease in triglyceride, low density lipoprotein and a significant increase in high density lipoprotein level. A significant effect on oral glucose tolerance was also noted. Chronic administration showed an improvement in the oral glucose tolerance curve. The effect was more pronounced when the test was done in rats fed the extract on the day of the test compared with tests done in rats which were not fed the extract on the same day.

Momordica charantia L., commonly known as bitter gourd, is used as a vegetable by the Asian community in Africa. It is frequently used as an antidiabetic herb for the management of the disease in the Ayurvedic system of medicine. The present study was aimed at evaluating the effects of M. charantia on glucose level, lipid profiles, and oxidative stress in diabetic rats subjected to a sucrose load. Five normal rats and 20 diabetic rats (diabetes induced by injecting alloxan monohydrate) were used for the experiment. Diabetic rats were divided into four groups: three experimental groups that received sucrose (4 g/kg of body weight) plus graded doses of M. charantia extract and a diabetic control group that received only sucrose (4 g/kg of body weight). Normal rats were used as the normal control group and received only sucrose (4 kg/kg of body weight). The experiment was run for 30 days, after which rats were bled to assay blood glucose, lipid profiles, and thiobarbituric acid-reactive substances and reduced glutathione. After this, all treatments were terminated. Rats in the normal control group, diabetic control group, and experimental group 3 were subjected to observation for 30 days and were bled on day 31 to assay parameters as stated above. Results indicated that M. charantia maintained the normal glucose levels in all experimental groups, reduced triglyceride and low-density lipoprotein levels, and increased high-density lipoprotein levels. It also improved the antioxidant status, indicated by low levels of thiobarbituric acid-reactive substances and normal levels of reduced glutathione. Rats reverted to diabetic conditions and were found to be under oxidative stress after termination of treatment. This study concludes that M. charantia maintains the normal glucose level, lipid profiles, and antioxidant condition in diabetic rats against the sucrose load.

This study aims to assess whether or not a methanol extract of Momordica charantia is able to normalise lipid and glucose levels in diabetic rats fed a high-fat and a low-carbohydrate diet. Different doses of the extract are administered orally for 45 days. The rats are bled at the beginning of the experiment and at 15-day intervals. Blood glucose, triglyceride, low-density lipoprotein (LDL), high-density lipoprotein (HDL) and cholesterol are estimated. Results showed that M. charantia extract normalised blood glucose level, reduced triglyceride and LDL levels and increased HDL level. The animals reverted to a diabetic state once the M. charantia extract was discontinued.