The Indian system of medicine has treated diabetes with its herbals for ages. Vegetables are among the numerous plant adjuncts tried for the treatment of diabetes mellitus. In recent years, there has been a renewed interest to screen such plant food materials, especially, to examine the long-term beneficial effect of dietary vegetables, to identify the active principle, and to understand the mechanism of action, which is at present unclear. Virtually, all forms of diabetes mellitus are caused by a deficiency of insulin secretion or by a combination of insulin resistance and inadequate insulin secretion. Hyperglycemia is the most consistent sign of diabetes, but is not a sensitive indicator at the onset of the disease. GHb, glycosylated haemoglobin is abnormally high in diabetes, with chronic hyperglycemia and often reflects their metabolic control . Liver is an insulin dependent tissue, which plays a pivotal role in glucose and lipid homeostasis and is severely affected during diabetes . During diabetes a profound alteration in the concentration and composition of lipid occurs . Decreased glycolysis, impeded glycogenesis and increased gluconeogenesis are some of the changes of glucose metabolism in the diabetic liver. Diabetes mellitus is known to cause hyperlipidemia through various metabolic derangements. Among several metabolic derangements, insulin deficiency has been known to stimulate lipolysis in the adipose tissue and give rise to hyperlipidemia and fatty liver. Thus, in diabetes hypercholesterolemia and hypertriglyceridemia often occur .
This paper describes the study of Momordica charantia Linn as an antidiabetic herbal.
M. charantia also known as bittermelon or bittergourd belongs to the family Cucurbitaceae. The hypoglycemic activity of Momordica charantia has been observed and documented on many occasions [5–8]. Its fruits, leaves and stems have been extensively used and reported for its hypoglycemic effect. Compounds isolated from the fruits & seeds that are believed to contribute to its hypoglycemic activity include charantin (a steroidal glycoside), vicine (a glycoalkaloid) and polypeptide 'p' (a 166 residue insulinomimetic peptide).
Momordica charantia has been hypothesized to act via both pancreatic and extra-pancreatic mechanisms [5, 6]. Various studies on M. charantia have suggested its potential benefit in diabetes. But a lack of proper biomarkers and appropriate parameters for standardization of its preparations has often resulted in varied efficacy and safety. This study was thus initiated with an aim of evaluating the effects of a standardized MCE on blood glucose, serum insulin, serum lipid levels, glucose uptake and glycogenesis in tissues of alloxan diabetic rats. It, thus, investigates the hypoglycemic activity and probable underlying mechanisms of action of the extract by determining changes in various biochemical & histopathological parameters. The study also evaluates the hypolipidemic activity of MCE in alloxan diabetic and old obese rats which would be beneficial in the overall treatment and control of diabetes mellitus.