A STUDY ON ANTIDIABETIC ACTIVITIES OF SOME INDIAN MEDICINAL PLANTS AND THEIR MODES OF ACTION

Abstract

Diabetes mellitus is complex metabolic disorder resulting from either insulin insufficiency (type I diabetes) or resistance of body towards the insulin (type II diabetes) and it leads to an improper regulation of carbohydrate and lipid metabolism. Both these conditions result in increased concentration of glucose in the blood, which in turn damages many of the body's systems. The major chronic complications associated with diabetes include retinopathy, neuropathy, nephropathy and artherosclerotic vascular disease. Diabetes is a multifunctional disease leading to several complications and therefore, demands a multiple therapeutic approach. Although several options for diabetes treatments are available in market, they are associated with various side effects and resistance of body towards their pharmacological effects. Hypoglycemia, weight gain, gastrointestinal disturbances, liver toxicity etc. are some of the associated side effects. Further the complex pathophysiology of this disorder disgraces the use of unidirectional and single drug therapeutic approach in the management of diabetes. In contrast, traditional medicine follows a holistic approach, its prime focus being activation of the body's defense, protective and repair mechanisms. Although traditional medicines have the immense potential to cure most of the disease, yet this system of medicine had not achieved the respect it deserved in the current scientific community. The prime reason of this situation is the lack of proper standardization and authentication of the herbal extracts. Due to increasing instances of drug associated secondary failures and body's resistance towards the conventional therapy measurements, traditional medicinal system is gaining new thrust. It follows a ii holistic approach including medicinal preparations containing herbs and other organic and inorganic materials for the treatment. The ancient texts of India, China, Egypt, Rome and Greek system of medicines are replete with mention of medicinal plants. Currently 80% of the world population depends on plant derived medicines for the first line of primary health care. The present thesis work is an attempt to validate antidiabetic, antihyperglycemic and hypolipidemic components of some of the Indian medicinal plants using various in vitro and in vivo approaches. Several medicinal plants were screened for their antidiabetic potential and further fractions rich in particular group of compounds were analyzed for their detailed mechanism of action. Two antidiabetic compounds were purified and their detailed mode of action was studied using in vivo and in vitro techniques. Flavonoids rich fraction of Eugeniajambolana and alkaloids rich fraction of Capparis decidua were used for the detailed analysis. Apart from these enriched fractions two potential antidiabetic and antihyperglycemic compounds guggulsterone and pterostilbene were isolated from Commiphora mukul and Pterocarpus marsupium, respectively. Detailed analysis of these compounds using in vitro and in vivo techniques was undertaken in order to prove the efficacy of these two compounds for the treatment of diabetes mellitus. in