Evaluation of in vitro anti-diabetic activity of methanolic extract of Ixora coccinea flowers

The aim of the present study was to explore the phytochemical bioactive compounds of the 80% methanolic extract of Ixora coccinea flowers and to investigate its in vitro anti-diabetic activity by α-amylase (starch iodine method) inhibition, αglucosidase (dinitrosalicylic acid (DNSA) method) inhibition. Preliminary phytochemical screening revealed that the methanolic extract of the flowers of I. coccinea possesses secondary metabolites like flavonoids, phenols, steroids and tannins. The total phenolic content of methanolic extract was estimated in the flowers of Ixora coccinea and the value was found to be 30.6mg /g dry weight. The assay results suggests that methanolic extract exhibit the dose-dependent increase (20 -100 μg/ml) in inhibitory effect on alpha-glucosidase enzyme (upto 70%), and alpha-amylase enzyme (upto 72%). The current study proves that the methanolic extract of Ixora coccinea flowers exhibit in vitro antidiabetic activity which may be attributed to the high amount of bioactive compounds such as polyphenolics. KeywordsAlpha-glucosidase, alpha-amylase, Ixora coccinea, phenolic, antidiabetic INTRODUCTION Diabetes mellitus is a metabolic disorder characterized by a loss of glucose homeostasis with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action, or both [1]. According to WHO, it is estimated that 3% of the world’s population have diabetes and the prevalence is expected to double by the year 2025 to 6.3% [2]. With a long course and serious complications often resulting in high deathrate, the treatment of diabetes spent vast amount of resources including medicines, diets, physical training and so on in all countries. Thus searching for a new class of compounds is essential to overcome diabetic problems. There is continuous search for alternative drugs [3]. Diabetes mellitus is one of the most common chronic diseases in nearly all countries, and continues to increase in numbers and significance, as changing lifestyles lead to reduce physical activity, and increase obesity. Estimates of the current and future burden of diabetes are important in order to allocate community and health resources, and to emphasis the role of lifestyle, and encourage measures to counteract trends for increasing prevalence [4]. Furthermore, taking into account its present rate of increase, within few decades it will be one of the world's commonest diseases and one of the biggest public-health problems with an estimated minimum of half-a-billion cases [5]. People suffering from diabetes are not able to produce or properly use insulin in the body and therefore chronic hyperglycemia occurs. In addition, the diabetic individual is prone to late onset complications, such as retinopathy, neuropathy and vascular diseases, that are largely responsible for the morbidity and mortality observed in diabetic patients [6]. There are two main types of diabetes, namely type I and type II. Type I diabetes, that is called insulin-dependent diabetes mellitus (IDDM) or juvenile-onset diabetes develops when the body's immune system destroys pancreatic β -cells, the only cells in the body that produce the hormone insulin that regulates blood glucose. This type of diabetes usually strikes children and adults and the need for insulin administration is determinant for survival. Type I diabetes accounts for 5% to 10% of all diagnosed cases of diabetes and the risk factors may be autoimmune, genetic, or environmental. On the other hand, type II diabetes, also called non–insulindependent diabetes mellitus (NIDDM) or adult-onset diabetes, accounts for about 90% to 95% of all diagnosed cases of diabetes. It usually begins as insulin resistance, a disorder in which the cells do not use insulin properly and as the need for insulin rises; the pancreas gradually loses its ability to produce it. This type of diabetes is associated with older age, obesity, family history of diabetes, history of gestational diabetes, impaired glucose metabolism, physical inactivity, and race/ethnicity. It must be noted thought that in the last decay type II diabetes in children and adolescents is being diagnosed more frequently [7]. In the case of the IDDM, insulin is of crucial importance for the survival of the patients. On the other hand, in the case of NIDDM the treatment includes medicines, diets and physical training. Up to now, many kinds of anti diabetic medicines have been developed for the patients and most of them are chemical or biochemical agents aiming at controlling or/and lowering blood glucose to a normal level. Despite the impressive advances in health sciences and medical care, there are many patients who are using alternative therapies alone or complementary to the prescribed medication. Management of diabetes without any side effect is still a challenge to the medical community. The use of the drugs is restricted by their pharmacokinetic properties, secondary failure rates and accompanying side effects [8]. Thus searching for a new class of compounds is essential to overcome diabetic problems. There is continuous search for alternative drugs [9, 10]. Traditional plant remedies or herbal formulations exist from ancient times and are still widely used, despite all the controversy concerning their efficacy and safety [11, 12], to treat hypoglycemic and Anila L et al /J. Pharm. Sci. & Res. Vol. 11(6), 2019, 2367-2372