Int.J.Curr.Microbiol.App.Sci (2013) 2(2):15-19 15 Original Research Article Phytochemical and in vitro anti-diabetic activity of methanolic extract of Psidium guajava leaves R. Manikandan*, A.Vijaya Anand 1 and G. Durai Muthumani 2 * Department of Chemistry, SSK Polytechnic College, Poolangulathupatti, Trichirappalli, Tamil Nadu, India. 1 P.G. Department of Biochemistry, M.I.E.T. Arts and Science College, Trichirappalli, Tamil Nadu, India 2 Department of Biochemistry, Kanchi Shri Krishna College of Arts and Science, Kilambi, Kancheepuram -631 551 Tamil Nadu, India. *Corresponding author: mani_r_trichy@yahoo.co.in ABSTRACT Introduction Diabetes mellitus is a complex and a diverse group of disorders that disturbs the metabolism of carbohydrate, fat and protein. The number of diabetes mellitus cases has been increasing worldwide in recent years. In 2000, the world health organization estimated a total of 171 million of people with diabetes mellitus from the global population, and this report projected to increase to 366 million by 2030 (Wild et al., 2004). With a long course and serious complications often resulting in high death- rate, 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 (Syamsudin, 2010). ISSN: 2319-7692 Volume 2 Number 2 (2013) pp.15 19 http://www.ijcmas.com Keywords Psidium guajava; Phytochemical; alpha- glucosidase; alpha-amylase The intestinal digestive enzymes alpha-glucosidase and alpha-amylase are plays a vital role in the carbohydrate digestion. One antidiabetic therapeutic approach reduces the post prandial glucose level in blood by the inhibition of alpha-glucosidase and alpha-amylase enzymes. These can be an important strategy in management of blood glucose. The aim of the present study was to investigate the phytochemical bioactive compounds of the methanolic extract of Psidium guajava leaves, its in vitro anti-diabetic activity. The assay results suggests that the presence of bioactive compounds, could be responsible for the versatile medicinal properties of this plant including diabetes, the extract exhibit the dose-dependent increase in inhibitory effect on alpha-glucosidase enzyme (upto 89.4%), and alpha-amylase enzyme (upto 96.3%). The current study proves that the antidiabetic activity of methanolic extract of Psidium guajava leaves by in vitro studies.