Original Article ALPHA AMYLASE AND ALPHA GLUCOSIDASE INHIBITION ACTIVITY OF SELECTED EDIBLE SEAWEEDS FROM SOUTH COAST AREA OF INDIA P. REKA 1* , THAHIRA BANU A. 2 , M. SEETHALAKSHMI 3 1,2 Department of Home Science, 3 Faculty of Agriculture and Animal Husbandry, Gandhigram Rural Institute (DU), Dindigul District, Tamilnadu, India 624302 Email: reka.vijivelu@gmail.com Received: 11 Feb 2017 Revised and Accepted: 20 Apr 2017 ABSTRACT Objective: The present work was to investigate the alpha amylase and alpha-glucosidase inhibitory activity of the selected edible seaweeds. Methods: The seaweeds namely Acanthophora spicifera, Gracilaria corticata, Gracilaria edulis, Ulva lactuca and Ulva reticulata were selected for this study. Six and eight hours of ethanol and aqueous extract were used for the estimation of alpha amylase using DNS method and alpha-glucosidase inhibition activity. Results: The study reported that the solvent from ethanol and aqueous in eight hours of extraction showed a higher inhibitory activity than six hours of extraction. Maximum of 89.1±0.96 and 79.55±3.08 percent of alpha-amylase and alpha-glucosidase inhibition activity were detected in the eight hours of aqueous extract (0.5 ml) of Ulva reticulata and Gracilaria edulis respectively. All the selected edible seaweeds had significant differences (p<0.05) in alpha amylase and alpha glucosidase inhibition activity between the selected seaweeds with different extracts. Conclusion: It was concluded that all the selected edible seaweeds have the potential to act as a potent inhibitor of the carbohydrate hydrolyzing enzyme. Thus, it was clear from the study that seaweeds incorporated in small amounts in the dishes consumed in the daily diet can bring a control on postprandial blood glucose level. Keywords: Seaweeds, Ulva reticulata, Aqueous, Alpha-amylase, Carbohydrate, Anti-diabetic activity, Blood glucose level © 2017 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) DOI: http://dx.doi.org/10.22159/ijpps.2017v9i6.17684 INTRODUCTION Diabetes mellitus is a chronic disease, which occurs when the pancreas does not produce enough insulin or when the body cannot efficiently utilize the insulin, it produces [1]. This leads to an increased concentration of glucose in the blood. Diabetes is a significant public health threat and responsible for various long-term complications such as retinopathy, nephropathy and neuropathy leading to severe socio-economic problems throughout the world [2]. According to International Diabetes Federation [3] the prevalence of diabetes among adults (aged 40–59 y) in the world was 382 million in 2013 and this will increase up to 592 million in 2035. Recent national ICMR-INDIAB study reported that more than 62.4 million people are affected with diabetes in India and around 77.2 million people have pre-diabetes. In Tamilnadu, around 4.8 million people are affected with diabetes and 3.9 million people have pre-diabetes [4]. Diabetes requires changes for a lifetime. An important goal of treatment is to provide the patient with the necessary tools to achieve the best possible control of glycemia, lipidemia and blood pressure to prevent, delay or arrest the microvascular and macrovascular complications of diabetes while minimizing hypoglycemia and excess weight gain [5, 6]. The approach for controlling postprandial hyperglycemia is to inhibit the carbohydrate hydrolyzing enzymes such as alpha amylase and alpha glucosidase in the digestive system [7]. Alpha-amylase is involved in the breakdown of long chain carbohydrate and alpha glucosidase breaks down starch and disaccharides to glucose [8]. Inhibition of these enzymes helps to reduce the rate of carbohydrate digestion and cause a reduction in the rate of absorption thereby lowering the postprandial serum glucose levels [9, 10]. The majority of the people in developing countries depend on alternative therapies including natural resources for their primary health care [11]. Zeng Sun and Feng Chen [2] reported that anti- diabetic agents from natural sources have attracted more and more attention because the clinical trials of several synthetic anti-diabetic drugs have been terminated due to safety concerns. In recent years many marine resources have attracted attention in the search for bioactive compounds to develop new drugs and health foods [12, 13]. Seaweeds are primitive non-flowering plants without root, stem and leaves. They comprise one of the commercially important marine renewable resources [14-16]. Many types of seaweeds have been traditionally used as food in Japan and New Zealand [17]. Seaweeds are a good source of dietary fibres, polysaccharide, polyphenols, polyunsaturated fatty acids, minerals and vitamins. Which possess various biological activities like anti-diabetic, anti- inflammatory, antioxidant activity, antibacterial, anticoagulant antiviral and apoptotic activity [18, 19]. Seaweeds contain a prolific source of bioactive compounds that can be exploited for the treatment of major chronic diseases like diabetes through the inhibition of starch digesting enzymes and the regulation of glucose- induced oxidative stress [20]. Recently, several studies reported that seaweeds can be potential interest for the development of novel drugs, functional foods and pharmaceutical applications. Hence, keeping the above facts in mind, present study was aimed to evaluate the alpha amylase and alpha glucosidase inhibitory activity of selected five edible seaweeds such as Acanthophora spicifera (Family-Rhodomelace), Gracilaria corticata (Family-Gracilariacea), Gracilaria edulis (Family- Garcilariacea) from red seaweeds, Ulva lactuca (Family-Ulvaceae) and Ulva reticulata (Family-Ulvaceae) from green seaweeds. MATERIALS AND METHODS Sample collection Five seaweeds namely Acanthophora spicifera, Gracilaria corticata, Gracilaria edulis, Ulva lactuca and Ulva reticulata were collected from the south coast area Rameswaram, Tamilnadu, India. The morphological characteristics namely type, colour, texture, shape and habitat of the collected seaweeds were observed and the taxonomical classification of the selected seaweed species was carried out International Journal of Pharmacy and Pharmaceutical Sciences ISSN- 0975-1491 Vol 9, Issue 6, 2017