Advances in Diabetes and Metabolism 4(1): 10-23, 2016 http://www.hrpub.org DOI: 10.13189/adm.2016.040102 Diabetes: Symptoms, Cause and Potential Natural Therapeutic Methods Anjali Awasthi 1,* , Nikhat Parween 2 , Vijay Kumar Singh 3 , Arif Anwar 2 , Birendra Prasad 2 , Jitendra Kumar 4,* 1 Department of Biology, School of Engineering, Presidency University Bangalore, India 2 Department of Botany/Biotechnology, Patna University, India 3 Centre for Biological Science (Bioinformatics), Central University of South Bihar, India 4 DBT-PU-IPLS Programme, Department of Botany/Biotechnology, Patna University, India Co-Corresponding Author: jitendra343@gmail.com; anjaliaw@gmail.com Copyright©2016 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract Diabetes mellitus (DM) commonly referred as diabetes is a complex, heterogeneous disorder characterized by high blood glucose level. Insulin insufficiency or ineffective insulin termed as insulin resistance contributes to diabetes etiology. There are two major forms of DM termed as type-1 diabetes and type-2 diabetes. Type-1 diabetes is an autoimmune disease resulting in destruction of pancreatic cell leading to severe lack of insulin. Whereas, type-2 diabetes develop due to inefficient insulin utilization referred as insulin resistance or insufficient quantity of insulin production. Diabetes has become a global disease and in 2014 WHO has reported 9% of adults (18 years and above) had diabetes. The above trend is expected to increase in forthcoming years due to sedentary lifestyle, unhealthy diet and excessive body weight. Insulin signaling pathway is the key pathway involved in regulating blood glucose level. There are several factors reported to alter insulin secretion as well as insulin signaling pathway resulting in etiology and progression of diabetes. Diabetes treatment aims at controlling blood glucose level. There are various kinds of chemical drug and herbal/natural products being used to effectively control blood glucose level. Composition, dosage and mode of action of chemical drugs are well established. However, the mode of action of traditional and herbal medications, which are used widely by 90% of the population in developing countries for primary healthcare, is still poorly investigated. Around 800 plants have been reported worldwide which have anti-diabetic potential. This review explores and gives the insight on the insulin signaling pathway and other known factors which modulates diabetes. It also collates the potential of various anti-diabetic herbal/phytochemical medications which have been scientifically investigated for their anti-diabetic virtue and mode of action. Keywords Diabetes, Insulin Signaling, Obesity, Herbal Medications 1. Introduction Diabetes mellitus (DM) commonly referred as diabetes is characterized by high blood glucose. It is a metabolic disorder caused due to insufficient or ineffective insulin [1]. Insulin is a hormone produced by the pancreas in the islets of langerhans which regulates the blood glucose level. In a diabetic person glucose is not absorbed properly by target cells, resulting in excessive blood glucose level (a condition known as hyperglycemia) in circulation. Hyperglycemia for prolonged period results in damage to nerves, blood vessels and body organs; ultimately it may lead to life-threatening complications. WHO has reported that, in 1995 around 4% of the world’s population was affected by diabetes and it is expected to increase up to 5.4% by the year 2025 [2]. It is a chronic disorder without any permanent cure. Only timely diagnosis, proper management and treatment of the disease can aid in leading a normal healthy life. Type-1 and type-2 are the two major forms of diabetes. Type-1 diabetes also termed as insulin-dependent diabetes is an autoimmune disorder [3]. It results in the destruction of most of the beta cells in the islets of langerhans (Pancreas) resulting in severe lack of insulin [3]. Approximately 10% of the total diabetic population is reported to be affected by type-1 diabetes and rest 90% are type-2 cases [4]. Type-1 diabetes is often referred as juvenile diabetes as it accounts for about 10% of diabetic cases in youth below the age of 25. Some of the symptoms of type-1 diabetes are: weight loss, frequent urination, fatigue, increased thirst, blurred vision [3]. Treatment of type-1 diabetes involves regular blood glucose monitoring and insulin administration, strict diet regime and exercise [5]. The type-2 diabetes is also known as non-insulin-dependent diabetes [6, 7]. In type-2 diabetes