**1. Introduction**

[79] Ishii T, Matsuki S, Iuchi Y et al. Accelerated impairment of spermatogenic cells in SOD1-knockout mice under heat stress. Free Radical Research 2005;39:697

316 Antioxidant-Antidiabetic Agents and Human Health

[80] Bajpayee P, Kumar K, Sharma et al. Prostatitis: Prevalence, health impacts and quali‐ ty improvement strategies. Acta Poloniae Pharmaceutica 2012;69(4):571-579

> Diabetes mellitus (DM) is one of the most common metabolic disorders worldwide with an estimated 143 million people suffering from the disease [1]. This number may double by 2030 [2]. Although understanding of the pathophysiological processes involved in DM has in‐ creased, with great feats achieved in the management of DM, yet serious diabetic complications still confront patients and physicians [3]. Diabetes mellitus is characterized by chronic hyperglycemia (very high blood glucose levels) and disturbances of carbohydrate, fat and protein metabolism associated with absolute or relative deficiency in insulin secretion or insulin action [4-5]. On the basis of aetiology and clinical presentation, DM is classified into two; type 1 diabetes mellitus also called insulin-dependent diabetes mellitus (IDDM) and type 2 which is the non-insulin dependent diabetes mellitus (NIDDM). The effects of DM include long term damage, dysfunction and failure of various organs, especially the eyes, kidneys, livers, hearts, and blood vessels [6].

> In the treatment of diabetes, many oral hypoglycemic agents like sulfonylureas, meglitinides, thiazolidines, D-phenylalanine and α-glucosidase inhibitors are used in addition to insulin treatment action along with appropriate diet and exercise [5]. However, none can be termed as an ideal one, due to their toxic side effects and sometimes diminution in response after prolonged use [7]. The limitations and side effects associated with existing synthetic oral hypoglycemic agents had necessitated the search for newer drugs. As a result, natural agents from plants and plant products have been the alternative target to source for new antioxidant and antidiabetic agents based on their traditional use.

© 2014 Oyenihi et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
