The potential beneficial role of isoflavones in type 2 diabetes mellitus

Diabetes is a chronic global disease afflicting a substantial number of people worldwide. Different mechanisms have been highlighted in the progression of this disease such as dysfunction of pancreatic β-cells, insulin resistance, elevated levels of free fatty acids which result in overproduction of reactive oxygen species, as well as pancreatic β-cell failure and apoptosis. Isoflavones, are polyphenolic phytochemicals found in most leguminous plants, and have been identified as potentially useful antidiabetic agents. The pleiotropic effects of isoflavones include the targeting of numerous cell signaling pathways involved in the pathogenesis of diabetes. Several observational studies have supported the direct relationship between isoflavones intake and a lowered risk of diabetes. The aim of this review was to summarize relevant findings on the effects of isoflavone intake and risk of type II diabetes mellitus (T2DM), and to highlight some of the possible anti-diabetic molecular mechanisms of these polyphenols. Despite the promising therapeutic effects of isoflavones to moderate risk of T2DM, the underlying mechanisms for their preventive effects are still largely unknown. The acceptable human dosage levels of these polyphenols remain a debatable topic as these have a profound influence on the observed benefits. Considerable numbers of well-controlled, long-term human clinical studies of these phytochemicals are highly recommended. Furthermore, combinations of isoflavones and their derivatives in combination with other naturally isolated compounds, and perhaps even those drugs currently used therapeutically to control diabetes mellitus in clinical practice, may be worth exploring in the future.