Nature's Prescription for Diabetes: Exploring the Role of Antidiabetic Plants

AbstractDiabetes mellitus is a chronic metabolic disease that is associated with a sustained hyperglycaemia,which is caused by defective insulin secretion, insulin action, or the combination of the two. Theincidence rate of diabetes keeps increasing at an alarming rate especially in the low and middleincome nations necessitating the development of effective, safe and cost effective treatment measures.Despite the effectiveness of conventional antidiabetic drugs in glycaemic management, the adverseeffects, high cost, and lack of complete effectiveness in preventing disease progression andcomplications are often limiting the use of these drugs in the long term. These restrictions have fueledinterests in the use of herbal and plant based interventions in the management of diabetes.This review critically analyzes the use of medicinal plants in diabetes mellitus with focus on theirphytochemical constituents, molecular targets as well as clinical evidence. The biological basis toherbal intervention is the pathophysiology of diabetes, which involves insulin resistance, dysfunctionof the pancreatic β cell, oxidative stress and chronic low grade inflammation. Some phytochemicalsare known to regulate the major metabolic processes including the AMP activated protein kinase,peroxisome proliferator activated receptor gamma, glucose transporter type 4, and carbohydratedigesting enzymes with the effect of improving insulin sensitivity, glucose uptake and postprandialhyperglycaemia.The most commonly used antidiabetic plants such as Momordica charantia, Gymnema sylvestre,Trigonella foenum graecum, Cinnamomum verum, Curcuma longa, Abelmoschus esculentus, andCoccinia grandis are discussed with regard to bioactive compounds and their mode of action. In vitro,animal and clinical trials evidence shows that they can lower glucose by exerting multitargeted andsynergistic effects. Safety, herb drug interactions, pharmacokinetic problems and standardization arealso brought to the fore. All in all, herbal antidiabetic preparations are very promising adjuncts in themanagement of diabetes, but strong clinical trials and standardization which are compliant andregulatory should be done before they can be successfully incorporated in the mainstream therapy.