A Review on Herbal Plants for Diabetes Management

Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia resulting from impaired insulin secretion, impaired insulin action, or a combination of both. The increasing prevalence of diabetes mellitus has become a major global public-health concern, particularly because of its long-term complications involving the cardiovascular system, kidneys, eyes, nerves, and other organs. Although conventional anti diabetic medicines are effective in controlling blood glucose, their use may be associated with adverse effects, treatment costs, limitations in long-term adherence, and, in some cases, inadequate glycemic control. Consequently, medicinal plants and herbal preparations have attracted considerable attention as potential complementary approaches for diabetes management. A large number of plants have traditionally been used in different systems of medicine for controlling blood glucose. Important medicinal plants investigated for antidiabetic activity include Momordica charantia (bitter melon), Gymnema sylvestre (gurmar), Trigonella foenum-graecum (fenugreek), Syzygium cumini (jamun), Cinnamomum verum and Cinnamomum cassia (cinnamon), Azadirachta indica (neem), Tinospora cordifolia (guduchi), Aloe vera, Ocimum sanctum (tulsi), Curcuma longa (turmeric), Pterocarpus marsupium (vijaysar), Berberis aristata, and Allium sativum (garlic). Phytochemicals such as polyphenols, flavonoids, alkaloids, terpenoids, saponins, tannins, polysaccharides, and other bioactive constituents may contribute to their antidiabetic effects through mechanisms including inhibition of carbohydrate-digesting enzymes, enhancement of insulin sensitivity, stimulation of insulin secretion, reduction of oxidative stress, modulation of glucose transport, and protection of pancreatic β-cells. However, evidence supporting herbal therapy varies considerably between plants and preparations. Much of the evidence remains based on laboratory and animal studies, while clinical evidence is often limited by small sample sizes, differences in extracts, dosage variations, short study durations, and inconsistent standardization. Herbal medicines should therefore not automatically be considered substitutes for established antidiabetic therapy. This review summarizes the classification of diabetes mellitus, the role of medicinal plants in diabetes management, important herbal plants and their proposed mechanisms, advantages and limitations, safety considerations, and future prospects for development of standardized herbal antidiabetic preparations.[1]