Antidiabetic Potential of Berberis aristata, Glycyrrhiza glabra and Terminalia chebula: Phytochemical and Pharmacological Perspectives

Diabetes mellitus (DM) is a chronic metabolic condition that is becoming more common worldwide and has significant treatment hurdles. Traditional plant-based medicines have gained popularity due to the limitations of contemporary methods. Licorice (Glycyrrhiza glabra), Indian barberry (Berberis aristata), and haritaki (Terminalia chebula), which are utilized in Ayurvedic and Chinese medicine for diabetes, exhibit encouraging antidiabetic qualities. Berberine and similar isoquinoline alkaloids (B. aristata), glycyrrhizin saponins and flavonoids (G. glabra), and hydrolyzable tannins (T. chebula, including chebulagic/chebulinic acids) are among the many antidiabetic phytochemicals found in these herbs. Mechanistically, berberine suppresses hepatic gluconeogenesis and lipogenesis, increases GLUT4 translocation and glycolysis, and activates AMP-activated protein kinase (AMPK) to produce multi-target actions. Glycyrrhizin, glabridin, and other components of licorice increase insulin secretion, encourage GLUT4-mediated uptake and α-glucosidase inhibition, and lessen oxidative stress. T. chebula tannins activate PPARγ/GLUT4 pathways and strongly block intestinal α-amylase/α-glucosidase (blunting postprandial glucose), while their antioxidant/glycation-inhibitory activities shield β-cells. In type 2 diabetes patients, berberine-containing extracts (e.g., 0.5–1.5 g/day) significantly lower fasting glucose, HbA1c, and lipids; however, there is little human data for licorice and T. chebula (frequently in polyherbal formulations). Safety profiles differ: excessive glycyrrhizin can result in pseudoaldosteronism; T. chebula extracts seem safe in animal tests; berberine is typically well-tolerated but contraindicated in pregnancy/G6PD deficiency. Therefore, these botanicals have therapeutic potential for managing diabetes; nevertheless, more carefully planned clinical trials and extract standardization are required to verify their safety and effectiveness.