Phytomedicinal approaches to postprandial hyperglycemia: Plants with α‑amylase and α‑glucosidase inhibitory effects (Review)

Diabetes mellitus (DM), a non‑communicable disease with a high disease burden, is characterized by insulin resistance and postprandial hyperglycemia. An estimated 589 million adults worldwide were suffering from DM in 2024, a number projected to exceed 853 million by the year 2050. Diabetes has an evolving epidemiological profile driven by rapid urbanization, dietary patterns characterized by the high consumption of refined carbohydrates, and longstanding ethnomedicinal practices involving native plants for glycemic management. Specific epidemiological data on the prevalence of diabetes for the present review were extrapolated from available regional and national estimates due to the lack of comprehensive population‑level data estimates. The digestive enzymes, α‑amylase and α‑glucosidase, are crucial in mediating hyperglycemia. Acarbose, miglitol and voglibose are potent inhibitors of intestinal α‑amylase and α‑glucosidase, and are routinely used in clinical practice. However, these drugs are associated with gastrointestinal side‑effects that affect patient compliance. The present review synthesized evidence from published in vitro, preclinical and clinical data, and highlights the potential of phytoconstituents, such as polyphenols, flavonoids, alkaloids, tannins, terpenoids and saponins, as α‑amylase and α‑glucosidase inhibitors. Accordingly, three botanicals of cultural and significant medicinal importance are highlighted: Azadirachta indica, Trigonella foenum‑graecum and Ocimum tenuiflorum. The present review discusses the potential of plant‑derived phytochemicals to modulate carbohydrate‑digesting enzymes and delay glucose absorption and also highlights the potential of using advanced cultivation techniques, such as hydroponics, CRISPR‑Cas9 gene editing and plant tissue culture to enhance phytoconstituent yield and batch consistency, to improve clinical applications. Some limitations in the context of overcoming gaps in the literature are addressed, which remain largely confined to preclinical data and scarce clinical data.