Dioscorea bulbifera: Phytotherapeutic Potential and Toxicological Risks, A Critical Review

Dioscorea bulbifera (air potato), a climbing perennial of the Dioscoreaceae family, is widely distributed in tropical regions and valued in Ayurveda, Traditional Chinese Medicine, and African ethnomedicine for managing inflammatory, infectious, metabolic, and neoplastic disorders. This systematic review critically evaluates its phytochemistry, pharmacology, and toxicology. Primary metabolites contribute to its nutritional value, whereas secondary metabolites-predominantly steroidal saponins, flavonoids, and diterpenoids from bulbils and tubers-underlie its wide range of reported bioactivities. African accessions are rich in clerodane diterpenoids, while Asian ones are rich in saponins and flavonoids, underscoring the need for comparative metabolomic and chemotaxonomic studies.

Preclinical studies confirm antiproliferative, antioxidant, anti-inflammatory, antimicrobial, antidiabetic, and neuroprotective effects. However, furanoid diterpenoids, particularly diosbulbin B and 8-epidiosbulbin E acetate, have been shown to induce hepatotoxicity, with additional risks of nephrotoxicity, cardiotoxicity, gastrointestinal irritation, and thyroid dysfunction. Traditional processing methods, such as boiling and roasting, as well as co-administration with protective herbs, mitigate toxicity. Despite promising activity, clinical translation remains hindered by phytochemical variability, non-standardised preparations, and the complete absence of human trials. Future research should therefore focus on developing detoxified, standardised extracts supported by pharmacokinetic studies and well-designed randomised controlled trials to establish D. bulbifera as a safe and effective phytotherapeutic agent.