Pharmacological Activities of Dioscorea spp.: A Narrative Review

Pharmacological research has become essential for the development of nature-based drugs to support the claimed therapeutic properties of medicinal plants. Dioscorea species are medicinal plants found to have an impressive pharmacological profile. This review aims to compile the pharmacological properties of three Dioscorea species, D. hispida, D. alata and D. bulbifera and their derived compounds through scientific findings, mainly focusing on the biological activities. Relevant clinical and preclinical studies on the pharmacological properties of these plants were identified, screened, and analysed. A systematic search using predetermined keywords on electronic databases (Scopus, Springer and ScienceDirect) was conducted. This review found these Dioscorea species to possess various pharmacological activities such as anti-inflammatory, antimicrobial, anticancer, antioxidant, anti-diabetic, antihypertensive and estrogenic effects. The plant tubers contain active compounds such as diosgenin that is responsible for anti-inflammatory and anti-diabetic activities in D. alata and D. bulbifera, respectively. Other compounds like dioscorine, phenolic, flavonoid and terpenoid elucidated from the yam tubers were found to be antimicrobial and showed prominent free radical scavenging effects. The plants demonstrated various pharmacological activities although data on their mechanisms of action is very limited. Therefore, further research is needed to explore the full potential of these plants as future therapeutic medicines.