ContextThe underground edible tuber ofDioscorea alataL. (Dioscoreaceae) is a functional food with high nutritive value and therapeutic potential. The tuber is known to possess anti-inflammatory properties in traditional medicine. ObjectiveThe present study explores the anti-inflammatory activity and standardisation ofD. alatatuber hydromethanol extract. Materials and methodsHydromethanol extract (70%) ofD. alatatuber was chemically characterised using HPLC and GC-MS techniques. Murine lymphocytes were cultured for 48 h with six different concentrations (0–80 μg/mL) of the extract. The expression of nitric oxide (NO), TNF-α, COX-1, COX-2, and PGE2were evaluated using colorimetric and ELISA methods. ResultsDioscorea alataextract inhibited the expression of NO and TNF-α with an IC50value of 134.51 ± 6.75 and 113.30 ± 7.44 μg/mL, respectively. The IC50values for inhibition of total COX, COX-1, COX-2 activities and PGE2level were 41.96 ± 3.07, 141.41 ± 8.99, 32.50 ± 1.69, and 186.34 ± 15.36 μg/mL, respectively. Inhibition of PGE2level and COX-2 activity was positively correlated (R2 = 0.9393). Gallic acid (GA), 4-hydroxy benzoic acid (4HBA), syringic acid (SYA),p-coumaric acid (PCA), and myricetin (MY) were identified and quantified using HPLC. GC-MS analysis revealed the presence of 13 different phytocompounds such as hexadecanoic acid, methyl stearate, cinnamyl cinnamate, and squalene. ConclusionTheD. alataextract significantly down-regulated the pro-inflammatory signals in a gradual manner compared with control (0 μg/mL). Different bioactive phytocompounds individually possessing anti-inflammatory activities contributed to the overall bioactivity of theD. alatatuber extract. [ABSTRACT FROM AUTHOR]