Context The roots of Ilex asprella (Hook. et Arn.) Champ. ex Benth. (Aquifoliaceae) are widely used in Chinese medicine to treat influenza, amygdalitis, pertussis, etc. Their mechanism of action is still unknown, which raises the need to identify new bioactive compounds in this plant. Objective In this study, we isolated a novel saponin containing sulphonic groups, namely, asprellcoside A (1) and a known phenolic glycoside compound (2) from the roots of Ilex asprella and evaluated their bioactivities. Materials and methods Molecular structures were elucidated by analysing their spectral and chemical properties. The viability of A549 cells was tested using a MTT assay. Ability of the compounds to inhibit viruses was determined using the neuraminidase activity assay. Their anti-inflammatory effects were tested using the IP-10 activity assay using various concentrations (compound 1: 0.6, 0.2, 0.6, 1.70, 5.00 and 15.00 μM; compound 2: 0.4, 1.2, 3.6, 11.0, 33.0 and 100 μM). Their inhibitory effect on platelet aggregation induced by adenosine diphosphate (ADP) in rabbit plasma was determined at 60 and 80 μM. Results Both compounds inhibit influenza virus strain A/PuertoRico/8/1934 (H1N1) strongly with EC50 values of 4.1 and 1.7 μM, respectively. Both compounds inhibit the secretion of IP-10 with EC50 values of 6.6 and 2.5 μM, respectively. Compound 1 alone inhibited platelet aggregation significantly, with the rate of suppression being 47 ± 8 and 38 ± 3%, at 60 and 80 μM, respectively. Conclusions The results suggest that both compounds may be valid therapeutics against influenza virus infection and that compound 1 may be a novel agent for treating thrombosis.
Keywords: IP-10; neuraminidases; phenolic glycoside; platelet aggregation; triterpenoid saponin.