UPLC-qToF-MS/MS analysis and anti-inflammatory activities of the soft coral Litophyton savignyi supported by bioactive molecular networking, network pharmacology, and molecular docking

Abstract

Litophyton savignyi of the Red Sea is one of the underexplored soft corals that is a prolific producer of bioactive metabolites. The anti-inflammatory activity of the hexane fraction of L. savignyi was superior to that of the methanol fraction, as revealed by reducing superoxide anion generation (32.05% ± 8.06%) and elastase release in fMLF/CB-induced human neutrophils (96.89% ± 3.69%). The bioactive non-polar fraction was subjected to systematic chemical investigation using UPLC-qToF-MS/MS analysis, and 650 metabolites were found to be exclusively present in the hexane part, of which steroids were the main class representing 26% of all features. Further fractionation of the hexane extract revealed that the polar subfractions ND90-1 and ND90-3 displayed the best inhibition of superoxide generation (96.79% ± 0.16% and 94.27% ± 4.12%, respectively) and elastase release (92.35% ± 2.75% and 91.28% ± 3.41%, respectively). Bioactive molecular networking and multivariate analysis showed that bioactive nodes (r > 0.65 and p < 0.05) and metabolites with top VIP scores (>2) belonged to steroids, sesquiterpenes, fatty amides, and sphingolipids. Network pharmacological studies on these metabolites showed that their hub targets were SRC, PTGS2 (COX-2), HSP90AA1, PPARG, and HIF1A, and they were significantly enriched in inflammatory responses and nuclear receptor–mediated steroid hormone signaling pathways. Molecular docking on COX-2 showed steroids to display scores comparable to those of celecoxib and indomethacin (COX-2 inhibitors as controls), which highlighted the promising anti-inflammatory potential of the hexane extract of Litophyton savignyi. Quantitative real-time PCR (qPCR) analysis revealed that the bioactive subfractions reduced the expression of the proinflammatory cytokines IL-6 and IL-1β, hence supporting the involvement of COX-2 mediated anti-inflammatory effect. A detailed analysis on its anti-inflammatory potential requires future in vivo investigations.