Chemical profiling and in-vitro anti-inflammatory activity of bioactive fraction(s) from Trichodesma indicum (L.) R.Br. against LPS induced inflammation in RAW 264.7 murine macrophage cells.

Abstract Ethnopharmacological relevance Trichodesma indicum (L.) R. Br. (family: Boraginaceae) is a medicinal herb largely used to treat arthralgia, rheumatoid arthritis, wound healing, dysentery, etc. It's mechanism of anti-inflammatory activity has not been systematically analyzed yet. Aim of the study The present study was undertaken to examine the anti-inflammatory effects of successive solvent extracts (n-hexane extract (HE), ethyl acetate extract (EA), ethanol extract (EE), aqueous extract (AE) and fractions of HE) from the aerial parts of Trichodesma indicum (TI) against lipopolysaccharide (LPS) stimulated inflammatory reaction using mouse macrophage RAW 264.7 cells. Materials and methods Cytotoxic effects of the extracts and fractions of TI were assessed by MTT assay. The effect of extracts and fractions on the production of nitric oxide (NO) in RAW 264.7 macrophages were measured using the Griess reagent method. IL - 6, IL - 1β, TNF-α, iNOS and COX-2 gene expressions were examined by a qRT-PCR method. Results RAW 264.7 macrophages pretreated with HE, EA, EE and AE of TI showed a significant decrease in the production of proinflammatory cytokines and NO without exhibiting cytotoxicity. The potent HE was fractionated using flash chromatography into FA, FB, FC, FD and FE. Among the five fractions, FE displayed a stronger ability to reduce IL - 1β, TNF-α, iNOS, COX2 and NO importantly no cytotoxicity was observed. The phytochemical compounds present in FE were further screened by Gas chromatography - Mass spectroscopy (GC-MS). GC-MS analysis revealed that 1,2-benzenedicarboxylic acid diisooctyl ester is the major compound in FE. Molecular docking analysis showed good inhibition of 1,2-benzenedicarboxylic acid diisooctyl ester against TLR-4, NIK and TACE. Conclusion Our results suggested that 1,2-benzenedicarboxylic acid diisooctyl ester could be a potential candidate in alleviating inflammatory reactions in TI.