Anti-inflammatory activity of nicotine isolated from Brassica oleracea in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease, associated with chronic inflammation of synoviocytes. Tumor necrosis factor α (TNF-α) plays a crucial role in the pathogenesis of RA through pro-inflammatory cytokines. Nicotine, an alkaloid used as herbal medicine, often worked as an anti-inflammatory agent. In the present study, we tried to uncover the anti-inflammatory impact of nicotine against RA.

Nicotine was isolated from Brassica oleracea, purified by high profile/phase liquid chromatography (HPLC). In-silico docking was carried out using bioinformatics tools SwissADME (absorption, distribution, metabolism and excretion), PASS, and Drug-induced Gene Expression Profile (DIGEP)-Pred to determine drug likeliness of nicotine. The in-vitro study was performed in TNFα-induced SW982 synoviocytes by qPCR. mRNA expression of pro-inflammatory cytokines (TNF, IL6, IL1β) and proteins (TRAF2, P50, P65) were analyzed followed by validation of P65 (RELA), pP65, IkBα by Western blot analysis.

Nicotine compound was extracted from Brassica oleracea and purified by HPLC method (Rt values at 2.67 min). The physicochemical, pharmacokinetic properties and drug-likeliness of nicotine were studied by in-silico analysis. In-vitro studies revealed that nicotine lowers the expression of inflammatory cytokines (TNF, IL6, IL1β) and proteins (TNF receptor-associated factor 2 (TRAF2), P50, P65) at 1 µg/ml in TNFα-induced SW982 cells.

Nicotine from natural sources (Brassica oleracea) has been found to be an effective anti- inflammatory compound at a low dosage; thus, identifying the role of nicotine present in the natural sources as a therapeutic option for RA, may be recommended as remedial drug instead of synthetic drug.