Anti-inflammatory potential of ursolic acid in Mycobacterium tuberculosis-sensitized and Concanavalin A-stimulated cells

Abstract

Ursolic acid (3--3-hydroxy-urs-12-ene-28-oic-acid; UA) is a triterpenoid carboxylic acid with various pharmaceutical properties. It is commonly found in apples, basil, berries, rosemary, peppermint, lavender, oregano, thyme, hawthorn and prunes. In the present study, the activities of UA against the Mycobacterium tuberculosis H37Rv-induced release of a panel of inflammatory cytokines, including tumor necrosis factor- (TNF-), interleukin (IL)-1 and IL-6 from RAW 264.7 murine macrophages, A549 alveolar epithelial cells and in concanavalin A (Con A)-stimulated rat splenocytes were investigated. In addition, the present study examined the ability of UA to reduce the expression levels of the inflammatory mediators, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in the stimulated cells. The reduction of nitric oxide (NO) release by UA was also examined in the stimulated cells. UA significantly inhibited the mRNA expression levels of TNF-, IL-1 and IL-6 in the stimulated cells. The expression levels of COX-2 and iNOS were also suppressed by UA, as was the release of NO at a significant level. The data indicated the potency of UA on different cell types, which may assist in the development of anti-inflammatory drugs. In the case of adjunct host-directed immune therapy for tuberculosis, UA may be used, in addition to established antibiotic therapies, to improve treatment efficacy and outcome due to their anti-inflammatory potential. Further detailed investigations are required to establish its use as an anti-inflammatory.