Benzyl isothiocyanate exhibits anti-inflammatory effects in murine macrophages and in mouse skin

Abstract

Benzyl isothiocyanate (BITC) is detected in abundance in Brassica vegetables, and some previous studies have demonstrated that BITC may potentially function as a chemopreventive agent in humans. This study examined whether BITC inhibits lipopolysaccharide (LPS)-induced inflammatory responses in Raw 264.7 macrophages and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema formation. The treatment of macrophages with various concentrations of BITC resulted in a dose-dependent reduction in the LPS-induced secretion of interleukin (IL)-1beta, TNF-alpha, and IL-6 and their corresponding mRNA levels, as well as in the production of nitric oxide and PGE(2). Consistent with these findings, BITC inhibited the LPS-induced expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 proteins and their corresponding mRNAs. BITC inhibited LPS-induced phosphorylation and the degradation of the inhibitor of kappaBalpha, translocation of p65 into the nucleus, and the DNA binding activity and transcriptional activity of NFkappaB. Moreover, the LPS-stimulated phosphorylation of extracellular signal regulated kinase (ERK)1/2 and Akt was suppressed by BITC. BITC also inhibited ear edema formation and the protein expression of iNOS and COX-2 in mouse skin treated with TPA. We demonstrate that BITC is a potent anti-inflammatory agent, and the anti-inflammatory properties of BITC may result from the downregulation of NFkappaB signaling.