Trichosanthes tricuspidata Lour. Methanol Extract Exhibits Anti-Inflammatory Activity by Targeting Syk, Src, and IRAK1 Kinase Activity

Trichosanthes tricuspidata Lour., also known as T. palmata Roxb, T. bracteata Lam., T. puber Blume, and Modecca bracteata, is a vine belonging to the Cucurbitaceae family (English name: redball snake gourd). Distributed in China, South and East Asia, and tropical Australia, it has been traditionally used as a medicinal plant for its antifever, laxative, anthelmintic properties and for migraine treatment. In this paper, we examined the effects of Trichosanthes tricuspidata Lour. ethanol extract (Tt-ME) in vitro and in vivo. To confirm the effects of Tt-ME on inflammatory responses, we conducted experimental analyses including level of nitric oxide (NO) production, RT-PCR, and immunoblotting and using a HCl/EtOH-induced gastritis animal model. Tt-ME attenuated the release of NO and decreased mRNA levels of inducible NO synthase (iNOS), TNF-α, and IL-6 in lipopolysaccharide- (LPS-) induced macrophages in a concentration-dependent manner. Tt-ME time-dependently suppressed nuclear translocation of nuclear factor kappa B (NF-κB) subunits p50 and p65, activator protein (AP-1) subunits c-Fos and c-Jun, and STAT3 transcriptional activity by inhibiting nuclear translocation of p50, p65, c-Fos, c-Jun, and STAT3. Tt-ME significantly downregulated NF-κB, MAPK, and JAK2 signaling by targeting Syk, Src, and IRAK1 protein kinases. Furthermore, matrix metalloproteinase-9 (MMP-9) expression and cell migration were observed to be downregulated by Tt-ME in LPS-activated macrophages. In vivo studies on Tt-ME also produced similar trends in Hcl/EtOH-induced gastritis mouse models by inhibiting proinflammatory cytokines and the inflammatory signaling pathway. Our results strongly suggest that Tt-ME exerted anti-inflammatory activity in LPS-stimulated macrophages and mouse models of acute inflammatory disease.