Vitex trifolia L. modulates inflammatory mediators via down-regulation of the NF-κB signaling pathway in carrageenan-induced acute inflammation in experimental rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Vitex trifolia L. (V. trifolia L.), commonly known as the three-leaved chaste tree, is extensively employed in traditional Chinese medicine (TCM) to treat various conditions associated with inflammation. AIM OF THE STUDY: The present study aimed to delineate the molecular mechanisms responsible for the anti-inflammatory effect of V. trifolia L. in carrageenan (CA)-induced acute inflammation in experimental rats. MATERIALS AND METHODS: CA-induced rat paw edema model was adopted to investigate the anti-inflammatory effect of methanolic extract from leaves of V. trifolia L. (VTME) in vivo. Leukocyte infiltration into the site of inflammation was determined by histopathological analysis. Further, the effect of VTME on CA-induced local and systemic levels of specific cytokines was quantified by enzyme-linked immunosorbent assay (ELISA). Moreover, its impact on the nuclear translocation of nuclear factor Kappa B (NF-κB) was analyzed by employing the western blotting technique. RESULTS: VTME at the doses of 100 mg/kg and 200 mg/kg significantly inhibited the paw edema induced by CA (p < 0.05) and effectively reduced the inflammatory leukocyte infiltration. Further, VTME markedly inhibited the CA-induced levels of Interleukin (IL)-1ß, IL-6, tumor necrosis factor (TNF)-α in tissue, and that of cytokine-induced neutrophil chemoattractant (CINC)-2/C-X-C motif chemokine (CXCL)3 and CINC-3/CXCL2 in tissue as well as in serum. On the other hand, VTME significantly upregulated the tissue concentration of anti-inflammatory cytokine IL-10. Moreover, VTME significantly attenuated the CA-induced IκBα degradation and nuclear translocation of NF-κB p65. CONCLUSIONS: Our results demonstrate the potent anti-inflammatory effect of V. trifolia L. in vivo, providing insight into its molecular mechanism, which is mediated through down-regulation of NF-κB signal transduction.

Local and Systemic Profiles of Inflammatory Cytokines in Carrageenan-induced Paw Inflammation in Rats.

OBJECTIVE: Carrageenan (CA)-induced edema has been described as highly reproducible model of acute inflammation. However, little is known about the cytokines attributed to the CA-induced inflammation. In this study, we aimed to investigate the local and systemic expression profiles of various inflammatory cytokines following the subplantar injection of CA in rats. METHODOLOGY: Acute inflammation was induced in male Wistar rats by subplantar injection of CA. Serum and paw tissue were examined for the level of 19 specific inflammatory cytokines using antibody array. Further, the CA-elicited level of key inflammatory cytokines, cytokine-induced neutrophil chemoattractant (CINC)-2, CINC-3, interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α, were quantified by enzyme-linked immunosorbent assay (ELISA). RESULTS: Edema was peaked 3 h postinjection of CA in hind paw. Among 19 specific cytokines profiled using antibody array, CA significantly (p < 0.05) elicited the levels of CINC-2, CINC-3, IL-1ß, IL-6, ß-NGF, TNF-α, and VEGF in paw tissue and that of CINC-2 and CINC-3 in serum. Consistently, levels of CINC-2, CINC-3, IL-1ß, IL-6, and TNF-α in tissue and CINC-2 and CINC-3 in serum were upregulated in CA-treated rats when compared to control, quantified by ELISA. CONCLUSIONS: This study corroborates the distinct pattern of inflammatory cytokines involved during CA-induced acute inflammation. Furthermore, data provide new evidence on elevated expression of rat CXC chemokines: CINC-2 and CINC-3 at the site of inflammation as well as their significant reflection in the circulation, thereby suggesting their frontline role in CA-induced acute inflammation.