Anti-inflammatory Effects of Ethanol Extract from Kummerowia striata (Thunb.) Schindl on LPS-Stimulated RAW 264.7 Cell

Kummerowia striata (Thunb.) Schindl has long been used as a fork herb in inflammation-related therapy. This study was undertaken to determine the anti-inflammatory effect of the plant. High performance liquid chromatography (HPLC) was used for evaluating the extract. While dexamethasone (DM) was used as a positive control, the effects of ethanol extract on the production of IL-1β, IL-6, NO, COX-2 and TNF-α, the expression of iNOS mRNA, TNF-α mRNA, COX-2 mRNA, protein production of COX-2 and HO-1, NF-κB and I-κB of LPS-stimulated RAW 264.7 cells were studied by sandwich ELISA, real-time PCR, Western blot analysis and immunocytochemistry assay respectively. The results showed that K. striata (Thunb.) Schindl had a good anti-inflammatory effect on LPS-stimulated RAW264.7 cell. On one hand, it could significantly inhibit the production of IL-1β, IL-6, NO, TNF-α, COX-2 in LPS-stimulated cell than that of single LPS stimulated cell (p < 0.01 or p < 0.05). On the other hand, it could increase the production of IL-10 and HO-1 than that of single LPS intervention cell (p < 0.01 or p < 0.05). Furthermore, the extract also could inhibit the production of NF-κB and I-κB compared to single LPS stimulated cell. In a word, it suggested that the anti-inflammatory actions of K. striata (Thunb.) Schindl ethanol extract might be due to the down-regulation of IL-1β, IL-6, NO, TNF-α and COX-2 via the suppression of NF-κB activation and conversation of I-κB production, and another pathway was up regulating the production of IL-10 and HO-1.