Evaluation for anti-inflammatory effects of Siegesbeckia glabrescens extract in vitro

The aim of this study is to elucidate the anti-inflammatory effects of Siegesbeckia glabrescens extract in vitro. The n-butanol fraction (100 µg/ml) of S. glabrescens had an approximately 92% inhibitory effect on nitrite production from lipopolysaccharide (LPS)-induced macrophage cells, whereas other fractions showed relatively low nitric oxide (NO) inhibition. The n-butanol and ethyl acetate fractions of S. glabrescens showed significant chemical NO quenching to approximately 39-46% in the cell-free system, and showed the decreases of inducible nitric oxide synthase (iNOS) transcription potently. The hexane, n-butanol, and ethyl acetate fractions of S. glabrescens showed approximately 90-96% inhibition of prostaglandin E2 (PGE2) synthesis. The ethyl acetate, n-butanol, and aqueous fractions of S. glabrescens showed a potent inhibition of LPS-induced cyclooxygenase-2 (COX-2) mRNA transcription. All S. glabrescens extract-fractions showed significant decreases of IL-1β biosynthesis to 69.7-97.0%, as compared to LPS-induced IL-1β production in macrophage cells.