Antioxidant and anti-inflammatory effects of Ruta chalepensis L. extracts on LPS-stimulated RAW 264.7 cells

Ruta chalepensis L. is used in the traditional herbal treatment of various diseases. The aim of this work is to investigate the effect of different extracts of R. chalepensis L. on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene expressions and their antioxidant capacity on murine RAW 264.7 macrophage challenged with lipopolysaccharide (LPS). In fact, this study shows that the ethanol and ethyl acetate extracts of R. chalepensis L. considerably decreased the nitric oxide (NO) production in murine RAW 264.7 macrophages stimulated with lipopolysaccharide. Thus, the treatment with both extracts significantly suppressed the levels of iNOS and COX-2 gene expressions through the inhibition of the nuclear factor-κB (NF-κB) activation. The preincubation of RAW 264.7 cells with various concentrations of ethanol and ethyl acetate extracts decreased the production of thiobarbituric acid-reactive substances (TBARS) in a dose-dependent manner. It also increased the activities of antioxidative enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in LPS-stimulated macrophages, compared to those in the cells treated only with LPS. Besides, the 1H NMR spectra of both extracts have demonstrated the presence of aromatic signals, thus confirming the existence of phenolic compounds such as flavonoids and polyphenols. So, the ethanol and ethyl acetate extracts of R. chalepensis L. have been shown to possess enough antioxidant and anti-inflammatory activities to prevent LPS-induced oxidative stress and inflammation in RAW 264.7 macrophages.