Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Total Glucosides of Paeonia lactiflora Pall Suppress Nitric Oxide Production and iNOS expression in Lipopolysaccharide-Stimulated RAW264.7 Macrophages

Gang Chen¹ , Ming-Liang Tan², Xue Gao², Shu-Zhen Kong²

¹School of Environmental and Biological Engineering; ²Chongqing Key Laboratory of Nature Medicine Research, Chongqing Technology and Business University, Chongqing 400067, China.

For correspondence:- Gang Chen Email: gangchtcm@hotmail.com Tel:+862362768059

Received: 19 December 2013 Accepted: 2 June 2014 Published: 18 August 2014

Citation: Chen G, Tan M, Gao X, Kong S. Total Glucosides of Paeonia lactiflora Pall Suppress Nitric Oxide Production and iNOS expression in Lipopolysaccharide-Stimulated RAW264.7 Macrophages. Trop J Pharm Res 2014; 13(8):1273-1278 doi: 10.4314/tjpr.v13i8.11

© 2014 The authors.
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Abstract

Purpose: To investigate the effect of total glucosides of Paeonia lactiflora (TGPL) on nitric oxide (NO) production and its potential mechanism in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells.

Methods: RAW264.7 cells were treated with 10 - 300 μg/ml TGPL and 1 μg/ml LPS. Cell survival was determined by MTT assay. NO level was determined by Griess reaction assay. Inducible NO synthase (iNOS) expression and inhibitor-κBα (IκBα) degradation were determined by Western blot assay. DNA binding activity of NF-κB was determined by ELISA assay using Trans AM™ kit for p65.

Results: The concentrations of TGPL (10 - 300 μg/ml) used in this study did not affect cell survival of RAW264.7 cells, which suggest that 10-300 μg/ml TGPL did not show cytotoxic effect on RAW264.7 cells. NO level and iNOS protein expression significantly increased in LPS-stimulated RAW264.7 cells compared to the unstimulated cells. However, 10 - 300 μg/ml TGPL significantly decreased LPS-induced NO level and iNOS protein expression compared to LPS-stimulated RAW264.7 cells alone. Furthermore, 10 - 300 μg/mL TGPL significantly reduced the content of IκBα protein in LPS-stimulated RAW264.7 cells, which suggests that TGPL inhibited LPS-induced degradation of IκBα protein. TGPL remarkably repressed LPS-induced DNA binding activity of P65 in RAW264.7 cells.

Conclusion: These findings suggest that TGP inhibits NO production and iNOS expression through suppression of NF-κB activation in LPS-stimulated RAW264.7 cells.

Keywords: Total glucosides, Paeonia lactiflora, Nitric oxide, iNOs, Nuclear factor-_4;B