Research

Inhibition of release of inflammatory mediators in primary and cultured cells by a Chinese herbal medicine formula for allergic rhinitis

George B Lenon¹ , Charlie CL Xue¹ , David F Story¹ , Frank CK Thien³ , Sarah McPhee² and Chun G Li¹

¹The RMIT Chinese Medicine Research Group, RMIT University, Plenty Road, Bundoora 3083, Australia

²The Natural Products Research Group, School of Medical Sciences, RMIT University, Plenty Road, Bundoora 3083, Australia

³Alfred Hospital & Monash University, Commercial Road, Melbourne 3004, Australia

author email corresponding author email

Chinese Medicine 2007, 2:2doi:10.1186/1749-8546-2-2

Published:	15 February 2007

Abstract

Background

We demonstrated that a Chinese herbal formula, which we refer to as RCM-101, developed from a traditional Chinese medicine formula, reduced nasal and non-nasal symptoms of seasonal allergic rhinitis (SAR). The present study in primary and cultured cells was undertaken to investigate the effects of RCM-101 on the production/release of inflammatory mediators known to be involved in SAR.

Methods

Compound 48/80-induced histamine release was studied in rat peritoneal mast cells. Production of leukotriene B₄ induced by the calcium ionophore A23187 was studied in porcine neutrophils using an HPLC assay and lipopolysaccharide-stimulated prostaglandin E₂ production was studied in murine macrophage (Raw 264.7) cells by immune-enzyme assay. Expression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) was determined in Raw 264.7 cells, using western blotting techniques.

Results

RCM-101 (1–100 μg/mL) produced concentration-dependent inhibition of compound 48/80-induced histamine release from rat peritoneal mast cells and of lipopolysaccharide-stimulated prostaglandin E₂ release from Raw 264.7 cells. Over the range 1 – 10 μg/mL, it inhibited A23187-induced leukotriene B₄ production in porcine neutrophils. In addition, RCM-101 (100 μg/mL) inhibited the expression of COX-2 protein but did not affect that of COX-1.

Conclusion

The findings indicate that RCM-101 inhibits the release and/or synthesis of histamine, leukotriene B₄ and prostaglandin E₂ in cultured cells. These interactions of RCM-101 with multiple inflammatory mediators are likely to be related to its ability to reduce symptoms of allergic rhinitis.