Anti-inflammatory properties of Rhododendron dauricum Linn. Inhibition of lipopolysaccharide induced septic shock and vascular permeability

Abstract

The anti inflammatory activity of the aqueous extract of leaves of Rhododendron dauricum L. was further evaluated in models which are mediated by tumour necrosis factor – alpha (TNFα). The effect of the extract on lipopolysaccharide (LPS) induced septic shock was evaluated by measuring the number of deaths and the level of serum alanine and aspartate aminotransferase following intraperitoneal injection of LPS (1µg/kg) into D-galactosamine primed mice. LPS-induced vascular permeability on the back skin of mice was measured by local accumulation of Evan’s blue after subcutaneous injection of LPS. Pretreatment with Rhododendron dauricum L.extract (10-80 mg/kg) produced a dose dependent inhibition of the septic shock syndrome in mice, with 80 mg/kg of the extract exhibiting comparable activity as pentoxifylline (100mg/kg). LPS- induced dye leakage in the skin of mice was also suppressed by the extract (10-80 mg/kg). This study suggests that one of the mechanisms of the anti inflammatory effects of Rhododendron dauricum L. possibly involves the suppression of TNFα up-regulation.

Keywords: Rhododendron dauricum; anti-inflammatory; tumour necrosis; lipopolysaccharide; septic shock; microvascular permeability