Abstract

Oxidative stress, specifically lipid peroxidation, contributes to the pathogenesis of asthma. A natural antioxidant could be a potential therapeutic intervention. Hydro-alcoholic extract of Ixora coccinea (ICE) exhibit the anti-asthmatic activity in an ovalbumin (OVA) induced asthmatic rat model. These facts led us to examine their antioxidant activities. The free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and the intracellularly antioxidant activity of ICE were determined. The protective effect of ICE against 2,2′ azobis (2-amidinopropane) hydrochloride (AAPH)-induced red blood cell lysis was also evaluated. It was found that ICE could scavenge DPPH with an IC₅₀ of 283.3 µg/ml and protected red blood cell against AAPH-induced hemolysis with an IC₅₀ of 72.92 versus 52.08 µg/ml for ascorbic acid. Erythrocytes obtained from the ICE-administrated rats showed an enhanced resistance to hemolysis. In OVA-induced asthma, rats were sensitized and challenged with ovalbumin. The effect of ICE at 1500 mg/kg per os on malondialdehyde (MDA) production and lung catalase activity were determined. ICE significantly reduced the lipid peroxidation and enhanced catalase activity in lung (p < 0.05). In conclusion, the hydro-alcoholic extract of I. coccinea possesses an antioxidant activity and protective effect against free-radical-induced hemolysis. This may explain the traditional use of this plant as a remedy against asthma and other diseases.

Key words: Asthma, oxidative stress, antioxidants, Ixora coccinea.

Abbreviation

ICE, Extract of Ixora coccinea; OVA, ovalbumin.