Amaranthus spinosus Linn. inhibits mast cell-mediated anaphylactic reactions

Protective effect of Achyranthes aspera against compound 48/80, histamine and ovalbumin-induced allergic disorders in murine model

BACKGROUND

Achyranthes aspera L. (family Amaranthaceae) is a plant species valued in Ayurveda for the treatment of respiratory ailments. Scientific validation of its antiallergic potential was aimed.

METHODS AND RESULTS

Three extracts of A. aspera [aqueous (AaAq), hydroalcoholic (AaHA), ethanolic (AaEt)] were evaluated for their potency against C48/80-induced anaphylaxis in mice at 200 mg/kg BW oral dose. The effective dose of the most potent extract was determined through its effect on C48/80-induced anaphylaxis, and was further analyzed through its effect on mast cell degranulation, histamine-induced bronchospasm and ovalbumin (OVA)-induced asthma in a murine model. Among the three extracts, AaAq was found to be most potent at 200 mg/kg BW. AaAq 400 (400 mg/kg BW) was found to be the most effective dose in terms of inhibition of mortality and histamine level. AaAq 400 prevented the peritoneal and mesenteric mast cells from undergoing morphological changes due to degranulation induced by C48/80. Further, AaAq 400 delayed pre-convulsive time in histamine-induced bronchospasm. In the OVA-induced asthma model, AaAq 400 inhibited the level of inflammatory cell count in blood, bronchoalveolar lavage fluid and peritoneal fluid of mice. The Th2 cytokines (IL-4, IL-5, IL-13), TGF-β and OVA-specific IgE were also reduced as evaluated by ELISA. Also, significant reduction in IL-5 (an eosinophilia indicator) transcript abundance and lung inflammatory score was observed. AaAq was safe up to 4000 mg/kg BW.

CONCLUSIONS

Thus AaAq 400 possesses significant antiallergic potential and acts via attenuation of C48/80-induced anaphylaxis and inhibition of mast cell degranulation. It reduces pre-convulsive dyspnea in histamine-induced bronchospasm and Th2 cytokines in asthmatic mice.