Methods: Liquid-liquid extraction, silica gel, and Sephadex LH20 column chromatographic methods were used for isolation and purification of compounds. IgE inhibitory effects on human B cells (U266 human myeloma cells), peripheral blood mononuclear cells (PBMCs) from allergic patients, and peanut sensitized and challenged murine asthma model was assessed.
Results: The compounds isolated and purified (purity is>95%) from Arctium lappa L.were identified as arctiin and arctigenin with dose-dependently and significantly inhibition of U266 cells IgE production (as low as 5μg/mL for arctiin and 2. 5μg/mL for arctigenin) without any sign of cytotoxicity. Arctiin and arctigenin (as low as 1μg/mL) also non-toxically abolished IL-4 and anti-CD40 stimulated IgE production by PBMCs from food allergic patients. Arctigenin (20mg/kg) decreased score of anaphylactic reactions, blocked body temperature decrease, and reduced peanut-specific IgE levels on peanut allergic mouse model.
Conclusions: Both arctiin and arctigenin inhibited IgE production in human B cell line and food allergic patient PBMCs. Arctigenin blocked anaphylactic reactions in a murine model of peanut allergy. Arctigenin may have potential for treatment of IgE associated inflammatory diseases, which requires further investigation.