Immunostimulatory activity of aqueous extract of Murraya koenigii (Linn.) Spreng. leaves

Leaves of Murraya koenigii (Linn.) Spreng. (Curry patta) are reported to possess antidiabetic, antimicrobial, cytotoxic and anti-inflammatory activity. In the present study immunomodulatory potential of aqueous extract of its leaves on specific (humoral and cell mediated) and non specific (macrophage) immunity in mice was investigated. Oral administration of the aqueous extract of leaves at the doses of 250 and 500 mg/kg significantly enhanced the delayed-type hypersensitivity reaction induced by ovalbumin however, the effect was not dose related. The extract also potentiated the production of circulating antibody titre significantly in response to ovalbumin. Pre-treatment of the extract restored the myelosuppressive effect of cyclophosphamide through ameliorating total white blood cells count. Significant increase in release of nitric oxide from mouse peritoneal macrophages in culture supernatant indicates enhancement of cytotoxic activity of macrophages. The present investigation thus reveals that aqueous extract of M. koenigii leaves possesses immunostimulatory activity by acting on both specific and non-specific immunity.