Immunomodulatory activities of Acacia catechu, a traditional thirst quencher of South India

BACKGROUND: Acacia catechu has been widely used in Ayurveda for treating many diseases. Its heartwood extract is used in asthma, cough, bronchitis, colic, diarrhea, dysentery, boils, skin afflictions, sores and for stomatitis. The decoction of heartwood is used for drinking purpose in southern part of India especially in Kerala. OBJECTIVE: The current study was carried out to evaluate immunomodulatory effects of heartwood extracts of A. catechu in Swiss albino mice. MATERIAL AND METHODS: In vivo immunomodulatory activity was analyzed by hemagglutinating antibody (HA) titer, plaque forming cell assay and delayed type hypersensitivity (DTH). In vitro immunomodulatory potential of the extracts was studied using peritoneal macrophages and splenocytes from mice. Effect of extracts on phagocytic activity of macrophages was analyzed by nitroblue tetrazolium (NBT) reduction assay and cellular lysosomal enzyme assay. Anti-inflammatory activity was studied by nitric oxide (NO) assay and production of TNF-α and IL-10. RESULTS: A dose dependent increase in antibody titer was observed with extracts treatment. Treatment with extracts produced an enhancement in the number of antibody producing cells in the spleen. DTH reaction was significantly decreased with extracts treatment. An increased phagocytic response was shown by peritoneal macrophages on treatment with the extracts as evidenced by its effect on NBT reduction and cellular lysosomal enzyme activity. The extracts inhibited the release of pro-inflammatory cytokine TNF-α and the production of NO. IL-10 production was significantly increased after extract treatment. CONCLUSION: The results of the present study indicate the immunomodulatory effects of A. catechu extracts on humoral, cell mediated and non-specific immune functions.