ISOLATION OF IMMUNOMODULATORY LECTIN FROM SEEDS OF ZIZYPHUS MAURITIANA.

Immunomodulation is the process in which immune response is altered either due to poor nutrition or infectious diseases. Usually the synthetic compounds as immunomodulators are employed to induce or suppress the immune system but they appear to have many adverse effects. Therefore, the use of natural compounds as immunomodulators with less or no side effects is the requirement of time. Plant lectins have been shown to have immunomodulatory activitiy. In this context, in the present study an isolated lectin from seeds of Zizyphus mauritiana was tested for its immunomodulatory activity in vitro. The lectin was isolated and purified by the standard procedures. Immunomoduatory activity was tested with sheep blood lymphocytes including MTT cytotoxicity assay, lymphocyte proliferation assay with XTT, phagocytic activity assay and lysosomal enzyme activity assay. The purified lectin was found to be tripeptide in nature. It was found that the lectin has little or no cytotoxicity towards sheep lymphocytes with maximum concentration up to 200 µg/ml (p<0.0001) and effective dose was found to be 12.5 µg/ml (p<0.0001). Lymphocyte proliferation with effective dose was found to be significantly increased as compared to controls (p<0.0001) and it was found to be more than the LPS (p<0.0001) and that of Con-A (p<0.05) as standard mitogens. Increased phagocytic and lysosomal enzyme activity of the macrophages was observed with purified lectin (12.5 µg/ml, p<0.0001) as compared to the control. Atropine solution, used as negative control, did not show any phagocytic activity (p<0.0001) and lysosomal enzyme activity (p<0.001). From these findings it appears that the lectin of Zizyphus mauritiana can be employed as natural immunomodulatory agent to advance human health.