IMMUNOMODULATORY ACTIVITY OF AN ACETONE EXTRACT OF TERMINALIA BELLERICA ROXB FRUIT ON THE MOUSE IMMUNE RESPONSE IN VITRO

Objectives: To investigate the immunomodulatory activity of an acetone extract of T. bellerica fruit. Methods: Mitogen induced-lymphocyte proliferation using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) technique, Th1- and Th2-related cytokine production by lymphocytes using ELISA and peritoneal macrophage function in ICR mice were assayed. Results: The results show that the extract had a mild inhibitory effect on the generation of oxidase enzyme (Phagocytic Index 0.8, 100 mg/ml) but did not influence acid phosphatase enzyme function during phagocytosis. The extract stimulated the proliferation of both T and B lymphocytes. The maximal activation (Stimulation Index 3.2, 100 mg/ml) was presented with concanavalin A induction, indicating a major effect on T lymphocyte proliferation. The extract reduced the production of IFN-γ (89%, 100 mg/ml) and IL-2 (98%, 100 mg/ml) but increased IL-10 secretion (231%, 100 mg/ml) compared to concanavalin A. Gallic acid, a pharmacological component contained in this plant, presented a similar effect as that of T. bellerica extract and may contribute to the immunomodulatory activity of T. bellerica fruits in cooperation with other phytocompounds. The decrease in the IFN-g/IL-10 ratio indicated a shift in the Th1/Th2 balance towards a Th2-type response, which might lead to a treatment for Th1-mediated inflammatory immune diseases. Conclusion: Our investigations show that the acetone extract of T. bellerica fruit possesses immunomodulatory activity, which could be used to explain its folklore applications and provide a pharmacological basis for its usefulness in immune-related disorders