IMMUNOSUPPRESSIVE EFFECT OF SWERTIA CHIRATA BUCH HAM. ON SWISS ALBINO MICE

Swertia chirata Buch Ham (Gentianaceae) commonly known as chiratais a perennial herb. The present study was undertaken to evaluate the immunomodulatory effect of methanolic extract of S. chirata aerial part on Swiss albino mice. Haemagglutination Test (Humoral antibody response) and Delayed-type hypersensitivity (DTH) response test and were done to investigate the effect of methanolic extract of S. chirata on humoral and cell mediated immunity responses and flow cytometric studies for the estimation of T lymphocytes (CD3 and CD19)  and Th1 cytokines (IL-2, IFN-γ and IL-4). Levamisole and Cyclophosphamide were used as immunostimulatory and immunosuppressive standard drugs. The methanolic extract of S. chirata showed dose related decrease in primary and secondary antibody response and Delayed type hypersensitivity (DTH) response with the maximum decrease at 200 mg kg^-1 b wt (primary antibody response- 5.41±0.24, secondary antibody response- 5.39±0.19 and DTH response- 0.62±0.05). It also showed dose dependent decrease in the production of T lymphocytes (CD3 and CD19) and Th 1 cytokines (IL-2, IFN-γ and IL-4). The maximum decrease in the production of CD3, CD19, IL-2, IFN-γ and IL-4 was 33.66, 19.70, 31.12, 35.09 and 14.63% at 200 mg kg^-1 b wt. The results revealed that S. chirata showed significant decrease in the production of CD3 and IFN-γ. Phytochemical screening showed the presence of phenolic compound such as flavonoids, tannins and alkaloids which may be responsible for the activity. The above results suggest that S. chirata can be further explored for the development of potent immunosuppressive drug.