Immunomodulatory activity of Nerium indicum through inhibition of nitric oxide and cyclooxygenase activity and modulation of TH1/TH2 cytokine balance in murine splenic lymphocytes.

Nerium indicum is a medicinal plant which is used in the treatment of wide range of illness in different ethnopharmacological practices. We have studied the immunomodulatory activity of the 70 % hydro-methanolic extract of N. indicum leaves (NILE) by studying plaque forming cell assay, haemagglutination titre, cell proliferation assay, inhibition of nitric oxide expression and cyclooxygenase activity, estimation of IL-2, IFN-γ, IL-4, IL-10, TNF-α and IgM levels. Furthermore, we have characterized NILE with Fourier Transform Infra-red (FTIR) spectroscopy. The results displayed that NILE possessed potent immunomodulatory activity by up-regulating IL-2, IFN-γ, IL-10 expression and down-regulating IL-4, TNF-α expression in vitro. NILE also stimulated the in vivo expression of immunoglobulin level in mouse. FTIR analysis revealed phytocompounds of diverse chemical nature present in NILE. Thus, the potent immunomodulatory activity of N. indicum may have serious implications in the treatment of inflammatory diseases in the future.