Deciphering the mechanism of extract on Th17 cells through in-depth transcriptomic profiling and analysis.

Naive CD4 T cells differentiate into effector (Th1, Th2, Th17) cells and immunosuppressive (Treg) cells upon antigenic stimulation in the presence of a specific cytokine milieu. The T cell culture system provides a very efficient model to study compounds' therapeutic activity and mechanism of action. (Willd.) Hook.f. & Thomson (Family. Menispermaceae) is one of the widely used drugs in (ancient Indian system of medicine) for various ailments such as inflammatory conditions, autoimmune disorders, and cancer as well as for promoting general health. and studies on immune cells comprising dendritic cells, macrophages, and B cells suggest its immune-modulating abilities. However, to date, the effect of on individual purified and polarized T cell subsets has not been studied. Studying drug effects on T cell subsets is needed to understand their immunomodulatory mechanism and to develop treatments for diseases linked with T cell abnormalities. In this study, we examined the immunomodulatory activity of on primary CD4 T cells, i.e., Th1, Th17, and iTreg cells. An aqueous extract of was non-cytotoxic at concentrations below 1500 µg/ml and moderately inhibited the proliferation of naive CD4 T cells stimulated with anti-CD3ε and anti-CD28 for 96 h. treatment of naive CD4 T cells differentiated under Th17-polarizing conditions exhibited reduced frequency of IL-17 producing cells with inhibition of differentiation and proliferation. For the first time, in-depth genome-wide expression profiling of treated naive CD4 T cells, polarized to Th17 cells, suggests the broad-spectrum activity of . It shows inhibition of the cytokine-receptor signaling pathway, majorly the JAK-STAT signaling pathway, subsequently causing inhibition of Th17 cell differentiation, proliferation, and effector function. Additionally, the molecular docking studies of the 69 metabolites of further substantiate the inhibitory activity of the cytokine-receptor signaling pathway. Furthermore, polarized Th1 and iTreg cells treated with extract also showed reduced IFN-γ production and FoxP3 expression, respectively. This study provides insight into the plausible mechanism/s of anti-inflammatory activity of involving T cells, mainly effective in Th17-associated autoimmune and inflammatory diseases.