Immunomodulatory effect of Pseudostellaria heterophylla peptide on spleen lymphocytes via Ca2+/CaN/NFATc1/IFN-γ pathway
Pseudostellaria heterophylla has been becoming a popular research topic because of its functional active components. The immunomodulatory activity of P. heterophylla peptide (PPH) derived from protein hydrolysate and its molecular mechanism underlying the immunomodulatory effect were investigated in this study. Immunomodulatory PPH achieved the highest stimulation index 1.53 at the concentration of 100 μg/mL for 48 h in spleen lymphocytes and promoted the secretions of tumor necrosis factor-α, interferon-γ, interleukin-10. Moreover, PPH could elevate intracellular Ca2+ concentration, calcineurin activity and nuclear factor of activated T cells (NFAT) c1 mRNA expression. Meanwhile these effects could be diminished by the treatment of verapamil and cyclosporin A, suggesting that PPH may activate spleen lymphocytes via Ca2+/CaN/NFATc1/IFN-γ signaling pathway. These findings demonstrate that P. heterophylla peptide has the potential prospect to be utilized as a nutraceutical supplement to strengthen immune system in the human body.