An indigenous herbal extract IM-133N containing extracts of Prosopis glandulosa Torr and Symplocos racemosa Roxb were evaluated for potential immunomodulatory effects using RAW264.7 and THP-1 cells. The incubation of the cells for 24 h with IM-133N over a dose range 0-125 µg/ml did not cause cytotoxicity that exceeded 10%. The results indicated that non-cytotoxic doses of IM-133N effectively up-regulated iNOS, TNFα, IL-6, IL-10, IL-8 and IFNγ gene expression in both the RAW264.7 and THP-1 cells. The results also indicated IM-133N elicited dose-related increases in nitric oxide (NO) and tumor necrosis factor (TNF)-α production by RAW264.7 or THP-1 cells. These results demonstrated that IM-133N could stimulate NO and induced pro-inflammatory cytokine expression by monocytes/macrophages. As clinical studies have shown IM-133N to be an effective immunomodulator without any adverse effects, the results of the present study provide further support for the potential use of this agent as an immunostimulant or as an immunotherapy adjuvant.
Keywords: Adjuvant; IFNγ; TNFα; herbal medicine; immunostimulant; interleukins.