A multiherbal formulation influencing immune response in vitro.

Aim: Aim of this study was to evaluate the effects of phytocomplexes of Uncaria, Shiitake and Ribes in terms of viability and inflammatory response on immune cell-derived cultures.

Methods: Standardized extracts of Uncaria, Shitake and Ribes and their commercial formulation were tested on cell lines PBMC, U937 and macrophage. The activity was evaluated in terms of cell viability (MTT test), variations of oxidative marker release (ROS and PGE2) and modulatory effects on immune response (gene expression of IL-6, IL-8 and TNFα, RT-PCR).

Results: Cell viability was not affected by extracts, except subtle variations observed only at higher doses (>250 µg/mL). The extract mixture was well tolerated, with no effects on cell viability up to doses of 500 µg/mL. Pre-treatment of macrophages with subtoxic doses of the extracts reduced the basal release of oxidative markers and enhanced the cell response to exogenous oxidant stimulation, as revealed by ROS and PGE2 release reduction. The same treatment on macrophage resulted in a selective modulation of the immune response, as shown by an increase of IL-6 mRNA and, partially, IL-8 mRNA, while a reduction was observed for TNFα mRNA.

Conclusion: Data confirm that extracts and their formulations can act as regulator of the immune system with mechanisms involving the oxidative stress and the release of selected proinflammatory cytokines.