Immunomodulatory Properties of Polyphenol-Rich Sugarcane Extract on Human Monocytes

As inflammatory lifestyle factors become more prevalent and as the population ages, the management of inflammation will become increasingly relevant. Plant polyphenols are powerful antioxidants that are known to have beneficial effects in a number of diseases with an inflammatory or oxidative component, such as malignancy, cardiovascular disease and arthritis. Polyphenol-rich sugarcane extract (PRSE) is a novel preparation with high concentrations of polyphenolic antioxidants, with some evidence to show benefits in health, but there is limited research investigating its effects on immunomodulation. This study determined the effects of PRSE on human monocyte cells in vitro. We show that PRSE has an immunomodulatory effect in U937 human monocyte cells, altering the expression of cellular surface markers, with an increased expression of CD16 and CD11b, as well as small changes in CD40, CD80, CD80, CD206 and MHCI. It also modulates the profile of secreted cytokines, increasing IL-1β, TNFα, IL-6, IL-8, IL-4 and IL-10. These changes are consistent with the advanced differentiation of the monocyte, as well as the switch from the M1 to M2 phenotype in macrophages. We also demonstrate that this effect is likely to be independent of the NF-κB signalling pathway, suggesting that other mechanisms drive this effect. PRSE exerts an immunomodulatory effect on U937 monocytes in vitro, potentially facilitating the conversion from inflammation to healing. Future studies should identify specific mechanisms underlying the changes and evaluate their effectiveness in animal models of disease.