West African Sorghum bicolor Leaf Sheaths Have Anti-Inflammatory and Immune-Modulating Properties In Vitro

The impact of chronic inflammatory conditions on immune function is substantial, and the simultaneous application of anti-inflammatory and immune modulating modalities has potential for reducing inflammation-induced immune suppression. Sorghum-based foods, teas, beers, and extracts are used in traditional medicine, placing an importance on obtaining an increased understanding of the biological effects of sorghum. This study examined selected anti-inflammatory and immune-modulating properties in vitro of Jobelyn (TM), containing the polyphenol-rich leaf sheaths from a West African variant of Sorghum bicolor (SBLS). Freshly isolated primary human polymorphonuclear (PMN) and mononuclear cell subsets were used to test selected cellular functions in the absence versus presence of aqueous and ethanol extracts of SBLS. Both aqueous and nonaqueous compounds contributed to reduced reactive oxygen species formation by inflammatory PMN cells, and reduced the migration of these cells in response to the inflammatory chemoattractant leukotriene B4. Distinct effects were seen on lymphocyte and monocyte subsets in cultures of peripheral blood mononuclear cells. The aqueous extract of SBLS triggered robust upregulation of the CD69 activation marker on CD3-CD56+natural killer (NK) cells, whereas the ethanol extract of SBLS triggered similar upregulation of CD69 on CD3+CD56+ NKT cells, CD3+ T lymphocytes, and monocytes. This was accompanied by many-fold increases in the chemokines RANTES/CCL5, Mip-1 alpha/CCL3, and MIP-1 beta/CCL4. Both aqueous and nonaqueous compounds contribute to anti-inflammatory effects, combined with multiple effects on immune cell activation status. These observations may help suggest mechanisms of action that contribute to the traditional use of sorghumbased products, beverages, and extracts for immune support.