Complementary cereals and legumes for health: Synergistic interaction of sorghum flavones and cowpea flavonols against LPS-induced inflammation in colonic myofibroblasts

ScopeCereals and legumes are traditionally consumed together in many cultures, and may provide complementary health benefits beyond what is known about improved indispensable amino acid intake. Here, we use an in vitro model of inflammatory pathways to investigate whether the different flavonoids in sorghum and cowpea could synergistically reduce inflammation. Methods and resultsInteractive effect of combining apigenin and quercetin, as well as extracts (70% acetone, v/v) from a flavone-dominated white sorghum and flavonol-dominated white cowpea, against LPS-induced NF-B and downstream cytokines (TNF-, IL-6, IL-8) gene and protein expression was evaluated using the CCD18Co colon myofibroblasts. Combination of apigenin and quercetin, and sorghum and cowpea extracts synergistically downregulated LPS-induced NF-B gene and protein expression in a dose-dependent manner, with additive effect producing IC50 values that were 14.6 and 14.0 times, respectively, higher than 1:1 combined treatments. Similar strong synergistic interactions were observed for the downstream cytokines (IC50 values for additive effect 8.3-21 times higher than combined treatments). Furthermore, the ratios of the different combined treatments significantly affected the magnitude of synergy. ConclusionCombining the structurally related cereal flavones and legume flavonols elicit strong synergistic anti-inflammatory response in LPS-stimulated nonmalignant colonocytes, likely by targeting interdependent mechanisms.