Cell surface ATP synthase-released H+ and ATP play key roles in cocoa butter intake-mediated regulation of gut immunity through releases of cytokines in rat.

Proper food intake is important for maintaining good health in humans. Chocolate is known to exert anti-inflammatory effects; however, the mechanisms remain unclear. In this study, we aimed to investigate the effects of cocoa butter intake on gut immunity in rats and rabbits. Cocoa butter intake increased the lymph flow, cell density, and IL-1β, IL-6 and IL-10 levels in mesenteric lymph. Clodronate, a macrophage depletion compound, significantly enhanced the release of all cytokines. The immunoreactivities of macrophage markers CD68 and F4/80 in the jejunal villi were significantly decreased with clodronate. Piceatannol, a selective cell surface ATP synthase inhibitor significantly reduced the cocoa butter intake-mediated releases of IL-1β, IL-6 and IL-10. The immunoreactivities of cell surface ATP synthase were observed in rat jejunal villi. Shear stress stimulation on the myofibroblast cells isolated from rat jejunum released ATP and carbon dioxide depended with H+ release. In rabbit in vivo experiments, cocoa butter intake increased the concentrations of ATP and H+ in the portal vein. The in vitro experiments with isolated cells of rat jejunal lamina propria the pH of 3.0 and 5.0 in the medium released significantly IL-1β and IL-6. ATP selectively released IL-10. These findings suggest that cocoa butter intake regulates the gut immunity through the release and transport of IL-1β, IL-6, and IL-10 into mesenteric lymph vessels in a negative feedback system. In addition, the H+ and ATP released from cell surface ATP synthase in jejunal villi play key roles in the cocoa butter intake-mediated regulation of gut immunity.