Abstract
The incidence of nonalcoholic steatohepatitis (NASH) is increasing worldwide. Activation of Kupffer cells (KCs) is central to the development of diet-induced NASH. We investigated whether a combination of two active chemical components, geniposide and chlorogenic acid (GC), at a specific ratio (67 : 1), ameliorates diet-induced NASH and the underlying mechanisms involved. C57BL/6J mice exposed to a high-fat and high-cholesterol (HFHC) diet containing cholesterol, choline, and high-sugar drinking water, as well as RAW264.7 cells stimulated with lipopolysaccharide (LPS) were studied. The combination exerted a therapeutic effect on HFHC-induced NASH in mice. Simultaneously, GC was found to reduce the expression of cytokines secreted by hepatic macrophages, including tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α), IL-1β, IL-6, monocyte chemotactic protein 1 (MCP-1), and granulocyte-macrophage colony-stimulating factor (GM-CSF). Moreover, GC reduced the number of KCs expressing F4/80. Furthermore, TNF-α, inducible nitric oxide synthase (INOS), IL-1β, and IL-6 mRNA and TNF-α protein expression levels were suppressed upon GC treatment in RAW264.7 cells. Our findings suggest that GC has a strong anti-inflammatory effect in NASH, and this effect can be attributed to the suppression of KC activity in the liver.