Protection Mechanisms Underlying Oral Administration of Chlorogenic Acid against Cadmium-Induced Hepatorenal Injury Related to Regulating Intestinal Flora Balance

Cadmium (Cd) is a heavy metal, which is widely used in the industry and daily life. It has a long half-life, so large amounts of Cd can accumulate in humans and become toxic. Chlorogenic acid (CGA) can eliminate free radicals and inhibit lipid peroxidation and is mainly used to prevent metal toxicity. In the present study, mice are given CGA by intraperitoneal injection or gavage, respectively, to explore the mechanism of preventing Cd toxicity. In acute Cd-exposed mice, CGA treatment (ip) alleviated Cd-induced oxidative damage and reduced the production of NO and MPO in the liver and kidney tissues, while TLR4 expression levels did not change significantly. After 8 weeks of Cd exposure, CGA administration (gavage) significantly alleviated gut dysbiosis by decreasing the Firmicutes to Bacteroidetes ratio, enhancing the relative abundances of bacteria, including Ruminiclostridium_9, Alloprevotella, and Rikenella, and inhibiting the activation of the TLR4/MyD88/NF-κB signaling pathway. These findings suggested that protection mechanisms underlying the oral administration of CGA against the Cd-induced hepatorenal injury was related to the regulation of the intestinal flora balance. CGA can be used as an effective component in daily diet to prevent Cd toxicity.