Berberine contributes to protecting against the cadmium-induced pancreatic damage: role of intestinal microbiome modulation and barrier function

Abstract

Cadmium (Cad) is a worldwide heavy metal pollutant associated with global health challenges. Alteration of the intestinal microbiome, due to chemicals’ exposure, plays a vital role in the pathogenesis of gastrointestinal diseases such as pancreatic disorders. Hence, modulation of the gut microbiota might be a targeted approach to manage pancreatic diseases. Using murine modeling, this study consisted of two dependent experiments to investigate the curative potential of berberine (BBR) in a Wistar rat model of Cad-provoked pancreatic toxicity and the possible contribution of gut microbiota to BBR protection. In experiment 1, Cad-induced pancreatic injury was established in rats via 8-week oral gavage of Cad at 4 mg/kg. The treatment group was exposed to BBR at 200 mg/kg body weight, oral gavage for 8 weeks. In experiment 2, transplantation of the fecal microbiome was done, in which the fecal microbiota in each group of experiment 1 was orally gavaged to the healthy rats of each corresponding group in experiment 2, once weekly for 8 weeks. The serum amylase and lipase levels, pancreatic inflammatory and oxidative markers, histological, and immunohistochemical analyses were evaluated. The markers of gut mucosal barrier, and mRNA expression of cell junction proteins were investigated for possible intestinal injury. 16S rRNA sequencing was applied to identify the gut bacterial changes and possible pancreatic bacterial translocation. Cad induced intestinal barrier disruption and elicited a state of pancreatic inflammation and apoptosis as indicated by TGF-β and BAX immunohistochemistry, which were relieved by BBR. A decreased firmicutes/bacteroidetes ratio and microbial migration due to interrupted intestinal mucosal barrier were reported. Furthermore, BBR restored the bacterial richness and proportions in the gut, thereby maintaining the intestinal microbial community, fixing the intestinal mucosal barrier structure, and inhibiting the pathway of bacterial migration. BBR protected against Cad-induced pancreatic damage, mostly through safeguarding the intestinal barrier function. Modulation of the intestinal bacterial community, repairing the gut barrier structure, and interference with the pancreatic bacterial migration and colonization were suggested BBR effects, potentially alleviating Cad-related pancreatic injury.