Effect of berberine on copper and zinc levels in chickens infected with Eimeria tenella

Berberine, a traditional Chinese medicine, was found to exhibit anticoccidial activity. However, its mechanism is unclear. Trace metals such as copper and zinc are extremely low (less than 0.01% of the total weight of the body) but play a vital role in organisms. In the present study, we investigated the effect of berberine on copper and zinc levels in chickens infected with Eimeria tenella. Firstly, our data confirmed that infected chickens with E. tenella exhibited classic impairment on the 8th day of post infection, such as weight loss and increased feed conversion. Further study showed that E. tenella infection decreased the contents of copper and zinc in the liver and serum of chickens. Berberine was similar to amprolium and significantly improved the pathogenic conditions. Berberine could restore copper and zinc imbalance caused by E. tenella in chickens to a large extent. Studies on the development of cecum lesions demonstrated that the protective effect of berberine on the intestinal cecum was similar to that of the Cu/Zn mixture. Additionally, the mRNA expression of several metal transport related genes of the chick small intestine, including zinc transporter 1, copper transporter 1 and divalent metal ion transporter 1, was elevated by the treatment with berberine. Taken together, we speculate that the anticoccidial activity of berberine may be related to the maintenance of certain metals (Cu/Zn) homeostasis by affecting mRNA expression of their transport genes. However, the mode of action of BBR on these vital metals in the chicks infected with E. tenella still needs to be further studied.