Preparation of pectin from fingered citron peel and its protective effect on cadmium-induced liver and kidney damage in mice

Citrus pectin has been proved for its ability to bind heavy metals from industrial wastewater. However, few studies have investigated the detoxification effect of citrus pectin on cadmium-induced damage through in vivo experiments. In this study, pectin was extracted from fingered citron peel and subjected to pH-temperature modification, and successful modification of pectin's molecular structure was confirmed by a decrease in the degree of esterification and the increase in the content of free carboxylate groups in the structure. In vitro studies suggested that the modified fingered citron peel pectin (mFCPP) showed higher cadmium removal ability compared to unmodified fingered citron peel pectin (FCPP). A 20-week study in cadmium-exposed mice suggested significant improvement in liver and kidney function with co-treatment of pectin. Co-treatment with FCPP or mFCPP ameliorated the cadmium-induced cell death and oxidative damage in the liver and kidney. Moreover, the study demonstrated that both FCPP and mFCPP were impermeable through the intestinal wall, suggesting their binding with the cadmium ions in the gastrointestinal tract, thus preventing cadmium ions absorption and entry into the systemic circulation.