Pyranoanthocyanins Mitigate Cadmium-Induced Reproduction Toxicity by Suppressing Intestinal Cadmium Absorption and Maintaining Reproductive Hormone Homeostasis

Cadmium (Cd) is a pervasive environmental contaminant that accumulates in the food chain, posing significant risks to animals and humans. This study investigated the potential of dietary pyranoanthocyanins, which can mitigate Cd toxicity. In a 1-week Cd-exposure experiment, Cd levels in the blood, small intestine, and feces dramatically increased in the Cd-exposed group, but cyanidin-3-glucoside-4-vinylcatechol (C3G_VC) intervention significantly reduced ileum Cd content while enhancing fecal Cd excretion. Furthermore, the Cd_C3G_VC group significantly upregulated the expression levels of tight junction (TJ) proteins in the small intestine, contributing to improving intestinal barrier integrity. In a 1-month Cd-exposure experiment, C3G_VC decreased blood Cd (-70.0%) and significantly improved sperm count and motility. It additionally restored testosterone levels (+81.7%) and luteinizing hormone levels via the hypothalamus-pituitary-gonadal axis. This was accompanied by upregulation of the expression of key proteins in the T synthesis pathway. Overall, C3G_VC showed protective efficacy by reducing intestinal Cd absorption, promoting Cd elimination, and preserving reproductive hormone homeostasis.