Effect of milk exposure on the redox profile of Caenorhabditis elegans

The consumption of bovine milk and its derivatives is associated with inflammation, gastrointestinal disorders and the development of diseases in humans. Most studies related to milk effects are based on either clinal trials or experimental models such as mice and cell cultures. In this study we present the nematode Caenorhabditis elegans as an alternative model to evaluate the effects of milk on oxidative stress in other animal models. The toxicological effect of 20% milk exposure for 8 h on C. elegans was evaluated by progeny quantification, body size and pharyngeal pumping rate. Treating the worms with milk did not affect the worms brood size but interfered with their fecundity by delaying the average number of eggs in the first day of oviposition when compared to the control group. The size of worms treated with milk were significantly smaller compared to control. The pharyngeal pumping rate of milk-treated animals was not significantly different compared to untreated animals. Taking together, the results suggest that 20% milk treatment is not toxic for the worms but induces a minor delay achieving its adulthood and therefore its reproduction period. Milk exposure did not reduce the worms' survival under stress conditions and increase endogenous ROS levels. This study contributes to characterize the effects of milk exposure on the C. elegans nematode.