Protein coronas formed by three blood proteins and food-borne carbon dots from roast mackerel: Effects on cytotoxicity and cellular metabolites

Food-borne carbon dots (FCDs) produced naturally during food thermal processing are one of important factors affecting human health. The FCDs will inevitably encounter blood proteins after oral administration and spon-taneously form protein coronas. In this study, the interaction of three major blood proteins, including albumin, gamma globulin, and fibrinogen, with FCDs from roasted mackerel was investigated for the first time. The purpose of the research is to explore the effect of the protein corona on the biological effects of cytotoxicity and the metabolic response. The results showed that FCDs spontaneously bound to the three blood proteins, and the process involved the participation of multiple interaction forces. Three protein coronas attenuated FCD-mediated cell viability damage, oxidative stress, and mitochondrial membrane potential. Further metabolomics analysis showed that FCDs disrupted cellular carbohydrate, amino acid, and nucleotide metabolism and significantly affected the expression of six metabolic pathways in normal rat kidney cells. The protein corona alleviated the disorder of energy and substance metabolism pathways. However, the protein corona inevitably expands the range of affected metabolic responses. The results of this study are of great value in exploring the toxicity characteristics of FCDs and their protein coronas.