Proteomic Analyses of 3-Monochloropropanediol 1-Monooleate and 1-Monostearate Induced Testicular Toxicity in a 90 Day Sprague-Dawley Rats' Study

Toxicology of 3-monochloropropane-1,2-diol and its esters: a narrative review

3-Monochloropropane-1,2-diol (3-MCPD) is a chiral molecule naturally existing as a racemic mixture of (R)- and (S)-enantiomers. It was thoroughly investigated during the 1970s as a male antifertility drug until research was abandoned because of the side effects observed in toxicity studies. More than 20 years later, 3-MCPD, both in the free form and esterified to the fatty acids, was detected in vegetable oil and discovered to be a widespread contaminant in different processed foods. This review summarises the main toxicological studies on 3-MCPD and its esters. Current knowledge shows that the kidney and reproductive system are the primary targets of 3-MCPD toxicity, followed by neurological and immune systems. Despite uncertainties, in vivo studies suggest that renal and reproductive toxicity is mediated by toxic metabolites, leading to inhibition of glycolysis and energy depletion. Few acute, short-term, and subchronic toxicity studies have investigated the 3-MCPD esters. The pattern of toxicity was similar to that of free 3-MCPD. Some evidence suggests that the toxicity of 3-MCPD diesters may be milder than 3-MCPD, likely because of an incomplete enzymatic hydrolysis in the equivalent free form in the gastrointestinal tract. Further research to clarify absorption, metabolism, and long-term toxicity of 3-MCPD esters would be pivotal to improve the risk assessment of these compounds via food.

Bibliometric Analysis of Research Trends on 3-Monochloropropane-1,2-Diol Esters in Foods

3-Monochloropropane-1,2-diol esters (3-MCPDE) are common food contaminants mainly formed in the edible oil refining process. Due to their potential hazards, 3-MCPDE has become a widespread food safety concern. In this study, CiteSpace and VOSviewer were used to conduct a bibliometric analysis on the 3-MCPDE research papers collected in the Web of Science Core Collection from 1998 to 2022. The results showed that the number of research publications on 3-MCPDE has increased rapidly since 2010. Analysis of the hotspots in 3-MCPDE studies showed that more attention has been paid to the exposure assessment, formation mechanism, detection methods, mitigation methods and toxicity, and toxicology of 3-MCPDE. Finally, the future trends of research on 3-MCPDE were analyzed and proposed. The mitigation methods and toxicology studies of 3-MCPDE are still the research hotspots in the future. In addition, nutritional intervention for 3-MCPDE toxicity will be an emerging trend.

Dysregulation of NrF2 expression mediates testicular injury and infertility in 3-monochloro-1,2-propandiol-intoxicated rats with special reference to accessory gland-related pathology

3-Monochloropropane-1,2-diol (3-MCPD) is a food contaminant formed during acid hydrolysis of vegetable proteins. The toxicological evaluation of smaller doses of 3-MCPD is essential for safety evaluation of this compound. The present study investigates the toxicologic potential of 3-MCPD on male genital organs of rats, applies a correlation between the induced infertility and developed lesions in testes, epididymis, and accessory glands and study the possible mechanisms of 3-MCPD-induced male infertility. Forty rats were randomly divided into four main groups of ten animals each: the control untreated group and three treated groups that were orally administered 3-MCPD at different doses (3, 7.5 and 15 mg/kg b.w) daily via stomach intubation for five successive days per week. Five rats from each group were euthanized after 30 days. The remaining rats were euthanized after 90 days to establish subacute and chronic toxicity studies. Oxidative stress markers, Nrf2 gene expression, semen analysis, and histopathological examination were performed at the end of each experimental period. Results indicated that 3-MCPD induces infertility in male rat via disruption of Nrf2 expression in the testicular tissue with subsequent increased oxidative stress indicators in the testis that affect spermatogenesis and induced testicular degeneration, in addition, induction of epididymal lesions that affect sperm motility and concentration and finally possible development of hyperplastic tissue reactions in accessory glands of intoxicated rats predicting the carcinogenic potential of this compound.