Endocrine and metabolism modulating effects of paracetamol: From in vitro signaling to in vivo metabolic reprogramming in male mice

Obesity is a major global health challenge associated with a cluster of comorbidities, including metabolic syndrome and type 2 diabetes, necessitating a deeper understanding of the environmental factors contributing to this epidemic. This study investigated the in vitro adipogenic/lipogenic potential of paracetamol and its in vivo endocrine and metabolic modulating effects following prenatal exposure. Using the 3T3-L1 preadipocyte model, cells were exposed to paracetamol at physiologically relevant concentrations. Results demonstrated that paracetamol promoted lipid accumulation and upregulated G3PDH activity. Furthermore, low concentrations significantly increased the protein expression of key adipogenic regulators (PPARγ, C/EBPα, LPL, and SREBP1), suggesting interference with transcriptional cascades governing adipogenesis and lipogenesis. To assess in vivo effects, pregnant CD1 mice were exposed to paracetamol at three human relevant doses (Cmax/10, Cmax, and Cmax×10). In male F1 offspring, prenatal exposure resulted in increased anogenital distance and a higher incidence of sperm morphological abnormalities, indicating reproductive developmental alterations despite unchanged circulating hormone levels. Metabolically, offspring exhibited dyslipidemia characterized by elevated serum triglycerides and total cholesterol. Although body weight and glucose tolerance remained unaffected, lipidomic profiling of epididymal adipose tissue revealed pronounced remodeling, including the accumulation of neutral lipids and altered membrane phospholipid composition. This was accompanied by the upregulation of the adipogenic genes Pparγ, Lpl, and Fasn in adipose tissue. Collectively, these findings suggest that paracetamol may act as an endocrine modulator and metabolic disruptor when exposed prenatally, inducing latent metabolic dysregulation that may predispose offspring to metabolic syndrome later in life, even in the absence of overt obesity