"Brij 35 inhibited the CYP2E1-mediated metabolism and P-gp mediated transport of Paracetamol in rats and in vitro models: Amelioration of Paracetamol Toxicity.

The harmful by-product of paracetamol is known as N-Acetyl-p-benzoquinoneimine, (NAPQI). When paracetamol is given at therapeutic dosages or in excess, it undergoes Phase I metabolism in the liver via Cytochrome P-450 2E1 (CYP2E1), and then it produces NAPQI. Previous studies reported that a non-ionic surfactant known as Brij 35 (Polyoxyethylene lauryl ether) has been shown to be an effective inhibitor of CYP2E1 and P-glycoprotein (P-gp). Hence, this in vitro and in vivo investigation set out to assess Brij 35 impact on paracetamol CYP2E1-mediated metabolism. For the in vitro investigation, isolated rat hepatocytes were used. Male Wistar rats were used for in vivo studies. There were thirty rats in total, with six individuals each group distributed among the five groups. The first group animals received 0.5% sodium carboxy methyl cellulose (control group); the second group animals treated with 300 mg/kg of paracetamol; the third group animals treated with Brij 35 (5 mg/kg) along with 300 mg/kg of paracetamol; the fourth group animals treated with 10 mg/kg of Brij 35 along with 300 mg/kg of paracetamol and the fifth group animals treated with 20 mg/kg of Brij 35 along with 300 mg/kg of paracetamol for consecutive 21 days. The current study found that paracetamol plasma concentrations were much higher and NAPQI plasma concentrations were much lower when Brij 35 was co-administered may be due to inhibition of CYP2E1-mediated metabolism and P-gp-mediated intestinal transport of paracetamol. Brij 35 also reduced the increased hepatic and renal markers with significant hepatoprotective and nephroprotective changes in the histopathological investigation.