Glucosamine enhances paracetamol bioavailability by reducing its metabolism

Area of Science:

• Pharmacology
• Hepatology
• Drug Metabolism

Background:

• Paracetamol's efficacy is limited by extensive first-pass metabolism, affecting bioavailability.
• Repeated dosing is often required, increasing the risk of paracetamol-induced hepatotoxicity.
• Developing strategies to improve paracetamol bioavailability and reduce liver injury is crucial.

Purpose of the Study:

• To investigate the potential of glucosamine (GlcN) to enhance paracetamol bioavailability in rats.
• To evaluate the impact of GlcN on paracetamol metabolism and its associated hepatotoxicity.
• To explore the mechanism by which GlcN influences paracetamol pharmacokinetics.

Main Methods:

• Administered paracetamol with and without GlcN to rats, analyzing pharmacokinetic parameters like AUC and Cmax.
• Assessed the effect of GlcN on liver homogenate metabolic reactions (Phase I and Phase I/II).
• Utilized in silico modeling to study GlcN binding to CYP2E1, a key enzyme in paracetamol metabolism.
• Monitored serum ALT and AST levels as indicators of liver injury.

Main Results:

• GlcN significantly increased paracetamol's area under the curve (AUC) by 99% and maximum concentration (Cmax) by 66% when co-administered.
• Pre-feeding rats with GlcN for 2 days resulted in a more substantial increase in paracetamol AUC (165%) and Cmax (88%).
• GlcN markedly reduced Phase I (48%) and Phase I/II (54%) metabolic reactions in liver homogenates.
• In silico analysis revealed favorable binding of GlcN to the CYP2E1 active site.
• Serum ALT and AST levels were significantly reduced in rats pre-treated with GlcN before high-dose paracetamol administration.

Conclusions:

• Glucosamine effectively increases paracetamol's relative bioavailability by inhibiting its hepatic metabolism.
• GlcN pre-treatment reduces paracetamol metabolism, leading to improved pharmacokinetic profiles.
• This GlcN-mediated reduction in metabolism is associated with decreased hepatocyte injury from high paracetamol doses.