Optimization of deep eutectic solvent extraction of Piper nigrum L. and evaluation of hepatoprotective effects against acute ethanol-induced liver injury in mice

Introduction

Alcohol-associated liver disease (ALD) represents a growing global health burden, for which safe and accessible therapeutic options remain limited. As a widely used medicinal and food plant, Piper nigrum L. contains piperine as its core hepatoprotective alkaloid. However, conventional organic solvent extraction poses environmental risks, leaves solvent residues, and causes loss of synergistic endogenous bioactives. As sustainable green extraction media, deep eutectic solvents (DESs) show great potential for phytochemical enrichment, yet their impacts on the hepatoprotective potency and gut microbiota-regulatory activity of black pepper extracts remain unclear.