In vitro and in vivo evaluation of an oral microemulsion formulation of Centaurea lycopifolia Boiss. Et Kotschy extract for analgesic and anti-inflammatory effects in a carrageenan-induced model.

Abstract

PURPOSE: Centaurea lycopifolia Boiss. et Kotschy (Asteraceae) is traditionally used in folk medicine for wound healing. This study aimed to develop and pharmacologically evaluate a novel oral microemulsion containing C. lycopifolia extract, focusing on its analgesic and anti-inflammatory effects in rodent models. METHODS: The extract, obtained from aerial parts of the plant, was characterized by LC-MS/MS. A microemulsion formulation was developed for oral administration. Antinociceptive activity was evaluated via hot plate (HP) and tail flick (TF) tests to assess central and spinal effects, respectively. Anti-inflammatory activity was assessed using carrageenan-induced paw edema, quantified by plethysmometry and Randall-Selitto tests. RESULTS: LC-MS/MS analysis identified quinic acid, chlorogenic acid, and protocatechuic acid as major phytoconstituents. In both HP and TF tests, the C. lycopifolia microemulsion demonstrated significantly stronger antinociceptive effects than aspirin. Similarly, its anti-inflammatory activity was comparable to aspirin. These pharmacological effects are possibly associated with the synergistic actions of the phenolic acids present in the extract. CONCLUSIONS: The C. lycopifolia-loaded microemulsion exhibited strong in vivo analgesic and anti-inflammatory activity, supporting its potential as a phytopharmaceutical candidate for inflammatory pain. The use of both central and peripheral pain models provided a robust pharmacodynamic basis for its therapeutic potential. Overall, these findings highlight the relevance of phenolic-rich phytochemicals in oral delivery systems for inflammation-related disorders.