A Chemically Characterized Extract of Centipeda minima Attenuates Inflammation in Macrophages and Alleviates Osteoarthritis Progression in Rats

Abstract

Centipeda minima, an edible herb with medicinal properties, contains bioactive sesquiterpene lactones with anti-inflammatory potential, but its nutraceutical application is limited by insufficient standardization. This study evaluated the anti-inflammatory mechanisms of a chemically characterized bioactive-rich extract from C. minima (CMXP) and its four isolated active compounds. In LPS-stimulated RAW 264.7 macrophages, CMXP and the four isolated sesquiterpene lactones inhibited nitric oxide (NO) production in a concentration-dependent manner. These inhibitory effects were evident within concentration ranges that did not markedly affect cell viability, whereas reduced cell viability was observed at the highest tested concentrations of CMXP (10 μg/mL), arnicolide C (10 μM), and brevilin A (10 μM). CMXP markedly suppressed iNOS and COX-2 expression, reducing ERK and JNK phosphorylation. In the MIA-induced osteoarthritis rat model, CMXP improved hind limb weight-bearing function, decreased serum IL-6 and cartilage MMP-3 expression, and attenuated subchondral bone loss, as confirmed by micro-computed tomography. CMXP demonstrated anti-inflammatory effects through MAPK pathway modulation and improved OA-associated functional and structural changes. The chemical characterization of CMXP provides a basis for further investigation of its potential application in OA.