Patchouli Alcohol Inhibits D-Gal Induced Oxidative Stress and Ameliorates the Quality of Aging Cartilage via Activating the Nrf2/HO-1 Pathway in Mice

Chondrocytes play an essential role in maintaining the structure and function of articular cartilage. Oxidative stress occurred in chondrocytes accelerates cell senescence and death, which contributes to the development of osteoarthritis (OA). Patchouli alcohol (PA), a kind of sesquiterpene in Pogostemon cablin, processes multiple bioactivities in treatment of many diseases. However, its effects of antisenescence and antioxidation on chondrocytes in a D-gal-induced aging mice model are still obscure. In this study, we found that PA treatment could ameliorate the degradation of cartilage extracellular matrix (ECM) in a D-gal-induced aging mice model. Further analyses through the immunofluorescent staining and western blot revealed that PA inhibited D-gal-induced chondrocyte senescence via the activation of antioxidative system. Besides, the damage caused by D-gal could not be recovered with PA treatment in Nrf2-silencing chondrocytes. In addition, molecular docking analysis between PA and Keap1 further suggested that the mechanism of PA's antisenescence and antioxidation was attributed to the activation of Nrf2/HO-1 pathway. Therefore, our results demonstrated that PA was a promising candidate for preventing the quality loss of aging cartilage through inhibiting oxidative stress-mediated senescence in chondrocytes.