Maclura tinctoria as a Modulator of Oxidative Stress and Inflammatory Responses

Oxidative stress plays a central role in the progression of inflammatory and degenerative diseases, highlighting the need for natural compounds with antioxidant and anti-inflammatory potential. This study investigated the biological activity of the dichloromethane extract of Maclura tinctoria leaves (DcMt), which was selected for further analyses after initial screening demonstrated superior antioxidant activity compared with the hexane extract (HxMt). Antioxidant capacity was evaluated by DPPH and FRAP assays, while cellular effects were assessed in RAW 264.7 macrophages through analyses of viability, cytokine gene expression, COX-2 modulation, catalase activity, and cell migration. LC-DAD-ESI-MS profiling revealed a well-defined chromatographic composition dominated by four major constituents, which were isolated and structurally elucidated by NMR and MS as prenylated flavonoids, several of which are reported here for the first time in M. tinctoria. DcMt exhibited strong antioxidant activity and preserved cell viability under oxidative stress, with optimal effects at 25 µg/mL, accompanied by increased catalase activity. The extract modulated inflammatory markers by increasing IL-10 and IL-6 gene expression, maintaining IL-1β levels, and regulating COX-2 expression. In addition, DcMt promoted macrophage migration, further supporting its potential role in modulating inflammatory responses. Importantly, all biological assays were performed using the crude extract, and the contribution of individual compounds remains to be further investigated. These findings support M. tinctoria as a promising source of bioactive compounds with antioxidant and immunomodulatory potential.