Binding affinity screening and MAPK/NF-κB mechanisms of antioxidant and anti-inflammatory phenolics compounds from Gynura procumbens stem extract (GPSE).

Gynura procumbens is a traditional medicinal plant widely used in Southeast to east Asia for its various therapeutic properties, but its stems are a byproduct that is less commonly utilized than its leaves. In this study, GPSE was fractionated using hexane, chloroform, ethyl acetate, butanol, and water, and HPLC-MS/MS analysis identified 11 phenolic compounds, including scopolin, caffeic acid, scopoletin, and 3,5-dicaffeoylquinic acid. Subsequently, we screened candidate phenolic compounds with antioxidant and anti-inflammatory activities using DPPH and COX-2 HPLC binding affinity assays. After that, the antioxidant and anti-inflammatory properties of each fraction were investigated. In vitro studies using LPS-induced RAW264.7 cells showed that the GPSE fraction significantly reduced reactive oxygen species (ROS) production, inhibited the inflammatory cytokines NO, PGE2, and IL-6, and suppressed the protein expression of iNOS and COX-2. Mechanism studies revealed that these anti-inflammatory effects are mediated through the inhibition of the MAPK and NFκB signaling pathways. In particular, scopoletin exhibited the highest binding affinity in COX-2 assays and effectively downregulated inflammatory mediators through the same molecular mechanism. The findings of this study indicate that GPSE and its active compounds possess considerable potential as high-value natural resources for the development of functional foods and pharmaceutical treatments.