Abstract
Oxidative stress is a key factor that activates several transcription factors and mediators involved in the inflammatory pathways responsible for the pathogenesis of many chronic diseases. Targeting the expression of these mediators represents a promising approach to preventing these diseases. Cassinopsis ilicifolia leaf infusion is traditionally used for treating conditions such as inflammation and pain relief. Thus, the present study assessed the antioxidant and anti-inflammatory activities of the hydroethanolic leaf extract of C. ilicifolia using in vitro and cell-based assays. As a result, C. ilicifolia extract exhibited the highest DPPH• and ABTS•+ radical scavenging potential. At the same time, it weakly scavenged the Fe3+-TPTZ radical up to 200 µg/mL, thus suggesting a different antioxidant mechanism triggered during each assay. Additionally, C. ilicifolia extract inhibited NO production and 15-LOX activity with IC50 values of 21.10 µg/mL and 40.28 µg/mL, respectively. Further, C. ilicifolia extract was found to strongly inhibit ROS production in LPS-activated RAW 264.7 cells, and the study of its mechanism of action showed that it exerts its anti-inflammatory effect by downregulating the expression of inflammatory mediators such as IL-1β, TNF-α, and COX-2. Overall, C. ilicifolia extract showed consistent potency in all assays, and the analysis of its phytochemical profile led to the identification of 30 compounds, among which the most abundant were secologanic acid (1), chlorogenic acid (3CQA) (2), monotropein (3), chlorogenic acid (5CQA) (4), geniposidic acid (5), rutin (6), quercetin 3-galactoside (7), astragalin-7-rhamnoside (8), and minecoside (9) that are possibly responsible for its anti-inflammatory and antioxidant activities. Therefore, our findings suggested the potential use of C. ilicifolia as an alternative source for developing plant-based products against oxidative stress and inflammation-related conditions.