Phytochemical Profile, Antioxidant Activity, and Anti-Neuroinflammatory Effects of a Novel Dry Extract of Libidibia...

Libidibia ferrea is traditionally medicine used in northeastern Brazil; however, studies addressing chemically characterized extracts and pharmacological properties remain limited. This study investigated the chemical composition and anti-neuroinflammatory activity of a dry extract of L. ferrea (DELF) in lipopolysaccharide (LPS)-stimulated microglial cells, as well as its possible mechanisms of action. The extract was characterized using UPLC-ESI-QTOF-MS, and methyl gallate, the major compound, was quantified (38.15 µg/mg dry extract). Cytotoxicity in BV-2 cells was evaluated by the MTT assay. Antioxidant activity was assessed using free radical scavenging assays, while nitric oxide (NO) and IL-6 levels were determined using the Griess reaction and ELISA. iNOS expression was analyzed by western blotting. Eighteen compounds were identified, including phenolic acids, flavonoids, and hydroxy fatty acids. DELF also presented relevant mineral content. The extract (up to 100 µg/mL) and methyl gallate (up to 1.9 µg/mL) were non-cytotoxic. DELF at 100 µg/mL reduced nitrite release by 67% in LPS-stimulated cells and significantly reduced IL-6 production by 55%. DELF decreased NO levels without altering iNOS expression and exhibited antioxidant activity (90.16% DPPH, 83.6% superoxide, and ∼45% hydroxyl radical scavenging at 100 µg/mL). These findings highlight DELF as a promising source of bioactive compounds with potential anti-neuroinflammatory applications.