Anti-inflammatory activity of <i>Avicennia germinans</i> ’ adventitious roots and first description of their metabolites

This study investigated the anti-inflammatory and antioxidant activity of adventitious roots (AR) of Guyanese mangrove <i>Avicennia germinans,</i> used in folk traditional medicine (FTM). Using bio-guided fractionation, we searched for extracts with activities that can be used for therapeutic purposes. Our findings revealed an interesting anti-inflammatory activity of CH₂Cl₂ and EtOAc fractions from which eight compounds were isolated and identified by NMR: two naphtoquinone derivatives: avicennone C (<b>1</b>) and dehydro-α-lapachone (<b>2</b>), two triterpenes: β-betulinic acid (<b>3</b>) and betulinaldehyde (<b>4</b>), two phenylethanoid glycosides: <i>trans</i>-verbascoside (<b>6</b>) and isoverbascoside (<b>8</b>), one iridoid: geniposidic acid (<b>5</b>) and one naphtoquinone: rubinaphtin A (<b>7</b>). These compounds are described for the first time in the AR of <i>A. germinans</i>. Among them, <b>3</b> was the most active and abundant, suggesting that it mainly contributed to the fractions' activity. This work reports the anti-inflammatory potential of <i>A. germinans</i> AR extracts for the first time and supports its use in FTM.