Plant Extracts and Phytochemicals from the Asteraceae Family with Antiviral Properties

Abstract

Asteraceae (Compositae), commonly known as the sunflower family, is one of the largest plant families in the world and includes several species with pharmacological properties. In the search for new antiviral candidates, an in vitro screening against dengue virus (DENV) was performed on a series of dichloromethane and methanolic extracts prepared from six Asteraceae species, including <i>Acmella bellidioides</i>, <i>Campuloclinium macrocephalum</i>, <i>Grindelia pulchella</i>, <i>Grindelia chiloensis</i>, <i>Helenium radiatum</i>, and <i>Viguiera tuberosa</i>, along with pure phytochemicals isolated from Asteraceae: mikanolide (<b>1</b>), eupatoriopicrin (<b>2</b>), eupahakonenin B (<b>3</b>), minimolide (<b>4</b>), estafietin (<b>5</b>), 2-oxo-8-deoxyligustrin (<b>6</b>), santhemoidin C (<b>7</b>), euparin (<b>8</b>), jaceidin (<b>9</b>), nepetin (<b>10</b>), jaceosidin (<b>11</b>), eryodictiol (<b>12</b>), eupatorin (<b>13</b>), and 5-demethylsinensetin (<b>14</b>). Results showed that the dichloromethane extracts of <i>C. macrocephalum</i> and <i>H. radiatum</i> and the methanolic extracts prepared from <i>C. macrocephalum</i> and <i>G. pulchella</i> were highly active and selective against DENV-2, affording EC₅₀ values of 0.11, 0.15, 1.80, and 3.85 µg/mL, respectively, and SIs of 171.0, 18.8, >17.36, and 64.9, respectively. From the pool of phytochemicals tested, compounds <b>6</b>, <b>7</b>, and <b>8</b> stand out as the most active (EC₅₀ = 3.7, 3.1, and 6.8 µM, respectively; SI = 5.9, 6.7, and >73.4, respectively). These results demonstrate that Asteraceae species and their chemical constituents represent valuable sources of new antiviral molecules.