Assessment of Immunomodulatory Activity of South American Medicinal Plants Traditionally Used for Inflammatory Disorders

Inflammation is an important defensive response; however, uncontrolled inflammatory responses can lead to various pathologies. Although currently used anti-inflammatory drugs are effective, they have some disadvantages, and their use is often limited by adverse effects, underscoring the need for the development of novel therapeutic interventions. Medicinal plants are valuable sources of immunomodulatory agents. In this study, we screened the immunomodulatory activities of *Acanthospermum hispidum*, *Aloysia gratissima*, *Aloysia virgata*, *Baccharis dracunculifolia*, *Baccharis notosergila*, and *Solanum sisymbriifolium*, which are medicinal plants traditionally used to treat inflammation in South America. Currently, there is limited information available on the anti-inflammatory activities of these plants. This study aimed to assess the immunomodulatory activity of six plants used in traditional South American medicine as anti-inflammatory agents. We screened the effects of these species on concanavalin A-induced lymphocyte proliferation and lipopolysaccharide-induced reactive oxygen species (ROS) production in murine splenocytes. Our findings indicate that these medicinal plants exhibit inhibitory effects on lymphocyte proliferation and ROS production, thereby validating their traditional use in treating inflammation. In conclusion, these plants possess *in vitro* immunomodulatory activity with anti-inflammatory potential and can be considered a source of novel immunomodulatory compounds.