Metabolite profiling and in vitro assessment of skin-related pharmacological activities in Baccharis trimera (Less.) DC

Abstract

Ethnopharmacological relevance: Baccharis trimera (Less.) DC. (Asteraceae), commonly known as “carqueja”, is a medicinal plant traditionally used in Brazil as an herbal remedy for gastrointestinal disorders. In some regions, its aerial parts are also used to treat skin-related diseases, including wounds. Despite growing interest in discovering new cosmeceutical ingredients from traditionally used medicinal plants, knowledge of this species and its po- tential skin-related applications remains limited. Aim of the study: We investigated the aerial parts of B. trimera for their anti-inflammatory, anti-aging, and skin- whitening properties. Materials and methods: The ethanolic extract (BtE) was fractionated via liquid-liquid extraction into hexane (BtEH), dichloromethane (BtED), ethyl acetate (BtEA), and hydroalcoholic (BtEHy) fractions. Chemical der- eplication of BtE and active fractions (BtEA and BtED) was performed using liquid chromatography coupled with high-resolution mass spectrometry (LC–HRMS). Enzyme inhibitory activity against tyrosinase and elastase was evaluated spectrophotometrically. Anti-inflammatory activity was assessed in lipopolysaccharide (LPS)-stimu- lated THP-1 macrophages by quantifying TNF-α, IL-1β, and IL-6 levels using ELISA. Results: The crude extract inhibited elastase activity, while its fractions reduced cytokine production and enhanced tyrosinase inhibition. Among these, the dichloromethane fraction showed the most pronounced effects, including tyrosinase inhibition, reduced secretion of TNF-α, IL-1β and IL-6, and a significant decrease in LPS- induced LDH release. Twenty compounds, including flavonoids, hydroxycinnamic acid derivatives, diterpenes, phenylpropanoids, and fatty acids, were annotated in the active ethanolic extract and its fractions from Baccharis trimera, several of which have previously shown anti-inflammatory activity. After fractionation, cirsimaritin, eupatorin, and jaceosidin were found exclusively in the dichloromethane fraction and may have contributed to its anti-inflammatory activity. In addition, the anti-tyrosinase activity observed in the medium-polarity fractions may be associated with the presence of rutin, apigenin flavone glucoside, and 3-hydroxy-copalic acid. Conclusion: Overall, this study expands the chemical characterization of this medicinal plant and underscores its potential for skincare applications. Notably, anti-tyrosinase activity was identified in the medium-polar fractions for the first time, highlighting their potential as a source of bioactive metabolites relevant for cosmetic and skin- related applications.