Ethnopharmacological relevance: Echinodorus macrophyllus is a medicinal plant traditionally used in Brazil to treat rheumatic diseases. It is listed as a priority species for the development of herbal preparations for the Brazilian Unified Health System (SUS). Previous studies have demonstrated the anti-inflammatory and antiedematogenic properties of extracts and fractions from this species, but these preparations were neither standardized nor optimized for anti-arthritis effects.
Aim of study: This study aimed to investigate the anti-inflammatory and antiarthritic effects of various standardized extracts from the aerial parts of E. macrophyllus and to outline their mechanisms of action. The goal was to define an extract suitable for future scientific validation and clinical use.
Material and methods: Extracts from the aerial parts of E. macrophyllus were prepared through percolation with 96°GL ethanol (EtOH) and hydroethanolic solutions at 90%, 70%, and 50% (v/v). They were standardized based on the contents of six chemical markers quantified by UPLC-DAD. Mice with acute or chronic antigen-induced arthritis (AIA) were treated with the extracts orally. The effects were evaluated by counting total and differential inflammatory cells, measuring cytokines by ELISA, and by histological analysis with toluidine blue staining. The mechanism of selected extracts was investigated in LPS-stimulated murine chondrocytes.
Results: All extracts, except for the 90% EtOH extract, exhibited significant anti-inflammatory activity in acute AIA, reducing the migration of total inflammatory cells, neutrophils, and monocytes to the intra-articular cavity. In chronic AIA, both the 96°GL EtOH and 70% EtOH extracts markedly reduced the migration of total inflammatory cells, neutrophils, and monocytes to the intra-articular cavity, decreased IL-1β and CXCL1 levels in the periarticular tissue, and diminished proteoglycan loss in the articular cartilage. Both extracts reduced IL-6 release and MMP-3 expression in LPS-stimulated chondrocytes. The 70% EtOH and 50% EtOH extracts showed heightened activity and higher levels of chemical markers, notably cinnamoyl-tartaric acid derivatives.
Conclusions: The standardized 70% EtOH and 50% EtOH extracts from the aerial parts of E. macrophyllus, which contain higher levels of chemical markers, exhibit potent anti-inflammatory activity and reduce proteoglycan degradation. These extracts are potentially useful for developing herbal preparations to manage arthritic conditions and should be prioritized for further studies.
Keywords: Antigen-induced arthritis; Chondrocytes; Echinodorus macrophyllus; MMP-3 expression; Standardized extracts.
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