Bioprospecção da comunidade endofítica fúngica de Lippia origanoides com potenciais ações antimicrobianas

Abstract

In this study, we conducted a bioprospective study of the fungal endophytic community of Lippia origanoides Kunth (Verbenaceae), a plant widely used in Brazilian folk medicine for the treatment of infectious diseases. The aim of this research was to investigate the antimicrobial potential of the fungal isolates obtained. The methodology involved the collection of plant material, isolation of endophytic fungi from leaves and stems, preparation of crude extracts using ethyl acetate partitioning, identification of bioactive isolates through antimicrobial tests (Agar Disc Diffusion and Broth Microdilution), screening of antioxidant activity (DPPH) and determination of the phytochemical profile of the extracts (CCD). A total of 129 fungal endophytic isolates were obtained. Of the crude extracts analyzed, 31 showed antioxidant activity and 29 demonstrated antimicrobial potential against at least one of the pathogenic microorganisms tested. The analysis of phytochemical profiles revealed the presence of phenolic compounds in all extracts, steroids and terpenes in 29 and coumarins in 7. Additionally, chemometric analyses were performed on the extracts of four promising isolates for the production of antimicrobials, evidencing similarities between groups belonging to the same species. The isolate 1LO-C3.1 BDA (Phoma-like) stood out for presenting MIC < 31.25 µg/mL against Candida albicans CCMB 286 and the dermatophytes Trichophyton tonsurans URM 4288 and Epidermophyton floccosum URM 6209. The isolates LO C 1.3 EMA (Alternaria alternata species complex) and LO C 3.2 EMA (Alternaria sp.) displayed MIC < 15.625 µg/mL against Staphylococcus aureus CCMB 263 and Microsporum canis URM 6969, also inhibiting the growth of E. floccosum URM 6209 at MICs of 62.5 and 31.25 µg/mL, respectively. The results obtained are considered promising and highlight the potential of L. origanoides as a source of endophytic fungi capable of producing bioactive molecules with antimicrobial properties.