Exploring the potential of Elaeocarpus sylvestris as natural biomaterials: in vitro antimicrobial and antioxidant properties, chemical constituents, and its effect on skin fibroblasts

Elaeocarpus sylvestris, an evergreen tree widely distributed in Jeju Island, South Korea, contains polyphenolic compounds (phenols and flavonoids) exhibiting antioxidant, antiviral, and antibacterial activities. This study examines the antimicrobial, antioxidant, and cytotoxicity profiles of E. sylvestris extracts. Leaf extract (LE) and branch extract (BE) of E. sylvestris obtained using 60% methanol were filtered and concentrated. The antimicrobial efficacy of these extracts against foodborne pathogens and lactic acid bacteria was examined. The antioxidant property was tested along with assays to assess cytotoxicity and effects on cell proliferation. The extracts were also subjected to antioxidant assays and tested for cytotoxicity and effects on cell proliferation using human skin fibroblasts (Detroit 551). LE completely inhibited the growth of Staphylococcus aureus and Listeria monocytogenes at 100 mg/mL. Seven strains of lactic acid bacteria were susceptible to the whole extracts. LE significantly suppressed the growth of Weisella confusa , Pediococcus acidilactici , and Leuconostoc mesenteroides ( p < 0.05). Yeasts ( Pichia anomala and Pichia fermentans ) exhibited significantly higher growth rates than lactic acid bacteria. Both extracts (100 mg/mL) significantly decreased H 2 O 2 formation (>50%). The confluency of Detroit 551 cells was 68.07–87.52% at concentrations of 0–50 μg/mL for 24 h. In total, 130 metabolites were identified in BE and 128 in LE, including metabolites with potential benefits for skin improvement and photoprotection. A methanolic extract of E. sylvestris could be a promising source of natural bioactive materials for both microbial biocontrol and functional skin care cosmetics, with a wide range of applications in the food, cosmetic, and pharmaceutical industries.