Conclusions

The extract of H. brasiliense and its isolated compound, uliginosin B, exhibited comparable inhibitory effects against various S. aureus strains, warranting further investigation into their antimicrobial activity. Both samples inhibited sessile growth and affected biofilm dynamics, while inducing oxidative stress and reducing bacterial metabolic activity, even at high cell densities. These findings suggest that their antibacterial effects may be associated with interference in cellular energy metabolism and redox balance. Although in silico analyses and phenotypic assays suggest a possible interaction between uliginosin B and NADH dehydrogenase (NDH-2), this mechanism remains hypothetical and requires direct enzymatic validation. The selectivity index indicates preferential activity against S. aureus compared to mammalian cells, while in silico pharmacokinetic predictions suggest that uliginosin B may present drug-like properties. However, these results should be interpreted as preliminary and require experimental confirmation. Importantly, this study has some limitations, including the absence of direct target validation and reliance on predictive models for pharmacokinetic assessment. Despite these limitations, the results support the potential of H. brasiliense hexane extract and uliginosin B as promising leads to the development of new antimicrobial strategies against drug-resistant S. aureus, warranting further mechanistic and in vivo investigations.