The current prevalence of such lifestyle diseases as mycobacteriosis and tuberculosis is a result of the growing resistance of microorganisms to the available antibiotics and their significant toxicity. Therefore, plants can successfully become a source of new therapeutic agents. The aim of this study was to investigate the effect of protein extract from Sida hermaphrodita seeds on the morphology, structure, and viability of Mycobacterium smegmatis and to carry out proteomic characterization of the protein extract. The analyses were carried out using fluorescence and transmission microscopy, atomic force microscopy, and spectroscopy. The proteomic studies were performed using liquid chromatography coupled to tandem mass spectrometry. The studies showed that the seed extract applied at concentrations of 50-150 µg/mL exerted a statistically significant effect on M. smegmatis cells, that is, a reduction of the viability of the bacteria and induction of changes in the structure of the mycobacterial cell wall. Additionally, the SEM analysis confirmed that the extract did not have a cytotoxic or cytopathic effect on fibroblast cells. The proteomic analysis revealed the presence of structural, storage, and enzymatic proteins and peptides in the extract, which are typical for seeds. Proteins and peptides with antimicrobial activity identified as vicillins and lipid-transporting proteins were also determined in the protein profile of the extract.
Keywords: Mycobacterium smegmatis; Sida hermaphrodita; Virginia mallow; antibacterial; plant antimicrobial peptides; plant extract; seeds.