Phytochemical Screening, Antibacterial Activity, and Toxicity of <i>Calathea lutea</i> Leaf Extracts

In Colombia, there is a long tradition of using bijao (<i>Calathea lutea</i>) leaves to package or wrap various foods. However, scientific studies on <i>C. lutea</i> are limited, and research to evaluate its toxicity and/or antibacterial activity has not yet been conducted. The objective of this research, therefore, was to evaluate the content of phytochemical compounds, levels of toxicity, and antibacterial activity of the extracts, fractions, and essential oil derived from <i>C. lutea</i> leaves. The plant material was subjected to extraction by maceration, Soxhlet extraction, and steam distillation, and fractions of hexane, dichloromethane, ethyl acetate, and a residual ethanol-water fraction were obtained. Preliminary phytochemical screening was performed using standard procedures with staining reagents. Estimation of the toxicity was carried out using the <i>Caenorhabditis elegans</i> biological model. Antibacterial activity was determined by broth microdilution against <i>Staphylococcus aureus</i> and <i>Escherichia coli</i>. The results showed that the characteristic metabolites were flavonoids, triterpenes, and tannins. At the concentrations tested, the extracts, fractions, and essential oil showed minimal toxicity levels. In terms of antibacterial activity, <i>E. coli</i> showed no susceptibility; meanwhile, the dichloromethane fraction had high antibacterial activity against <i>S. aureus</i>, with a growth inhibition rate of 81.2%. The results suggested that the of dichloromethane fraction of <i>C. lutea</i> has antibacterial activity against <i>S. aureus</i>, suggesting its potential as a possible candidate as a natural antibacterial agent in the food industry. This alternative could offer a safer and more sustainable solution compared to the conventional synthetic preservatives.