Nanoemulsions With Essential Oils of Piper spp. and Their Antifungal and Cytotoxic Potential

Nanoemulsions containing essential oils from Piper species remain underexplored for addressing significant public health issues, including cell proliferative disorders and pathogenic microorganisms, highlighting the need to expand research in this field. This study aimed to develop and characterize nanoformulations containing essential oils from Piper spp., and to evaluate their safety and efficacy in cell lines, as well as their antimicrobial potential against pathogenic microorganisms. To prepare the nanoemulsions, the essential oils were mixed with Tween 80 in varying ratios (1:1, 1:1.5, 1:2, and 1:2.5). The stability of the nanoformulations was monitored through visual inspection and measurements of particle size, zeta potential, and pH, along with characterization by transmission electron microscopy. Cytotoxic and antimicrobial activities were assessed using colorimetric assays with breast cancer cells (MDA-MB-231) and Vero cells (CCL81), as well as pathogenic bacteria and fungi such as Aspergillus spp., Candida spp., and Penicillium sp. The Piper aduncum nanoemulsion was the most promising sample, eliminating essential oil toxicity to healthy cells (IC50 >100 µg/mL) and exhibiting the strongest antifungal activity, with MIC values of 125 µg/mL against Penicillium adametzii and 250 µg/mL against Aspergillus flavus, compared to 1000 µg/mL for the free essential oil. These nanoemulsions remained stable for up to 360 days and had particle sizes ranging from 26.4 ± 0.42 to 265 ± 0.00 nm with zeta potentials between -24.95 ± 0.92 mV and -55.65 ± 0.21 mV. This study demonstrates that nanoemulsions derived from Piper spp. are promising candidates against pathogenic microorganisms, with potentials applications in health and food preservation.