Bergamot essential oil nanoemulsions: antimicrobial and cytotoxic activity

Abstract

<jats:title>Abstract</jats:title><jats:p>Bergamot essential oil (BEO) is well-known for its food preservation activity, as well as anticancer efficacy. However, the poor BEO water solubility and deriving low bioaccessibility have limited its wider applications. The incorporation in nanoemulsions of BEO and its refined fractions was investigated to enhance its dispersibility in water to promote its antimicrobial activity, tested against <jats:italic>Escherichia coli</jats:italic>, <jats:italic>Lactobacillus delbrueckii,</jats:italic> and <jats:italic>Saccharomyces cerevisiae</jats:italic>, and its cytotoxicity already at low concentrations. Different nanoemulsion formulations were tested based on food-grade ingredients, which were characterized in terms of hydrodynamic diameter and polydispersity index, and physical stability. The antimicrobial activity against all the tested micro-organisms was observed to be higher for BEO in its initial composition, than the light fraction, richer in <jats:sc>d</jats:sc>-limonene, <jats:italic>ß</jats:italic>-pinene, and γ-terpinene, or the heavy fraction, richer in linalyl acetate and linalool. Remarkably, the use of BEO nanoemulsions notably enhanced the antimicrobial activity for all the tested oils. BEO exhibited also a measurable cytotoxic activity against Caco-2 cells, which was also enhanced by the use of the different nanoemulsions tested, in comparison with free oil, which discourages the direct use of BEO nanoemulsions as a food preservative. Conversely, BEO nanoemulsions might find use in therapeutic applications as anticarcinogenic agents.</jats:p>

A Fresh Look at Mouthwashes—What Is Inside and What Is It For?

“…They may also serve as preservatives. Antioxidant, anti-inflammatory, local anaesthetic and analgesic effects are other relevant properties [ 99 , 100 ]. Nevertheless, they play an important role in oral hygiene as fragrances.…”

“…Benzyl alcohol is mainly used as a fragrance and preservative [ 114 , 115 ] and only its derivative (2,4-dichlorobenzyl alcohol) is used as a mild oral and pharyngeal antiseptic. Limonene [ 99 , 116 , 117 ], linalool [ 99 , 117 ], citral [ 118 ] and cinnamal (cinnamaldehyde) [ 119 ] exhibit a non-negligible activity against oral pathogenic microorganisms. Geraniol [ 120 ] and anethole [ 121 ] also show some antimicrobial properties.…”

Development and Evaluations of Transdermally Delivered Luteolin Loaded Cationic Nanoemulsion: In Vitro and Ex Vivo Evaluations

“…Ansari et al reported 3-fold higher permeation of LUT loaded in a self-nanoemulsifying drug delivery system (SNEDDS) in rats [ 12 ]. BO is an essential oil of the generally regarded as safe (GRAS) category and is reported to have more cytotoxic potential when formulated in nanoemulsions [ 49 ]. Thus, improved permeation of LUT loaded cationic nanogobules may be detrimental to cancerous cells.…”

Microemulsification of essential oils for the development of antimicrobial and mosquito repellent functional coatings for textiles

“…Previous research has demonstrated the antimicrobial activity of EO emulsions, for example bergamot EO nanoemulsions reduced E. coli by up to 4·5 log 10 CFU per ml after 5 h (Marchese et al . 2020). Textile challenge tests show that microemulsion‐treated polyester and cotton also possessed good antimicrobial activity, with a complete reduction achieved by both treated fabrics after 24 h for all test bacteria (Fig.…”