Modulation of antibiotic resistance by the essential oil of Ocimum gratissimum L. in association with light-emitting diodes (LED) lights

Abstract

<jats:title>Abstract</jats:title><jats:p>This study aimed to evaluate the antibacterial and antibiotic-enhancing effects of the essential oil obtained from <jats:italic>Ocimum gratissimum</jats:italic> L. (OEOg) alone or in association with light-emitting diodes (LED) lights. The essential oil was obtained by hydrodistillation and its chemical composition analysed by gas chromatography coupled to mass spectrometry. The antibacterial and antibiotic-enhancing activities against multiresistant strains of <jats:italic>Staphylococcus aureus</jats:italic> and <jats:italic>Escherichia coli</jats:italic> were evaluated by the gaseous contact method. The analysis of the photoinductive effect on the antibacterial activity of the OEOg and antibiotics was assessed through exposure to different LED lights (red, blue and yellow). The phytochemical analysis identified five compounds, including eugenol, as the major constituent. The OEOg caused a significant inhibition of the halo, indicating a direct antibacterial effect. Exposure to the LED lights significantly enhanced the activity of the OEOg against <jats:italic>E. coli</jats:italic>. On the other hand, the action of the essential oil against <jats:italic>S. aureus</jats:italic> was enhanced by exposure to both blue and yellow lights. The effects of LED light exposure on the activity of conventional antibiotics varied significantly according to the drug and the bacterial strain. However, most combinations of LED lights and the OEOg presented synergistic effects against resistant bacterial strains, indicating enhanced antibacterial activity. Thus, these <jats:italic>in vitro</jats:italic> findings suggest that both OEOg and LED lights have promising antibacterial effects. Nevertheless, further research is required to evaluate <jats:italic>in vivo</jats:italic> the potential of these therapies for the treatment of infectious skin diseases.</jats:p>

Photobiological effect of eugenol‐derived 3‐benzoylcoumarin associated with led lights against MDR microorganisms

“…The yellow and red lights caused bacterial growth inhibitions. For S. aureus, the study showed an improvement in the antibacterial effect by association with red light, while the blue and yellow lights showed an antagonistic effect [17]. This effect was similar to that observed in the present study regarding the behavior of C1 and C4 against S. aureus.…”

ATIVIDADE ANTIBACTERIANA E MODULATORIA DO Α-Pineno ASSOCIADO AO APARELHO DE LUZ LED

“…O efeito sinérgico das luzes de LED com produtos naturais já foi observado em outro estudo recente (Leandro et al, 2020). Assim como no nosso estudo, esses autores avaliaram cepas multirresistentes de S. aureus e E. coli, contudo, na presença de um óleo essencial de Ocimum gratissimum.…”

Journal of Phytomoleculs & Pharmacology: ‘Why a new journal?’

“…This has been previously investigated with natural products used in combination with anticancer drugs and antimicrobials. This therapeutic approach can chemosensitize chemoresistant cancer cells, fungi and bacterial strains by, for instance, inhibiting the cellular active efflux system, a conserved drug resistance mechanism that pumps xenobiotics out of the cell [2][3][4][5][6][7][8][9][10][11][12].…”