The Mode of Action of Cyclic Monoterpenes (−)-Limonene and (+)-α-Pinene on Bacterial Cells

Abstract

A broad spectrum of volatile organic compounds’ (VOCs’) biological activities has attracted significant scientific interest, but their mechanisms of action remain little understood. The mechanism of action of two VOCs—the cyclic monoterpenes (−)-limonene and (+)-α-pinene—on bacteria was studied in this work. We used genetically engineered Escherichia coli bioluminescent strains harboring stress-responsive promoters (responsive to oxidative stress, DNA damage, SOS response, protein damage, heatshock, membrane damage) fused to the luxCDABE genes of Photorhabdus luminescens. We showed that (−)-limonene induces the PkatG and PsoxS promoters due to the formation of reactive oxygen species and, as a result, causes damage to DNA (SOSresponse), proteins (heat shock), and membrane (increases its permeability). The experimental data indicate that the action of (−)-limonene at high concentrations and prolonged incubation time makes degrading processes in cells irreversible. The effect of (+)-α-pinene is much weaker: it induces only heat shock in the bacteria. Moreover, we showed for the first time that (−)-limonene completely inhibits the DnaKJE–ClpB bichaperone-dependent refolding of heat-inactivated bacterial luciferase in both E. coli wild type and mutant ΔibpB strains. (+)-α-Pinene partially inhibits refolding only in ΔibpB mutant strain.

Evaluation of lemon peel essential oil on fecal microbial diversity of tropical Holstein dairy cows

“…The decrease in Prevotellaceae bacteria in the faecal microbial community indicates a decrease in proteolytic activity in the rumen (Daning et al, 2022b). The decline in the Bacteriodetes family and the Prevotellaceae genus was due to the ability of the limonene compound from lemon peel essential oil to quickly damage cell membranes and inhibited membrane protein synthesis (Melkina et al, 2021).…”

In Vitro Evaluation Of Antioxidant And Cytotoxic Activity Of Isolated Compounds From Pittosporum Eugenioides

“…Activities of the antioxidant enzymes SOD, CAT, GPX, APX and GR were significantly elevated, thereby indicating the enhanced generation of reactive oxygen species (ROS) upon alpha-pinene exposure. Increased levels of scavenging enzymes indicate their induction as a secondary defense mechanism in response to alphapinene [42]. The antioxidant and cytotoxic properties of the methanol extract may be attributed to the synergistic effects of its diverse major and minor components.…”

Chemical profile, antimicrobial activity, and leaf anatomy of Adenophyllum porophyllum var. cancellatum

“…In cells of the yeast, Zygosaccharomyces rouxii , limonene destroys yeast proteins, inhibits their synthesis, produces nucleic acid leakage, and alters membrane permeability ( Cai et al, 2019 ). In E. coli , (-)-limonene acts by producing oxidative stress through the formation of significant amounts of hydrogen peroxide and superoxide anion radicals, which damage DNA and the cell membrane, increase permeability, resulting in cell death ( Melkina et al, 2021 ).…”