Department of Biology, Lakehead University, Thunder Bay, Ontario, Canada.
Medical Sciences Division, Northern Ontario School of Medicine, Thunder Bay, Ontario, Canada.
Crit Rev Food Sci Nutr. 2020;60(18):3042-3053. doi: 10.1080/10408398.2019.1675585. Epub 2019 Oct 16.
Most of the antibacterial activities of essential oils from the Lamiaceae herbaceous plant family thyme and oregano are attributed to their bioactive isomeric monoterpenoid constituents, carvacrol and thymol. Commercially available antibiotics of thymol or carvacrol have not yet been developed but health products have incorporated thymol into their formulations for their antimicrobial properties. Carvacrol and thymol are generally considered safe for consumption and they have been used in dental applications, approved as food flavorings and have been considered as antibacterial additives in food and feed. Many studies have demonstrated that carvacrol and thymol are potent antibacterial agents against both Gram-positive and Gram-negative bacteria. The most frequently reported mechanism of antibacterial action of both isomers involves the disruption of bacterial membrane leading to bacterial lysis and leakage of intracellular contents resulting in death. Other proposed mechanisms of antibacterial action include the inhibition of efflux pumps, prevention in the formation and disruption of preformed biofilms, inhibition of bacterial motility, and inhibition of membrane ATPases. In addition, both isomers have been found to act additively or synergistically with conventional antibiotics important in overcoming the problem of bacteria resistance in food and disease.
大多数来自唇形科草本植物百里香和牛至的精油的抗菌活性归因于它们的生物活性同分异物体单萜成分，香芹酚和百里香酚。尚未开发出市售的百里香酚或香芹酚抗生素，但保健品已将百里香酚纳入其配方，以发挥其抗菌特性。香芹酚和百里香酚通常被认为可安全食用，它们已被用于牙科应用，被批准为食品香料，并被认为是食品和饲料中的抗菌添加剂。许多研究表明，香芹酚和百里香酚是对抗革兰氏阳性和革兰氏阴性细菌的有效抗菌剂。这两种异构体的抗菌作用的最常见机制涉及破坏细菌膜，导致细菌裂解和细胞内内容物泄漏，从而导致死亡。其他提出的抗菌作用机制包括抑制外排泵，防止形成和破坏预先形成的生物膜，抑制细菌运动性以及抑制膜 ATP 酶。此外，已经发现这两种异构体与在克服食品和疾病中细菌耐药性问题方面很重要的常规抗生素具有相加或协同作用。
