Universidade Regional do Cariri - URCA, Crato, CE, Brazil.
Centro Universitário Dr. Leão Sampaio - UNILEÃO, Juazeiro do Norte, CE, Brazil.
J Photochem Photobiol B. 2019 Oct;199:111604. doi: 10.1016/j.jphotobiol.2019.111604. Epub 2019 Aug 23.
The indiscriminate use of antibiotics has made bacterial resistance an important public health problem, since many antibiotics have become ineffective. Phototherapy can be considered an alternative to reduce the abusive use of antimicrobials, thus impacting microbial resistance. The objective of this study was to determine the chemical profile and to evaluate the effect of blue LED lights on the antibacterial activity of essential oils from Piper species, as well as their aminoglycoside antibiotic activity modulation using the microdilution method to determine the Minimum Inhibitory Concentration (MIC). The antibiotic activity modulating effect of these oils was also determined using the broth microdilution method with 96-well plates which were exposed to LED light for 20 min. Chemical components were characterized by gas chromatography coupled to mass spectrometry, revealing β-copaen-4-α-ol, germacrene A and germacrene B as major essential oil constituents for Piper arboreum (OEPar), Piper aduncum (OEPad) and Piper gaudichaudianum (OEPg), respectively. OEPar obtained a MIC of 512 μg/mL against Staphylococcus aureus and a MIC ≥ 1024 μg/mL against Escherichia coli. OEPad and OEPg showed MIC values ≥ 1024 μg/mL against the utilized strains. The essential oils modulated the effect of the antibiotics amikacin and gentamicin, with this effect being potentiated when exposed to blue LED. The blue LED light in the absence of the essential oil also showed an ability to modulate aminoglycoside antibiotic activity in this study, presenting mostly synergistic effects. In conclusion, the results obtained in this study demonstrate that photodynamic therapy using blue LED light interferes with the antibacterial action of P. arboreum, P. aduncum and P. gaudichaudianum essential oils and aminoglycoside antibiotic activity.
抗生素的滥用使得细菌耐药性成为一个重要的公共卫生问题，因为许多抗生素已经失效。光疗可以被认为是减少抗生素滥用的一种替代方法，从而影响微生物耐药性。本研究的目的是确定化学特征，并评估蓝 LED 灯对 Piper 属植物精油的抗菌活性的影响，以及使用微量稀释法测定最小抑菌浓度（MIC）来评估其对氨基糖苷类抗生素活性的调制作用。还使用 96 孔板微量稀释法，在蓝 LED 光下暴露 20 分钟，确定这些油的抗生素活性调制作用。通过气相色谱-质谱联用分析鉴定化学成分，发现 β-古巴烯-4-α-醇、大根香叶烯 A 和大根香叶烯 B 分别为 Piper arboreum（OEPar）、 Piper aduncum（OEPad）和 Piper gaudichaudianum（OEPg）的主要精油成分。OEPar 对金黄色葡萄球菌的 MIC 为 512μg/mL，对大肠杆菌的 MIC≥1024μg/mL。OEPad 和 OEPg 对所用菌株的 MIC 值均≥1024μg/mL。精油调节了氨基糖苷类抗生素阿米卡星和庆大霉素的作用，当暴露于蓝 LED 时，这种作用增强。在本研究中，在没有精油的情况下，蓝 LED 光也显示出调节氨基糖苷类抗生素活性的能力，主要表现出协同作用。总之，本研究结果表明，使用蓝 LED 光的光动力疗法会干扰 P. arboreum、P. aduncum 和 P. gaudichaudianum 精油的抗菌作用以及氨基糖苷类抗生素的活性。
