Universidade Regional do Cariri, URCA, Cel Antônio Luis, 1161, 63105-000, Pimenta, Crato, CE, Brazil.
Universidade Federal do Paraná, UFPR, XV de Novembro, 1299, 80.060-000, Centro, Curitiba, PR, Brazil.
Microb Pathog. 2019 Nov;136:103700. doi: 10.1016/j.micpath.2019.103700. Epub 2019 Aug 28.
The secular use of plants in popular medicine has emerged as a source for the discovery of new compounds capable of curing infections. Among microbial resistance to commercial drugs, species such as Piper diospyrifolium Kunth, which are used in popular therapy, are targets for pharmacological studies. With this in mind, antimicrobial experiments with the essential oil from the P. diospyrifolium (PDEO) species were performed and its constituents were elucidated. The oil compounds were identified by gas chromatography coupled to mass spectrometry (GC/MS). The broth microdilution method with colorimetric readings for bacterial tests (Escherichia coli and Staphylococcus aureus) and spectrophotometric readings for fungal tests (Candida albicans and Candida tropicalis), whose data were used to create a cell viability curve and calculate its IC against fungal cells, were used to determine the minimum inhibitory concentration of the oil and its combined action with commercial drugs. The oil's minimal fungicidal concentration and its action over fungal morphological transition were analyzed by subculture and microculture, respectively. Chemical analysis revealed Z-Carpacin, Pogostol and E-Caryophyllene as the most abundant compounds. Results from the intrinsic analysis were considered clinically irrelevant, however the oil presented a synergistic effect against multiresistant E. coli and S. aureus strains when associated with gentamicin, and against the standard and isolated C. tropicalis strains with fluconazole. A fungicidal effect was observed against the C. albicans isolate. Candida spp. hyphae inhibition was verified for all strains at the highest tested concentrations. The P. diospyrifolium essential oil presented a promising effect when associated with commercial drugs and against a fungal virulence factor. Thus, the oil presented active compounds which may help the development of new drugs, however, new studies are needed in order to clarify the oil's mechanism of action, as well as to identify its active constituents.
植物在民间医学中的长期使用已经成为发现能够治愈感染的新化合物的来源。在商业药物的微生物耐药性中，像 Piper diospyrifolium Kunth 这样被用于民间疗法的物种是药理学研究的目标。考虑到这一点，对 Piper diospyrifolium（PDEO）物种的精油进行了抗菌实验，并阐明了其成分。油类化合物通过气相色谱-质谱联用仪（GC/MS）进行鉴定。采用肉汤微量稀释法进行细菌试验（大肠杆菌和金黄色葡萄球菌）和真菌试验（白色念珠菌和热带假丝酵母）的比色读数，并使用这些数据创建细胞活力曲线并计算其对真菌细胞的 IC，以确定油的最小抑菌浓度及其与商业药物的联合作用。通过传代培养和微培养分别分析油的最小杀菌浓度及其对真菌形态转变的作用。化学分析表明 Z-Carpacin、Pogostol 和 E-Caryophyllene 是最丰富的化合物。内在分析的结果被认为在临床上是无关紧要的，但是当与庆大霉素联合使用时，该油对多耐药大肠杆菌和金黄色葡萄球菌菌株表现出协同作用，并且对标准和分离的热带假丝酵母菌株与氟康唑联合使用时也表现出协同作用。观察到对白色念珠菌分离株的杀菌作用。在最高测试浓度下，所有菌株均对 Candida spp. 菌丝抑制作用。当与商业药物联合使用时，Piper diospyrifolium 精油表现出有希望的效果，并且对真菌毒力因子具有抑制作用。因此，该油具有活性化合物，可能有助于开发新药物，但是需要进一步研究以阐明油的作用机制，并鉴定其活性成分。
