Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon; Department of Biochemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon.
Department of Chemistry, Faculty of Science, University of Dschang, Dschang, Cameroon.
J Ethnopharmacol. 2021 Sep 15;277:114257. doi: 10.1016/j.jep.2021.114257. Epub 2021 May 29.
Infections due to multidrug-resistant (MDR) bacteria constitute a real problem in the public health worldwide. Hypericum roeperianum Schimp. ex A. Rich (Hypericaceae) is used traditionally for treatment of various ailments such as abdominal pains, constipation, diarrhea, indigestion, nausea, and bacterial diseases.
This study was aimed at investigating the antibacterial and antibiotic-modifying activity of the crude methanol extracts (HRB), ethyl-acetate soluble fraction (HRBa), residual material (HRBb), and 11 compounds from the bark of Hypericum roeperianum against multi-drug resistant (MDR) bacteria expressing active efflux pumps.
The antibacterial activity, the efflux pump effect using the efflux pump inhibitor (EPI), phenylalanine-arginine-ß-naphthylamide (PAβN), as well as the antibiotic-modifying activity of samples were determined using the broth micro-dilution method. Spectrophotometric methods were used to evaluate the effects of HRB and 8,8-bis(dihydroconiferyl) diferulate (11) on bacterial growth, and bacterial membrane damage, whereas follow-up of the acidification of the bacterial culture was used to study their effects on bacteria proton-ATPase pumps.
The crude extract (HRB), HRBa, and HRBb had selective antibacterial activity with MICs ranging from 16 to 512 μg/mL. Phytochemical 11 displayed the best antibacterial activity (0.5 ≤ MIC ≤ 2 μg/mL). The activity of HRB and 11 in the presence of EPI significantly increased on the tested bacteria strains (up to 32-fold). The activity of cloxacillin (CLO), doxycycline (DOX), and tetracycline (TET), was considerably improved (up to 64-fold) towards the multidrug-resistant Enterobacter aerogenes EA-CM64 strain. The crude extract (HRB) and 11 induced the leakage of bacterial intracellular components and inhibited the proton-ATPase pumps.
The crude extract (HRB) and 8,8-bis(dihydroconiferyl)diferulate from the bark of Hypericum roeperianum are good antibacterial candidates that deserve further investigations to achieve antibacterial drugs to fight infections involving MDR bacteria.
由多药耐药（MDR）细菌引起的感染是全球公共卫生领域的一个实际问题。贯叶金丝桃（Hypericaceae）传统上用于治疗各种疾病，如腹痛、便秘、腹泻、消化不良、恶心和细菌疾病。
本研究旨在研究贯叶金丝桃树皮的粗甲醇提取物（HRB）、乙酸乙酯可溶部分（HRBa）、残余物（HRBb）和 11 种化合物对表达主动外排泵的多药耐药（MDR）细菌的抗菌和抗生素修饰活性。
使用肉汤微量稀释法测定样品的抗菌活性、用外排泵抑制剂（EPI）苯丙氨酸-精氨酸-ß-萘基酰胺（PAβN）的外排泵作用以及抗生素修饰活性。分光光度法用于评估 HRB 和 8,8-双（二氢桂皮酰）二呋喃（11）对细菌生长和细菌膜损伤的影响，而跟踪细菌培养物的酸化用于研究它们对细菌质子-ATP 酶泵的影响。
粗提取物（HRB）、HRBa 和 HRBb 对 16 至 512 μg/mL 范围内的 MIC 具有选择性抗菌活性。化合物 11 显示出最佳的抗菌活性（0.5≤MIC≤2μg/mL）。在存在 EPI 的情况下，HRB 和 11 在测试细菌菌株上的活性显著增加（高达 32 倍）。对多药耐药的产气肠杆菌 EA-CM64 菌株，氯唑西林（CLO）、强力霉素（DOX）和四环素（TET）的活性得到了显著改善（高达 64 倍）。粗提取物（HRB）和 11 诱导细菌细胞内成分泄漏并抑制质子-ATP 酶泵。
贯叶金丝桃树皮的粗提取物（HRB）和 8,8-双（二氢桂皮酰）二呋喃是很好的抗菌候选物，值得进一步研究以获得用于治疗涉及 MDR 细菌感染的抗菌药物。
