Universidad de Buenos Aires, Facultad de Odontología, Farmacología, M. T. de Alvear 2142, 1122 AAH. Buenos Aires, Argentina.
Universidad de Buenos Aires, Facultad de Odontología, Farmacología, M. T. de Alvear 2142, 1122 AAH. Buenos Aires, Argentina.
J Mycol Med. 2022 May;32(2):101247. doi: 10.1016/j.mycmed.2022.101247. Epub 2022 Jan 31.
The flavonoid 2', 4'-dihydroxy-5'-(1''', 1'''-dimethylallyl)-8-prenylpinocembrin (8PP) obtained from Dalea elegans roots inhibits cell growth and cdr pumps, in addition to reversing fluconazole (FCZ) resistance in Candida albicans.
To study the effects of 8PP and FCZ on cdr-associated ATPase and cell energy generation in azole-resistant C. albicans planktonic cultures.
ATPase activity was measured as oligomycin-sensitive release of inorganic phosphate in fractions containing plasmatic membranes. Cell oxidoreductase activity was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) reduction in C. albicans cells.
FCZ, 8PP and their combination at a concentration of 125 µM of each compound inhibit ATPase activity by 61; 58 and 70, respectively. Inhibitory concentration 50 % (IC) of 8PP was 78.59 ± 1.45 and 104.70 ± 1.25 µM for FCZ. In combination with 125 µM 8PP, FCZ IC was reduced by 3 times. K was 0.96 ± 0.35 mM and V 43.58 ± 5.49 picomoles/mg protein.min. At 125 µM, 8PP shifts the ATP saturation plot to right. A Dixon study using 2 and 5 mM ATP suggests a competitive interaction of 8PP and ATP for the hydrolysis enzymatic site. FCZ, 8PP or their combination at 125 µM does not produce cytotoxicity dependent on oxidoreductase activity. At higher concentrations, toxic effects are observed with both drugs at the MTT assay. IC (µM) was 355 ± 6 and 789 ± 11, for 8PP and FCZ, respectively.
The flavonoid 8PP inhibits competitively oligomycin-sensitive ATPase activity associated to cdr transporters and decreases oxidoreductase-dependent cell viability in azole-resistant Candida albicans.
从黄牡丹根部分离得到的黄酮类化合物 2',4'-二羟基-5'-(1'',1'''-二甲基丙烯基)-8-异戊烯基 pinocembrin (8PP) 除了能逆转白色念珠菌对氟康唑（FCZ）的耐药性外，还能抑制细胞生长和 cdr 泵。
研究 8PP 和 FCZ 对唑类耐药白色念珠菌浮游培养物中 cdr 相关 ATP 酶和细胞能量产生的影响。
用寡霉素敏感的无机磷酸盐释放法测量含有质膜的部分的 ATP 酶活性。通过 3-(4,5-二甲基-2-噻唑基)-2,5-二苯基-2H-四唑溴化物（MTT）还原法评估细胞氧化还原酶活性。
FCZ、8PP 及其浓度为 125µM 的混合物分别抑制 ATP 酶活性 61%、58%和 70%。8PP 的半数抑制浓度（IC）为 78.59±1.45µM，FCZ 的 IC 为 104.70±1.25µM。与 125µM 8PP 联合使用时，FCZ 的 IC 降低了 3 倍。K 值为 0.96±0.35mM，V 值为 43.58±5.49 皮摩尔/mg 蛋白.min。在 125µM 时，8PP 将 ATP 饱和曲线向右移动。用 2 和 5mM ATP 进行的 Dixon 研究表明，8PP 和 ATP 对水解酶位点具有竞争性相互作用。FCZ、8PP 或其浓度为 125µM 的混合物在 MTT 测定中不产生依赖于氧化还原酶活性的细胞毒性。在更高的浓度下，两种药物在 MTT 测定中都会产生毒性作用。8PP 和 FCZ 的 IC（µM）分别为 355±6 和 789±11。
黄酮类化合物 8PP 竞争性抑制 cdr 转运蛋白的寡霉素敏感 ATP 酶活性，并降低唑类耐药白色念珠菌中依赖氧化还原酶的细胞活力。
