Zhang Xiao-Yu, Li Wen-Guang, Wu Yong-Jie, Bai De-Cheng, Liu Nai-Fa
Department of Physiology, College of Basci Medicine and Key Laboratory of Preclinical Study for New Traditional Chinese Medicine of Gansu Province, Lanzhou University, People's Republic of China.
Can J Physiol Pharmacol. 2005 Mar;83(3):309-18. doi: 10.1139/y05-018.
With the aim of enhancing the efficacy of chemotherapeutic agents, we investigated the antitumor actions and reversal effect on drug resistance of proanthocyanidin plus doxorubicin. The results showed that proanthocyanidin 12.5-200 mg/L significantly inhibited proliferation of K562, K562/DOX, SPC-A-1, and Lewis cells in vitro in a time- and concentration-dependent manner, as determined by microculture tetrazolium assay. A combination of proanthocyani din 12.5, or 25 mg/L and doxorubicin treatment synergistically inhibited cell proliferation with decreased IC50 values. Proanthocyanidin reverses drug resistance in doxorubicin-resistant K562/DOX cells, and IC50 values were decreased by 9.19 (3.64-23.19), 2.56 (1.48-.44), and 0.94 (0.81-1.09) mg/L, respectively, after 24 h treatment with doxorubicin 0.1-9.0 mg/L alone or in combination with proanthocyanidin 12.5 or 25 mg/L; the proanthocyanidin reversal fold was 3.6 and 9.8, respectively. Under confocal laser scanning microscope, the combination of proanthocyanidin 25 or 50 mg/L with doxorubicin 3 mg/L significantly increased the accumulation of intracellular doxorubicin, Ca2+, and Mg2+, and reduced the pH value and mitochondrial membrane potential in K562/DOX cells as compared with doxorubicin alone (p < 0.01). Additionally, the apoptosis rate was increased by 11.3% +/- 3.3%, 14.2% +/- 5.4%, and 23.8% +/- 2.8%, respectively, for doxorubicin 3 mg/L alone or with proanthocyanidin 12.5 or 25 mg/L, as compared with controls (3.0% +/- 1.4%), as demonstrated by flow cytometry. In vivo experiments demonstrated that i.p. administration of proanthocyanidin 10 mg/kg with doxorubicin 2 mg/kg had an inhibitory effect on the growth of transplantation tumor sarcoma 180 and hepatoma 22 in mice as compared with doxorubicin alone (p < 0.05). These results suggest that proanthocyanidin enhances doxorubicin-induced antitumor effect and reverses drug resistance, and its mechanism is attributed partially to the promotion of doxorubicin-induced apoptosis through an elevation of intracellular doxorubicin, and Ca2+, Mg2+ concentration, and a reduction of pH value and mitochondrial membrane potential.
为提高化疗药物的疗效，我们研究了原花青素联合阿霉素的抗肿瘤作用及对耐药性的逆转作用。结果显示，12.5 - 200 mg/L的原花青素以时间和浓度依赖性方式显著抑制K562、K562/DOX、SPC - A - 1和Lewis细胞的体外增殖，这通过微量培养四氮唑蓝法测定。12.5或25 mg/L的原花青素与阿霉素联合处理协同抑制细胞增殖，使半数抑制浓度（IC50）值降低。原花青素可逆转阿霉素耐药的K562/DOX细胞的耐药性，在用0.1 - 9.0 mg/L阿霉素单独或与12.5或25 mg/L原花青素联合处理24小时后，IC50值分别降低9.19（3.64 - 23.19）、2.56（1.48 - 4.4）和0.94（0.81 - 1.09）mg/L；原花青素的逆转倍数分别为3.6和9.8。在共聚焦激光扫描显微镜下，25或50 mg/L原花青素与3 mg/L阿霉素联合处理相比单独使用阿霉素，显著增加了K562/DOX细胞内阿霉素、Ca2 +和Mg2 +的积累，并降低了pH值和线粒体膜电位（p < 0.01）。此外，通过流式细胞术检测，与对照组（3.0% ± 1.4%）相比，3 mg/L阿霉素单独或与12.5或25 mg/L原花青素联合处理时，凋亡率分别增加了11.3% ± 3.3%、14.2% ± 5.4%和23.8% ± 2.8%。体内实验表明，与单独使用阿霉素相比，腹腔注射10 mg/kg原花青素与2 mg/kg阿霉素对小鼠移植性肿瘤肉瘤180和肝癌22的生长有抑制作用（p < 0.05）。这些结果表明，原花青素增强了阿霉素诱导的抗肿瘤作用并逆转耐药性，其机制部分归因于通过提高细胞内阿霉素、Ca2 +和Mg2 +浓度以及降低pH值和线粒体膜电位来促进阿霉素诱导的细胞凋亡。
