Enhanced activity of punicalagin delivered via polymeric implants against benzo[a]pyrene-induced DNA adducts
Enhanced activity of punicalagin delivered via polymeric implants against benzo[a]pyrene-induced DNA adducts
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DOI：
10.1016/j.mrgentox.2011.12.022
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发表时间：
2012-03-18
影响因子：
1.9
通讯作者：
Gupta, Ramesh C.
中科院分区：
文献类型：
--
作者：
Aqil, Farrukh;Vadhanam, Manicka V.;Gupta, Ramesh C.
我们在体内外研究了PINICALAGIN(PC)对苯并[a]芘(BP)诱导的DNA加合物的影响。BP(1 MU M)与大鼠肝微粒体、适当的辅因子和DNA在赋形剂或Punicalagin(1-40 mU M)存在下对DNA加合物的抑制呈剂量依赖关系，在40 mU M时基本上完全抑制(97%)。然而，在体外非微粒体系统中，PC不能抑制抗BPDE-包括DNA加合物，这表明PC对微粒体BP-DNA加合物的抑制是由于PC对P450 1A1的抑制。为确定其体内药效，雌性S/D大鼠通过饲料(1500ppm，相当于19 mg/d/只)或皮下聚合物植入物(2个2 cm，200 mg，20%载药量；40mgPC/植入物)，然后通过一个皮下聚合物植入物(2 cm，200 mg，10%载药量；20mgBP/植入物)连续给予小剂量BP，10d后安乐死。P-32后标记分析显示，通过植入物给药的PC对DNA加合物有显著的抑制作用(60%；p=0.029)；饮食途径对DNA加合物的抑制不明显(34%)，但统计学上不显著。此外，与饮食途径相比，植入物给药的PC总量大约低38倍。肺微粒体分析显示，细胞色素13450-1A1活性受到明显抑制，谷胱甘肽的诱导作用明显增强。PC从植入物中的释放被发现是双相的，从突然释放开始，然后逐渐下降。超高效液相色谱分析表明，在血浆中检测不到PC，但很容易检测到其水解物--鞣花酸。植入组大鼠的血浆鞣花酸浓度(589+/-78 ng/m L)比饮食组(4.36+/-0.83 ng/m L)高两个数量级以上。总之，我们的数据表明，植入物可以显著降低PC的有效剂量，体内DNA加合物的抑制可能是由于PC转化为鞣花酸所致。(C)2012爱思唯尔B.V.保留所有权利。
We investigated the effect of punicalagin (PC) on benzo[a]pyrene (BP)-induced DNA adducts in vitro and in vivo. Incubation of BP (1 mu M) with rat liver microsomes, appropriate co-factors and DNA in the presence of vehicle or punicalagin (1-40 mu M) showed dose-dependent inhibition of the resultant DNA adducts, with essentially complete (97%) inhibition at 40 mu M. However, PC failed to inhibit anti-BPDE-inclucecl DNA adducts when tested in an in vitro non-microsomal system, suggesting that the inhibition of the microsomal BP-DNA adducts occurred due to inhibition of P450 1A1 by PC. To determine its efficacy in vivo, female S/D rats were administered punicalagin via the diet (1500 ppm; similar to 19 mg/day/animal) or subcutaneous polymeric implants (two 2-cm, 200 mg with 20% drug load; 40 mg PC/implant) and then treated with continuous low-dose of BP by a subcutaneous polymeric implant (2 cm, 200 mg with 10% load; 20 mg BP/implant) and euthanized after 10 days. Analysis of the lung DNA by P-32-postlabeling showed significant (60%; p = 0.029) inhibition of DNA adducts by PC administered via the implants; the dietary route showed modest (34%) but statistically insignificant inhibition. Furthermore, total PC administered by implants was approximately 38-fold lower compared with the dietary route. Analysis of the lung microsomes showed significant inhibition of cytochrome 13450 1A1 activity and induction of glutathione. Release of PC from the implants was found to be biphasic starting with a burst release, followed by a gradual decline. Ultra performance liquid chromatography analysis showed no detectable PC in the plasma but its hydrolyzed product, ellagic acid was readily detected. The plasma concentration of ellagic acid was over two orders of magnitude higher (589 +/- 78 ng/mL) in the implant group compared with diet (4.36 +/- 0.83 ng/mL). Together, our data show that delivery of PC by implants can reduce its effective dose substantially, and that the inhibition of DNA adducts in vivo occurred presumably due to the conversion of PC to ellagic acid. (C) 2012 Elsevier B.V. All rights reserved.