J Munasinghe T C, Seneviratne C K, Thabrew M I, Abeysekera A M
Department of Biochemistry, Faculty of Medical Sciences, University of Sri Jayawardenepura, Nugegoda, Sri Lanka.
Phytother Res. 2001 Sep;15(6):519-23. doi: 10.1002/ptr.994.
Reactive oxygen species (ROS) are implicated in many pathogenic processes including the cardiovascular system. Detoxification of ROS by antioxidants (AO) therefore affords protection against such diseases. There is a growing body of evidence suggesting that antioxidants contribute to cardioprotection. Therefore, nine plants that are components of Ayurvedic formulations used for the therapy of cardiovascular diseases were investigated to determine whether antioxidant activity is one of the mechanisms by which these plants exert cardioprotection. Initially aqueous freeze dried extracts of the plants were prepared and the antioxidant activity was measured (a) in vitro, by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging and deoxyribose damage protection assays, and (b) in vivo, by effects on lipid peroxidation. Terminalia arjuna showed significant DPPH radical scavenging activity with EC(50) 8.3 +/- 0.3 microg/mL (similar to L-ascorbic acid). The potency of this activity was much lower in Cassia fistula (EC(50) = 59.0 +/- 2.7 microg/mL). The other seven extracts demonstrated no such activity in the concentration range tested. In the deoxyribose damage protection assay, T. arjuna> demonstrated no significant effect in the concentration range 0-20 microg/mL, but above -20 microg/mL concentration (20-125 microg/mL), a pro-oxidant activity was observed (although markedly less than demonstrated by L-ascorbic acid). A similar trend was observed with Vitex negundo. In contrast, C. fistula afforded a 30% protection against such damage at 125 microg/mL concentration. Other plant extracts did not show any activity in this assay. At a dose of 90 mg/kg (single dose) T. arjuna, cardiac lipid peroxidation in male Wistar rats was reduced by 38.8% +/- 2.6% (p<0.05) whereas the reduction was only 11.6% +/- 3.5% in the case of C. fistula even at a dose of 120 mg/kg. Of all the plants tested, T. arjuna demonstrated the highest antioxidant activity. Overall results show that only some plants used in the therapy of cardiovascular disease exert their beneficial effects via antioxidant activity.
活性氧（ROS）与包括心血管系统在内的许多致病过程有关。因此，抗氧化剂（AO）对ROS的解毒作用可提供针对此类疾病的保护。越来越多的证据表明抗氧化剂有助于心脏保护。因此，对九种用于治疗心血管疾病的阿育吠陀配方中的植物成分进行了研究，以确定抗氧化活性是否是这些植物发挥心脏保护作用的机制之一。最初制备了这些植物的水冻干提取物，并通过以下方法测量抗氧化活性：（a）体外，通过DPPH（1,1-二苯基-2-苦基肼）自由基清除和脱氧核糖损伤保护试验；（b）体内，通过对脂质过氧化的影响。诃子显示出显著的DPPH自由基清除活性，EC（50）为8.3±0.3微克/毫升（与L-抗坏血酸相似）。决明子的这种活性效力要低得多（EC（50）=59.0±2.7微克/毫升）。其他七种提取物在测试浓度范围内未显示出这种活性。在脱氧核糖损伤保护试验中，诃子在0至-20微克/毫升浓度范围内未显示出显著影响，但在高于-20微克/毫升浓度（20至125微克/毫升）时，观察到促氧化活性（尽管明显低于L-抗坏血酸）。黄荆也观察到类似趋势。相比之下，决明子在125微克/毫升浓度下对此类损伤提供了30%的保护。其他植物提取物在该试验中未显示任何活性。在90毫克/千克（单次剂量）的诃子剂量下，雄性Wistar大鼠的心脏脂质过氧化降低了38.8%±2.6%（p<0.05），而即使在120毫克/千克剂量下，决明子的降低率仅为11.6%±3.5%。在所有测试的植物中，诃子显示出最高的抗氧化活性。总体结果表明，只有一些用于治疗心血管疾病的植物通过抗氧化活性发挥其有益作用。
