Chawla Raman, Arora Rajesh, Sagar Ravinder K, Singh Shikha, Puri Satish C, Kumar Raj, Singh Surender, Sharmaa Ashok K, Prasada Jagdish, Khan Haider A, Sharma Rakesh Kumar, Dhar Kanaya Lal, Spiteller Michael, Qazi Ghulam Nabi
Department of Radiation Biology, Institute of Nuclear Medicine and Allied Sciences, Delhi, India.
Z Naturforsch C J Biosci. 2005 Sep-Oct;60(9-10):728-38. doi: 10.1515/znc-2005-9-1012.
The aqueous-ethanolic extract (AEE) of high altitude Podophyllum hexandrum has earlier been reported to render a radioprotective effect against lethal gamma radiation in in vitro model. AEE has also been reported to possess metal chelating and DNA protecting properties. The present study was undertaken to isolate and characterize the bioactive principle present in AEE and investigate its role in radiation protection. A novel molecule was found to be present in AEE and was assigned as 3-O-beta-D-galactoside of quercetin by acid hydrolysis, LC-MS, LC-APCI-MS/MS and 13C NMR spectra. Various biological activities were investigated at in vitro level. The antioxidant potential of AEE in lipid and aqueous phase was determined against numerous stresses. AEE was found to be significantly (p < 0.05) protective, i.e., against Fe2+ and Cu2+-induced linoleic acid degradation, respectively. Radiation-induced lipid oxidation studies revealed that AEE maximally works at a [lignan]/0.25 kGy ratio 400 (ratio of concentration of AEE divided by the radiation dose, i.e., 0.25 kGy) and no drug-induced lipid oxidation at all concentrations tested was found. In a time-dependent study, total antioxidant activity was maximally exhibited at 1 mg/ml. The site-specific and non-site-specific deoxyribose degradation assay exhibited a dose-dependant hydroxyl scavenging potential of AEE (0.05-500 microg/ml). The anti-lipid peroxidation ability of AEE against radiation (0.25 kGy)-induced lipid peroxidation was higher in case of neural tissue homogenate as compared to kidney homogenate [activity ratio: 0.039 (brain) < 0.24 (kidney)]. The protein protection study using bovine serum albumin was also done for two time intervals (2 h and 4 h) and significant (p < 0.05) protection was observed at 500 microg/ml (> 97%). This study implies that 3-O-beta-D-galactoside present in AEE renders radioprotection by protecting lipids, proteins in renal and neural model system against supra-lethal (0.25 kGy) gamma radiation.
早前有报道称，高海拔桃儿七的水乙醇提取物（AEE）在体外模型中对致死性γ辐射具有辐射防护作用。也有报道称AEE具有金属螯合和DNA保护特性。本研究旨在分离并鉴定AEE中存在的生物活性成分，并研究其在辐射防护中的作用。通过酸水解、液相色谱 - 质谱联用（LC-MS）、液相色谱 - 大气压化学电离串联质谱（LC-APCI-MS/MS）和13C核磁共振光谱，发现AEE中存在一种新分子，并将其鉴定为槲皮素的3 - O - β - D - 半乳糖苷。在体外水平研究了其各种生物学活性。测定了AEE在脂质和水相中的抗氧化潜力，以应对多种应激。结果发现AEE具有显著（p < 0.05）的保护作用，即分别对Fe2+和Cu2+诱导的亚油酸降解具有保护作用。辐射诱导的脂质氧化研究表明，AEE在[木脂素]/0.25 kGy比率为400时（即AEE浓度与辐射剂量0.25 kGy的比值）作用最大，且在所测试的所有浓度下均未发现药物诱导的脂质氧化。在一项时间依赖性研究中，总抗氧化活性在1 mg/ml时最大程度地表现出来。位点特异性和非位点特异性脱氧核糖降解试验显示AEE具有剂量依赖性的羟自由基清除潜力（0.05 - 500 μg/ml）。与肾匀浆相比，AEE对辐射（0.25 kGy）诱导的神经组织匀浆脂质过氧化的抗脂质过氧化能力更高[活性比率：0.039（脑）< 0.24（肾）]。还使用牛血清白蛋白进行了两个时间间隔（2小时和4小时）的蛋白质保护研究，在500 μg/ml时观察到显著（p < 0.05）的保护作用（> 97%）。本研究表明，AEE中存在的3 - O - β - D - 半乳糖苷通过保护肾和神经模型系统中的脂质、蛋白质免受超致死剂量（0.25 kGy）的γ辐射而发挥辐射防护作用。
