Meghashri S, Gopal S
Department of Studies in Microbiology, University of Mysore, Manasagangotri, Mysore, Karnataka, India.
J Pharm Bioallied Sci. 2012 Oct;4(4):341-4. doi: 10.4103/0975-7406.103277.
Antioxidants are quenchers of free radical that are responsible for inducing oxidative stress generated via reactive oxygen species-induced degenerative diseases such as cancer, diabetes, and cardiovascular diseases etc. Plant and plant products are recognized as safe and potential health promoting and nutritive sources.
To investigate the antioxidant potency of polyphenol extract (PE) of Nyctanthes arbortristis leaves and identification of the active constituent by HPLC.
PE of N. arbortristis leaves was investigated for antioxidant activity employing various established in vitro systems, such as lipid peroxidation in liposome, DPPH and hydroxyl radical scavenging, reducing power assay, and iron ion chelation. Identification of active constituent in PE of N. arbortristis responsible for antioxidant activity by HPLC.
All experiments were carried out in triplicates. Data were shown as mean ± standard deviation (SD). SPSS 10.0.5 version for windows (SPSS software Inc., USA) computer program was used for statistical analysis.
Identification of active constituent in PE revealed gallic acid 75.8 ± 0.21, protocatechuic acid 14.6 ± 0.5, chlorogenic acid 6.79 ± 0.43, and caffeic acid 5.34 ± 0.2 μg/ml. PE showed strong inhibitory activity of 73% at 200 μg/ml toward lipid peroxidation in egg lecithin, concentration-dependent inhibition of deoxyribose oxidation at 200 μg/ml was 85% inhibition, and considerable antioxidant activity in DPPH radical assay system at 200 μg/ml was 79% inhibition. BHA and gallic acid showed significant observations.
The antioxidant potency significantly correlated with the phenolic content of PE. Considering that medicinal herbs contain potent phytochemicals, which is effectively utilized for various degenerative disease, these in vitro results showed that N. arbortristis leaves could be effectively employed in functional food, to alleviate oxidative stress.
抗氧化剂是自由基清除剂，自由基会引发由活性氧诱导的退行性疾病（如癌症、糖尿病和心血管疾病等）所产生的氧化应激。植物及植物产品被认为是安全且具有潜在健康促进作用和营养的来源。
研究夜花树叶多酚提取物（PE）的抗氧化能力，并通过高效液相色谱法鉴定其活性成分。
采用多种已建立的体外系统研究夜花树叶PE的抗氧化活性，如脂质体中的脂质过氧化、二苯基苦味酰基自由基（DPPH）和羟自由基清除、还原能力测定以及铁离子螯合。通过高效液相色谱法鉴定夜花树叶PE中负责抗氧化活性的活性成分。
所有实验均重复三次。数据以平均值±标准差（SD）表示。使用适用于Windows的SPSS 10.0.5版本（美国SPSS软件公司）计算机程序进行统计分析。
PE中活性成分的鉴定结果显示没食子酸为75.8±0.21、原儿茶酸为14.6±0.5、绿原酸为6.79±0.43、咖啡酸为5.34±0.2μg/ml。PE在200μg/ml时对卵磷脂脂质过氧化表现出73%的强抑制活性，在200μg/ml时对脱氧核糖氧化的浓度依赖性抑制率为85%，在200μg/ml的DPPH自由基测定系统中具有相当的抗氧化活性，抑制率为79%。丁基羟基茴香醚（BHA）和没食子酸显示出显著结果。
抗氧化能力与PE的酚类含量显著相关。鉴于草药含有有效的植物化学物质，可有效用于各种退行性疾病，这些体外研究结果表明夜花树叶可有效用于功能性食品，以减轻氧化应激。
