Singh Nandita, Rajini P S
Food Protectants and Infestation Control Department, Central Food Technological Research Institute, Mysore 570013, India.
Chem Biol Interact. 2008 May 28;173(2):97-104. doi: 10.1016/j.cbi.2008.03.008. Epub 2008 Mar 22.
Potato peels are waste by-product of the potato processing industry. They are reportedly rich in polyphenols. Our earlier studies have shown that extracts derived from potato peel (PPE) possess strong antioxidant activity in chemical and biological model systems in vitro, attributable to its polyphenolic content. The main objective of this study was to investigate the ability of PPE to protect erythrocytes against oxidative damage, in vitro. The protection rendered by PPE in erythrocytes was studied in terms of resistance to oxidative damage, morphological alterations as well as membrane structural alterations. The total polyphenolic content in PPE was found to be 3.93 mg/g powder. The major phenolic acids present in PPE were predominantly: gallic acid, caffeic acid, chlorogenic acid and protocatechuic acid. We chose the experimental prooxidant system: FeSO(4) and ascorbic acid to induce lipid peroxidation in rat RBCs and human RBC membranes. PPE was found to inhibit lipid peroxidation with similar effectiveness in both the systems (about 80-85% inhibition by PPE at 2.5 mg/ml). While PPE per se did not cause any morphological alteration in the erythrocytes, under the experimental conditions, PPE significantly inhibited the H(2)O(2)-induced morphological alterations in rat RBCs as revealed by scanning electron microscopy. Further, PPE was found to offer significant protection to human erythrocyte membrane proteins from oxidative damage induced by ferrous-ascorbate. In conclusion, our results indicate that PPE is capable of protecting erythrocytes against oxidative damage probably by acting as a strong antioxidant.
土豆皮是土豆加工业的废弃副产品。据报道，它们富含多酚。我们早期的研究表明，从土豆皮中提取的提取物（PPE）在体外化学和生物模型系统中具有很强的抗氧化活性，这归因于其多酚含量。本研究的主要目的是在体外研究PPE保护红细胞免受氧化损伤的能力。从抗氧化损伤、形态改变以及膜结构改变方面研究了PPE对红细胞的保护作用。发现PPE中的总多酚含量为3.93毫克/克粉末。PPE中存在的主要酚酸主要是：没食子酸、咖啡酸、绿原酸和原儿茶酸。我们选择实验性促氧化剂系统：硫酸亚铁（FeSO₄）和抗坏血酸来诱导大鼠红细胞和人红细胞膜中的脂质过氧化。发现PPE在两个系统中抑制脂质过氧化的效果相似（在2.5毫克/毫升时，PPE的抑制率约为80 - 85%）。虽然PPE本身在实验条件下不会引起红细胞的任何形态改变，但扫描电子显微镜显示，PPE能显著抑制过氧化氢诱导的大鼠红细胞形态改变。此外，发现PPE能显著保护人红细胞膜蛋白免受亚铁 - 抗坏血酸诱导的氧化损伤。总之，我们的结果表明，PPE可能通过作为一种强抗氧化剂来保护红细胞免受氧化损伤。
