Department of Biochemistry, Seth GSMC and KEMH Parel Mumbai, Maharashtra, India.
Department of Biochemistry, G.M.C. Nandurbar, Maharashtra, India.
Indian J Ophthalmol. 2024 Oct 1;72(10):1506-1511. doi: 10.4103/IJO.IJO_19_24. Epub 2024 Sep 27.
The main factor that causes cataracts is the increased oxidative stress and imbalance of an antioxidant defense mechanism, which leads to significant changes in the lens microarchitecture. Senile cataract is the most common type of acquired cataracts due to aging.
We carried out a case-control study in the biochemistry department to examine the antioxidant status (catalase and total antioxidant capacity [TAC]) and lipid peroxidation marker, that is, malondialdehyde (MDA) in human lens epithelial cells (HLECs) of different grades of senile cortical, nuclear, and posterior subcapsular cataracts. We collected 150 samples from patients aged 50-90 years. These included 50 samples of cortical cataracts, 50 of nuclear cataracts, and 50 samples of posterior subcapsular cataracts. We measured catalase activity by the Beer method, TAC by the Benzie and Strain method, and protein by the Bradford method. We also estimated TAC in the aqueous extract of HLECs by the ferric reducing ability of plasma (FRAP) method and MDA by the thiobarbituric acid assay method.
The results of this study showed that the level of catalase enzyme was higher in the first grade of nuclear, posterior subcapsular, and cortical cataracts than in other grades. This suggests that the catalase enzyme activity drops sharply in the second and third grades of these types of cataracts. The same pattern was observed for TAC, which was higher in the first grade of nuclear, posterior subcapsular, and cortical cataracts than in other grades. There were significant differences between catalase and TAC in different grades of cataracts, indicating that as the grading increases, both catalase and TAC decrease.
The results of this study showed that the levels of MDA were higher and the levels of catalase and TAC were lower in patients with more severe cataracts compared to the healthy controls.
导致白内障的主要因素是氧化应激增加和抗氧化防御机制失衡，这导致晶状体微结构发生显著变化。老年性白内障是最常见的获得性白内障类型，是由于衰老引起的。
我们在生物化学系进行了一项病例对照研究，以检查不同等级的老年性皮质性、核性和后囊下白内障患者的人晶状体上皮细胞（HLEC）中的抗氧化状态（过氧化氢酶和总抗氧化能力[TAC]）和脂质过氧化标志物，即丙二醛（MDA）。我们收集了 150 名年龄在 50-90 岁的患者的样本。其中包括皮质性白内障 50 例，核性白内障 50 例，后囊下白内障 50 例。我们通过 Beer 法测定过氧化氢酶活性，通过 Benzie 和 Strain 法测定 TAC，通过 Bradford 法测定蛋白质。我们还通过血浆还原能力的铁法（FRAP）测定 HLEC 水提取物中的 TAC，通过硫代巴比妥酸法测定 MDA。
本研究结果表明，在核性、后囊下和皮质性白内障的一级中，过氧化氢酶酶的水平高于其他等级。这表明在这些类型的白内障的第二和第三级中，过氧化氢酶酶活性急剧下降。TAC 也呈现出相同的模式，在核性、后囊下和皮质性白内障的一级中高于其他等级。在不同等级的白内障中，过氧化氢酶和 TAC 之间存在显著差异，表明随着分级的增加，过氧化氢酶和 TAC 都降低。
本研究结果表明，与健康对照组相比，白内障程度越严重的患者 MDA 水平越高，过氧化氢酶和 TAC 水平越低。
