Dias Tânia R, Alves Marco G, Casal Susana, Silva Branca M, Oliveira Pedro F
Health Sciences Research Centre, University of Beira Interior, 6200-506 Covilhã, Portugal.
LAQV/REQUIMTE - Laboratory of Bromatology and Hydrology, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal.
Food Funct. 2016 Mar;7(3):1301-5. doi: 10.1039/c5fo01611h.
Caffeine, epigallocatechin-3-gallate (EGCG) and L-theanine are the major components of tea (Camellia sinensis L.) and the main representatives of the classes of methylxanthines, catechins and free amino acids present in this beverage. There are many studies reporting tea's health benefits, however it is not clear if those effects are mediated by a single component or a synergistic action. This study aimed to evaluate the individual and synergistic effects of tea's major components on rat epididymal spermatozoa survival and oxidative profile during 3-day storage at room temperature (RT). For that, spermatozoa were incubated with caffeine (71 μg mL(-1)), EGCG (82 μg mL(-1)), or L-theanine (19 μg mL(-1)), alone or in combination. Spermatozoa viability was assessed by the eosin-nigrosin staining technique. The oxidative profile was established by evaluating the levels of carbonyl groups, protein nitration and lipid peroxidation. Supplementation of sperm storage medium with the three compounds together improved sperm viability, after 24, 48 and 72 h of incubation, relative to the control and the groups incubated with each component individually. However, at the end of the 72 h of incubation, there was an increase in protein oxidation in the group exposed to the three compounds, illustrating that the combined treatment triggers different alterations in sperm proteins during their maturational process in the epididymis. This study highlights the importance of the synergism between tea components for the beneficial effects usually attributed to this beverage, particularly in sperm storage at RT.
咖啡因、表没食子儿茶素-3-没食子酸酯（EGCG）和L-茶氨酸是茶叶（茶树）的主要成分，也是该饮品中甲基黄嘌呤、儿茶素和游离氨基酸类别的主要代表。有许多研究报道了茶对健康的益处，然而尚不清楚这些作用是由单一成分介导还是协同作用所致。本研究旨在评估茶的主要成分在室温下储存3天期间对大鼠附睾精子存活和氧化状态的单独及协同作用。为此，精子与咖啡因（71μg/mL）、EGCG（82μg/mL）或L-茶氨酸（19μg/mL）单独或组合孵育。通过伊红-黑色素染色技术评估精子活力。通过评估羰基、蛋白质硝化和脂质过氧化水平来确定氧化状态。与对照组和单独用每种成分孵育的组相比，在孵育24、48和72小时后，向精子储存培养基中添加这三种化合物可共同提高精子活力。然而，在孵育72小时结束时，暴露于这三种化合物的组中蛋白质氧化增加，这表明联合处理在精子在附睾成熟过程中引发了精子蛋白质的不同改变。本研究强调了茶成分之间协同作用对于通常归因于该饮品的有益作用的重要性，特别是在室温下储存精子方面。
