Kagaya Noritaka, Hara Yukihiko, Saijo Ryoyasu, Kamiyoshi Akiko, Tagawa Yoh-Ichi, Kawase Masaya, Yagi Kiyohito
Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan.
J Biosci Bioeng. 2003;96(6):559-63. doi: 10.1016/S1389-1723(04)70149-8.
Epigallocatechin-3-(3''-O-methyl)gallate (EGCg-3''-OMe) is a rare component in green tea leaf and its bioactivity is hardly known. In this paper, we report that EGCg-3''-OMe has the function for cold preservation of primary rat hepatocytes. Confluent primary cultured hepatocytes were suspended in a storage solution, culture medium or cell banker (CB). EGCg-3''-OMe was tested as a supplement in the storage solution together with a general cryoprotectant, dimethylsulfoxide (DMSO). After 24 h cold preservation of cells at 4 degrees C followed by 1 h rewarming, cell viability and urea-synthesizing activity, one of the most important liver functions, were measured. EGCg-3''-OMe dose-dependently maintained cell viability and this effect was equal to that of a commercial CB at the highest concentration. Cell viability was also maintained after a further 24 h incubation at 37 degrees C of the cold-preserved hepatocytes. Conversely, urea-synthesizing activity was dose-dependently reduced by EGCg-3''-OMe. Cell protection by EGCg-3''-OMe due to the decrease in metabolic activity in cold-preserved cells was suggested. The decreased hepatic function of cells caused by EGCg-3''-OMe was rescued after a further 24 h incubation of cells at 37 degrees C.
表没食子儿茶素 -3-（3''-O-甲基）没食子酸酯（EGCg-3''-OMe）是绿茶叶片中的一种稀有成分，其生物活性鲜为人知。在本文中，我们报道EGCg-3''-OMe具有对原代大鼠肝细胞进行低温保存的功能。将汇合的原代培养肝细胞悬浮于储存溶液、培养基或细胞冻存液（CB）中。EGCg-3''-OMe作为一种补充剂与通用的冷冻保护剂二甲基亚砜（DMSO）一起加入到储存溶液中进行测试。在4℃对细胞进行24小时低温保存后再进行1小时复温，然后测量细胞活力以及尿素合成活性（肝脏最重要的功能之一）。EGCg-3''-OMe呈剂量依赖性地维持细胞活力，在最高浓度时这种作用与市售细胞冻存液相当。对低温保存的肝细胞在37℃进一步孵育24小时后，细胞活力也得以维持。相反，EGCg-3''-OMe使尿素合成活性呈剂量依赖性降低。提示EGCg-3''-OMe对细胞的保护作用是由于低温保存细胞的代谢活性降低所致。在细胞于37℃进一步孵育24小时后，由EGCg-3''-OMe导致的细胞肝功能下降得以恢复。
