Novel Function of Rare Catechin, Epigallocatechin-3-(3"-O-methyl) gallate, against Cold Injury in Primary Rat Hepatocytes

Abstract 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°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°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°C.