Hippocampal Neuroprotection by Minocycline and Epigallo-Catechin-3-Gallate Against Cardiopulmonary Bypass-Associated Injury.

Surgical correction of congenital cardiac malformations mostly implies the use of cardiopulmonary bypass (CPB). However, a possible negative impact of CPB on cerebral structures like the hippocampus cannot be neglected. Therefore, we investigated the effect of CPB on hippocampus CA1 and CA3 regions without or with the addition of epigallocatechin-3-gallate (EGCG) or minocycline. We studied 42 piglets and divided them into six experimental groups: control without or with EGCG or minocycline, CPB without or with EGCG or minocycline. The piglets underwent 90 minutes CPB and subsequently, a 120-minute recovery and reperfusion phase. Thereafter, histology of the hippocampus was performed and the adenosine triphosphate (ATP) content was measured. Histologic evaluation revealed that CPB produced a significant peri-cellular edema in both CA regions. Moreover, we found an increased number of cells stained with markers for hypoxia, apoptosis and nitrosative stress. Most of these alterations were significantly reduced to or near to control levels by application of EGCG or minocycline. ATP content was significantly reduced within the hippocampus after CPB. This reduction could not be antagonized by EGCG or minocycline. In conclusion, CPB had a significant negative impact on the integrity of hippocampal neural cells. This cellular damage could be significantly attenuated by addition of EGCG or minocycline.