RNase protection assay of myocarditis. TNF-alpha mRNA level was markedly decreased in the catechin treated group compared with that of control group.  On the other hand, mRNA levels of Th2 cytokines such as IL-4 and IL-10 in the catechin treated group (20 mg/kg/day, THEA-FLAN 90S) were markedly enhanced compared with that of control group.