Galactosamine is known to induce hepatic injury in rats and the galactosamine-induced hepatitis is believed to be similar to viral hepatitis both morphologically and functionally. In the present study, we examined how drinking green tea affects the gene expression of inflammatory cytokines which may be up-regulated in galactosamine-induced hepatitis. As has been reported, galactosamine caused hepatic injury in rats as evidenced by an increase in serum transaminase activities and histological observations of the liver. The results of the reverse transcription and polymerase chain reaction indicated an increased gene expression of inflammatory cytokines, tumor necrosis factor-α and interleukin-1β, in the injured liver and the enzyme linked immunoassay showed an increase in the serum levels of these cytokines. Oral administration of green tea rich in catechins (Healthya green tea) restored these biomarkers in the galacotsamine-treated rats to near the control levels. These results suggest that the drinking of green tea with a high catechin content may help to prevent and/or attenuate the development of a certain type of hepatitis.

Previously, we reported that the oral administration of green tea rich in catechins restored levels of several biomarkers increasing in galactosamine-treated rats to nearly control values. These biomarkers included serum transaminase activities, serum concentrations of tumor necrosis factor-α and interleukin 1-β, and the hepatic mRNA expression of these inflammatory cytokines. In the present study, we examined possible anti-fibrotic effects of green tea in galactosamine-induced hepatitis. The results of the reverse transcription and polymerase chain reaction indicated that the increase in gene expression of the α1 chain of collagen type 1 and transforming growth factor β-1 in the injured liver 24 h post-injection of galactosamine was suppressed by the administration of green tea. Masson's trichrome staining demonstrated that the extent of fibrogenesis after 14 days was greater in the galactosamine-injured livers not treated with green tea than the treated ones. These results suggest that the drinking of green tea with a high catechin content may help to prevent and/or attenuate the development of fibrosis in hepatitis.