Effects of vitamin E on the proliferation and collagen synthesis of rat hepatic stellate cells treated with IL-2 or TNF-alpha.

OBJECTIVE: To study the effects of vitamin E on the proliferation and collagen synthesis of rat hepatic stellate cells treated with interleukin-2 (IL-2) or tumor necrosis factor-alpha (TNF-alpha). METHODS: Hepatic stellate cells were isolated from male Sprague-Dawley rats by using modified Friedman's method. Using the isolated cells cultured and treated with IL-2 or TNF-alpha, we studied the effects of vitamin E on their proliferation and collagen synthesis through an (3)H-thymidine and (3)H-proline incorporation assay, as well as through observation of these cells under a contrary phase microscope. RESULTS: Adding IL-2 increased the both proliferation and collagen synthesis of hepatic stellate cells. Their proliferation was also increased by the addition of TNF-alpha, although it decreased collagen synthesis. Vitamin E had marked inhibitory effects on the ability of cells treated with IL-2 or TNF-alpha to reproduce or synthesize collagen. CONCLUSION: Vitamin E can inhibit the proliferation and collagen synthesis of hepatic stellate cells. It is possible that vitamin E affects liver fibrosis through these activities.