Effects of glycyrrhizin on immune-mediated cytotoxicity |
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| Authors: | MASAHIDE YOSHIKAWA YUJI MATSUI HIROSHI KAWAMOTO NORIE UMEMOTO KAZUMI OKU MASAKI KOIZUMI JUNICHI YAMAO SHIGEKI KURIYAMA HIROSHI NAKANO NOBUMICHI HOZUMI SHIGEAKI ISHIZAKA HIROSHI FUKUI |
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| Affiliation: | *Third Department of Internal Medicine, Nara Medical University, Kashihara, Nara, Japan;†Department of Clinico-Diagnostics, Nara Medical University, Kashihara, Nara, Japan;‡Department of Medical Genetics, Mount Sinai Hospital Research Institute, University of Toronto, Toronto, Canada |
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| Abstract: | Intravenous administration of glycyrrhizin is known to decrease elevated plasma transaminase levels in patients with chronic viral hepatitis, in which immune-mediated cytotoxicity by cytotoxic T lymphocytes and tumour necrosis factor (TNF)-α is considered to play an important pathogenic role. However, the immunological interpretation of the transaminase-lowering action of glycyrrhizin is not known. Studies were performed to elucidate this action immunologically by assessing the effects of glycyrrhizin on immune-mediated cytotoxicity using an antigen-specific murine CD4+ T hybridoma line, which exhibits cytotoxicity against antigen-presenting cells after stimulation with specific antigen, and a murine TNF-α-sensitive fibroblast line. Glycyrrhizin inhibited the cytotoxic activity of the T cells against antigen-presenting cells and also suppressed TNF-α-induced cytotoxicity in the TNF-α-sensitive cell line in vitro. These results suggest that the decrease of elevated transaminase levels by glycyrrhizin in patients with chronic viral hepatitis is mediated in part by inhibition of immune-mediated cytotoxicity against hepatocytes. |
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| Keywords: | antigen presentation, apoptosis, CD4+ Tlymphocyte, glycyrrhizin, T cell-mediated cytotoxicity, tumour necrosis factor-α. |
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