Protection of liver cells from experimentally induced liver cell injury by glycyrrhizin.

Liver cell damage is induced when isolated liver cells coated with specific antibody against the liver cell membrane are cultured with peripheral blood mononuclear cells. Although this antibody-dependent cell-mediated cytotoxicity (ADCC) was induced by closed contact of effector cells with targets via specific antibody, a cytotoxic factor or factors causing inhibition of protein synthesis in liver cells was detected in the culture supernatant of the ADCC reaction. Similarly, peritoneal exudate macrophages activated by endotoxin lipopolysaccharide (LPS) also had cytotoxic effects on isolated liver cells by producing a cytotoxic substance or substances. These liver cell injuries caused by either ADCC or activated macrophage culture supernatants were significantly reduced by pretreatment of the isolated liver cells with glycyrrhizin before the addition of the cytotoxic culture supernatants. These results suggest that glycyrrhizin may protect liver cells from immunological injuries.