A Comparison of the Antihepatotoxic Activity between Glycyrrhizin and Glycyrrhetinic Acid

Abstract

A comparison of antihepatotoxic activities between glycyrrhizin (18 beta-GL) and its genuine aglycone, glycyrrhetinic acid (18 beta-GA), was carried out using in vivo and in vitro assay methods. The oral administration of 18 beta-GA at 1, 24, and 48 h before D-galactosamine (GalN) treatment significantly reduced the increase of serum transaminase activities 24 h after GalN treatment, whereas 18 beta-GL did not inhibit the increase of serum transaminase activities. The intraperitoneal administration of 18 beta-GA 1 h before GalN treatment restored the increase of serum transaminase activities with lower doses than 18 beta-GL. In CCl4-induced cytotoxicity of primary cultured rat hepatocytes, 18 beta-GA protected the CCl4-induced leakage of transaminase at doses of 5 to 50 micrograms/ml, whereas 18 beta-GL inhibited slightly the leakage at a dose of 1000 micrograms/ml. In the same way, 18 alpha-GA, the alpha-isomer of 18 beta-GA, reduced the CCl4-induced cytotoxicity more strongly than 18 alpha-GL. Furthermore, the adsorbability of 18 alpha, beta-GA on primary cultured rat hepatocytes was higher than that of 18 alpha, beta-GL. These results suggest that 18 alpha, beta-GA is a more potent antihepatotoxic agent than 18 alpha, beta-GL, and that the potency of the antihepatotoxic compounds parallels their adsorbability in hepatocytes.

Metabolism of Constituents in Huangqin-Tang, a Prescription in Traditional Chinese Medicine, by Human Intestinal Flora

“…Some papers reported that the metabolites of traditional Chinese materia medica, such as GA and PM-I, yield stronger pharmacological effect than the original compound, [27][28][29][30][31][32] and they were the ultimate active components in vivo. The metabolic mechanism of HIF is an important link for the pharmacological study of Chinese material medica.…”

Anti-Inflammatory Actions of Pentacyclic Triterpenes

“…Oral administration of 18/3-GA, but not of GL, protected rats against GaIN induced increase in serum transaminases, whereas both GA and CL were active when administered i. p. (41). GL in rats (i. v. or i.p.)…”

Hepatoprotective Constituents in Plants 14. Effects of Soyasapogenol B, Sophoradiol, and Their Glucuronides on the Cytotoxicity of tert-Butyl Hydroperoxide to HepG2 Cells1)

“…3) Saikosaponins [4][5][6] and glycyrrhizin [7][8][9] are the most well-known of these. In Japan, glycyrrhizin has been widely used as a drug to treat hepatitis.…”