According to joint research by Nagoya City University, Daiichi University of Pharmacy, Chiba University, and Kameda General Hospital, the causative agent of the side effect "pseudoaldosteronism" that frequently occurs when using Chinese herbs is glycyrrhizic acid contained in the raw drug licorice. It was revealed that the metabolite 18β-glycyrrhizyl-3-O-sulfate is likely to be.
With the expansion of the use of Chinese herbs, the onset of side effects has become a problem.Pseudoaldosteronism, in particular, can lead to serious conditions if detected late, but onset varies from person to person and is difficult to predict.
Until now, the causative substance of pseudoaldosteronism has been considered to be glycyrrhetinic acid (GA), which is a metabolite of glycyrrhizic acid (GL), which is a component of licorice contained in about 7% of medical Chinese herbal extract preparations. rice field.However, GA is detected in the blood of almost all humans and does not explain the individual differences in the onset of pseudoaldosteronism.
Subsequent studies suggest that there are metabolites of GL that appear in the blood and urine only when the function of the protein Mrp2 involved in bile excretion is impaired, which may be the true causative agent of pseudoaldosteronism. Was done.Therefore, in this study, we identified these metabolites in rats with Mrp2 dysfunction, and among them, 18β-glycyrrhetinyl-3-O-sulfate detected at high concentration in the serum of patients who actually developed pseudoaldosteronism was found. We conclude that it is likely to be the causative agent of pseudoaldosteronism. When Mrp2 function declines, 18β-glycyrrhetinyl-3-O-sulfate cannot be transferred into bile and is excreted in urine, and by inhibiting 11β-hydroxysteroid dehydrogenase 2 present in renal tubules, pseudoaldosteronism occurs. It is thought that it will develop.
From this result, it can be said that 18β-glycyrrhetinyl-3-O-sulfuric acid may be useful as a biomarker for the prevention of side effects of Chinese herbs.
Paper information:[Scientific Reports] 18β-glycyrrhetyl-3-O-sulfate would be a causative agent of licorice-induced pseudoaldosteronism
