| Licorice is a substance that is widely used in traditional Chinesemedicine. Its main active component is glycyrrhizic acid (GL). GL hastwo epimers, namelyα-GL andβ-GL. Magnesium isoglycyrrhizinate is anew pharmaceutical with anti-inflammatory and hepatoproteciveactivities. It was obtained from the crude glycyrrhizic acid by refining thesalt after alkali catalyzing and isomerizing. It is just containingα-GLwhile compound glycyrrhizin is the monomer ofβ-GL. This papercompared the distribution of Magnesium isoglycyrrhizinate andCompound glycyrrhizin in rat tissues.OBJECTIVE: To examine the characters of distribution of two epimersof glycyrrhizic acid (GL) includingα-GL andβ-GL in rats. METHODS:After iv administration of a singleα-GL orβ-GL (21 mg·kg-1) in rats, theconcentrations ofα-GL orβ-GL in some tissues of the rats at 5, 15, 30, 60,and 180 min were determined by RP-HPLC method, and the distributionsofα-GL andβ-GL were evaluated and compared. RESULTS:α-GL andβ-GL were all quickly distributed. The concentration ofα-GL in liver wassignificantly higher than that ofβ-GL, but it was lower than or similar tothat ofβ-GL in the other tissues at 5 min after iv. The concentrations ofα-GL in all the tissues declined rapidly, and were lower than or similar to the limit detection of quantification at 180 min after iv administration.Meanwhile,β-GL remained rather high in the tissues, which maintained10%～50% of its peak-value. CONCLUSION: There are distinctdifferences in the distribution and metabolism in the rat tissues after ivadministration of the two epimers of GL. After iv administration,α-GL istarget to the liver, and can be efficiently converted to more glycyrrheticacid (GA) thanβ-GL, and it nearly has no accumulation in the tissues.The distribution ofβ-GL in rat tissues appears to be wide throughout thebody, and its metabolism is slower than that ofα-GL to accumulating insome tissues. These differences are closely related with the differentconfiguration ofα-GL andβ-GL.
|
PDF Full Text Request