RESUMEN
Phase II glucuronidation metabolism of side-chain propranolol was studied using microsomes from rats treated with the inducers beta-naphthoflavone (BNF) or dexamethasone (Dex). The glucuronide concentrations of propranolol enantiomers were assayed by RP-HPLC. The kinetic constants of glucuronidation, Km, Vmax and Clint were determined. There are significant differences between the R- and S-enantiomeric glucuronide in Km, Vmax and Clint P < 0.05, P < 0.01 and P < 0.05 in control microsome. There are significant differences in Km and Clint (P < 0.01 or P < 0.001) but no significant differences in Vmax (P > 0.05) between R and S-enantiomeric glucuronide in the microsomes induced with Dex and BNF. The formation of S-(-)-propranolol glucuronide was inhibited by R-(+)-propranolol from the rat microsomes pretreated with BNF and Dex. The glucuronidation metabolism of propranolol enantiomers exhibited the stereoselectivity in rat hepatic microsomes induced with BNF or Dex. Multiple UGT1A and 2B may be involved in stereoselective O-glucuronidation of propranolol enantiomers in rat liver microsomes. The glucuronides produced were in favor of the R-enantiomer. There is an interaction between the glucuronidation of R- and S-enantiomer.
Asunto(s)
Antagonistas Adrenérgicos beta/farmacocinética , Glucurónidos/química , Microsomas Hepáticos/metabolismo , Propranolol/farmacocinética , Animales , Dexametasona/farmacología , Inhibidores Enzimáticos/farmacología , Glucocorticoides/farmacología , Técnicas In Vitro , Cinética , Masculino , Ratas , Ratas Sprague-Dawley , Soluciones , Estereoisomerismo , beta-naftoflavona/farmacologíaRESUMEN
OBJECTIVE: To study the anticancer activity of Syngnathus in vitro. METHOD: Observing the influence of different extracts from Syngnathus on growth of different cancer cell strains by MTT method. RESULT: It has been found out that the fat-soluble nonsaponified extract from Temminck et Schlegel and the alcoholic extract from Syngnathus acus have cytotoxic activities. The nonsaponified extract from Temminck et Schlegel can inhibit the growth of cancer cell strains KB, Hela, PAA, K562, and Bcap37, and the alcoholic extract from Syngnathus acus can inhibit the growth of cancer cell strin KB, But Bloch shows no apparent anticancer activity. CONCLUSION: Syngnathus has promising prospects as an anticancer Chinese medicine.
