Study on human UDP-glucuronosyltransferase (UGT) isoforms involved in in vitro metabolism of trans-resveratrol / 中国中药杂志

<p><b>OBJECTIVE</b>To study major human UGT isoforms involved in trans-resveratrol (TR) phase II metabolism.</p><p><b>METHOD</b>trans-resveratrol and 12 major human UGT isoforms were incubated in vitro and then glucuronic acid metabolites were determined by HPLC-MS, in order to preliminarily analyze the structure and observe the effect of different UGT isoforms on the generation rate of glucuronic acid metabolites.</p><p><b>RESULT</b>In in vitro metabolic system, two metabolites-4'-O-monoglucuronide resveratrol (M-1) and 3-0-monoglucuronide resveratrol (M-2)-were generated from trans-resveratrol after being catalyzed by UGT. During the cause, generation of M-1 and M-2 were catalyzed by UGT1A1, UGT1A3, 1A8, 1A9 andlA10, whereas only UGT1A6 and 1A7 contributed to the forma-tion of M-2. Both the formation rate of M-1 and M-2 catalyzed by UGT1A1, 1A10 and the formation of M-2 catalyzed by UGT1A8 slowed down with the increasing concentration of substrates, causing the phenomenon of "substrate inhibition".</p><p><b>CONCLUSION</b>UGT1A1, 1A8, 1A9, 1A10 get involved in the formation of M-1, and of them UGTIA9 is the most important contributor. UGT1A3 also makes small contribution to the formation of M-1 and M-2, while other UGT isoforms show hardly any reaction with the trans-resveratrol phase II metabolites.</p>

Self-microemulsifying drug delivery system increasing solubility and intestinal absorption in situ of tanshinones / 中国中药杂志

<p><b>OBJECTIVE</b>Study the effect of self-microemulsifying drug delivery system(SMEDDS) on the solubility and absorption of tanshinones to guide the selection of composition of tanshinone SMEDDS.</p><p><b>METHOD</b>The solubility of tanshinones in the solution of SMEDDS was determined by UV-spectrometer and the absorption of tanshinone SMEDDS was determined by HPLC as the detection method.</p><p><b>RESULT</b>The solubility of tanshinones in solution of SMEDDS was 10 times in water and 2.5 times in micelle solution. The solubility of tanshinones in solution of SMEDDS was increased with the increasing of oil (MCT) in composition of tanshinone SMEDDS. The absorption constants (Ka) in SMEDDS and micelle solution was 0.479 h(-1) and 0.326 h(-1) respectively, and the absorption half life (t1/2) was 1.44 h and 2.12 h respectively. The absorption was increased with the oil increasing in composition of tanshinone SMEDDS.</p><p><b>CONCLUSION</b>SMEDDS can increase the solubility and absorption of tanshinones significantly and the increasing of oil content (MCT) in SMEDDS composition promote the dissolution and absorption of tanshinones.</p>