Abstract
BACKGROUND: Compatibility with Panax notoginseng (PN) reduced the plasma concentration of triptolide and delayed the T(max) of Tripterygium wilfordii (TW), the sovereign medicine of Qing-Luo Tong-Bi decoction, which hinted the absorption process of triptolide might be involved in decreasing the toxicity in liver and kidney. METHODS: The absorption of triptolide, triptonide, wilforlide and tripterine from monomer, TW, TW-PN, TW-Caulis Sinomenii (TW-CS) and Qing-Luo Tong-Bi were analyzed in duodenum, jejunum, ileum and colon of rat via single-pass intestinal perfusion model. An UPLC-MS/MS analysis method was developed to determine the concentration of triptolide, triptonide, wilforlide and tripterine in the inlet and outlet. Then P(eff), 10 cm%ABS and K(a) were calculated based on the perfusate flux, perfusate volume and candidate chemicals concentration. RESULTS: The absorption of triptolide, triptonide, wilforlide and tripterine in duodenum, jejunum, ileum and colon was independent of concentration within range of 3-9 μg/mL. The target compounds, triptolide, triptonide, wilforlide and tripterine from the TW extract, showed higher absorption extent and rate than those administrated alone, and compared with the absorption situation of the chemicals of TW extract, the absorption of triptolide, triptonide and wilforlide of the extract of TW-PN, TW-CS and Qing-Luo Tong-Bi were decreased in these intestinal segments. However, PN-promoted tripterine absorption was observed in the intestine. CONCLUSIONS: Modulation of absorption of chemicals in TW by subsidiary herbs may be responsible for reinforcing the actions and neutralizing the adverse effects through compatibility in the formula of Qing-Luo Tong-Bi. PN inhibits the absorption of triptolide of TW and promote the absorption of tripterine.