三七皂苷中人参皂苷Rg1与Rb1口服吸收及其体内药代动力学的研究和比较

分别考察三七总皂苷(PNS)在大鼠灌胃和静脉给药后的人参皂苷Rg₁(Rg₁)、人参皂苷Rb₁(Rb₁)的胆汁排泄；采用平衡透析法测定药物的血浆蛋白结合率；并结合药代动力学的实验结果，研究和比较Rg₁与Rb₁的口服吸收及其体内药代动力学性质。结果表明，静脉给药后10 h，Rg₁及Rb₁胆汁排泄累积量分别为给药剂量的(61.48±18.30)%和(3.94±1.49)%；灌胃给药后12 h，Rg₁及Rb₁胆汁排泄累积量分别为给药剂量的(0.91±0.51)%和(0.055±0.02)%。Rg₁及Rb₁的血浆蛋白结合率分别为6.56%～12.74%和80.11%～89.69%。Rg₁的胃、肠和肝的通过率(F_S，F_I和F_H)分别为49.85%，13.05%和50.56%；Rb₁分别为25.82%，4.18%和65.77%。因此，肠壁吸收差是Rg₁和Rb₁生物利用度低的主要原因。Rg₁具有较高的胆汁排泄和较低的血浆蛋白结合率，Rb₁的胆汁排泄较低，而血浆蛋白结合率较高。Rb₁的肠黏膜透过性和体内消除速度都低于Rg₁，但前者的平均滞留时间(MRT)和血药浓度曲线下面积(AUC)均大于后者。

Comparison between the characteristics of absorption and pharmacokinetic behavior of ginsenoside Rg1 and ginsenoside Rb1 of panax notoginseng saponins

To compare the characteristics of absorption and pharmacokinetic behavior of ginsenoside Rg1 (Rg1) with ginsenoside Rb1 (Rb1) of panax notoginseng saponins (PNS), bile excretion of both Rg1 and Rb1 were studied after i.v. and i.g. of PNS solution. Plasma protein binding ratios were studied using equilibrium dialysis method, and referred to pharmacokinetic parameters. It shows that (61.48 +/- 18.30)% dose of Rg1 and (3.94 +/- 1.49)% dose of Rb1 were separately excreted into bile 10 hours after i.v. administration (PNS 50 mg x mL(-1)), and (0.91 +/- 0.51)% dose of Rg1 and (0.055 +/- 0.02)% dose of Rb1 were excreted into bile 12 hours after i.g. administration (PNS 1 500 mg x mL(-1)). Plasma protein binding degrees of Rg1 and Rb1 were 6.56% - 12.74% and 80.1% - 89.69%, respectively. Stomach, intestinal and hepatic throughput efficiency (F(S), F1 and F(H)) for Rg1 were 49.85%, 13.05%, 50.56%, respectively, and 25.82%, 4.18%, 65.77% for Rb1. Therefore, poor intestinal absorption is a primary reason for the low bioavailability of both Rg1 and Rb1. Rg1 possesses relatively high bile excretion and low plasma protein binding rate, in contrast, Rb1 possesses low bile excretion and high plasma protein binding rate. Membrane permeability and elimination rate of Rb1 were lower than that of Rg1, meanwhile, longer MRT and bigger AUC could be found for Rb1.