ABSTRACT
OBJECTIVE: To study the pharmacokinetics of rhein in 12 healthy volunteers after oral administration of rhubarb extract. METHOD: The blood sample were obtained at 0,0.083,0.5,1,1.5,2,3,4,5,7,10 h after a single dose oral administration of rhubarb (50 mg x kg(-1)). The plasma rhein concentration was determined by HPLC. The pharmacokinetics of rhein were analysed by 3P97 program. RESULT: The absorption of rhein was very fastafter oral administration of rhubarb extract in the healthy volunteers. The main pharmacokinetic parameters of rhein were C(max) (3.20 +/- 1.08) microg x mL(-1); t(max) (1.03 +/- 0.41) h; t(1/2alpha) (0.21 +/- 0.02) h; t(1/2beta) (2.68 +/- 1.09) h; MRT(5.31 +/- 1.78) h; AUC(0-infinity) (1 573.08 +/- 366.48) microg x mL(-1) min(-1), respectively. CONCLUSION: Rhein could be absorbed rapidly and its pharmacokinetics was consistent with two-compartment model.
Subject(s)
Anthraquinones/pharmacokinetics , Drugs, Chinese Herbal/pharmacokinetics , Plants, Medicinal , Rheum , Administration, Oral , Adult , Anthraquinones/blood , Area Under Curve , Chromatography, High Pressure Liquid , Drugs, Chinese Herbal/administration & dosage , Drugs, Chinese Herbal/isolation & purification , Female , Humans , Male , Plants, Medicinal/chemistry , Rheum/chemistryABSTRACT
Rhubarb is a common herb used in traditional Chinese medicine. However, few publications exist about its pharmacokinetic profiles in animals or healthy volunteers. Whether retention enema administration of rhubarb extract affects its pharmacokinetics as well as its tolerability is unknown. Therefore, we set out to compare the pharmacokinetic parameters of rhein administered by retention enemas with those of conventional oral dosing of rhubarb extract. Eight healthy male volunteers were enrolled in a prospective crossover study. All subjects received a single dose of rhubarb extract (50 mg.kg(-1)) on two separate occasions, once orally, once by a retention enema. Rhein plasma concentration was measured by HPLC. The C(max), AUC(0-infinity), AUMC were significantly higher in oral administration than those in retention enema administration (p < 0.05), while V(d) of rhein after oral administration of rhubarb extract was significantly lower (p < 0.05) than that after retention enema administration. However, no statistically significant differences between the two treatments were observed for any of the other pharmacokinetic parameters (T(max), t(1/2), MRT(0-infinity), CL). Dosage adjustment is advisable for retention enema administration of rhubarb extract in patients.
Subject(s)
Anthraquinones/pharmacokinetics , Enzyme Inhibitors/pharmacokinetics , Phytotherapy/methods , Plant Extracts/administration & dosage , Rheum , Administration, Oral , Administration, Rectal , Adult , Anthraquinones/administration & dosage , Anthraquinones/blood , Chromatography, High Pressure Liquid , Cross-Over Studies , Enema , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/blood , Humans , Male , Plant Extracts/pharmacokinetics , Prospective StudiesABSTRACT
OBJECTIVE: To investigate the triterpenoids chemical constituents in rhizome of Alisma gramineum. METHOD: Silicon gel chromatography and HPLC techniques were employed for isolation and purification of the constituents, and the structures were elucidated by various spectral analyses such as NMR, MS and IR. RESULT: 5 protostane-type tetracyclic triterpenoids were isolated and identified as 16,23-oxidoalisol B(1), 11-deoxyalisol C(2), alisol F(3), 16beta-methoxyalisol B acetate (4), 16beta-hydroxyalisol B acetate (5). CONCLUSION: All of these compounds were found from A. gramineum for the first time.
