[Effect of kaempferol on the pharmacokinetics of nifedipine in rats].
To investigate the effect of kaempferol on the pharmacokinetics of nifedipine (NFP) in rats.



Twenty male SD rats, weighing 220-260 g, were distributed randomly into 4 groups. The animals were fasted, but allowed free access to water for 12 h before the administration of drugs. NFP dissolved in corn oil was administered via gastric intubation to the rats in control group at a dose of 10 mg/kg. Kaempferol was administered orally to the other three groups with dose of 5, 10, 15 mg/kg, respectively, followed by oral administration of NFP 10 mg/kg. Blood samples were collected through tail vein in heparinized plastic microcentrifuge tubes before and after drug administration. The plasma concentration of NFP was monitored with reversed phase high-performance liquid chromatography (RP-HPLC). Nimodipine was used as the internal standard. Statistical data evaluation was performed with Student's t-test and one-way analysis of variances.



The maximal plasma concentration (C(max)) of the three treated groups were 0.51, 0.70 and 0.81 microg/ml, respectively. The area under the concentration-time curve (AUC(0-8)) were 1.81, 2.83 and 3.63 microg/(h.ml(-1)), respectively. The C(max), AUC(0-8) and the mean retention time (MRT(0-8)) of NFP were significantly increased by simultaneous oral treatment with kaempferol (P<0.01). On the other hand, there were no significant differences in the mean peak value time in plasma (T(max)) and the elimination half-life (t1/2(ke)) between the control and the treated groups.



The concomitant oral use of kaempferol with NFP may influence the pharmacokinetic parameters of NFP in rats, which suggests that kaempferol might reduce the first-pass metabolism of NFP.
Institute of Medical Nutrition and Food Hygiene, Zhejiang University, Hangzhou 310031, China.
Mei
M
Xu
Min
M
Yang
Yi-fan
YF
Zheng
Hui-juan
HJ
Zhu
Xin-qiang
XQ
Zhu
D000818:Animals; D019540:Area Under Curve; D002121:Calcium Channel Blockers / Q000493:pharmacokinetics*; D041743:Herb-Drug Interactions; D066298:In Vitro Techniques; D044949:Kaempferols / Q000494:pharmacology*; D008297:Male; D009543:Nifedipine / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley
D002121:Calcium Channel Blockers; D044949:Kaempferols; C006552:kaempferol; D009543:Nifedipine