Objective: To establish a HPLC method for determination of gallic acid

caffeine

epicatechin gallate and kaempferol in plasma of rats with atherosclerosis after intragastric administration of green tea extract. Method: After being administrated green tea extract

the rats' blood were taken at different time points

separation was carried out on a Hypersil ODS2 column (4.6 mm×250 mm

5 μm)

the mobile phase was methanol-0.03% phosphoric acid aqueous solution

the flow rate was 0.7 mL·min-1 and the detection wavelength was set at 278 nm

the column temperature was maintained at 30℃. Result: The calibration curves of gallic acid

caffeine

epicatechin gallate and kaempferol were in good linearity over the range of 0.255-20.40

0.430-86.00

0.245-19.60

0.270-21.60 mg·L-1.RSDs of inter-day and intra-day assay were less than 9.0%.The average method separating degree for four ingredients and their extraction recoveries were more than 87%.After acidification

main pharmacokinetic parameters of the area under the curve (AUC0-t) were (8.902±1.235)

(198.5±12.5)

(7.367±0.412)

(4.426±0.251) mg·h·L-1 and the apparent volume of distribution (Vd) were (0.990±0.134)

(1.409±0.201)

(0.501±0.243)

(0.029±0.009) L·kg-1

respectively;the peak time (Tmax) of these four ingredients were 1.5 h. Conclusion: This method has good separation which can be used to detect blood drug concentration of four effective ingredients from green tea extract.