Xin Zhou
Guizhou Normal University, China
Title: Pharmacokinetics, tissue distribution and excretion of gallic acid and protocatechuic acid after oral administration of Polygonum capitatum extract in rats
Biography
Biography: Xin Zhou
Abstract
A sensitive, reliable and accurate HPLC-MS-MS method was developed and validated for the quantification of Gallic Acid (GA) and Protocatechuic Acid (PCA) in rat plasma, tissue and excretion. A single-step protein precipitation by acidic acetonitrile was used to prepare samples. GA, PCA and bergenin (internal standard, IS) were separated by using a C18 column and a mobile phase consisted of acetonitrile and water containing 0.1% formic acid running at a flow rate of 0.2 ml/min for 10 min. Detection and quantification were performed using a mass spectrometer by the multiple-reaction monitoring (MRM) in positive electrospray ionization mode. The optimized mass transition ion pairs (m/z) for quantitation were [M+H] 169.181 →
125.268 (GA)ã€152.918 → 109.244 (PCA) and 326.922 → 192.167 (IS) , respectively. After oral administration of 0.36, 1.08 and 2.16 g·kg-1 of Polygonum capitatum extract, respective values of pharmacokinetic parameters for GA and PCA were: t1/2 1128.52/42.81ã€93.72/90.15
and 114.70/49.80min; Cmax 245.98/11.90, 477.20/24.66, and 805.76/31.04 ng·ml-1. Linear pharmacokinetics was established based on high correlation coefficients (γ > 0.90) of pharmacokinetic parameters. The results of tissue distribution showed that GA mainly distributed in kidney, lung, and liver, while PCA mainly distributed in kidnry and lung. Less than 23.08% and 19.39% prototype of GA and PCA , respectively, were excreted from urine and feces path indicating that GA and PCA are extensively metabolized in rat.