title: The Tissue Distribution and Urinary Excretion Study of Gallic Acid and Protocatechuic Acid after Oral Administration of Polygonum Capitatum Extract in Rats.
abstract: In the present study, we investigated the tissue distribution and urinary excretion of gallic acid (GA) and protocatechuic acid (PCA) after rat oral administration of aqueous extract of Polygonum capitatum (P. capitatum, named Herba Polygoni Capitati in China). An UHPLC-MS/MS analytical method was developed and adopted for quantification of GA and PCA in different tissue homogenate and urine samples. Interestingly, we found that GA and PCA showed a relatively targeted distribution in kidney tissue after dosing 60 mg/kg P. capitatum extract (equivalent to 12 mg/kg of GA and 0.9 mg/kg of PCA). The concentrations of GA and PCA in the kidney tissue reached 1218.62 ng/g and 43.98 ng/g, respectively, at one hour after oral administration. The results helped explain the empirical use of P. capitatum for kidney diseases in folk medicine. Further studies on urinary excretion of P. capitatum extract indicated that GA and PCA followed a concentrated elimination over a 4-h period. The predominant metabolites were putatively identified to be 4-methylgallic acid (4-OMeGA) and 4-methylprotocatechuic acid (4-OMePCA) by analyzing their precursor ions and characteristic fragment ions using tandem mass spectrometry. However, the amount of unchanged GA and PCA that survived the metabolism were about 14.60% and 15.72% of the total intake, respectively, which is reported for the first time in this study.
authors.affiliation: Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment, Guizhou Normal University, Guiyang 550001, China. mfw200422501212@163.com.|Guizhou Engineering Laboratory for Quality Control &amp; Evaluation Technology of Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. mfw200422501212@163.com.|The Research Center for Quality Control of Natural Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. mfw200422501212@163.com.
authors.forename: Feng-Wei
authors.initials: FW
authors.lastname: Ma
authors.affiliation: Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment, Guizhou Normal University, Guiyang 550001, China. dqf_2012@126.com.|Guizhou Engineering Laboratory for Quality Control &amp; Evaluation Technology of Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. dqf_2012@126.com.|The Research Center for Quality Control of Natural Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. dqf_2012@126.com.
authors.forename: Qing-Fang
authors.initials: QF
authors.lastname: Deng
authors.affiliation: Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment, Guizhou Normal University, Guiyang 550001, China. alice9800@sina.com.|Guizhou Engineering Laboratory for Quality Control &amp; Evaluation Technology of Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. alice9800@sina.com.|The Research Center for Quality Control of Natural Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. alice9800@sina.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment, Guizhou Normal University, Guiyang 550001, China. gongxiaojian1@163.com.|Guizhou Engineering Laboratory for Quality Control &amp; Evaluation Technology of Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. gongxiaojian1@163.com.|The Research Center for Quality Control of Natural Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. gongxiaojian1@163.com.
authors.forename: Xiao-Jian
authors.initials: XJ
authors.lastname: Gong
authors.affiliation: Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment, Guizhou Normal University, Guiyang 550001, China. bestyangzhao@gmail.com.|Guizhou Engineering Laboratory for Quality Control &amp; Evaluation Technology of Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. bestyangzhao@gmail.com.|The Research Center for Quality Control of Natural Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. bestyangzhao@gmail.com.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment, Guizhou Normal University, Guiyang 550001, China. huaguochen81@gmail.com.|Guizhou Engineering Laboratory for Quality Control &amp; Evaluation Technology of Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. huaguochen81@gmail.com.|The Research Center for Quality Control of Natural Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. huaguochen81@gmail.com.
authors.forename: Hua-Guo
authors.initials: HG
authors.lastname: Chen
authors.affiliation: Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment, Guizhou Normal University, Guiyang 550001, China. chaozhao@126.com.|Guizhou Engineering Laboratory for Quality Control &amp; Evaluation Technology of Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. chaozhao@126.com.|The Research Center for Quality Control of Natural Medicine, Guizhou Normal University, 116 Baoshan North Road, Guiyang 550001, China. chaozhao@126.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhao
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002681:China; D002851:Chromatography, High Pressure Liquid; D004365:Drugs, Chinese Herbal / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D005707:Gallic Acid / Q000008:administration & dosage* / Q000493:pharmacokinetics; D062385:Hydroxybenzoates / Q000008:administration & dosage* / Q000493:pharmacokinetics; D007668:Kidney / Q000187:drug effects; D010936:Plant Extracts / Q000008:administration & dosage* / Q000737:chemistry; D028502:Polygonum / Q000737:chemistry; D051381:Rats; D053719:Tandem Mass Spectrometry; D014018:Tissue Distribution
chemical_list: D004365:Drugs, Chinese Herbal; D062385:Hydroxybenzoates; D010936:Plant Extracts; C009091:protocatechuic acid; D005707:Gallic Acid
keywords: Polygonum capitatum extract; distribution; excretion; gallic acid; protocatechuic acid