title: Oxidative Tea Polyphenols Greatly Inhibit the Absorption of Atenolol.
abstract: Oxidative tea polyphenols (OTPs) is the oxidative polymerization product of epigallocatechin-3-O-gallate (EGCG) forms during the process of Pu-er tea fermentation, and possesses absorption property, which may absorbs on drugs thus impact the drug bioavailability when taking medicines with Pu-er tea. Here we demonstrated that OTP inhibited the absorption of atenolol in the intestine, which was determined by testing atenolol levels of plasma via high performance liquid chromatography (HPLC). After administration of atenolol (50 mg/kg), atenolol was absorbed (T max: 1.867 h) with the half-life (t1/2) of 6.663 h in control group; Compared with atenolol group, AUC0-t (h*ng/ml), AUC0-∞(h(∗)ng/ml), and C max of OTP+atenolol group (OTP 500 mg/kg + atenolol 50 mg/kg) reduced 38.7, 27, and 51%, respectively, the atenolol concentration of plasma was reduced by OTP approximately 43, 49, and 55.5% at 30 min, 1 and 2 h, respectively, (P < 0.01). Furthermore, the level of atenolol in feces was higher in the OTP+atenolol group, indicating that the absorption of atenolol in rats was inhibited by OTP. Isothermal titration calorimetry assay identified that EGCG can bind to atenolol and the in vitro results showed that OTP absorbed on atenolol and formed precipitate in acid condition, demonstrating a significant positive relationship between atenolol levels and OTP dosage. Taken together, these results suggested that consuming Pu-er tea with atenolol might inhibit atenolol absorption and possible other drugs.
authors.affiliation: Key Laboratory of Pu-er Tea Science, Ministry of Education, Yunnan Agricultural UniversityKunming, China; College of Pu-er Tea, Yunnan Agricultural UniversityKunming, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Shan
authors.affiliation: Key Laboratory of Pu-er Tea Science, Ministry of Education, Yunnan Agricultural UniversityKunming, China; College of Food Science and Technology, Yunnan Agricultural UniversityKunming, China.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Pu-er Tea Science, Ministry of Education, Yunnan Agricultural UniversityKunming, China; College of Life Science, Jilin UniversityChangchun, China.
authors.forename: Tengfei
authors.initials: T
authors.lastname: Wang
authors.affiliation: Key Laboratory of Pu-er Tea Science, Ministry of Education, Yunnan Agricultural UniversityKunming, China; College of Food Science and Technology, Yunnan Agricultural UniversityKunming, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Huang
authors.affiliation: Key Laboratory of Pu-er Tea Science, Ministry of Education, Yunnan Agricultural UniversityKunming, China; College of Food Science and Technology, Yunnan Agricultural UniversityKunming, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Yin
authors.affiliation: College of Food Science and Technology, Yunnan Agricultural University Kunming, China.
authors.forename: Zemin
authors.initials: Z
authors.lastname: Xiang
authors.affiliation: Key Laboratory of Pu-er Tea Science, Ministry of Education, Yunnan Agricultural UniversityKunming, China; College of Pu-er Tea, Yunnan Agricultural UniversityKunming, China; State Key Laboratory for Conservation and Utilization of Bio-Resources in YunnanKunming, China.
authors.forename: Xuanjun
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Pu-er Tea Science, Ministry of Education, Yunnan Agricultural UniversityKunming, China; College of Life Science, Jilin UniversityChangchun, China; State Key Laboratory for Conservation and Utilization of Bio-Resources in YunnanKunming, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Sheng
keywords: HPLC; atenolol; drug absorption; interaction; oxidative tea polyphenols