Pharmacokinetic, antihypertension and deep sequencing MiRNomes analysis of aorta from SHR fed with EGCG

Mechanism (s) of the epigallocatechin-3-gallate (EGCG) as major effective components in green tea regarding the reduction of hypertensive risk might associate with microRNAs (miRNAs). The plasma distribution of EGCG and epigallocatechin (EGC) in Sprague-Dawley rats were analyzed pharmacokinetically and found that they did not distribute well in plasma but widely in tissues, and their plasma deposition best fitted a mono-compartmental model with Cmax (6.65 vs 4.45 µg/mL) and Tmax (15 vs 10 min). Blood pressure monitoring of spontaneously hypertensive rats (SHR) intragastrically administrated with 300 mg/kg BW showed that systolic blood pressure (SBP) decreased to the lowest point by 34.04 mmHg and recovered by 23.39 mmHg after 15 and 30 min of administration, respectively, and it decreased again at 60 min and recovered at time 2 h. Total 150 upregulated and 18 downregulated miRNAs were identified via the deep sequencing and were 1.0 or 0.5 fold to the control group (P<0.01) after EGCG administration. And, hypertension-associated miRNA-126-3p and miRNA-150 were further validated by qRT-PCR. It might help explore novel pathways involving antihypertensive effect of EGCG. Overall design: Sprague-Dawley (SD) male rats (8 weeks of age) from Shanghai Slac Laboratory Animal Co., Ltd. (Shanghai, China) were housed in cages, and they were maintained under specific pathogen-free conditions with a 12 h light/dark cycle at Center of Experimental Animal, Jiangsu Vocational College of Medicine.Three SHRs were randomly chosen to form three groups, defined as HD group (fed with EGCG at high dose, 300 mg/kg BW), LD group (fed with EGCG at low dose, 30 mg/kg BW) and Control group (fed with 0.7% saline solution). TRIzol reagent (Invitrogen, CA, USA) was used to extract the total RNAs from each sample, and the quality and concentration of the total RNAs in each samples were assessed by Nanodrop (ND-1000) with 260/280 ratio. Then the extracted total RNAs from three samples within each group were mixed in equal amount, and the small RNA libraries were constructed as previously described. Each small RNA library was sequenced in individual lane for 36 cycles using Illumina Genome Analyser II (Illumina, San Diego, CA, USA).Â