(−)-Epicatechin Reduces Blood Pressure and Improves Left Ventricular Function and Compliance in Deoxycorticosterone Acetate-Salt Hypertensive Rats

Abstract

(−)-Epicatechin (E) is a flavanol found in green tea and cocoa and has been shown to attenuate tumour necrosis factor alpha (TNF-α)-mediated inflammation, improve nitric oxide levels, promote endothelial nitric oxide synthase (eNOS) activation and inhibit NADPH oxidase. This study investigated the effect of 28 days of low epicatechin dosing (1 mg/kg/day) on the cardiovascular function of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Wistar rats (n = 120, 8 weeks of age) underwent uninephrectomy and were randomised into four groups (uninephrectomy (UNX), UNX + E, DOCA, DOCA + E). DOCA and DOCA + E rats received 1% NaCl drinking water along with subcutaneous injections of 25 mg deoxycorticosterone-acetate (in 0.4 mL of dimethylformamide) every fourth day. UNX + E and DOCA + E rats received 1 mg/kg/day of epicatechin by oral gavage. Single-cell micro-electrode electrophysiology, Langendorff isolated-heart assessment and isolated aorta and mesenteric organ baths were used to assess cardiovascular parameters. Serum malondialdehyde concentration was used as a marker of oxidative stress. Myocardial stiffness was increased and left ventricular compliance significantly diminished in the DOCA control group, and these changes were attenuated by epicatechin treatment (p < 0.05). Additionally, the DOCA + E rats showed significantly reduced blood pressure and malondialdehyde concentrations; however, there was no improvement in left ventricular hypertrophy, electrophysiology or vascular function. This study demonstrates the ability of epicatechin to reduce blood pressure, prevent myocardial stiffening and preserve cardiac compliance in hypertrophied DOCA-salt rat hearts.

Arginase inhibition by (−)-Epicatechin reverses endothelial cell aging

“…Being aging a less aggressive and slower “damaging” process than hypertension it also helps to explain the difference in Epi-mediated effects. Indeed, vasodilatory responses were improved in aged rat aortas which possess a “more” functional endothelium in contrast to hypertensive rat aortas which, have a significantly damaged endothelium ( Durante et al, 2007 ; Jackson et al, 2018 ; Ming et al, 2004 ; Nelin et al, 2005 ; Wei et al, 2000 ).…”

Pu-Erh Tea Relaxes the Thoracic Aorta of Rats by Reducing Intracellular Calcium

“…Additionally, in modern medicine, pu-erh tea aqueous extract could lower blood pressure (Li et al, 2012) and could synergize with the antihypertensive drug nifedipine in spontaneous hypertension rats (Li et al, 2015). Moreover, many components in pu-erh tea, including EGCG (Potenza et al, 2007; Al Disi et al, 2015; Anwar et al, 2016), EC (Galleano et al, 2013; Jackson et al, 2018), gallic acid (GA) (Jin et al, 2017; Jin et al, 2018a), caffeine (CAF) (Conde et al, 2012; Yeh et al, 2014), etc., could lower blood pressure and ameliorate hypertensive symptoms in different animal models of hypertension. However, the antihypertensive mechanisms of pu-erh tea and its active components are unclear.…”

Geranylgeraniol prevents statin-induced skeletal muscle fatigue without causing adverse effects in cardiac or vascular smooth muscle performance

“…Cleaned 5 mm sections of isolated thoracic aortas were threaded onto stainless steel hooks, anchored into organ baths containing TPSS, and allowed to equilibrate for 30 minutes. 45 Aortas were set to a resting tension of 10 mN and then cumulative concentration-response curves (CRCs) to acetylcholine, sodium nitroprusside, and noradrenaline were performed (bath concentration range: 1 £ 10 À9 MÀ3 £ 10 À4 M).…”

“…Second-order mesenteric arteries were dissected, cut into 2 mm segments and mounted into a wire myograph system (containing TPSS) using a 40-mm diameter stainless-steel wire (DMT-Asia Pacific). 45 Tissues were normalized to a transmural pressure of 100 mmHg and rested for 30 minutes. CRCs to acetylcholine, sodium nitroprusside, and noradrenaline were performed.…”