Potential Antihypertensive Effects Research Articles

Effects of enzymatically hydrolysed poultry byproduct meal in extruded diets on serum angiotensin-converting enzyme activity and aldosterone in cats

ABSTRACT Several peptides found in hydrolysed poultry byproduct meal can inhibit angiotensin-converting enzyme (ACE) activity, a property that indicates potential antihypertensive and health-promoting effects. This study aimed to assess the effects of extruded diets containing enzymatically hydrolysed poultry byproduct meal (HPM) on cat serum ACE activity and aldosterone (ALD) concentration, nutrient digestibility, and faecal characteristics. On the basis of a preliminary in vitro ACE inhibitory activity assay, a commercial HPM and a commercial conventional poultry byproduct meal (CPM) were selected for further investigation. Two isoenergetic and isonitrogenous diets were formulated: CPM diet (25.7% CPM) and HPM diet (24.7% HPM). In trial 1, the effect of diet on serum ACE activity and ALD concentration was evaluated using 8 healthy cats (4 female and 4 male, 4.1 ± 0.38 kg BW) in a crossover design, with 5 d of adaptation and blood collection on d 6. In trial 2, apparent total tract digestibility and faecal characteristics were evaluated using 12 cats (6 female and 6 male, 4.0 ± 0.72 kg BW) in a completely randomised design. Serum ACE and ALD were analysed using a mixed model, with diet as the fixed effect and cat as the random effect. Data from trial 2 were subjected to analysis of variance, and means were compared by Tukey’s test. In vitro ACE inhibitory activity of HPM (90.4%) was higher than that of CPM (52.0%). Cats fed the HPM diet tended to have lower serum ACE activity than those fed the CPM diet (126 versus 142 U/l, p = 0.09). Serum ALD was not influenced by diet. Diets had similar digestibility values, and faecal consistency scores tended to be higher (firmer faeces) in cats fed the CPM diet than in cats fed the HPM diet (4.6 versus 4.0, p = 0.09). Inclusion of HPM in extruded diets may reduce cat serum ACE activity and promote good faecal consistency without affecting digestibility. Further investigations are needed to explore the potential health benefits of HPM in hypertensive cats.

Effect of barberry (Berberis vulgaris) consumption on blood pressure, plasma lipids, and inflammation in patients with hypertension and other cardiovascular risk factors: study protocol for a randomized clinical trial

BackgroundCardiovascular diseases (CVDs) remain the leading causes of morbidity and mortality in the world. Hypertension is an important and prevalent cardiovascular risk factor. The present study will be conducted to investigate the effect of barberry as a cardio-protective fruit on the blood pressure in patients with hypertension and other CVD risk factors. Furthermore, plasma concentrations of lipids and inflammatory biomarkers will be evaluated.Methods/designThis is an 8-week, prospective, single-blinded, parallel assigned, randomized controlled clinical trial (RCT) in which eligible men and women with hypertension and other cardiovascular risk factors will be randomized to either placebo powder (PP; containing 9 g maltodextrin, 1 g citric acid, 1 g milled sucrose and edible red color (n = 37)) or barberry powder (BP; containing 10 g milled dried barberry and 1 g of milled sucrose (n = 37)) groups. At baseline and after 8 weeks of intervention, plasma lipids and inflammatory markers, 24-h urinary nitrite/nitrate and sodium excretion, and 24-h ambulatory blood pressure monitoring (ABPM) will be measured. Anthropometric measures and dietary assessment will be performed as well. Data analysis will be done using SPSS version-21 software.DiscussionThe interest in natural and functional food products has increased globally. This RCT will add to the growing literature for the potential antihypertensive, lipid-lowering, and anti-inflammatory effects of barberry in humans.Trial registrationClinicalTrials.gov (NCT number) NCT04084847. Registered on 10 December 2019.

Interaction mechanism of egg white- derived ACE inhibitory peptide TNGIIR with ACE and its effect on the expression of ACE and AT1 receptor

The egg white-derived hexapeptide TNGIIR inhibits angiotensin-converting enzyme (ACE) activity in vitro. In this work, molecular docking revealed that TNGIIR established hydrogen bonds with the S1 (Ala 354), S2 (Gln 281, His 513, Tyr 520 and Lys 511) and S1′ (Glu 162) pockets of ACE. In addition, the potential antihypertensive effect of the oral administration of TNGIIR in spontaneously hypertensive rats (SHR) was investigated, as was the effect of this peptide on the mRNA expression of ACE and angiotensin type 1 (AT1) and type 2 (AT2) receptors in renal tissue. The oral administration of TNGIIR (2, 10 and 50 mg/kg) for up to four weeks did not reduce the blood pressure of SHR, in contrast to captopril (10 mg/kg, orally), but attenuated the mRNA expression of ACE and AT1 receptor (as did captopril). In contrast, both TNGIIR and captopril enhanced the expression of AT2 receptor mRNA. There was no change in the circulating concentration of angiotensin I, but a slight decrease (about 10%) was seen in the concentration of circulating angiotensin II with TNGIIR and captopril.

A Review of Endothelium-Dependent and -Independent Vasodilation Induced by Phytochemicals in Isolated Rat Aorta.

This review discusses the contribution of the use of the isolated rat aorta (IRA) as a model for the evaluation of extracts and metabolites produced by plants with a vasodilator effect in animals. This model continues to be a valuable approach for the search and development of new phytochemicals consumed as medicinal plants or foods. In most cases, the sources of phytochemicals have been used in folk medicine to treat ailments that include hypertension. In this model, the endothelium is emphasized as a key component that modulates the vessel contractility, and therefore the basal tone and blood pressure. Based on the functional nature of the model, we focused on studies that determined the endothelium-dependent and -independent vasodilatory activity of phytochemicals. We describe the mechanisms that account for aorta contraction and relaxation, and subsequently show the vasoactive effect of a series of phytochemicals acting as vasodilators and its endothelium dependence. We highlight information regarding the cardiovascular benefits of phytochemicals, especially their potential antihypertensive effect. On this basis, we discuss the advantages of the IRA as a predictive model to support the research and development of new drugs that may be of help in the prevention and treatment of cardiovascular diseases, the number one cause of death worldwide.

Acute Soy Supplementation Improves 20-km Time Trial Performance, Power, and Speed.

Isoflavones, a chemical class of phytoestrogens found in soybeans and soy products, may have biological functions similar to estradiol. After binding with ERβ or perhaps independently of estrogen receptors, isoflavones may augment vascular endothelial relaxation, contributing to improved limb blood flow. To determine if acute fermented soy extract supplementation influences 20-km time trial cycling performance and cardiac hemodynamics compared with a placebo. Subjects included 25 cyclists and triathletes (31 ± 8 yr, V˙O2peak: 55.1 ± 8.4 mL·kg·min). Each subject completed a V˙O2peak assessment, familiarization, and two 20-km time trials in randomized order after ingestion of a fermented soy extract supplement or placebo. The fermented soy extract consisted of 30 g powdered supplement in 16 fl. ounces of water. The placebo contained the same quantities of organic cocoa powder and water. Each trial consisted of 60 min of rest, 30 min at 55% Wpeak, and a self-paced 20-km time trial. Soy supplementation elicited a faster time to 20-km completion (-0.22 ± 0.51 min; -13 s), lower average HR (-5 ± 7 bpm), and significantly greater power (7 ± 3 W) and speed (0.42 ± 0.16 km·h) during the last 5 km of the time trial compared with placebo. Analysis of the results by relative fitness level (<57 vs ≥ 57 mL⋅kg⋅min) indicated that those with a higher level of fitness reaped the largest performance improvement alongside a reduced HR (-5 ± 7 bpm). Ingestion of a fermented soy extract supplement improved sprint-distance performance through improvements in both power and speed. For those with great aerobic fitness, soy supplementation may help to decrease cardiac demand alongside performance improvement.

DPP-4 Inhibitors as Potential Candidates for Antihypertensive Therapy: Improving Vascular Inflammation and Assisting the Action of Traditional Antihypertensive Drugs.

Dipeptidyl peptidase-4 (DPP-4) is an important protease that is widely expressed on the surface of human cells and plays a key role in immune-regulation, inflammation, oxidative stress, cell adhesion, and apoptosis by targeting different substrates. DPP-4 inhibitors (DPP-4i) are commonly used as hypoglycemic agents. However, in addition to their hypoglycemic effect, DPP-4i have also shown potent activities in the cardiovascular system, particularly in the regulation of blood pressure (BP). Previous studies have shown that the regulatory actions of DPP-4i in controlling BP are complex and that the mechanisms involved include the functional activities of the nerves, kidneys, hormones, blood vessels, and insulin. Recent work has also shown that inflammation is closely associated with the elevation of BP, and that the inhibition of DPP-4 can reduce BP by regulating the function of the immune system, by reducing inflammatory reactions and by improving oxidative stress. In this review, we describe the potential anti-hypertensive effects of DPP-4i and discuss potential new anti-hypertensive therapies. Our analysis indicated that DPP-4i treatment has a mild anti-hypertensive effect as a monotherapy and causes a significant reduction in BP when used in combined treatments. However, the combination of DPP-4i with high-dose angiotensin converting enzyme inhibitors (ACEI) can lead to increased BP. We suggest that DPP-4i improves vascular endothelial function in hypertensive patients by suppressing inflammatory responses and by alleviating oxidative stress. In addition, DPP-4i can also regulate BP by activating the sympathetic nervous system, interfering with the renin angiotensin aldosterone system (RAAS), regulating Na/H2O metabolism, and attenuating insulin resistance (IR).

Acute and sub-chronic antihypertensive properties of Taraxacum officinale leaf (TOL) and root (TOR)

Taraxacum officinale (T. officinale) is a leafy vegetable that is commonly used traditionally as a diuretic agent. In the current study, we aimed at exploring the potential antihypertensive effect of T. officinale using two animal models of hypertension. Acute and sub-chronic antihypertensive effects of TOL and TOR at 500 mg/kg/bwt were evaluated in spontaneously hypertensive rats and L-NAME-induced hypertensive rats, respectively. Wistar rats were treated daily with L-NAME (40 mg/kg/bwt) until they became hypertensive and were then allocated to various treatment groups: control, furosemide (10 mg/kg/bwt) TOL (500 mg/kg/bwt) and TOR (500 mg/kg/bwt) for 4 weeks. Blood samples were collected for determination of the lipid profile. Results showed that one-off oral administration of TOL and TOR significantly (p < 0.05) reduced systolic, diastolic and mean arterial blood pressure in the 2nd and 4th hours. In the sub-chronic study, TOL and TOR significantly (p < 0.05) prevented an increase in blood pressure throughout the period of treatment. However, TOL and TOR increased HDL-cholesterol and triglyceride levels in this study. T. officinale possesses antihypertensive effects with the aerial part most active at the used dosage which however, supports further development of the extract as a potential therapeutically useful natural antihypertensive agent.

Anti-hangover and anti-hypertensive effects in vitro of fermented persimmon juice

ABSTRACTThis study aimed to develop and characterize a fermented persimmon juice with potential anti-hangover and anti-hypertensive effects using gamma-aminobutyric acid (GABA)-producing lactic acid bacteria. Results showed the co-fermentation of Lactobacillus plantarum C17 and Lactobacillus pentosus Lp-B produced the highest yield of 2.102 mmol/L of GABA. After 48 h of fermentation, GABA was produced at the conversion rate of 69.32% from glutamate. The alcohol dehydrogenase activation rate, acetaldehyde dehydrogenase activation activity and hydroxyl inhibition rate of fermented persimmon juice were 38.91%, 34.72%, and 16.79%, respectively, which displayed higher anti-hangover activity compared to unfermented persimmon. Moreover, the angiotensin-converting enzyme inhibition ability of fermented persimmon juice was 42.34% and the expression level of human endothelin-1 was reduced to 34.64 μg/mL. These findings indicated GABA-enriched fermented persimmon juice had potential anti-hangover and anti-hypertensive properties.

A whole foxtail millet diet reduces blood pressure in subjects with mild hypertension

The potential anti-hypertensive effect of foxtail millet was investigated. Participants were recruited to a 12 wk open-label and self-controlled trial, considering the appearance and flavor of whole foxtail millet products. After screening, 45 subjects with untreated mild hypertension received a daily average of approximately 50 g of whole foxtail millet, replacing their partial regular staple food for the clinical intervention, and were included in the analyses. Measurements included blood pressure, renin–angiotensin–aldosterone system, blood lipids, fasting blood glucose, anthropometric indices, body composition and bone density. After 12 wk of whole foxtail millet diet intervention, significant reductions in the participants' SBP (4.13 mmHg, P = 0.022) and DBP (3.49 mmHg, P = 0.002) were observed. In addition, the body mass index, body fat percentage, and fat mass significantly decreased (p < 0.05). The intake of whole foxtail millet also improved the subjects’ fasting blood glucose (p = 0.051). Whole foxtail millet, which serves as a potential source of nutraceutical and functional food, may ameliorate hypertension and alleviate related cardiovascular diseases.

Antihypertensive potential of linalool and linalool complexed with β-cyclodextrin: Effects of subchronic treatment on blood pressure and vascular reactivity

Linalool (LIN) is a monoterpene alcohol present in some aromatic medicinal plants with biological activities that can impact cardiovascular diseases. This chemical class is highly volatile and β-cyclodextrin (β-CD) has been employed to improve the pharmacological properties of monoterpenes. Thus, the aim of this study was to evaluate the cardiovascular effects of LIN free focusing on the antihypertensive properties of this monoterpene and to study whether LIN, complexed in β-cyclodextrin (LIN-βCD) is able to improve the pharmacological activity of LIN. Spontaneously hypertensive rats (SHR) were randomly divided into 5 groups, each treated daily for 21 days, in the following manner: group 1 (vehicle solution); group 2 (captopril; 30 mg/kg/day); group 3 (LIN; 100 mg/kg/day); group 4 (LIN; 50 mg/kg/day) and group 5 (LIN/β-CD; 50 mg/kg/day). Daily body weight measurements were conducted and mean arterial pressure and heart rate were measured every 5 days. The mesenteric artery from treated animals was tested for phenylephrine and sodium nitroprusside (SNP) sensitivity. The SHR treated with vehicle demonstrated progressive increase in mean arterial pressure and captopril, a positive control, induced a significant decrease. After 21 days of treatment, the blood pressure of the SHR treated by (−)-LIN (100 mg/kg) was significantly reduced. In addition, various important cardiovascular parameters improved, including: the treatment with LIN prevented the development of cardiac hypertrophy, increased levels of the anti-inflammatory cytokine (IL-10), increased vasodilator responsiveness and reduced sensitivity to the sympathetic agonist. Furthermore, the inclusion complex containing LIN in β-CD produced a higher antihypertensive profile when compared with uncomplexed form. Taking together, our results suggested that LIN shown a potential antihypertensive effect and β-CD may be an important tool to improve the cardiovascular activity of LIN and other water-insoluble compounds.

English

There are reports of the presence of vasodilatory alkaloids in Heimia salicifolia extracts. The action mechanisms of the potential antihypertensive effect of such alkaloids have not however, been elucidated. The objective of the present study was to corroborate the antihypertensive and vasorelaxant activities of the isolated alkaloids from H. salicifolia, and to characterize their vasorelaxant actions. A chloroform extract (HSCE) was obtained from H. salicifolia. The alkaloids were separated by thin layer chromatography, extracted from silica gel, and evaluated using spectroscopy. The alkaloid with the most potent vasorelaxant activity was identified as lythrine. The antihypertensive effect of the HSCE was corroborated on normotensive rats and on animals with N&omega;-nitro-L-arginine-methyl ester (L-NAME) induced hypertension. The action mechanisms of the HSCE and lythrine were studied on isolated and perfused rat mesenteric vascular bed (MVB) preparations. HSCE administration produced a concentration-dependent relaxation, but in preparations without vascular endothelium, the relaxant response to HSCE was significantly diminished. In MVB preparations with intact vascular endothelium, pre-contracted with phenylephrine or L-NAME, perfusion with lythrine produced concentration-dependent relaxation; a similar effect was produced by acetylcholine. Wortmannin (phosphatidylinositol 3-kinase inhibitor) and methylene blue (guanylate cyclase inhibitor) decreased the relaxant effect of lythrine. These data suggest that the vascular relaxation induced by alkaloids isolated from H. salicifolia is dependent on the activation of the nitric oxide/guanylate cyclase pathway. Key words: Heimia salicifolia, lythrine alkaloid, hypertension, N&omega;-nitro-L-arginine-methyl ester (L-NAME), mesenteric vascular bed. &nbsp

Reduced density gradient as a novel approach for estimating QSAR descriptors, and its application to 1, 4-dihydropyridine derivatives with potential antihypertensive effects.

The relationship between the chemical structure and biological activity (log IC50) of 40 derivatives of 1,4-dihydropyridines (DHPs) was studied using density functional theory (DFT) and multiple linear regression analysis methods. With the aim of improving the quantitative structure-activity relationship (QSAR) model, the reduced density gradient s( r) of the optimized equilibrium geometries was used as a descriptor to include weak non-covalent interactions. The QSAR model highlights the correlation between the log IC50 with highest molecular orbital energy (E HOMO), molecular volume (V), partition coefficient (log P), non-covalent interactions NCI(H4-G) and the dual descriptor [Δf(r)]. The model yielded values of R 2=79.57 and Q 2=69.67 that were validated with the next four internal analytical validations DK=0.076, DQ=-0.006, R P =0.056, and R N=0.000, and the external validation Q 2boot=64.26. The QSAR model found can be used to estimate biological activity with high reliability in new compounds based on a DHP series. Graphical abstract The good correlation between the log IC50 with the NCI (H4-G) estimated by the reduced density gradient approach of the DHP derivatives.

Effects of blueberry supplementation on blood pressure: a systematic review and meta-analysis of randomized clinical trials.

Blueberries belong to the genus Vaccinium of the family Ericaceae. A series of epidemiological studies have demonstrated that blueberry polyphenols, particularly blueberry anthocyanins provide significant beneficial effects for humans. However, the findings of clinical studies have been equivocal. Therefore, we sought to assess the potential anti-hypertensive effects of blueberry supplementation through a meta-analysis of available randomized controlled trials (RCTs). A comprehensive literature search of PubMed, The Cochrane Library, AMED (Allied and Complementary Medicine Database), Embase, Web of Science, Wanfang Database, and China National Knowledge Infrastructure were performed to identify potential studies published before June 2015. The standardized mean difference and 95% confidence interval (CI) were used as summary statistics. Net changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) between the blueberry and placebo groups were calculated by subtracting the values at the end of follow-up from those at baseline. Meta-regression was used to identify potential moderators of effect size. Six RCT studies with 204 participants were included in our meta-analysis. There was no significant effect of blueberry supplementation on changes in blood pressure (BP) relative to baseline, and there was a mean difference of -0.28 (95% CI: -1.11 to 0.56, I2=87%) and -0.5 (95% CI: -1.24 to 0.24, I2=84%) mmHg for SBP and DBP, respectively. In summary, the results from this meta-analysis do not favor any clinical efficacy of blueberry supplementation in improving BP. Further well-designed larger RCTs are required to verify the association between blueberry supplementation and BP.

Effect of foxtail millet protein hydrolysates on lowering blood pressure in spontaneously hypertensive rats

The objective of this study was to determine the effect of foxtail millet protein hydrolysates on lowering blood pressure in spontaneously hypertensive rats (SHRs). The protein of foxtail millet after extruding or fermenting and the raw foxtail millet was extracted and hydrolyzed by digestive protease to generate angiotensin-converting enzyme (ACE) inhibitory peptides. The potential antihypertensive effect of protein hydrolysates from foxtail millet in SHRs was investigated. After 4weeks of treatment with 200mg peptides/kg of body weight of protein hydrolysates, blood pressure was lowered significantly, and the raw and extruded samples were more effective than the fermented samples. The serum ACE activity and angiotensin II levels in the treatment groups were significantly lower than that of the control. The percent heart weight decreased in the treatment groups. Thus, ingestion of foxtail millet protein hydrolysates especially for the raw and extruded hydrolysates may ameliorate hypertension and alleviate related cardiovascular diseases.

Evidences of antihypertensive potential of extract from Solanum capsicoides All. in spontaneously hypertensive rats

BackgroundSolanum capsicoides All. is morphologically similar to Solanum sisymbriifolium Lam. which is used in folk medicine in South America for antihypertensive and diuretics purposes. This similarity has led to species identification errors, which therefore may result in errors by patients. PurposeTo evaluate the antihypertensive and diuretics potential of the methanol extract from Solanum capsicoides All. (MeOH–Sc), in vitro and in vivo, in spontaneously hypertensive rats (SHR). MethodsInitial experiments were performed in rat mesenteric artery to evaluate the in vitro vascular effect of MeOH–Sc and its fractions, in addition to the mechanisms involved during the observed effect. Mean arterial pressure (MAP) and heart rate (HR) were recorded in non-anesthetised hypertensive and normotensive rats. In another set of experiments, MeOH–Sc was administered for 21 consecutive days. Daily body weight measurements were conducted and MAP, HR and urinary volume were measured every 5 days. The mesenteric artery from treated animals was tested for phenylephrine and sodium nitroprussiate (SNP) sensitivity. ResultsInitially, MeOH–Sc and fractions relaxed phenylephrine-induced contractions in mesenteric artery rings. The vasorelaxant effect was not changed in the presence of a blocker of eNOS (L-NAME) in rings with an intact endothelium. In denuded-endothelium rings, the vasorelaxant response was significantly reduced in the presence of a cAMP inhibitor (SQ 22536 10µM) in SHR but not in Wistar Kyoto rats (WKY). However, in the presence of a cGMP inhibitor (ODQ 10µM), a curve shift to the right was observed in WKY animals, but not in SHR. Intravenous bolus injections of MeOH–Sc into non-anesthetised SHR and WKY, induced hypotension that was associated with an increase in HR. A significant antihypertensive effect was observed in animals that received MeOH–Sc orally for 21 days, which also prevented the development of cardiac hypertrophy. Urine volume from animals treated with MeOH–Sc significantly increased. Finally, MeOH–Sc induced beneficial changes in vascular responsiveness. ConclusionMeOH–Sc has a potential antihypertensive effect in SHR.

Vasorelaxant Effect of a Baccharis Trimera Infusion on Precontracted Rat Aortic Rings

Baccharis trimera (Less.) DC is a South American plant that in folk medicine is considered to produce reduction in blood pressure. One aspect of this putative effect is the vasorelaxation. The aim of this work was to evaluate the ability of a B. trimera extract to relax rat aortic rings precontracted with noradrenaline. As the infusion is the usual way of intake of this plant, an infusion of B. trimera was prepared using 100 g of the plant (leaves) boiled in water, frozen and lyophilized. Working solutions were prepared using different concentrations of the dried extract diluted in Krebs Henseleit solution. It was proved that the infusion relaxed the aortic rings in a dose dependent manner 100 minutes after adding the exract to the bath. Considering as 100% the maximum contraction achieved with noradrenaline, a relaxation of 101.1 ± 2.3% was observed with the highest dose of the infusion used in these experiments (0.32 mg/mL). While in control rings relaxation was 12.9 ± 2.4%. In aortic rings denuded from endothelium the percentage of vasoralaxation did not show statistically significant differences when compared to intact rings. These data support the hypothesis of a vasorelaxant effect of this plant and constitutes the first approach to the scientific basis of a potential antihypertensive effect.

Adherence to Antihypertensive Medication in Treatment-Resistant Hypertension Undergoing Renal Denervation.

BackgroundAdherence to medication has been repeatedly proposed to represent a major cause of treatment‐resistant hypertension (TRH); however, treatment decisions such as treating TRH with renal denervation depend on accurate judgment of adherence. We carefully analyzed adherence rates to medication before and after renal denervation and its effect on blood pressure (BP) control.Methods and ResultsEighty patients with TRH were included in 2 prospective observational studies that assessed the difference of potential antihypertensive and nephroprotective effects of renal denervation. To compare prescribed with actual medication intake (representing a measure of adherence), we analyzed urine samples collected at baseline and at 6 months after renal denervation for antihypertensive compounds or metabolites (by liquid chromatography–mass spectrometry). In addition to office BP, 24‐hour ambulatory BP and central hemodynamics (central systolic pressure, central pulse pressure) were assessed. Informed consent for analyses of urine metabolites was obtained from 79 of 80 patients. Actual intake of all antihypertensive drugs was detected at baseline and at 6 months after renal denervation in 44 (56%) and 52 (66%) patients, respectively; 1 drug was missing in 22 (28%) and 17 (22%) patients, respectively, and ≥2 drugs were missing in 13 (16%) and 10 (13%) patients, respectively. At baseline, 24‐hour ambulatory BP (P=0.049) and central systolic BP (P=0.012) were higher in nonadherent patients. Adherence did not significantly change overall (McNemar‐Bowker test, P=0.362). An increase in adherence was observed in 21 patients, and a decrease was observed in 11 patients. The decrease in 24‐hour ambulatory BP was not different in those with stable adherence 6 months after renal denervation (n=41, −7±13 mm Hg) compared with those with increased adherence (n=21, −10±13 mm Hg) and decreased adherence (n=11, −7±14 mm Hg) (P>0.20). Our study is limited by the relatively small sample size and potentially by the specific health environment of our university center (Northern Bavaria, Germany).ConclusionsNonadherence to medication among patients with TRH was relatively low: ≈1 of 6 patients with TRH did not take ≥2 of the prescribed drugs. Adherence pattern did not change significantly after renal denervation and had no impact on the overall observed BP changes, supporting the concept that renal denervation is an effective treatment in patients with TRH.Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00888433, NCT01442883 and NCT01687725.

Soluble expression and purification of the recombinant bioactive peptide precursor BPP-1 in Escherichia coli using a cELP-SUMO dual fusion system

A bioactive peptide precursor (BPP-1, 14.3 kDa/115AA), a newly designed polypeptide that may exert a potential antihypertensive effect in vivo, is composed of many different ACE inhibitory peptides and antioxidant peptides tandemly linked according to the restriction sites of gastrointestinal proteases. In this report, we present a novel method to obtain soluble BPP-1 in Escherichia coli using cationic elastin-like polypeptide and SUMO (cELP-SUMO) tags. The cELP-SUMO-tagged fusion protein was expressed in soluble form at 20 °C for 20 h. After purification based on the inverse transition cycling (ITC) method, the purified cELP-SUMO–CFPP fusion protein was subsequently cleaved by a SUMO protease to release the mature BPP-1. After a subsequent simple salt precipitation process, approximately 167.2 mg of recombinant BPP-1 was obtained from 1 l of bacterial culture with at least 92% purity. The molecular mass (Mr) of the recombinant BPP-1 was confirmed by MALDI-TOF MS to equal 14,347. The purified BPP-1 was subjected to simulated gastrointestinal digestion, and the resulting hydrolysates exhibited notable ACE inhibitory and antioxidant activities in vitro. This report provides the first description of the soluble production of a bioactive peptide multimer with potential ACE inhibitory and antioxidant activities in E. coli using a cELP-SUMO tag.

Effect of sour tea (Hibiscus sabdariffa L.) on arterial hypertension: A systematic review and meta-analysis of randomized controlled trials

Background: Hibiscus sabdariffa L. is a tropical wild plant rich in organic acids, polyphenols, anthocyanins, polysaccharides, and volatile constituents that are beneficial for the cardiovascular system. Hibiscus sabdariffa beverages are commonly consumed to treat arterial hypertension, yet the evidence from randomized controlled trials (RCTs) has not been fully conclusive. Therefore, we aimed to assess the potential antihypertensive effects of H. sabdariffa through systematic review of literature and meta-analysis of available RCTs. Methods: The search included PUBMED, Cochrane Library, Scopus, and EMBASE (up to July 2014) to identify RCTs investigating the efficacy of H. sabdariffa supplementation on SBP and DBP values. Two independent reviewers extracted data on the study characteristics, methods, and outcomes. Quantitative data synthesis and meta-regression were performed using a fixed-effect model, and sensitivity analysis using leave-one-out method. Five RCTs (comprising seven treatment arms) were selected for the meta-analysis. In total, 390 participants were randomized, of whom 225 were allocated to the H. sabdariffa supplementation group and 165 to the control group in the selected studies. Results: Fixed-effect meta-regression indicated a significant effect of H. sabdariffa supplementation in lowering both SBP (weighed mean difference � 7.58mmHg, 95% confidence interval � 9.69 to � 5.46, P <0.00001) and DBP (weighed mean difference � 3.53mmHg, 95% confidence interval � 5.16 to � 1.89, P <0.0001). These effects were inversely associated with baseline BP values, and were robust in sensitivity analyses. Conclusion: This meta-analysis of RCTs showed a significant effect of H. sabdariffa in lowering both SBP and DBP. Further well designed trials are necessary to validate these results.

Hypotensive effect of alpha-lipoic acid after a single administration in rats

Objective:The effect of alpha-lipoic acid on blood pressure was investigated many times in chronic studies, but there are no studies on the effect of this compound after a single administration. Alpha-lipoic acid is a drug used in diabetic neuropathy, often in obese patients, to treat hypertension. Therefore, knowledge of the potential antihypertensive effect of alpha-lipoic acid even after a single dose and possibly too much pressure reduction is interesting and useful.Methods:The mechanism of the hypotensive effect of alpha-lipoic acid was examined in normotensive rats in vivo after a single intraperitoneal administration, blood pressure in the left carotid artery of the rats was measured prior to the administration of the compounds (alpha- lipoic acid and/or glibenclamide) and 80 min thereafter.Results:Alpha-lipoic acid at a dosage of 50 mg/kg b.w. i.p. significantly decreased the blood pressure from the 50th min after drug administration. This cardiovascular effect of this compound was reversed by glibenclamide, a selective KATP blocker. Glibenclamide alone at this dose did not significantly affect the blood pressure. Statistical significance was evaluated using two-way ANOVA.Conclusion:This suggests that alpha-lipoic acid affects ATP-dependent potassium channels. It is possible that this is an indirect effect of hydrogen sulfide because alpha-lipoic acid can increase its concentration. The results obtained in this study are very important because the patients taking alpha-lipoic acid may be treated for co-existing hypertension. Therefore, the possibility of blood pressure lowering by alpha-lipoic acid should be taken into account, although it does not lead to excessive orthostatic hypotension.