Oral L-histidine exerts antihypertensive effects via central histamine H3 receptors and decreases nitric oxide content in the rostral ventrolateral medulla in spontaneously hypertensive rats

To explore pharmacodynamic substances and mechanism of Xuanfei Baidu Decoction on LPS-induced ALI / ARDS by pharmacochemistry and metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Xuanfei Baidu Decoction (XFBD) is made up of five classic prescriptions, which is composed of 13 traditional Chinese medicines, which have the effects of dispersing lung and resolving dampness, clearing heat and evil, purging lung and detoxification. It is used for epidemic diseases caused by damp toxin obstructing lung. In this paper, the endogenous and exogenous metabolites of ALI/ARDS rats after oral administration of XFBD were studied and the material basis and metabolic pathway of XFBD in relieving ALI/ARDS were explained.

MATERIALS AND METHODS

In this study, UPLC-Q-TOF/MS qualitative analysis method was established, and plasma-urine-feces pharmacochemistry was used to identify metabolites in plasma, urine and feces after oral administration of XFBD in rats. RT-PCR and immunohistochemistry were used to study the expression of CYP protein in XFBD and monomeric compounds. In addition, the functional mechanism of XFBD in ALI/ARDS rats was elucidated by non-targeted metabolomics.

RESULTS

A total of 77 prototype components and 389 metabolites in plasma, urine and feces were identified by exogenous components, mainly including oxidation, reduction, hydrolysis, glucuronidation, sulfation and other reactions. The results of RT-PCR and immunohistochemistry showed that the activity of CYP was inhibited under the pathological state of ALI/ARDS. At the same time, XFBD and its monomeric compounds can change the metabolic process of drugs in vivo by inducing or inhibiting the activity of CYPs. The metabolic process of drugs in vivo is the result of the combined action of different CYPs. In addition, a total of 33 differential metabolites were identified in plasma, 45 in urine and 14 in feces, which were mainly related to the synthesis and degradation of ketone bodies, phenylalanine metabolism, tyrosine metabolism, histidine metabolism, butyric acid metabolism and other metabolic pathways.

CONCLUSIONS

This study conducted a relatively scientific and systematic analysis of XFBD. A UPLC-Q-TOF/MS qualitative analysis method was established to identify 77 prototype components and 389 metabolites in plasma, urine and feces of rats after oral administration of XFBD.An ARDS rat model was established to analyze the pharmacokinetic differences of XFBD in normal and ARDS model rats and its regulation effect on CYPs.Non-targeted metabolomics was used to identify the pattern recognition of ARDS pathological model, the diagnosis of disease and the intervention effect of XFBD on ARDS. Preliminary discussion was conducted to provide a theoretical basis for clinical rational drug use.

Impact of resistance training and chicken intake on vascular and muscle health in elderly women

BACKGROUND

Resistance training is a well-known exercise therapy for preventing and improving lacks of muscle mass, strength, and quality with advances in age; however, its effects on arterial stiffness are not beneficial. Additionally, a higher intake of protein, which is an effective nutrient for muscle health, results in lower arterial stiffness. Whether the combination of moderate to high-intensity resistance training and high-protein intake would improve muscle mass, strength, and quality and cancel the resistance training-induced increase in arterial stiffness in elderly women remains unclear.

METHODS

Ninety-three elderly women (67.2 ± 5.3 years) were randomly divided into four groups; sedentary control (CON), higher dietary animal protein intake (HP), resistance training (RT), and combination of RT and HP (RT + HP) groups. Participants in the RT and RT + HP groups completed 12 weeks of resistance training (exercise intensity at 70% of one-repetition maximum (1-RM), three sets with 10 repetitions of leg extension and curls, 3 days/week). In addition to the daily diet, the HP and RT + HP groups consumed steamed chicken breast as a high-protein diet.

RESULTS

Percent changes in thickness (indices of muscle mass) and echo intensity (index of muscle quality) in the quadriceps muscle, 1-RM of leg extension and curls (index of muscle strength), and circulating C1q levels (a potential biomarker of muscle fibrosis) in the RT and RT + HP groups significantly improved after both RT and RT + HP interventions (P < 0.05). Percent changes in carotid-femoral pulse wave velocity (cfPWV) and carotid β-stiffness (indices of arterial stiffness), and circulating angiotensin II (a vasoconstrictor peptide hormone) levels via each intervention were significantly higher in the RT group (4.9 ± 12.7%, 13.8 ± 13.5%, 94.9 ± 132.7%, respectively), as compared with the CON group (-2.5 ± 5.9%, 0.2 ± 8.1%, 21.2 ± 79.3%, respectively) (P < 0.05). Of note, no significant differences in the cfPWV, carotid β-stiffness, and circulating angiotensin II levels between the RT + HP (-2.4 ± 9.3%, 2.4 ± 10.3%, -5.7 ± 29.6%, respectively) and CON groups were observed. Furthermore, significant positive relationships between the percent changes in circulating angiotensin II levels, and cfPWV (r = 0.438, P < 0.01) and carotid β-stiffness (r = 0.328, P < 0.01) were observed.

CONCLUSIONS

The combination of moderate to high-intensity resistance training and regular intake of steamed chicken breast as a high-protein food could increase muscle mass, strength, and quality and could cancel resistance training-induced increases in arterial stiffness in elderly women.

Exploring altered free amino acids and metabolites: Insights into the metabolic landscape of preeclampsia

INTRODUCTION

Preeclampsia (PE) is a complex disease that poses a risk for maternal and perinatal morbidity and mortality. This study aimed to investigate the role of maternal serum amino acids (AAs) levels in PE.

MATERIALS AND METHODS

A total of 56 pregnant women (26 with PE and 30 controls) were included in the study. The participants had a confirmed gestational age between 24 and 37 weeks. The mean body mass index (BMI) for the PE group was 33.1 kg/m2, while the control group had a mean BMI of 29.6 kg/m2. AAs levels were quantified, and statistical analyses were performed to identify significant differences between the two groups. Receiver Operating Characteristic (ROC) curve analysis was employed the diagnostic potential of specific AAs.

RESULTS

We observed significantly elevated levels of multiple AAs in the PE group, including citrulline, lysine, ethanolamine, ornithine and histidine. Citrulline exhibited exceptional predictive power for PE with 100.0% sensitivity and specificity at a cutoff of 7.79 µmol/L, reflected in an area under the curve (AUC) of 1.000.

DISCUSSION

Our study highlights the crucial involvement of altered amino acid levels, specifically in the urea cycle, disruptions in lysine and ethanolamine metabolism in PE development. Exploring these changes may reveal new therapeutic targets, providing insights into the disease's molecular mechanisms. Understanding amino acid metabolism in PE not only informs therapeutic strategies but also holds the potential to revolutionize early diagnosis and intervention.

The inverse associations of glycine and histidine in diet with hyperlipidemia and hypertension

BACKGROUND

Amino acids are crucial for nutrition and metabolism, regulating metabolic pathways and activities vital to organismal health and stability. Glycine and histidine act as potent antioxidants and anti-inflammatory agents; however, limited knowledge exists regarding the associations between these amino acids and hyperlipidemia and hypertension. The purpose of this study is to investigate the relationship between dietary glycine and histidine, and hyperlipidemia and hypertension.

METHODS

This population-based cross-sectional study evaluated the influence of dietary glycine and histidine, as well as their combined effect, on hyperlipidemia and hypertension in Chinese adults participating in the Nutrition Health Atlas Project (NHAP). General characteristics were acquired using a verified Internet-based Dietary Questionnaire for the Chinese. Binary logistic regression, along with gender, age groups, and median energy intake subgroup analyses, was employed to investigate the associations between dietary glycine and histidine and hyperlipidemia and hypertension. A sensitivity analysis was conducted to assess the impact of excluding individuals who smoke and consume alcohol on the results.

RESULTS

Based on the study's findings, 418 out of 1091 cases had hyperlipidemia, whereas 673 had hypertension. A significant inverse relationship was found between dietary glycine, histidine, and glycine + histidine and hyperlipidemia and hypertension. Compared with the 1st and 2nd tertiles, the multivariable-adjusted odd ratios (ORs) (95% confidence intervals) (CIs) of the 3rd tertile of dietary glycine for hyperlipidemia and hypertension were 0.64 (0.49-0.84) (p < 0.01) and 0.70 (0.56-0.88) (p < 0.001); histidine was 0.63 (0.49-0.82) (p < 0.01) and 0.80 (0.64-0.99) (p < 0.01); and glycine + histidine was 0.64 (0.49-0.83) (p < 0.01) and 0.74 (0.59-0.92) (p < 0.001), respectively. High glycine and high histidine (HGHH) intake were negatively associated with hyperlipidemia and hypertension OR (95% CIs) were: 0.71 (0.58-0.88) (p < 0.01) and 0.73 (0.61-0.87) (p < 0.01), respectively.

CONCLUSIONS

Dietary glycine and histidine, as well as their HGHH group, revealed an inverse relationship with hyperlipidemia and hypertension. Further investigations are needed to validate these findings.

Plant-based diets in patients with chronic kidney disease

Dietary protein restriction has been considered to be a nutritional-related strategy to reduce risk for end-stage kidney disease among patients with non-dialysis-dependent chronic kidney disease (CKD). However, there is insufficient evidence to recommend a particular type of protein to slow down the CKD progression. Recently, various plant-based diets could demonstrate some additional benefits such as a blood pressure-lowering effect, a reduction of metabolic acidosis as well as hyperphosphatemia, and gut-derived uremic toxins. Furthermore, the former concerns about the risk of undernutrition and hyperkalemia observed with plant-based diets may be inconsistent in real clinical practice. In this review, we summarize the current evidence of the proposed pleiotropic effects of plant-based diets and their associations with clinical outcomes among pre-dialysis CKD patients.

Amino acid profiles: exploring their diagnostic and pathophysiological significance in hypertension

Hypertension, a major contributor to cardiovascular morbidity, is closely linked to amino acid metabolism. Amino acids, particularly branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs), may play pivotal roles in the pathogenesis and potential management of hypertension. This review investigated the relationships between amino acid profiles, specifically BCAAs and AAAs, and hypertension, and examined their potential as diagnostic and therapeutic targets. An in-depth analysis was conducted on studies highlighting the associations of specific amino acids such as arginine, glycine, proline, glutamine, and the BCAAs and AAAs with hypertension. BCAAs and AAAs, alongside other amino acids like arginine, glycine, and proline, showed significant correlations with hypertension. These amino acids influence multiple pathways including nitric oxide synthesis, vascular remodeling, and neurotransmitter production, among others. Distinct amino acid profiles were discerned between hypertensive and non-hypertensive individuals. Amino acid profiling, particularly the levels of BCAAs and AAAs, offers promising avenues in the diagnostic and therapeutic strategies for hypertension. Future studies are crucial to confirm these findings and to delineate amino acid-based interventions for hypertension treatment.

Early vascular ageing phenotypes and urinary targeted metabolomics in children and young adults: the ExAMIN Youth SA and African-PREDICT studies

Some individuals are susceptible to accelerated biological ageing, resulting in premature alterations in arterial structure and function. Identifying early-onset vascular ageing characterised by arterial stiffening is vital for intervention and preventive strategies. We stratified and phenotyped healthy children (5-9 yrs) and young adults (20-30 yrs) into their vascular ageing extremes established by carotid-femoral pulse wave velocity (cfPWV) percentiles (i.e., healthy vascular ageing (HVA) and early vascular ageing (EVA)). We compared anthropometric, cardiovascular, and metabolomic profiles and explored associations between cfPWV and urinary metabolites. Children and adults in the EVA groups displayed higher levels of adiposity, cardiovascular, and lifestyle risk factors (adults only) (all p ≤ 0.018). In adults, several urinary metabolites were lower in the EVA group (all q ≤ 0.039) when compared to the HVA group, with no differences observed in children. In multiple regression analysis (adults only), we found inverse associations between cfPWV with histidine (adj. R2 = 0.038; β = -0.192; p = 0.013) and beta-alanine (adj. R2 = 0.034; β = -0.181; p = 0.019) in the EVA group, but with arginine (adj. R2 = 0.021; β = -0.160; p = 0.024) in the HVA group. The inverse associations of beta-alanine and histidine with cfPWV in the EVA group is suggestive that asymptomatic young adults who present with an altered metabolomic and less desired cardiovascular profile in combination with unfavourable lifestyle behaviours may be predisposed to early-onset vascular ageing. Taken together, screening on both a phenotypic and metabolic level may prove important in the early detection, prevention, and intervention of advanced biological ageing.

Amino acid intake with protein food source and incident dyslipidemia in Korean adults from the Ansan and Ansung Study and the Health Examinee Study

Background

Dyslipidemia is a major risk factor for cardiovascular diseases and appropriate intake of amino acids may be helpful for the management of dyslipidemia. However, evidence of an association between amino acid intake and dyslipidemia in Korean adults is limited.

Objective

The purpose of this study was to investigate how the incidence of dyslipidemia in Korean adults is associated with the consumption of amino acids, essential and nonessential types, as well as the sources of these amino acids from food.

Methods

Data from 35,478 study participants without dyslipidemia at baseline from the Ansan and Ansung Study and the Health Examinee Study were used for the analysis. Dyslipidemia and its components such as hypertriglyceridemia, hypercholesterolemia, hyper-low-density lipoprotein (LDL) cholesterolemia and hypo-high-density lipoprotein (HDL) cholesterolemia were the main outcome in this study. The participants were categorized into quartiles, based on the intake of amino acids and plant-/animal-based proteins.

Results

On average, the follow-up period lasted for 5.7 years. The two major food groups that contributed to one-half of the intake for each type of amino acid were whole grain mixed rice and white rice. Compared to the lowest quartile group, the highest quartile groups of essential amino acid intake [men: hazard ratio (HR) = 0.78; 95% confidence interval (CI), 0.63-0.97; P for trend = 0.0088; women: HR = 0.86; 95% CI, 0.76-0.99; P for trend = 0.0201] and nonessential amino acid intake (men: HR = 0.75; 95% CI, 0.60-0.94; P for trend = 0.0069; women: HR = 0.81; 95% CI, 0.71-0.93; P for trend = 0.0024) had a decreased risk of dyslipidemia. Plant-based protein intake had a negative association and animal-based protein intake had a nonsignificant association with dyslipidemia after adjustment for energy-adjusted fat intake. Furthermore, the essential and nonessential amino acid intake showed stronger negative associations with dyslipidemia after further adjustment for energy-adjusted fat intake.

Conclusion

To conclude, the intake of amino acids may have a protective effect against dyslipidemia in Korean adults who are aged 40 years or older, regardless of their protein food sources.

Adiposity and insulin resistance mediate the inverse association between legume intake and blood pressure: a cross-sectional analysis in secondary cardiovascular prevention

This study aimed to evaluate the association between legume intake and blood pressure, as well as the mediating role of cardiometabolic risk factors in patients in secondary cardiovascular prevention. Socio-demographic, anthropometric, clinical and food intake data were collected from the baseline of the multicentre study Brazilian Cardioprotective Nutritional Program Trial - BALANCE (RCT: NCT01620398). The relationships between variables were explored through path analysis. In total, 2247 individuals with a median age of 63·0 (45-91) years, 58·8 % (n 1321) male and 96·5 % (n 2168) with diagnosis of hypertension were included. Negative associations were observed between histidine intake and systolic blood pressure (SBP) (standardised coefficient (SC) = -0·057; P = 0·012) and between legume intake and BMI (SC = -0·061; P = 0·006). BMI was positively associated with triglycerides-glucose (TyG) index (SC = 0·173; P < 0·001), SBP (SC = 0·144; P < 0·001) and diastolic blood pressure (DBP) (SC = 0·177; P < 0·001), and TyG index was positively associated with DBP (SC = 0·079; P = 0·001). A negative indirect effect was observed between the intake of legumes, SBP and DBP, mediated by BMI (SC = -0·009; P = 0·011; SC = -0·011; P = 0·010, respectively). In addition, an indirect negative effect was found between the intake of legumes and the DBP, mediated simultaneously by BMI and TyG index (SC = -0·001; P = 0·037). In conclusion, legume intake presented a negative indirect association with blood pressure, mediated by insulin resistance (TyG) and adiposity (BMI) in individuals of secondary care in cardiology.

Cross-Sectional Blood Metabolite Markers of Hypertension: A Multicohort Analysis of 44,306 Individuals from the COnsortium of METabolomics Studies

Hypertension is the main modifiable risk factor for cardiovascular morbidity and mortality but discovering molecular mechanisms for targeted treatment has been challenging. Here we investigate associations of blood metabolite markers with hypertension by integrating data from nine intercontinental cohorts from the COnsortium of METabolomics Studies. We included 44,306 individuals with circulating metabolites (up to 813). Metabolites were aligned and inverse normalised to allow intra-platform comparison. Logistic models adjusting for covariates were performed in each cohort and results were combined using random-effect inverse-variance meta-analyses adjusting for multiple testing. We further conducted canonical pathway analysis to investigate the pathways underlying the hypertension-associated metabolites. In 12,479 hypertensive cases and 31,827 controls without renal impairment, we identified 38 metabolites, associated with hypertension after adjusting for age, sex, body mass index, ethnicity, and multiple testing. Of these, 32 metabolite associations, predominantly lipid (steroids and fatty acyls) and organic acids (amino-, hydroxy-, and keto-acids) remained after further adjusting for comorbidities and dietary intake. Among the identified metabolites, 5 were novel, including 2 bile acids, 2 glycerophospholipids, and ketoleucine. Pathway analysis further implicates the role of the amino-acids, serine/glycine, and bile acids in hypertension regulation. In the largest cross-sectional hypertension-metabolomics study to date, we identify 32 circulating metabolites (of which 5 novel and 27 confirmed) that are potentially actionable targets for intervention. Further in-vivo studies are needed to identify their specific role in the aetiology or progression of hypertension.

Green and Oolong Tea Extracts With Different Phytochemical Compositions Prevent Hypertension and Modulate the Intestinal Flora in a High-Salt Diet Fed Wistar Rats

Green tea (GT) and oolong tea (OLT) are widely consumed beverages, and their preventive and regulatory effects on hypertension have been reported. However, the interventional effects of GT and OLT on hypertension induced by a high-salt diet and its mechanism have not been fully explored. This study evaluated the anti-hypertensive effects of GT and OLT and their underlying mechanisms. The in vivo anti-hypertensive effects of GT and OLT and their capability to prevent hypertension and regulate the intestinal microbiota in Wistar rats fed with a high-salt diet were evaluated. Our results show that GT and OLT supplementations could regulate oxidative stress, inflammation, gene expression, and parameter levels related to blood pressure (BP) and prevent the increase in BP induced by a high-salt diet. Furthermore, both GT and OLT boosted the richness and diversity of intestinal microbiota, increased the abundance of beneficial bacteria and reduced the abundance of harmful bacteria and conditionally pathogenic bacteria, and regulated the intestinal microbial metabolism pathway related to BP. Among them, OLT presented better effects than GT. These findings indicate that GT and OLT can prevent hypertension caused by high-salt diets, which may be due to the regulation of intestinal flora by GT and OLT.

A network pharmacology-based approach to explore the active ingredients and molecular mechanism of Lei-gong-gen formula granule on a spontaneously hypertensive rat model

Background

Lei-gong-gen formula granule (LFG) is a folk prescription derived from Zhuang nationality, the largest ethnic minority among 56 nationalities in China. It consists of three herbs, namely Eclipta prostrata (L.) L., Smilax glabra Roxb, and Centella asiatica (L.) Urb. It has been widely used as health protection tea for hundreds of years to prevent hypertension in Guangxi Zhuang Autonomous Region. The purpose of this study is to validate the antihypertensive effect of LFG on the spontaneously hypertensive rat (SHR) model, and to further identify the effective components and anti-hypertension mechanism of LFG.

Methods

The effects of LFG on blood pressure, body weight, and heart rate were investigated in vivo using the SHR model. The levels of NO, ANG II, and ET-1 in the serum were measured, and pathological changes in the heart were examined by H&E staining. The main active components of LFG, their corresponding targets, and hypertension associated pathways were discerned through network pharmacology analysis based on the Traditional Chinese Medicine Systems Pharmacology (TCMSP), Traditional Chinese Medicine Integrated Database (TCMID), and the Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine (BATMAN-TCM). Then the predicted results were further verified by molecular biology experiments such as RT-qPCR and western blot. Additionally, the potential active compounds were predicted by molecular docking technology, and the chemical constituents of LFG were analyzed and identified by UPLC-QTOF/MS technology. Finally, an in vitro assay was performed to investigate the protective effects of potential active compounds against hydrogen peroxide (H₂O₂) induced oxidative damage in human umbilical vein endothelial cells (HUVEC).

Results

LFG could effectively reduce blood pressure and increase serum NO content in SHR model. Histological results showed that LFG could ameliorate pathological changes such as cardiac hypertrophy and interstitial inflammation. From network pharmacology analysis, 53 candidate active compounds of LFG were collected, which linked to 765 potential targets, and 828 hypertension associated targets were retrieved, from which 12 overlapped targets both related to candidate active compounds from LFG and hypertension were screened and used as the potential targets of LFG on antihypertensive effect. The molecular biology experiments of the 12 overlapped targets showed that LFG could upregulate the mRNA and protein expressions of NOS3 and proto-oncogene tyrosine-protein kinase SRC (SRC) in the thoracic aorta. Pathway enrichment analysis showed that the PI3K-AKT signaling pathway was closely related to the expression of NOS3 and SRC. Moreover, western blot results showed that LFG significantly increased the protein expression levels of PI3K and phosphorylated AKT in SHR model, suggesting that LFG may active the PI3K-AKT signaling pathway to decrease hypertension. Molecular docking study further supported that p-hydroxybenzoic acid, cedar acid, shikimic acid, salicylic acid, nicotinic acid, linalool, and histidine can be well binding with NOS3, SRC, PI3K, and AKT. UPLC-QTOF/MS analysis confirmed that p-hydroxybenzoic acid, shikimic acid, salicylic acid, and nicotinic acid existed in LFG. Pre-treatment of HUVEC with nicotinic acid could alleviate the effect on cell viability induced by H₂O₂ and increase the NO level in cell supernatants.

Conclusions

LFG can reduce the blood pressure in SHR model, which might be attributed to increasing the NO level in serum for promoting vasodilation via upregulating SRC expression level and activating the PI3K-AKT-NOS3 signaling pathway. Nicotinic acid might be the potential compound for LFG antihypertensive effect.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00507-1.

Restructuring the Gut Microbiota by Intermittent Fasting Lowers Blood Pressure

[Figure: see text].

Association of Circulating Metabolites in Plasma or Serum and Risk of Stroke: Meta-analysis From 7 Prospective Cohorts

OBJECTIVE

To conduct a comprehensive analysis of circulating metabolites and incident stroke in large prospective population-based settings.

METHODS

We investigated the association of metabolites with risk of stroke in 7 prospective cohort studies including 1,791 incident stroke events among 38,797 participants in whom circulating metabolites were measured by nuclear magnetic resonance technology. The relationship between metabolites and stroke was assessed with Cox proportional hazards regression models. The analyses were performed considering all incident stroke events and ischemic and hemorrhagic events separately.

RESULTS

The analyses revealed 10 significant metabolite associations. Amino acid histidine (hazard ratio [HR] per SD 0.90, 95% confidence interval [CI] 0.85, 0.94; p = 4.45 × 10-5), glycolysis-related metabolite pyruvate (HR per SD 1.09, 95% CI 1.04, 1.14; p = 7.45 × 10-4), acute-phase reaction marker glycoprotein acetyls (HR per SD 1.09, 95% CI 1.03, 1.15; p = 1.27 × 10-3), cholesterol in high-density lipoprotein (HDL) 2, and several other lipoprotein particles were associated with risk of stroke. When focused on incident ischemic stroke, a significant association was observed with phenylalanine (HR per SD 1.12, 95% CI 1.05, 1.19; p = 4.13 × 10-4) and total and free cholesterol in large HDL particles.

CONCLUSIONS

We found association of amino acids, glycolysis-related metabolites, acute-phase reaction markers, and several lipoprotein subfractions with the risk of stroke. These findings support the potential of metabolomics to provide new insights into the metabolic changes preceding stroke.

Protective effect of oral histidine on hypertension in Dahl salt-sensitive rats induced by high-salt diet

AIMS

Salt-sensitive hypertension is a risk factor for cardiovascular disease. Previous studies have shown that insufficient arginine in the kidney caused by metabolic imbalance is an important factor in salt-sensitive hypertension. Whether the high nitrogen content of histidine can affect the balance of nitrogen metabolism in Dahl salt-sensitive (SS) rats. This article aimed to study the effects of oral histidine on salt-sensitive hypertension, kidney damage and metabolic patterns of high-salt diet in SS rats.

MAIN METHODS

Adult rats were divided into four groups, and blood pressure was measured using a non-invasive tail-cuff system. Gas chromatography-mass spectrometry analyzed metabolites in serum and kidney tissues.

KEY FINDINGS

High-salt diet significantly increased the blood pressure of rats and aggravated kidney damage. Of note, histidine can attenuate salt-sensitive hypertension and kidney damage by improving metabolic pattern, reducing Reactive Oxygen Species (ROS) and increasing nitric oxide levels in SS rats.

SIGNIFICANCE

These results suggest that histidine could be a potential adjuvant to prevent and control salt-sensitive hypertension.

Sexual Dimorphism of Metabolomic Profile in Arterial Hypertension

Metabolomic studies have demonstrated the existence of biological signatures in blood of patients with arterial hypertension, but no study has hitherto reported the sexual dimorphism of these signatures. We compared the plasma metabolomic profiles of 28 individuals (13 women and 15 men) with essential arterial hypertension with those of a healthy control group (18 women and 18 men), using targeted metabolomics. Among the 188 metabolites explored, 152 were accurately measured. Supervised OPLS-DA (orthogonal partial least squares-discriminant analysis) showed good predictive performance for hypertension in both sexes (Q2cum = 0.59 in women and 0.60 in men) with low risk of overfitting (p-value-CV ANOVA = 0.004 in women and men). Seventy-five and 65 discriminant metabolites with a VIP (variable importance for the projection) greater than 1 were evidenced in women and men, respectively. Both sexes showed a considerable increase in phosphatidylcholines, a decrease in C16:0 with an increase in C28:1 lysophosphatidylcholines, an increase in sphingomyelins, as well as an increase of symmetric dimethylarginine (SDMA), acetyl-ornithine and hydroxyproline. Twenty-nine metabolites, involved in phospholipidic and cardiac remodeling, arginine/nitric oxide pathway and antihypertensive and insulin resistance mechanisms, discriminated the metabolic sexual dimorphism of hypertension. Our results highlight the importance of sexual dimorphism in arterial hypertension.

Patterns of amino acid intake are strongly associated with cardiovascular mortality, independently of the sources of protein

Background

The intake of specific amino acids (AA) has been associated with cardiovascular health, but amino acids are consumed together as dietary protein. Here we investigated the association between identified patterns of amino acid intake and cardiovascular mortality.

Methods

A total of 2216 cardiovascular deaths among 79 838 men and women from the Adventist Health Study-2 were included in our analysis. Baseline dietary patterns based on the participants' amino acids intakes were derived by factor analysis. Using Cox regression analyses, we estimated multivariate-adjusted hazard ratios (HRs) adjusted for sociodemographic and lifestyle factors and other dietary components.

Results

Three patterns of amino acids were identified. Factor 1 was positively associated with cardiovascular disease (CVD) mortality [hazard ratio (HR)Q5-Q1: 1.62, 98.75% confidence interval (CI): 1.15, 2.28; P-trend &lt;0.001]; and Factors 2 and 3 were inversely associated with CVD mortality (HR Q5-Q1 Factor 2: 0.74, 98.75% CI: 0.53, 1.04; P-trend &lt;0.01 and HR Q5-Q1 Factor 3: 0.65, 98.75% CI: 0.44, 0.95; P-trend &lt;0.05]. The associations with Factor 1 (with high loadings on indispensable amino acids such as branched chain amino acids, lysine, methionine) and Factor 3 (with high loadings on non-indispensable amino acids, namely arginine, glycine, aspartate+asparagine) remained significant after further adjustment for nutrient intake and for the five protein source patterns identified previously (HR Q5-Q1: 1.56 (0.99, 2.45) and 0.55 (0.35, 0.85); P-trends &lt; 0.01).

Conclusions

Indispensable AA have a positive and some non-indispensable AA have a negative, independent, strong association with the risk of cardiovascular mortality.

Effective prevention of sorafenib-related vascular damage induced adverse events and maintenance of hepatic function by dried bonito broth and histidine

Background: Sorafenib (SOR) is an anti-angiogenic chemotherapeutic that prolongs the survival rates of patients with hepatocellular carcinoma. However, SOR also damages normal vasculature and causes associated adverse events, including hand-foot syndrome and hypertension (HT). We previously reported in an animal study that vascular damage resulted in the narrowing of the normal vascular dimension area in medaka fish (Oryzias), and histidine (HIS), a major amino acid contained in dried bonito broth (DBB), prevented these changes. Therefore, in the study, we analyzed the effects of DBB and HIS on SOR-related vascular damages and associated adverse events in patients. Materials and methods: Three-dimensional (3D) vascular images of abdominal regions reconstituted from computed tomography were assessed to compare vascular diameter prior to and following SOR administration in groups receiving SOR monotherapy, DBB+SOR, and HIS+SOR. The clinical courses of hand-foot syndrome and HT and the toxicities of SOR in biochemical assays were monitored and compared between the groups. Correlations between hepatic function and SOR-related changes in the portal venous area dimension were also assessed. Results: SOR-related vascular damage revealed narrowing of the normal abdominal vasculature in the human body, which was monitored using 3D images. The damage was ameliorated by DBB and HIS, however, HIS had a more marked effect, particularly on the renal arteries and portal vein (PV). Maintenance of blood flow contributed to the maintenance of total cholesterol, prothrombin time, albumin (ALB), and renal functions. Changes in the 3D vascular area dimension of the PV and level of serum ALB were significantly correlated. The occurrences of the clinical symptoms of hand-foot syndrome and HT were lower in the DBB- and HIS-treated groups. Conclusion: Our results clearly demonstrate that DBB and HIS prevented SOR-related abdominal vascular damage and effectively maintained hepatic function, and prevented clinical symptoms and toxicity. Trial registration: This study was registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000025937 and UMIN000026898).

Novel Metabolites Are Associated With Augmentation Index and Pulse Wave Velocity: Findings From the Bogalusa Heart Study

BACKGROUND

Metabolomics study may help identify novel mechanisms underlying arterial stiffening.

METHODS

We performed untargeted metabolomics profiling among 1,239 participants of the Bogalusa Heart Study. After quality control, 1,202 metabolites were evaluated for associations with augmentation index (AI) and pulse wave velocity (PWV), using multivariate linear regression adjusting for age, sex, race, education, smoking, drinking, body weight, body height, physical activity, and estimated glomerular filtration rate. Heart rate, blood pressure and antihypertensive medication usage, lipids, and fasting glucose were sequentially adjusted in the sensitivity analyses for significant metabolites. Weighted correlation network analysis was applied to build metabolite networks.

RESULTS

Six novel metabolites were negatively associated with AI, of which, 3-methyl-2-oxobutyrate had the lowest P value and the largest effect size (β = -6.67, P = 5.99 × 10-6). Heart rate contributed to a large proportion (25%-58%) of the association for each metabolite. Twenty-one novel metabolites were identified for PWV, of which, fructose (β = 0.61, P = 6.18 × 10-10) was most significant, and histidine had the largest effect size (β = -1.09, P = 2.51 × 10-7). Blood pressure played a major contribution (9%-54%) to the association for each metabolite. Furthermore, 16 metabolites were associated with arterial stiffness independent of traditional risk factors. Network analysis identified 2 modules associated with both AI and PWV (P < 8.00 × 10-4). One was composed of metabolites from the glycerolipids synthesis and recycling pathway, and the other was involved in valine, leucine, and isoleucine metabolism. One module related to sphingomyelin metabolism was associated with PWV only (P = 0.002).

CONCLUSIONS

This study has identified novel and important metabolites and metabolic networks associated with arterial stiffness.

Effect of histidine on sorafenib-induced vascular damage: Analysis using novel medaka fish model

BACKGROUND

Sorafenib (SFN) is an anti-angiogenic chemotherapeutic that prolongs survival of patients with hepatocellular carcinoma (HCC); its side effects, including vascular damages such as hand-foot syndrome (HFS), are a major cause of therapy discontinuation. We previously reported that maintenance of peripheral blood flow by intake of dried bonito broth (DBB) significantly prevented HFS and prolonged the administration period. The amino acids contained in DBB probably contribute to its effects, but the mechanism has not been clarified. We hypothesized that histidine, the largest component among the amino acids contained in DBB, has effects on SFN-induced vascular damage, and evaluated this possibility using a novel medaka fish model.

METHODS

The fli::GFP transgenic medaka fish model has a fluorescently visible systemic vasculature. We fed the fish with SFN with and without histidine to compare blood flow and vascular structure among the differently fed models. The vascular cross-sectional area of each fish was measured to determine vascular diameter changes.

RESULTS

Our results demonstrated that SFN-fed medaka developed a narrower vascular diameter. In addition, this narrowing was counteracted by addition of histidine to the medaka diet. We observed no positive effect of histidine on regeneration of cut vessels or on cell growth of endothelial cells and HCC cell lines.

CONCLUSION

We proved the efficacy of the medaka model to assess vascular changes after administration of specific chemicals. And our results suggest that SFN causes vascular damage by narrowing peripheral vessel diameter, and that histidine effectively counteracts these changes to maintain blood flow.

Ovo-vegetarian diet is associated with lower systemic blood pressure in Taiwanese women

OBJECTIVE

This study was designed to investigate blood pressure (BP) profiles among Taiwanese women with different dietary patterns.

STUDY DESIGN

Cross-sectional study.

METHODS

A total of 269 non-hypertensive Taiwanese women, 40 years of age or older, were surveyed using structured questionnaires, and measurements of BP and physiological parameters were made. To assess differences among vegans, ovo-vegetarians, and meat eaters in terms of BP, demographic, and health behavior data, the chi-squared and Fisher's exact tests were employed for categorical variables, and analysis of variance and independent t-tests were performed for continuous variables. Multiple regression analysis was used to examine the relationship between BP and dietary patterns while controlling for potential confounding factors.

RESULTS

A significant difference was found among the three test groups in terms of age, education, employment, stress, and waist-hip ratio. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) significantly differed among the three groups. After controlling for age, body weight, waist circumference, and hip circumference, the three groups were observed to be a significant risk factor of the SBP and DBP. The SBP and DBP of the ovo-vegetarian group were significantly lower than those of the meat-eater group. No significant differences were found between the vegan and meat-eater groups in terms of SBP and DBP.

CONCLUSION

Dietary pattern is a likely risk factor for SBP and DBP outcomes in Taiwanese women. In particular, the SBP and DBP of ovo-vegetarians are the lowest among the values observed for all dietary patterns. This finding suggests that an ovo-vegetarian diet is beneficial for long-term BP control and prevention of hypertension in females.

Amino Acid Intakes Are Inversely Associated with Arterial Stiffness and Central Blood Pressure in Women

BACKGROUND

Although data suggest that intakes of total protein and specific amino acids (AAs) reduce blood pressure, data on other cardiovascular disease risk factors are limited.

OBJECTIVE

We examined associations between intakes of AAs with known mechanistic links to cardiovascular health and direct measures of arterial stiffness, central blood pressure, and atherosclerosis.

METHODS

In a cross-sectional study of 1898 female twins aged 18-75 y from the TwinsUK registry, intakes of 7 cardioprotective AAs (arginine, cysteine, glutamic acid, glycine, histidine, leucine, and tyrosine) were calculated from food-frequency questionnaires. Direct measures of arterial stiffness and atherosclerosis included central systolic blood pressure (cSBP), mean arterial pressure (MAP), augmentation index (AI), pulse wave velocity (PWV), and intima-media thickness (IMT). ANCOVA was used to assess the associations between endpoints of arterial stiffness and intake (per quintile), adjusting for potential confounders.

RESULTS

In multivariable analyses, higher intakes of total protein and 7 potentially cardioprotective AAs were associated with lower cSBP, MAP, and PWV. Higher intakes of glutamic acid, leucine, and tyrosine were most strongly associated with PWV, with respective differences of -0.4 ± 0.2 m/s (P-trend = 0.02), -0.4 ± 0.2 m/s (P-trend = 0.03), and -0.4 ± 0.2 m/s (P-trend = 0.03), comparing extreme quintiles. There was a significant interaction between AA intakes and protein source, and higher intakes of AAs from vegetable sources were associated with lower central blood pressure and AI. Higher intakes of glutamic acid, leucine, and tyrosine from animal sources were associated with lower PWV.

CONCLUSIONS

These data provide evidence to suggest that intakes of several AAs are associated with cardiovascular benefits beyond blood pressure reduction in healthy women. The magnitude of the observed associations was similar to those previously reported for other lifestyle factors. Increasing intakes of these AAs could be an important and readily achievable way to reduce cardiovascular disease risk.

Dietary protein and amino acids intake and its relationship with blood pressure in adolescents: the HELENA STUDY

OBJECTIVE

To analyze the association between dietary protein and amino acids intake and systolic (SBP) and diastolic (DBP) blood pressure in European adolescents.

METHODS

Participants were from the cross-sectional study performed in Europe, Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA study; n = 1605; 12.5-17.5 years; 833 girls) selected by complex sampling. The associations between dietary protein and amino acids intake and SBP/DBP were examined by multilevel linear regression models (context variable by school); the analysis being stratified by sex. Cities, seasonality, age, socioeconomic level, parental education level, body mass index, waist circumference, Tanner stage and physical activity were used as covariates.

RESULTS

In boys, we found an inverse association between protein (animal and vegetable) intake and DBP; and a positive association between histidine and SBP. In girls, we observed a positive association among tryptophan, histidine with SBP and methionine with DBP. On the other hand, we observed an inverse association between tyrosine and both SBP and DBP levels in girls.

CONCLUSIONS

The association between amino acids and BP levels is controversial and depends on the type of amino acids, and protein intake can help control the DBP in boys.

Dietary amino acids and blood pressure: a cohort study of patients with cardiovascular disease

BACKGROUND

Dietary protein has been variably reported to either lower or raise blood pressure. The purpose of this study was to determine whether intakes of specific amino acids differentially associate with blood pressure.

STUDY DESIGN

Observational cohort study by secondary analysis of clinical trial data.

SETTING & PARTICIPANTS

Study of low-fat versus Mediterranean-style diets in patients with prevalent cardiovascular disease.

PREDICTOR

Dietary amino acids.

OUTCOMES

Systolic and diastolic blood pressure.

MEASUREMENTS

Dietary nutrients and cardiovascular risk factors were assessed at baseline, 3 and 6 months, and then every 6 months for 2 years.

RESULTS

Baseline blood pressure was 119 ± 16 (SD)/72 ± 10 (SD) mm Hg (n = 92) and dietary protein intake was 80 ± 31 g/d. Independent amino acid variables (quartiles of intake) were analyzed by generalized estimating equation models with prespecified covariates for time-varying systolic and diastolic blood pressure. The odds of each 1-SD higher systolic or diastolic blood pressure (ie, 16 and 10 mm Hg, respectively) were increased per quartile of intake for methionine (ORs of 1.29 [95% CI, 1.14-1.46] and 1.21 [95% CI, 1.05-1.39], respectively) and alanine (ORs of 1.17 [95% CI, 1.05-1.30] and 1.22 [95% CI, 1.07-1.38], respectively). Quartiles of intake for threonine (ORs of 0.84 [95% CI, 0.74-0.96] and 0.87 [95% CI, 0.75-1.01], respectively) and histidine (ORs of 0.92 [95% CI, 0.86-1.00] and 0.89 [95% CI, 0.82-0.97], respectively) had inverse associations with the same degree of difference in blood pressure.

LIMITATIONS

Modest sample-size biases toward the chance of false-negative results; potential for residual confounding; colinearity between amino acids may obscure relevant relationships to blood pressure; associational findings do not establish causality.

CONCLUSIONS

Intakes of methionine and alanine were associated positively with higher blood pressure, whereas intakes of threonine and histidine had inverse associations. These amino acids merit further study for advancing dietary approaches to blood pressure reduction.