Alamandine alleviates hypertension and renal damage via oxidative-stress attenuation in Dahl rats

Alamandine (Ala) is a novel member of the renin–angiotensin-system (RAS) family. The present study aimed to explore the effects of Ala on hypertension and renal damage of Dahl salt-sensitive (SS) rats high-salt diet-induced, and the mechanisms of Ala on renal-damage alleviation. Dahl rats were fed with high-salt diets to induce hypertension and renal damage in vivo, and HK-2 cells were treated with sodium chloride (NaCl) to induce renal injury in vitro. Ala administration alleviated the high-salt diet-induced hypertension, renal dysfunction, and renal fibrosis and apoptosis in Dahl SS rats. The HK-2 cells’ damage, and the increases in the levels of cleaved (c)-caspase3, c-caspase8, and c-poly(ADP-ribose) polymerase (PARP) induced by NaCl were inhibited by Ala. Ala attenuated the NaCl-induced oxidative stress in the kidney and HK-2 cells. DETC, an inhibitor of SOD, reversed the inhibitory effect of Ala on the apoptosis of HK-2 cells induced by NaCl. The NaCl-induced increase in the PKC level was suppressed by Ala in HK-2 cells. Notably, PKC overexpression reversed the moderating effects of Ala on the NaCl-induced apoptosis of HK-2 cells. These results show that Ala alleviates high-salt diet-induced hypertension and renal dysfunction. Ala attenuates the renal damage via inhibiting the PKC/reactive oxygen species (ROS) signaling pathway, thereby suppressing the apoptosis in renal tubular cells.

Parkia biglobosa aqueous extract ameliorates risk markers of cardiometabolic diseases in spironolactone treated and high-salt fed Sprague-Dawley male rat

Background: The numbers of people with salt-sensitive hypertension and cardiometabolic diseases (CMD) are increasing due to high-salt diet (HSD) consumption globally. Parkia biglobosa (PB), an African locust bean tree, has been reported to have several cardiovascular protective properties but its ameliorative effects on CMD are scarcely reported. Therefore, this study aimed at investigating the effects of PB stem bark aqueous extract on some risk markers of CMD in weanling male rats subjected to HSD and Spironolactone (Sp) treatment.Twenty-five weanling male rats (95-105 g) were divided into 5 groups: Group 1 (Control); Group 2 (untreated HSD) fed on normal chow and HSD (8% NaCl); Group 3 (HSD+Sp); Group 4 (HSD+PB); Group 5 (HSD+Sp+PB) fed on HSD (8% NaCl) and received either 80 mg/kg of Sp or 400 mg/kg of PB and both as treatment, respectively. After 6 weeks of treatment, blood samples and heart were collected from each animal for biochemical analysis.Results: Administration of both PB and Sp or only PB, significantly decreased the plasma or cardiac adenosine deaminase, xanthine oxidase, C-reactive protein, lipids (except high density lipoprotein), uric acid, sodium, and potassium concentrations. Contrarily, the plasma as well as cardiac nitric oxide and endothelial nitric oxide synthase increased significantly by the same treatment.Conclusion: Parkia biglobosa or its administration with Spironolactone ameliorates associated-risk markers of cardiometabolic disease which are triggered by high salt diet.

High-Salt Diet in the Pre- and Postweaning Periods Leads to Amygdala Oxidative Stress and Changes in Locomotion and Anxiety-Like Behaviors of Male Wistar Rats

High-salt (HS) diets have recently been linked to oxidative stress in the brain, a fact that may be a precursor to behavioral changes, such as those involving anxiety-like behavior. However, to the best of our knowledge, no study has evaluated the amygdala redox status after consuming a HS diet in the pre- or postweaning periods. This study aimed to evaluate the amygdala redox status and anxiety-like behaviors in adulthood, after inclusion of HS diet in two periods: preconception, gestation, and lactation (preweaning); and only after weaning (postweaning). Initially, 18 females and 9 male Wistar rats received a standard (n = 9 females and 4 males) or a HS diet (n = 9 females and 5 males) for 120 days. After mating, females continued to receive the aforementioned diets during gestation and lactation. Weaning occurred at 21-day-old Wistar rats and the male offspring were subdivided: control-control (C-C)—offspring of standard diet fed dams who received a standard diet after weaning (n = 9–11), control-HS (C-HS)—offspring of standard diet fed dams who received a HS diet after weaning (n = 9–11), HS-C—offspring of HS diet fed dams who received a standard diet after weaning (n = 9–11), and HS-HS—offspring of HS diet fed dams who received a HS diet after weaning (n = 9–11). At adulthood, the male offspring performed the elevated plus maze and open field tests. At 152-day-old Wistar rats, the offspring were euthanized and the amygdala was removed for redox state analysis. The HS-HS group showed higher locomotion and rearing frequency in the open field test. These results indicate that this group developed hyperactivity. The C-HS group had a higher ratio of entries and time spent in the open arms of the elevated plus maze test in addition to a higher head-dipping frequency. These results suggest less anxiety-like behaviors. In the analysis of the redox state, less activity of antioxidant enzymes and higher levels of the thiobarbituric acid reactive substances (TBARS) in the amygdala were shown in the amygdala of animals that received a high-salt diet regardless of the period (pre- or postweaning). In conclusion, the high-salt diet promoted hyperactivity when administered in the pre- and postweaning periods. In animals that received only in the postweaning period, the addition of salt induced a reduction in anxiety-like behaviors. Also, regardless of the period, salt provided amygdala oxidative stress, which may be linked to the observed behaviors.

Effect of a low-salt diet on chronic kidney disease outcomes: a systematic review and meta-analysis

ObjectiveThe benefits of a low-salt diet for patients with chronic kidney disease (CKD) are controversial. We conducted a systematic review and meta-analysis of the effect of a low-salt diet on major clinical outcomes.DesignSystematic review and meta-analysis.Data sourcesMEDLINE by Ovid, EMBASE and the Cochrane Library databases.Eligibility criteria for selecting studiesWe included randomised controlled trials (RCTs) and cohort studies that assessed the effect of a low-salt diet on the renal composite outcomes (more than 50% decline in estimated glomerular filtration rate (eGFR) during follow-up, doubling of serum creatinine or end-stage renal disease), rate of eGFR decline, change in proteinuria, all-cause mortality events, cardiovascular (CV) events, and changes in systolic blood pressure and diastolic blood pressure.Data extraction and synthesisTwo independent researchers extracted data and evaluated their quality. Relative risks (RRs) with 95% CIs were used for dichotomous data. Differences in means (MDs) or standardised mean differences (SMDs) with 95% CIs were used to pool continuous data. We used the Cochrane Collaboration risk-of-bias tool to evaluate the quality of RCTs, and Newcastle–Ottawa Scale to evaluate the quality of cohort studies.ResultsWe found 9948 potential research records. After removing duplicates, we reviewed the titles and abstracts, and screened the full text of 230 publications. Thirty-three studies with 101 077 participants were included. A low-salt diet produced a 28% reduction in renal composite outcome events (RR: 0.72; 95% CI: 0.58 to 0.89). No significant effects were found in terms of changes in proteinuria (SMD: −0.71; 95% CI: −1.66 to 0.24), rate of eGFR (decline MD: 1.16; 95% CI: −2.02 to 4.33), risk of all-cause mortality (RR: 0.92; 95% CI: 0.58 to 1.46) and CV events (RR: 1.01; 95% CI: 0.46 to 2.22).ConclusionA low-salt diet seems to reduce the risk for renal composite outcome events in patients with CKD. However, no compelling evidence indicated that such a diet would reduce the eGFR decline rate, proteinuria, incidence of all-cause mortality and CV events. Further, more definitive studies are needed.PROSPERO registration numberCRD42017072395.

High-Salt Attenuates the Efficacy of Dapagliflozin in Tubular Protection by Impairing Fatty Acid Metabolism in Diabetic Kidney Disease

High-salt intake leads to kidney damage and even limits the effectiveness of drugs. However, it is unclear whether excessive intake of salt affects renal tubular energy metabolism and the efficacy of dapagliflozin on renal function in diabetic kidney disease (DKD). In this study, we enrolled 350 DKD patients and examined the correlation between sodium level and renal function, and analyzed influencing factors. The results demonstrated that patients with macroalbuminuria have higher 24 h urinary sodium levels. After establishment of type 2 diabetes mellitus model, the animals received a high-salt diet or normal-salt diet. In the presence of high-salt diet, the renal fibrosis was aggravated with fatty acid metabolism dysregulation. Furthermore, Na+/K+-ATPase expression was up-regulated in the renal tubules of diabetic mice, while the fatty acid metabolism was improved by inhibiting Na+/K+-ATPase of renal tubular epithelial cells. Of note, the administration with dapagliflozin improved renal fibrosis and enhanced fatty acid metabolism. But high salt weakened the above-mentioned renal protective effects of dapagliflozin in DKD. Similar results were recapitulated in vitro after incubating proximal tubular epithelial cells in high-glucose and high-salt medium. In conclusion, our results indicate that high salt can lead to fatty acid metabolism disorders by increasing Na+/K+-ATPase expression in the renal tubules of DKD. High salt intake diminishes the reno-protective effect of dapagliflozin in DKD.

Calcitriol ameliorates damage in high-salt diet-induced hypertension: Evidence of communication with the gut–kidney axis

Several studies have established a link between high-salt diet, inflammation, and hypertension. Vitamin D supplementation has shown anti-inflammatory effects in many diseases; gut microbiota is also associated with a wide variety of cardiovascular diseases, but potential role of vitamin D and gut microbiota in high-salt diet-induced hypertension remains unclear. Therefore, we used rats with hypertension induced by a high-salt diet as the research object and analyzed the transcriptome of their tissues (kidney and colon) and gut microbiome to conduct an overall analysis of the gut–kidney axis. We aimed to confirm the effects of high salt and calcitriol on the gut–kidney immune system and the composition of the intestinal flora. We demonstrate that consumption of a high-salt diet results in hypertension and inflammation in the colon and kidney and alteration of gut microbiota composition and function. High-salt diet-induced hypertension was found to be associated with seven microbial taxa and mainly associated with reduced production of the protective short-chain fatty acid butyrate. Calcitriol can reduce colon and kidney inflammation, and there are gene expression changes consistent with restored intestinal barrier function. The protective effect of calcitriol may be mediated indirectly by immunological properties. Additionally, the molecular pathways of the gut microbiota-mediated blood pressure regulation may be related to circadian rhythm signals, which needs to be further investigated. An innovative association analysis of the microbiota may be a key strategy to understanding the association between gene patterns and host.

Association of Genetic Variants of Klotho with BP Responses to Dietary Sodium or Potassium Intervention and Long-Term BP Progression

<b><i>Objectives:</i></b> Klotho (<i>KL</i>) plays pivotal roles in the progression of salt-sensitive hypertension. Salt-sensitive hypertension was associated with <i>KL</i> genotypes. We aimed to explore the association of common genetic variants of <i>KL</i> with individual blood pressure (BP) responses to sodium and potassium through a dietary intervention study as well as long-term BP progression. <b><i>Methods:</i></b> We conducted family-based dietary interventions among 344 participants from 126 families in rural villages of northern China in 2004. Subjects sequentially underwent a baseline diet, a low-salt diet (51.3 mmol/day Na), a high-salt diet (307.8 mmol/day Na), and a high-salt + potassium supplementation diet (307.8 mmol/day Na + 60 mmol/day K). After dietary intervention, we followed up with these participants in 2009 and 2012. The associations between 6 single-nucleotide polymorphisms (SNPs) of <i>KL</i> and phenotypes were analyzed through a linear mixed-effects model. <b><i>Results:</i></b> SNPs rs211247 and rs1207568 were positively correlated with the BP response to high-salt diet in the dominant model after adjusting for confounders (β = 1.670 and 2.163, <i>p</i> = 0.032 and 0.005, respectively). BPs rs526906 and rs525014 were in a haplotype block. Block rs526906-rs525014 was positively correlated with diastolic BP response to potassium and potassium sensitivity in the additive model (β = 0.845, <i>p</i> = 0.032). In addition, regression analysis indicated that rs211247 was associated with long-term systolic BP alterations after 8 years of follow-up in the recessive model (β = 20.47, <i>p</i> = 0.032). <b><i>Conclusions:</i></b> Common variants of the <i>KL</i> gene might modify individual BP sensitivity to sodium or potassium and influence the long-term progression of BP, suggesting a potential role in the development of salt-sensitive hypertension. Thus, <i>KL</i> may be a new early intervention target for salt-sensitive hypertension.

Low Salt Diet Counseling as an Effort to Increase Knowledge of Hypertension Patients

The prevalence of hypertension has increased throughout the year. Hypertension spreads widely because of the lack of knowledge and a healthy lifestyle. People's lifestyle which is more practical has an impact on the implementation of inappropriate hypertension diets and triggers various diseases. Based on this phenomenon, it is necessary to increase public knowledge about hypertension diets. The purpose of this activity was to provide counseling about a low-salt diet as an effort to increase knowledge of hypertension patients. The method was done by giving counseling about low salt diet through lectures to 30 hypertension patients who were routinely monitored at the Panti Rahayu Clinic. The pre test showed that almost all of the hypertension patients (80%) were in the poor category of knowledge. The post test showed that after being given counseling the knowledge of hypertension patients increased almost half (46%) were in the good category. Knowledge of hypertension patients increased after getting information through counseling activities about a low salt diet. Suggestions for clinics are expected to hold regular and periodic health education or promotion programs to provide information so as to increase the knowledge of hypertension patients.