Hypertension in African Populations: Review and Computational Insights

In vitro comparative quality evaluation of different brands of Amlodipine Tablets Commercially available in Jimma Town, South-western Ethiopia

BACKGROUND

The incidence of hypertension in persons 25 years of age and older is estimated to be 46% in Africa, where it is still very common. This concerning rate could be explained by the pharmaceutical markets' accessibility to poor quality antihypertensive drugs. Thus, the purpose of this study was to evaluate and compare the quality different brands of Amlodipine Tablets Commercially available in Jimma Town, South-western Ethiopia.

METHODS

The quality control test was conducted from August 30, 2019 to February 27, 2020 at Jimma University in the Laboratory of Drug Quality Control (JuLaDQ). The laboratory test was carried out in accordance with WHO inspection guidelines and United States Pharmacopeia. A statistically significant was considered when P<0.05. For further comparison of the in-vitro dissolution profiles of amlodipine tablets, model-independent model-dependent parameters and statistical Dunnetts tests for ensuring bioequivalence were used to further compare the in-vitro dissolution profiles.

RESULTS

With the exception of brand AMD-5 (1/10), the remaining nine (n = 9) brands were within WHO visual inspection criteria. The quality control parameters such as friability, weight variation, identity, assay, and dissolution test were within the United States Pharmacopeia. The model independent parameters (f1, and f2) confirmed that, all generic products were bio-equivalence, and interchangeable with comparator product. The model dependent approaches revealed the Weibull model (AMD-10), the Zero order (AMD-3), and the Korsemeyer-Peppas models were the most effective predictions for the release of the pharmaceutical substance from the dosage form. The Korsemeyer-Peppas model (r2 ≥0.9695) was the best descriptive model for determining the amlodipine drug kinetics from the point of view of all brands examined. The evaluated amlodipine brand tablets were in line with quality standards. The model independent methods confirmed that the generic brand tablets were interchangeable in clinical practice. The tested products follow more than two drug release kinetics.

CONCLUSION

The study revealed a manifest discrepancy in the dissolution profiles' releases. Therefore, it is strongly advised to use appropriately designed dissolution profile evaluation methods with various pH values in the dissolution media, as well as to do comprehensive visual inspections. This will make it easier to do a thorough investigation of any potential quality issues that might be related to various generic products available in the pharmaceutical market.

Effects of Environmental Conditions on Athlete's Cardiovascular System

Environmental factors such as extreme temperatures, humidity, wind, pollution, altitude, and diving can significantly impact athletes' cardiovascular systems, potentially hindering their performance, particularly in outdoor sports. The urgency of this issue is heightened by the increasing prevalence of climate change and its associated conditions, including fluctuating pollution levels, temperature variations, and the spread of infectious diseases. Despite its critical importance, this topic is often overlooked in sports medicine. This narrative review seeks to address this gap by providing a comprehensive, evidence-based evaluation of how athletes respond to environmental stresses. A thorough assessment of current knowledge is essential to better prepare athletes for competition under environmental stress and to minimize the harmful effects of these factors. Specifically, adaptative strategies and preventative measures are vital to mitigating these environmental influences and ensuring athletes' safety.

Single nucleotide polymorphism-based biomarker in primary hypertension

Primary hypertension is a multiplex and multifactorial disease influenced by various strong components including genetics. Extensive research such as Genome-wide association studies and candidate gene studies have revealed various single nucleotide polymorphisms (SNPs) related to hypertension, providing insights into the genetic basis of the condition. This review summarizes the current status of SNP research in primary hypertension, including examples of hypertension-related SNPs, their location, function, and frequency in different populations. The potential clinical implications of SNP research for primary hypertension management are also discussed, including disease risk prediction, personalized medicine, mechanistic understanding, and lifestyle modifications. Furthermore, this review highlights emerging technologies and methodologies that have the potential to revolutionize the vast understanding of the basis of genetics in primary hypertension. Gene editing holds the potential to target and correct any kind of genetic mutations that contribute to the development of hypertension or modify genes involved in blood pressure regulation to prevent or treat the condition. Advances in computational biology and machine learning enable researchers to analyze large datasets and identify complex genetic interactions contributing to hypertension risk. In conclusion, SNP research in primary hypertension is rapidly evolving with emerging technologies and methodologies that have the potential to transform the knowledge about genetic basis related to the condition. These advances hold promise for personalized prevention and treatment strategies tailored to an individual's genetic profile ultimately improving patient outcomes and reducing healthcare costs.

Network pharmacology and molecular docking: combined computational approaches to explore the antihypertensive potential of Fabaceae species

Hypertension is a major global public health issue, affecting quarter of adults worldwide. Numerous synthetic drugs are available for treating hypertension; however, they often come with a higher risk of side effects and long-term therapy. Modern formulations with active phytoconstituents are gaining popularity, addressing some of these issues. This study aims to discover novel antihypertensive compounds in Cassia fistula, Senna alexandrina, and Cassia occidentalis from family Fabaceae and understand their interaction mechanism with hypertension targeted genes, using network pharmacology and molecular docking. Total 414 compounds were identified; initial screening was conducted based on their pharmacokinetic and ADMET properties, with a particular emphasis on adherence to Lipinski's rules. 6 compounds, namely Germichrysone, Benzeneacetic acid, Flavan-3-ol, 5,7,3',4'-Tetrahydroxy-6, 8-dimethoxyflavon, Dihydrokaempferol, and Epiafzelechin, were identified as effective agents. Most of the compounds found non-toxic against various indicators with greater bioactivity score. 161 common targets were obtained against these compounds and hypertension followed by compound-target network construction and protein-protein interaction, which showed their role in diverse biological system. Top hub genes identified were TLR4, MMP9, MAPK14, AKT1, VEGFA and HSP90AA1 with their respective associates. Higher binding affinities was found with three compounds Dihydrokaempferol, Flavan-3-ol and Germichrysone, -7.1, -9.0 and -8.0 kcal/mol, respectively. The MD simulation results validate the structural flexibility of two complexes Flavan-MMP9 and Germich-TLR4 based on no. of hydrogen bonds, root mean square deviations and interaction energies. This study concluded that C. fistula (Dihydrokaempferol, Flavan-3-ol) and C. occidentalis (Germichrysone) have potential therapeutic active constituents to treat hypertension and in future novel drug formulation.

No Association Between AGT Gene Polymorphisms with Hypertension in a South African Population

Purpose

Hypertension is a leading cause of cardiovascular-related morbidity and mortality worldwide, with a prevalence increasing at an alarming rate in both middle- and low-income countries. Various environmental and genetic factors have been attributed to play a significant role in the increasing prevalence of hypertension. Single nucleotide polymorphisms (SNPs) in the angiotensinogen (AGT) gene are reported to have a significant association with hypertension; however, there are limited studies done on South African populations. Therefore, this case-control study aimed to investigate the association between AGT SNPs (rs2004776, rs3789678, rs5051 and rs7079) with hypertension in a study population of isiXhosa-speaking participants from the Eastern Cape Province in South Africa.

Materials and Methods

The SNPs were genotyped in 250 hypertensive cases and 237 normotensive controls, using TaqMan genotyping assays.

Results

For the SNP rs2004776, the frequency of CC genotype (18.4%) and C allele (44%) in hypertensive cases showed no significant differences (p = 0.52, χ2 = 1.32), when compared to the normotensive control group (CC: 19.8% and C allele: 43%). Similar results were obtained for the genotypic and allelic frequencies between hypertensive cases and normotensive controls for rs3789678 (p = 0.88, χ2=0.26) and rs5051 (p = 0.57, χ2=1.12), and rs7079 (p = 0.33, χ2=2.23). These findings demonstrate that there were no significant associations between the SNPs rs2004776, rs3789678, rs7079, rs5051 with hypertension in our study population.

Conclusion

These findings suggest that AGT gene polymorphisms are not associated with the development of hypertension in the studied population. The present study represents the first genetic report to investigate the AGT gene polymorphisms with hypertension in an isiXhosa-speaking South African population.

Genetic Factors Contributing to the Pathogenesis of Essential Hypertension in Two African Populations

The African continent has the highest prevalence of hypertension globally, with South Africa reporting the highest prevalence in Southern Africa. While the influence of genetic variability in the pathogenesis of hypertension is well described internationally, limited reports are available for African populations. This study aimed to assess the association of genetic variants and essential hypertension in a cohort of two ethnic South African population groups. Two hundred and seventy-seven hypertensive and one hundred and seventy-six normotensive individuals were genotyped for 78 variants. Genotyping was performed using the Illumina GoldenGate Assay and allele-specific polymerase chain reaction. The association of variants was assessed using the Fisher Exact test under the additive and allelic genetic models, while multivariate logistic regression was used to predict the development of hypertension. Five variants (CYP11B2 rs179998, AGT rs5051 and rs699, AGTR1 rs5186, and ACE rs4646994) were significantly associated with essential hypertension in the cohort under study. Furthermore, AGTR1 rs5186 and AGT rs699 were identified as risk factors for the development of hypertension in both ethnic groups. In two ethnic South African populations, an association was observed between renin-angiotensin-aldosterone system (RAAS)-related genes and the development of hypertension.

Pharmacogenomics of Hypertension in Africa: Paving the Way for a Pharmacogenetic-Based Approach for the Treatment of Hypertension in Africans

In Africa, the burden of hypertension has been rising at an alarming rate for the last two decades and is a major cause for cardiovascular disease (CVD) mortality and morbidity. Hypertension is characterised by elevated blood pressure (BP) ≥ 140/90 mmHg. Current hypertension guidelines recommend the use of antihypertensives belonging to the following classes: calcium channel blockers (CCB), angiotensin converting inhibitors (ACEI), angiotensin receptor blockers (ARB), diuretics, β-blockers, and mineralocorticoid receptor antagonists (MRAs), to manage hypertension. Still, a considerable number of hypertensives in Africa have their BP uncontrolled due to poor drug response and remain at the risk of CVD events. Genetic factors are a major contributing factor, accounting for 20% to 80% of individual variability in therapy and poor response. Poor response to antihypertensive drug therapy is characterised by elevated BPs and occurrence of adverse drug reactions (ADRs). As a result, there have been numerous studies which have examined the role of genetic variation and its influence on antihypertensive drug response. These studies are predominantly carried out in non-African populations, including Europeans and Asians, with few or no Africans participating. It is important to note that the greatest genetic diversity is observed in African populations as well as the highest prevalence of hypertension. As a result, this warrants a need to focus on how genetic variation affects response to therapeutic interventions used to manage hypertension in African populations. In this paper, we discuss the implications of genetic diversity in CYP11B2, GRK4, NEDD4L, NPPA, SCNN1B, UMOD, CYP411, WNK, CYP3A4/5, ACE, ADBR1/2, GNB3, NOS3, B2, BEST3, SLC25A31, LRRC15 genes, and chromosome 12q loci on hypertension susceptibility and response to antihypertensive therapy. We show that African populations are poorly explored genetically, and for the few characterised genes, they exhibit qualitative and quantitative differences in the profile of pharmacogene variants when compared to other ethnic groups. We conclude by proposing prioritization of pharmacogenetics research in Africa and possible adoption of pharmacogenetic-guided therapies for hypertension in African patients. Finally, we outline the implications, challenges, and opportunities these studies present for populations of non-European descent.

Genetic Variations in Angiotensinogen Gene and Risk of Preeclampsia: A Pilot Study

Preeclampsia (PE) is a typical hypertensive disorders of pregnancy (HDP) which can cause substantial morbidity and mortality in both pregnant women and fetuses. The renin-angiotensin system (RAS) genes are the main HDP-causing genes, and Angiotensinogen (AGT) as the initial substrate can directly reflect the activity of the entire RAS. However, the association between AGT SNPs and PE risk has rarely been confirmed. This study was carried out to determine whether AGT SNPs could affect the risk of PE in 228 cases and 358 controls. The genotyping result revealed that the AGT rs7079 TT carrier was related to increased PE risk. Further stratified analysis illustrated that the rs7079 TT genotype significantly increased the PE risk in subgroups of Age < 35, BMI < 25, Albumin (ALB) ≥ 30 and Aspartate aminotransferase (AST) < 30. These findings demonstrated that the rs7079 might be a promising candidate SNP strongly associated with PE susceptibility.

Association Between Night Shift and Hypertension: A Cross-Sectional Study in Chinese Adults

OBJECTIVE

The purpose of this study was to explore the effect of night-shift work on the risk of hypertension for improving workers' health.

METHODS

A total of 10,038 Chinese participants were constituted in the cross-sectional study. Logistic regression and restricted cubic spline were used to estimate the effect of night shift on hypertension.

RESULTS

There were higher odds of having hypertension in any night-shift workers (odds ratio [OR], 1.16 [95% confidence interval, 1.03-1.30]) when compared with day workers. Having 5 to 10 night shifts per month were significantly more likely to be hypertensive (OR, 1.19 [95% confidence interval, 1.03-1.38]). The OR for hypertension increased as the number of night shifts increased as the result of the restricted cubic spline.

CONCLUSIONS

Our results support the hypothesis that night shift is associated with an elevated risk of hypertension.

A protective erythropoietin evolutionary landscape, NLRP3 inflammasome regulation, and multisystem inflammatory syndrome in children

The low incidence of pediatric severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and the associated multisystem inflammatory syndrome (MIS-C) lack a unifying pathophysiological explanation, impeding effective prevention and therapy. Activation of the NACHT, LRR, and PYD domains-containing protein (NLRP) 3 inflammasome in SARS-CoV-2 with perturbed regulation in MIS-C, has been reported. We posit that, early age physiological states and genetic determinants, such as certain polymorphisms of renin-angiotensin aldosterone system (RAAS) molecules, promote a controlled RAAS hyperactive state, and form an evolutionary landscape involving an age-dependent erythropoietin (EPO) elevation, mediating ancestral innate immune defenses that, through appropriate NLRP3 regulation, mitigate tissue injury and pathogen invasion. SARS-CoV-2-induced downregulation of angiotensin-converting enzyme (ACE)2 expression in endothelial cells (EC), impairment of endothelial nitric oxide (NO) synthase (eNOS) activity and downstream NO bioavailability, may promote a hyperactive RAAS with elevated angiotensin II and aldosterone that, can trigger, and accelerate NLRP3 inflammasome activation, while EPO-eNOS/NO abrogate it. Young age and a protective EPO evolutionary landscape may successfully inhibit SARS-CoV-2 and contain NLRP3 inflammasome activation. By contrast, increasing age and falling EPO levels, in genetically susceptible children with adverse genetic variants and co-morbidities, may lead to unopposed RAAS hyperactivity, NLRP3 inflammasome dysregulation, severe endotheliitis with pyroptotic cytokine storm, and development of autoantibodies, as already described in MIS-C. Our haplotype estimates, predicted from allele frequencies in population databases, are in concordance with MIS-C incidence reports in Europeans but indicate lower risks for Asians and African Americans. Targeted Mendelian approaches dissecting the influence of relevant genetic variants are needed.

The association of MTHFR (rs1801133) with hypertension in an indigenous south African population

Aims: The current study sought to investigate the association between the methylenetetrahydrofolate reductase (MTHFR) variant (rs1801133) and the risk of developing hypertension (HTN) in an indigenous South African population.

Methods: A total of 442 participants (hypertensive, n = 279 and non-hypertensive, n = 163) from the indigenous tribe residing in Mthatha, Eastern Cape (South Africa) were recruited. HTN was defined as a systolic (SBP) and diastolic blood pressure (DBP) of ≥130/80 mmHg following American Heart Association guidelines. The genotyping of MTHFR (rs1801133) was assessed using MassARRAY^® System. Thereafter, the association between rs1801133 in various genetic models and HTN was determined by logistic regression model analysis. Furthermore, the interaction between rs1801133 and selected risk factors on HTN was performed using the open-source multifactor dimensionality reduction (MDR).

Results: The low frequency of the T allele (5%) was also observed when compared with the C allele (95%) in both cases and controls. After adjusting for confounding factors (gender, smoking status, BMI, and blood glucose levels), there were no significant associations were observed between rs1801133 and the risk of HTN in all genetic models: genotypic (OR 0.75, 95% CI 0.29–1.95, p = 0.56), dominant (OR 0.86, 95% CI 0.35–2.16, p = 0.75), co-dominant (OR 1.33, 95% CI 0.51–3.48, p = 0.55) and allelic (OR 0.80, 95% CI 0.49–1.62, p = 0.70) in logistic regression analysis. However, a significant interaction was reported among rs1801133, age, and gender (p < 0.0001) with the risk of HTN.

Conclusion: The present study reports on the lack of association between MTHFR (rs1801133) and the risk of HTN in an indigenous South African tribe. However, an interaction between gender, age, and rs1801133 was observed. Thus, future studies with a large sample size are required to further validate these findings.

Novel angiotensin-converting enzyme inhibitory peptides from tuna byproducts—milts: Preparation, characterization, molecular docking study, and antioxidant function on H2O2-damaged human umbilical vein endothelial cells

To prepare peptides with high angiotensin-converting enzyme (ACE) inhibitory (ACEi) activity, Alcalase was screened from five proteases and employed to prepare protein hydrolysate (TMH) of skipjack tuna (Katsuwonus pelamis) milts. Subsequently, 10 novel ACEi peptides were isolated from the high-ACEi activity TMH and identified as Tyr-Asp-Asp (YDD), Thr-Arg-Glu (TRE), Arg-Asp-Tyr (RDY), Thr-Glu-Arg-Met (TERM), Asp-Arg-Arg-Tyr-Gly (DRRYG), Ile-Cys-Tyr (ICY), Leu-Ser-Phe-Arg (LSFR), Gly-Val-Arg-Phe (GVRF), Lys-Leu-Tyr-Ala-Leu-Phe (KLYALF), and Ile-Tyr-Ser-Pro (IYSP) with molecular weights of 411.35, 404.41, 452.45, 535.60, 665.69, 397.48, 521.61, 477.55, 753.91, and 478.53 Da, respectively. Among them, the IC₅₀ values of ICY, LSFR, and IYSP on ACE were 0.48, 0.59, and 0.76 mg/mL, respectively. The significant ACEi activity of ICY, LSFR, and IYSP with affinities of −7.0, −8.5, and −8.3 kcal/mol mainly attributed to effectively combining with the ACEi active sites through hydrogen bonding, electrostatic force, and hydrophobic interaction. Moreover, ICY, LSFR, and IYSP could positively influence the production of nitric oxide (NO) and endothelin-1 (ET-1) secretion in human umbilical vein endothelial cells (HUVECs) and weaken the adverse impact of norepinephrine (NE) on the production of NO and ET-1. In addition, ICY, LSFR, and IYSP could provide significant protection to HUVECs against H₂O₂ damage by increasing antioxidase levels to decrease the contents of reactive oxide species and malondialdehyde. Therefore, the ACEi peptides of ICY, LSFR, and IYSP are beneficial functional molecules for healthy foods against hypertension and cardiovascular diseases.

Methylenetetrahydrofolate Reductase Polymorphism (rs1801133) and the Risk of Hypertension among African Populations: A Narrative Synthesis of Literature

In this review, we have gathered and analyzed the available genetic evidence on the association between the methylenetetrahydrofolate reductase gene (MTHFR), rs1801133 and the risk of Hypertension (HTN) in African populations, which was further compared to the global data evidence. This review was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol and Human Genome Epidemiology Network (HuGENet) guidelines. Literature was retrieved through major search databases, including PubMed, Scopus, Web of Science, and African Journal Online. We identified 64 potential studies, of which 4 studies were from the African continent and 60 studies were reported globally. Among the studies conducted in Africa, only two (n = 2) reported a significant association between the MTHFR (rs1801133) and the risk of developing HTN. Only one (n = 1) study population was purely composed of black Africans, while others were of other ethnicities. Among studies conducted in other continents (n = 60), forty-seven (n = 47) studies reported a positive association between MTHFR (rs1801133) and the risk of developing HTN, whereas the remaining studies (n = 14) did not show a significant association. Available literature suggests an apparent association between rs1801133 and HTN in global regions; however, such information is still scarce in Africa, especially in the black African population.

Functionally significant polymorphisms of the MMP9 gene are associated with primary open-angle glaucoma in the population of Russia

PURPOSE

The aim of this study was to investigate the role of functionally significant loci of the matrix metalloproteinases genes 1, 3, 9 (MMP1, MMP3, and MMP9) in the development of primary open-angle glaucoma (POAG) in Caucasians of the Central region of Russia.

METHODS

In total 604 participants were recruited for the study, including 208 patients with POAG and 396 healthy controls. They were genotyped at eight single nucleotide polymorphisms (SNPs) of the three MMP genes. The association was analyzed using logistic and log-linear regression. POAG-associated loci and their proxies were in silico assessed for their functional prediction.

RESULTS

Variant allele G*rs2250889 of MMP9 was significantly associated with higher risk of POAG (OR_cov = 1.57-1.71). Haplotype CCA [rs3918242-rs3918249-rs17576] of the MMP9 gene was associated with lower risk of POAG (OR_cov = 0.33). Allele А*rs3787268 of MMP9 was associated with the low intraocular pressure in the POAG patients (β_cov = -0.176 - -0.272), and so were haplotypes AA [rs17576-rs3787268] (β_cov = -0.577) and AAC [rs17576-rs3787268- rs2250889] (β_cov = -0.742) of the same gene, whereas allele 2G*rs1799750 of MMP1 was associated with the earlier onset of the disease (β_cov = -0.112 - -0.218). In silico analysis of the polymorphisms suggested the functionality of POAG-associated SNPs and their proxies (epigenetic potential, expression and alternative splicing effects for several genes).

CONCLUSIONS

The MMP9 gene polymorphisms are associated with POAG and intraocular pressure in POAG patients; rs1799750 of MMP1 was associated with the earlier age of manifestation of the disease symptoms.