Red blood cell abnormalities and hypertension

Genetic association between gut microbiome and blood pressure and blood cell count as mediator: A two-step Mendelian randomization analysis

BACKGROUND

Previous studies have established a genetic link between gut microbiota and hypertension, but whether blood cell count plays a mediating role in this remains unknown. This study aims to explore genetic associations and causal factors involving the gut microbiome, peripheral blood cell count, and blood pressure.

METHODS

We utilized summary statistics derived from genome-wide association studies to conduct a two-sample mediation Mendelian randomization analysis (https://gwas.mrcieu.ac.uk/). We applied inverse variance weighted (IVW) estimation method as the primary method, along with MR Egger, Weighted median, Simple mode and Weighted mode as complementary methods. To ensure the robustness of the results, several sensitivity analyses were conducted.

RESULTS

Genetic variants significantly associated with the microbiome, blood pressure, or peripheral blood cell counts were selected as instrumental variables. Fourteen microbial taxa were found to have suggestive associations with diastolic blood pressure (DBP), while fifteen microbial taxa showed suggestive associations with systolic blood pressure (SBP). Meanwhile, red blood cell count, lymphocyte count, and platelet count were identified to mediate the influence of the gut microbiome on blood pressure. Specifically, red cell count was identified to mediate the effects of the phylum Cyanobacteria on DBP (mediated proportion: 8.262 %). Lymphocyte count was found mediate the effects of the genus Subdoligranulum (mediated proportion: 2.642 %) and genus Collinsella (mediated proportion: 2.749 %) on SBP. Additionally, platelet count was found to mediate the relationship between the genus Eubacterium ventriosum group and SBP, explaining 3.421 % of the mediated proportion.

CONCLUSIONS

Our findings highlighted that gut microbiota may have causal influence on the blood pressure by modulating blood cell counts, which sheds new light on the pathogenesis and potential clinical interventions through the intricate axis of gut microbiome, blood cell counts, and blood pressure.

Bayesian network-based Mendelian randomization for variant prioritization and phenotypic causal inference

Mendelian randomization is a powerful method for inferring causal relationships. However, obtaining suitable genetic instrumental variables is often challenging due to gene interaction, linkage, and pleiotropy. We propose Bayesian network-based Mendelian randomization (BNMR), a Bayesian causal learning and inference framework using individual-level data. BNMR employs the random graph forest, an ensemble Bayesian network structural learning process, to prioritize candidate genetic variants and select appropriate instrumental variables, and then obtains a pleiotropy-robust estimate by incorporating a shrinkage prior in the Bayesian framework. Simulations demonstrate BNMR can efficiently reduce the false-positive discoveries in variant selection, and outperforms existing MR methods in terms of accuracy and statistical power in effect estimation. With application to the UK Biobank, BNMR exhibits its capacity in handling modern genomic data, and reveals the causal relationships from hematological traits to blood pressures and psychiatric disorders. Its effectiveness in handling complex genetic structures and modern genomic data highlights the potential to facilitate real-world evidence studies, making it a promising tool for advancing our understanding of causal mechanisms.

Effects of Sitting and Supine Positions on Tongue Color as Measured by Tongue Image Analyzing System and Its Relation to Biometric Information

Tongue diagnosis is one of the important diagnostic methods in Kampo (traditional Japanese) medicine, in which the color and shape of the tongue are used to determine the patient's constitution and systemic symptoms. Tongue diagnosis is performed with the patient in the sitting or supine positions; however, the differences in tongue color in these two different positions have not been analyzed. We developed tongue image analyzing system (TIAS), which can quantify tongue color by capturing tongue images in the sitting and supine positions. We analyzed the effects on tongue color in two different body positions. Tongue color was quantified as L∗a∗b∗ from tongue images of 18 patients in two different body positions by taking images with TIAS. The CIEDE 2000 color difference equation (ΔE00) was used to assess the difference in tongue color in two different body positions. Correlations were also determined between ΔE00, physical characteristics, and laboratory test values. The mean and median ΔE00 for 18 patients were 2.85 and 2.34, respectively. Of these patients, 77.8% had a ΔE00 < 4.1. A weak positive correlation was obtained between ΔE00 and systolic blood pressure and fasting plasma glucose. Approximately 80% of patients' tongue color did not change between the sitting and supine positions. This indicates that the diagnostic results of tongue color are trustworthy even if medical professionals perform tongue diagnosis in two different body positions.

Hematological predictors of preeclampsia among pregnant women attending ante-natal clinic at Arba Minch General Hospital, South Ethiopia: A comparative cross-sectional study

Background

Preeclampsia is a kind of pregnancy-related hypertension that affects 5.47 % of pregnancies in Ethiopia and 18.25 % of pregnant women who visit Arba Minch public health facilities for antenatal care. This study sought to identify hematological preeclampsia markers in pregnant women who received prenatal care at Arba Minch General Hospital.

Methodology

An institution-based comparative cross-sectional study was done from July 22 to October 30, 2021 at Arba Minch General Hospital. A total of 136 pregnant women were included in the study (46 with preeclampsia and 90 without preeclampsia). Epidata version 4.4. was used to enter data, and SPSS version 25.0 and Stata version17 were used for analysis. An independent sample t-test was used to examine the hematological parameter differences between study groups. Potential hematological markers were determined using receiver operating characteristic (ROC) analysis of the area under the curve (AUC). Statistical significance was defined if P value less than 0.05.

Results

A total of 136 pregnant women were studied. The complete blood count analysis showed that there were means differences in Red Cell Distribution (RDW) (p < 0.036), neutrophil-to-lymphocyte ratio (NLR) (p < 0.016) and relative lymphocyte count (Lymp%) (p < 0.047). The ROC analysis of the AUC for RDW, NLR and Lymp% resulted in 0.607, 0.609, 0.600 respectively.

Conclusion

RDW, NLR and Lymphocyte count could be potential candidate tools for the diagnosis and screening of preeclampsia. However, the robustness of the markers should be tested with prospective studies assessing changes present in each trimester.

An individualized Bayesian method for estimating genomic variants of hypertension

BACKGROUND

Genomic variants of the disease are often discovered nowadays through population-based genome-wide association studies (GWAS). Identifying genomic variations potentially underlying a phenotype, such as hypertension, in an individual is important for designing personalized treatment; however, population-level models, such as GWAS, may not capture all the important, individualized factors well. In addition, GWAS typically requires a large sample size to detect the association of low-frequency genomic variants with sufficient power. Here, we report an individualized Bayesian inference (IBI) algorithm for estimating the genomic variants that influence complex traits, such as hypertension, at the level of an individual (e.g., a patient). By modeling at the level of the individual, IBI seeks to find genomic variants observed in the individual's genome that provide a strong explanation of the phenotype observed in this individual.

RESULTS

We applied the IBI algorithm to the data from the Framingham Heart Study to explore the genomic influences of hypertension. Among the top-ranking variants identified by IBI and GWAS, there is a significant number of shared variants (intersection); the unique variants identified only by IBI tend to have relatively lower minor allele frequency than those identified by GWAS. In addition, IBI discovered more individualized and diverse variants that explain hypertension patients better than GWAS. Furthermore, IBI found several well-known low-frequency variants as well as genes related to blood pressure that GWAS missed in the same cohort. Finally, IBI identified top-ranked variants that predicted hypertension better than GWAS, according to the area under the ROC curve.

CONCLUSIONS

The results support IBI as a promising approach for complementing GWAS, especially in detecting low-frequency genomic variants as well as learning personalized genomic variants of clinical traits and disease, such as the complex trait of hypertension, to help advance precision medicine.

Prevalence of anemia and associated factors among adult hypertensive patients in Referral Hospitals, Amhara Regional State

Anemia is a risk factor for adverse cardiovascular disease outcomes in hypertensive patients. Chronic anemia increases preload, reduces afterload, and leads to increased cardiac output in hypertension patients. In the long term, this may result in maladaptive left ventricular hypertrophy, which in turn is a well-recognized risk factor for cardiovascular disease outcomes and all-cause mortality in hypertension. Low hemoglobin and hematocrit levels might be strongly indicate hypertensive end-organ damage, specifically kidney failure. Therefore, this study determined the prevalence of anemia and associated factors among hypertensive patients in Referral Hospitals, Amhara Regional State, Ethiopia, in 2020. An institution-based cross-sectional study was conducted in Amhara Regional Referral Hospitals from February 20 to April 30, 2020. Random and systemic sampling techniques were used to select 428 study participants. Data were entered and coded in to Epi data version 3.0 and then exported into STATA 14 for analysis. In bivariable logistic regression, variables with a p-value of < 0.25 were included in multivariable logistic regression. Using a 95% confidence interval, variables having a p-value ≤ 0.05 in multivariable logistic regression were declared as statistically significant variables. In this study, a total of 428 study participants were involved with 99.5% response rate. The prevalence of anemia among hypertensive patients was 17.6%, with a 95% CI (14.3-21.5%). Estimated glomerular filtration rate (eGFR) < 90 ml/min (AOR = 2.77, 95% CI 1.56- 4.92)], duration of hypertension (HTN) ≥ 5 years (AOR = 2.37, 95% CI 1.36-4.15), uncontrolled blood pressure (AOR = 1.91, 95% CI 1.08-3.35), and higher pulse pressure (AOR = 1.05 (95% CI 1.02-1.08) were significantly associated with anemia. Nearly one out of five hypertensive patients had anemia. Impaired estimated glomerular filtration rate, duration of HTN, blood pressure status, and pulse pressure were the independent predictors of anemia among hypertensive patients. Screening hemoglobin level at a regular interval is recommended for the hypertensive patients to take an appropriate intervention.

Cardiomodulatory and Antioxidative Potentials of Almond-Citrus Peel Fortified Shortbread in High Fat Diet/L-NAME-Induced Hyperlipidemic-Hypertensive Rats

In folk medicine, the almond nut (Terminalia catappa) and orange peel (Citrus sinensis) are cost-effective sources of nutraceutical utilized in the treatment of degenerative diseases. Hyperlipidemia and hypertension are two pathological conditions implicated in cardiovascular disorders. This study sought to evaluate the cardiomodulatory effect of almond-citrus peel fortified shortbread in hyperlipidemic-hypertensive rats induced by high fat diet and Nω-nitro-l-arginine methyl ester. The experimental animals were divided into eight groups. The experimental rats were fed with shortbread supplemented with almond and citrus peel at varying inclusions of 0.2% citrus, 50% almond, and almond (50%)- citrus (0.2%) for 21 days. The mean arterial blood pressure (MABP), systolic blood pressure (SBP), and lipid profile of the experimental rats were measured. Thereafter, the activities of angiotensin-1-converting enzyme (ACE), arginase, malondialdehyde (MDA), phosphodiesterase-5, nitric oxide (NO), and antioxidant indices were evaluated. The result showed significant elevation in SBP, MABP, blood cholesterol, triglyceride, ACE, arginase, activities, and MDA levels in the heart tissue of the untreated rats. In contrast, the antioxidant status and NO level were significantly decreased in the untreated groups. Remarkably, the treatment with almond-citrus peel fortified shortbread and the individual effect of almond (50%) and citrus peel (0.2%) all reversed these trends in the hyperlipidemic-hypertensive rats. Intriguingly, the blend of almond (50%)-citrus peel (0.2%) fortified shortbread showed the best antioxidative and cardioprotective effect. The results suggest that almond and citrus peel offer potentials as therapeutic agent in the prevention and management of hyperlipidemia and hypertension.

Gender differences in the associations of circulating erythrocytes and hemoglobin with hypertension risk

OBJECTIVE

Studies on associations of erythrocytes parameters with hypertension risk are scarce. We aimed to examine associations of the erythrocytes parameters with the hypertension risk and potential effect modification by gender using data from the China Health and Nutrition Survey.

METHODS

A total of 5419 eligible participants (2468 men, 45.5%) without hypertension at baseline in 2009 were included and followed for a median of 6.1 years. Parameters of erythrocytes and hemoglobin were measured at baseline. Multivariable Cox proportional hazards models were used to estimate the hazard ratio for the associations between these parameters and hypertension risk. Data were collected from 2009 to 2015 and analyzed in 2021.

RESULTS

A total of 1178 incident cases of hypertension were identified during the follow-up. In women, erythrocytes and hemoglobin were positively associated with risk of hypertension, yielding the highest hazard ratio in the third quartile of 1.59 (95% confidence interval, 1.28-1.97, P trend < 0.001) for erythrocytes and in the fourth quartile of 1.64 (95% confidence interval, 1.23-2.17, P trend < 0.001) for hemoglobin compared with their first quartile, respectively. In addition, quartiles of erythrocytes and hemoglobin were not associated with risk of hypertension in men ( P trend > 0.050).

CONCLUSION

Erythrocytes and hemoglobin were associated with an increased risk of hypertension in women, but not in men. Our findings suggest that special attention for the prevention of hypertension should be given to those women with the moderate to high level of circulating erythrocytes and higher level of hemoglobin.

Proteomic Analysis of the Role of the Adenylyl Cyclase-cAMP Pathway in Red Blood Cell Mechanical Responses

Red blood cell (RBC) deformability is modulated by the phosphorylation status of the cytoskeletal proteins that regulate the interactions of integral transmembrane complexes. Proteomic studies have revealed that receptor-related signaling molecules and regulatory proteins involved in signaling cascades are present in RBCs. In this study, we investigated the roles of the cAMP signaling mechanism in modulating shear-induced RBC deformability and examined changes in the phosphorylation of the RBC proteome. We implemented the inhibitors of adenylyl cyclase (SQ22536), protein kinase A (H89), and phosphodiesterase (PDE) (pentoxifylline) to whole blood samples, applied 5 Pa shear stress (SS) for 300 s with a capillary tubing system, and evaluated RBC deformability using a LORRCA MaxSis. The inhibition of signaling molecules significantly deteriorated shear-induced RBC deformability (p < 0.05). Capillary SS slightly increased the phosphorylation of RBC cytoskeletal proteins. Tyrosine phosphorylation was significantly elevated by the modulation of the cAMP/PKA pathway (p < 0.05), while serine phosphorylation significantly decreased as a result of the inhibition of PDE (p < 0.05). AC is the core element of this signaling pathway, and PDE works as a negative feedback mechanism that could have potential roles in SS-induced RBC deformability. The cAMP/PKA pathway could regulate RBC deformability during capillary transit by triggering significant alterations in the phosphorylation state of RBCs.

Single cell force spectroscopy of erythrocytes at physiological and febrile temperatures reveals mechano-modulatory effects of atorvastatin

RBCs are mechanically active cells and constantly deform as they circulate through vasculature. Their mechanical properties can be significantly altered by various pathophysiological conditions, and the alterations in RBC mechanics can, in turn, have functional consequences. Although numerous mechanical studies have been conducted on RBCs, surprisingly, strain-rate and temperature dependent mechanics of RBCs have not been systematically examined, and current data is primarily based on measurements at room temperature. Here, we have used state-of-the-art single-cell optical tweezers to probe atorvastatin-induced changes of RBC mechanics and its strain-rate dependency at physiologically and medically relevant temperatures. Our data indicate that RBC mechanics is strain-rate and temperature dependent, and atorvastatin treatment softens RBCs at physiological temperature, but not at febrile temperature. The observed mechanical change is a notable side effect of the drug in some therapeutic applications. However, the mechano-modulatory effects of atorvastatin on erythrocytes at physiological temperature might offer new therapeutic possibilities for diseases related to blood cell mechanics.

Erythrocyte Deformability and Na,K-ATPase Activity in Various Pathophysiological Situations and Their Protection by Selected Nutritional Antioxidants in Humans

The physicochemical and functional properties of erythrocytes are worsened in a variety of diseases. Erythrocyte deformability refers to their ability to adjust their shape according to external forces exerted against them in the circulation. It is influenced by the functionality of the Na,K-ATPase enzyme, which is localized in their membranes. The proposed review is focused on knowledge regarding changes in erythrocyte Na,K-ATPase activity, and their impact on erythrocyte deformability in various pathophysiological situations observed exclusively in human studies, as well as on the potential erytroprotective effects of selected natural nutritional antioxidants. A clear link between the erythrocyte properties and the parameters of oxidative stress was observed. The undesirable consequences of oxidative stress on erythrocyte quality and hemorheology could be at least partially prevented by intake of diverse antioxidants occurring naturally in foodstuffs. Despite intensive research concerning the effect of antioxidants, only a small number of investigations on erythrocyte properties in humans is available in databases. It is worth shifting attention from animal and in vitro experiments and focusing more on antioxidant administration in human studies in order to establish what type of antioxidant, in what concentration, and in which individuals it may provide a beneficial effect on the human organism, by protecting erythrocyte properties.

Association of sulfur content in erythrocytes with cardiovascular parameters and blood pressure

OBJECTIVE

The study aims at assessing the relationship between blood pressure, heart geometry parameters, and the erythrocyte content of sulfur, potassium, chlorine and phosphorus, in a group of patients with laboratory systolic and diastolic blood pressure (SBP, DBP) below 140 or 90 mm Hg, respectively, who were otherwise healthy and untreated.

METHODS

The study group consisted of 42 adults recruited in a primary care setting. The individuals were healthy, not undergoing any therapy and free from smoking. For each individual, data were obtained on: average 24-hour SBP and DBP, left ventricle geometry, complete blood count, lipids profile, fibrinogen, hs-CRP and the erythrocyte concentration of sulfur (S), potassium (K), chlorine (Cl) and phosphorus (P).

RESULTS

Multivariate regression analysis showed statistically significant relationships of diastolic posterior wall thickness (PWTd) and relative wall thickness (RWT) with the concentration ratio of sulfur and potassium (S/K) in erythrocytes: PWTd and RWT increase as the S/K ratio increases. Also, SBP was found to be positively correlated with the S/K ratio.

CONCLUSIONS

The increase in sulfur content in RBCs could be an indicator of the downregulation of nitric oxide (NO) erythrocyte bioavailability exerted by endogenously produced hydrogen sulfide (H2S), and, in consequence, a marker of the development of hypertension and/or adverse changes in heart geometry.

Correlation of dynamic membrane fluctuations in red blood cells with diabetes mellitus and cardiovascular risks

The rheological and physiological properties of red blood cells (RBCs) are affected by many factors in the vascular environment. Among them, membrane fluctuations (MFs), particularly dynamic fluctuations in RBC cell membrane thickness (RBC-MFs), are likely to be altered by the level of glycation of haemoglobin in patients with diabetes mellitus (DM). We investigated the associations of RBC-MFs with physiological variables associated with DM and cardiovascular diseases (CVDs). Forty-one healthy control subjects and 59 patients with DM were enrolled. Five-microliter samples of blood were collected and diluted 400 times. To measure the RBC-MFs, holotomography was used, which non-invasively and precisely analyses the optical characteristics of RBCs. Associations between the RBC-MFs and biochemical parameters related to glucose homeostasis and lipid profiles were investigated. Independent associations of the RBC-MFs with the presence of CVDs were also analysed. RBC-MFs were lower in patients with DM than in healthy participants (61.64 ± 7.49 nm vs 70.65 ± 6.65 nm, P = 1.4 × 10⁻⁸). RBC-MFs correlated modestly with glycated haemoglobin level (ρ = − 0.47) and weakly with age (ρ = − 0.36), duration of diabetes (ρ = − 0.36), fasting plasma glucose level (ρ = − 0.37), and the 10-year Framingham risk score (ρ = − 0.38) (all P < 0.05). Low RBC-MFs were independently associated with the presence of CVDs after adjusting for CVD risk factors. The weak but significant associations of RBC-MFs with cardiometabolic risk factors and CVDs suggest that such deformity of circulating RBCs may be a useful marker of vascular complications of DM.

Predialysis and Dialysis Therapies Differently Affect Nitric Oxide Synthetic Pathway in Red Blood Cells from Uremic Patients: Focus on Peritoneal Dialysis

Red blood cells (RBCs) have been found to synthesize and release both nitric oxide (NO) and cyclic guanosine monophosphate (cGMP), contributing to systemic NO bioavailability. These RBC functions resulted impaired in chronic kidney disease (CKD). This study aimed to evaluate whether predialysis (conservative therapy, CT) and dialysis (peritoneal dialysis, PD; hemodialysis, HD) therapies used during CKD progression may differently affect NO-synthetic pathway in RBCs. Our data demonstrated that compared to PD, although endothelial-NO-synthase activation was similarly increased, HD and CT were associated to cGMP RBCs accumulation, caused by reduced activity of cGMP membrane transporter (MRP4). In parallel, plasma cGMP levels were increased by both CT and HD and they significantly decreased after hemodialysis, suggesting that this might be caused by reduced cGMP renal clearance. As conceivable, compared to healthy subjects, plasma nitrite levels were significantly reduced by HD and CT but not in patients on PD. Additionally, the increased carotid intima-media thickness (IMT) values did not reach the significance exclusively in patients on PD. Therefore, our results show that PD might better preserve the synthetic NO-pathway in CKD-erythrocytes. Whether this translates into a reduced development of uremic vascular complications requires further investigation.

Mechanisms Modified by (-)-Epicatechin and Taxifolin Relevant for the Treatment of Hypertension and Viral Infection: Knowledge from Preclinical Studies

Various studies have shown that certain flavonoids, flavonoid-containing plant extracts, and foods can improve human health. Experimental studies showed that flavonoids have the capacity to alter physiological processes as well as cellular and molecular mechanisms associated with their antioxidant properties. An important function of flavonoids was determined in the cardiovascular system, namely their capacity to lower blood pressure and to improve endothelial function. (-)-Epicatechin and taxifolin are two flavonoids with notable antihypertensive effects and multiple beneficial actions in the cardiovascular system, but they also possess antiviral effects, which may be of particular importance in the ongoing pandemic situation. Thus, this review is focused on the current knowledge of (-)-epicatechin as well as (+)-taxifolin and/or (-)-taxifolin-modified biological action and underlining molecular mechanisms determined in preclinical studies, which are relevant not only to the treatment of hypertension per se but may provide additional antiviral benefits that could be relevant to the treatment of hypertensive subjects with SARS-CoV-2 infection.

Improved Erythrocyte Deformability Induced by Sodium-Glucose Cotransporter 2 Inhibitors in Type 2 Diabetic Patients

PURPOSE

Sodium-glucose cotransporter 2 (SGLT-2) inhibitors are antidiabetic drugs that improve cardiovascular outcomes. Hemoglobin and hematocrit values increase after SGLT-2 inhibitor administration. Although these factors increase blood viscosity and the risk of cardiovascular disease, SGLT-2 inhibitors have protective effects on the cardiovascular system. The mechanisms for this paradoxical phenomenon remain unclear, and the effect of SGLT-2 inhibitors on hemorheology has not been studied.

METHODS

We evaluated the hemorheological parameters of 63 patients of whom 38 received metformin with a dipeptidyl peptidase 4 (DPP-4) inhibitor, while 25 received metformin with SGLT-2 inhibitor. Blood viscosity was measured using a cone-and-plate viscometer, erythrocyte aggregation was measured using a modified erythrocyte sedimentation rate method, and erythrocyte membrane fluctuation was measured as deformability, using a diffraction optical tomography.

RESULTS

Both blood viscosity and erythrocyte aggregation increased in the SGLT-2 inhibitor group, although erythrocyte deformability was significantly improved compared with that of the DPP-4 inhibitor group (DPP-4 inhibitor 43.71 ± 5.13 nm; SGLT-2 inhibitor 53.88 ± 4.88 nm; p < 0.001). When the two groups were compared after propensity score matching, no differences in blood viscosity at high shear rates and erythrocyte aggregation were observed, although erythrocyte deformability was significantly improved in the SGLT-2 inhibitor group (DPP-4 inhibitor 45.01 ± 5.28 nm; SGLT-2 inhibitor 53.14 ± 4.72 nm; p = 0.001).

CONCLUSION

This study demonstrates that erythrocyte deformability was improved in the SGLT-2 inhibitor group compared with that in the DPP-4 inhibitor group. This improvement in erythrocyte deformability is expected to have a protective effect on the cardiovascular system.

Effects of caffeine and caffeic acid on selected biochemical parameters in L-NAME-induced hypertensive rats

Biologically active compounds such as caffeine and caffeic acid can be obtained in plants especially cocoa and coffee. Hence, the combinatory effect of caffeine and caffeic acid as well as their individual effect were assessed on the activities of arginase, angiotensin-1-converting enzyme (ACE) as well as nitric oxide (NOx), and malondialdehyde (MDA) level in the Nω-Nitro-L-arginine-methylester (L-NAME)-induced hypertensive rats. The individual and combinatory effect of caffeine and caffeic acid were investigated in L-NAME-induced rats. Animals were grouped into eleven containing six animals each. Hemodynamic parameter was determined by tail-cuff plethysmography. Furthermore, the result showed a notable rise in ACE and arginase activities of L-NAME-induced group compared with the control group. However, pretreatment with test compounds lowered ACE, arginase activities, and MDA content with rise in NOx. This study supports that caffeine and caffeic acid combinations demonstrated antihypertensive properties by lowering the systolic blood pressure in L-NAME-induced rats. PRATICAL APPLICATIONS: This duo bioactive compounds; caffeine (alkaloid) and caffeic acid (phenolic acid) are lavishly distributed in coffee. Their cardiopotective and cardiomodulatory roles have been investigated due to their biological activities. As far as we are aware, this could be foremost in-depth study on the antihypertensive and cardioprotective effect of the combinations of caffeine and caffeic acid targeting the key enzymes system relevant to hypertension. Decreased ACE and arginase activities as well as high nitric oxide (NOx) and low MDA level may be associated with its antihypertensive effect. This present study suggests that the combinations of this phenolics and alkaloid compound might proffer a therapeutic strategy in the management of hypertension.