Comparative study on free radical injury in the endothelium of SHR and WKY aorta

The effect of sesame oil consumption compared to sunflower oil on lipid profile, blood pressure, and anthropometric indices in women with non-alcoholic fatty liver disease: a randomized double-blind controlled trial

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases in the world. There is strong evidence that dyslipidemia and other cardio-metabolic disorders are highly prevalent in patients with NAFLD. This trial aimed at examining the effect of sesame oil (SO) in the context of a weight loss program on lipid profile, blood pressure, and anthropometric indices in women with NAFLD.

METHODS

This randomized, double-blind, controlled trial was carried out on 60 women with NAFLD. Subjects were randomly assigned to the SO group (n = 30) and sunflower oil (SFO) group (n = 30), each person consuming 30 g of oil per day for 12 weeks. All the participants received a hypocaloric diet (- 500 kcal/day) during the study. Lipid profile, blood pressure, and anthropometric indices were assessed at pre- and post-intervention phases.

RESULTS

In total, 53 participants completed the study. Following 12 weeks of intervention, anthropometric indices (p < 0.001) and systolic blood pressure (SBP) (p < 0.05) were significantly decreased in both groups and diastolic blood pressure (DBP) was significantly decreased in So group (p = 0.03). There was no significant change in lipid profile in both groups (p > 0.05). After adjusting for confounders, DBP (p = 0.031) and total cholesterol (TC) divided by high-density lipoprotein cholesterol (HDL-C) (p = 0.039) in the SO group were significantly reduced compared to the SFO group (p < 0.05).

CONCLUSIONS

The present clinical trial revealed that SO and SFO may not differently affect anthropometric indices, SBP, and lipid profile except for TC/HDL-C. In addition, SO may be effective in improvement of DBP and TC/HDL-C compared to the SFO group.

TRIAL REGISTRATION

Ethical approval of this trial was obtained at Isfahan University of Medical Sciences with the reference number of IR.MUI.

RESEARCH

REC.1399.548 ( https://ethics.

RESEARCH

ac.ir/ProposalCertificateEn.php?id=158942&Print=true&NoPrintHeader=true&NoPrintFooter=true&NoPrintPageBorder=true&LetterPrint=true ), and it was registered before the start of the patient recruitment on December 12th, 2020 in the Iranian Registry of Clinical Trials (IRCT) with the registration number of IRCT20140208016529N6 .

The effects of sesame oil on metabolic biomarkers: a systematic review and meta-analysis of clinical trials

Background

Clinical evidences showing the effects of sesame oil on metabolic biomarkers led to inconsistent results.

Propose

This meta-analysis was designed to examine the effects of sesame oil on metabolic biomarkers in adults, including the maximum number of clinical trials.

Methods

Google Scholar, PubMed, Web of Science, and Scopus were systematically searched to date up to July 2021 to identify eligible clinical trial studies. We obtained the pooled estimates of weighted mean differences (WMDs) with their 95% confidence intervals (CIs) using random-effects meta-analysis.

Result

Meta-analysis showed that sesame oil consumption significantly lowered the levels of fasting blood glucose (FBG) (WMD: -3.268 mg/dl; 95% CI: -4.677, -1.86; P < 0.001), and malondialdehyde (MDA) (WMD: -4.847 nmol/dL; 95% CI: -7.051, -2.698; P < 0.001) between the intervention and control groups. Also, this study showed sesame oil consumption significantly decreased HbA1C (WMD: -2.057%; 95% CI: -3.467, -0.646; P = 0.004), systolic blood pressure (SBP) (WMD: -2.679 mmHg; 95% CI: -5.257, -0.101; P < 0.001), diastolic blood pressure (DBP) (WMD: -1.981 mmHg; 95% CI: -3.916, -0.046; P = 0.045), body weight (WMD: -0.346 kg; 95% CI: -0.641, -0.051; P = 0.021), and body mass index (BMI) (WMD: -0.385 kg/m2; 95% CI:-0.721, -0.049; P = 0.025) after intervention. No significant effect was seen in serum insulin levels (p > .05).

Conclusions

The current study provided some evidence regarding the beneficial effects of sesame oil on metabolic biomarkers. Further studies are still required to confirm our results.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-00997-2.

Can sesame consumption improve blood pressure? A systematic review and meta-analysis of controlled trials

Hypertension is a major risk factor for cardiovascular disease, myocardial infarction, stroke and renal failure. Sesame consumption may benefit blood pressure (BP) owing to its high polyunsaturated fatty acid, fibre, phytosterol and lignan contents. To clarify this, a systematic review and meta-analysis of controlled trials was conducted. The PubMed (MEDLINE), Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Cochrane Library (Central) databases were systematically searched until August 2016. Eight controlled trials with a total of 843 participants met the eligibility criteria. A random effect meta-analysis showed that sesame consumption can reduce systolic BP (-7.83 mmHg, 95% CI: -14.12, -1.54; P < 0.05, I²  = 99%) and diastolic BP (-5.83 mmHg, 95% CI: -9.58, -2.08; P < 0.01, I²  = 98%). To reduce the heterogeneity, the meta-analysis was limited to high methodology quality trials (n = 4), which resulted in a significant reduction in systolic BP (-3.23 mmHg, 95% CI: -5.67, -0.79; I²  = 33%) and a non-significant reduction in diastolic BP (-2.08 mmHg, 95% CI: -4.85, 0.69; I²  = 62%). This study concluded that sesame consumption can reduce systolic and diastolic BP. However, further investigations with larger sample sizes and better methodology quality are required to confirm the BP-lowering effect of sesame consumption. © 2017 Society of Chemical Industry.

Effects of the Intake of Sesame Seeds (Sesamum indicum L.) and Derivatives on Oxidative Stress: A Systematic Review

This study is aimed at assessing the scientific evidence on the effect of the intake of sesame seeds and derivatives on oxidative stress of individuals with systemic hypertension, dyslipidemia, and type 2 diabetes mellitus. A systematic review was conducted in seven databases (Lilacs, PubMed, ISI Web of Knowledge, Cochrane Library, Scopus, Trip Database, and Scielo) from September 2013 to January 2014. Clinical trials on the intake of sesame seeds and derivatives assessing the outcomes related to oxidative stress were retrieved. The risk of bias in the results of the studies selected was assessed according to the criteria of the Cochrane Handbook for Systematic Reviews of Interventions. This review included seven clinical trials showing that the intake of sesame resulted in the increase in enzymatic and nonenzymatic antioxidants, as well as in a reduction in oxidative stress markers. This was mainly observed with the use of sesame oil for hypertensive individuals during 2 months and black sesame meal capsules for prehypertensive individuals during four weeks. Most studies involved a small number of participants, sample size being considered a limiting factor for this review. In addition, a significant heterogeneity was observed in the type of population studied and the type of sesame and derivatives used, as well as their amount. The follow-up time was considered a limiting factor, because it varied in the different studies. The high risk of randomization and blinding biases found in the studies assessed determines lower scientific evidence of the results. Despite the limitations and biases identified in this systematic review, sesame showed relevant effects on oxidative stress, suggesting it could increase the antioxidant capacity.

Antihypertensive and antioxidant effects of dietary black sesame meal in pre-hypertensive humans

BACKGROUND

It has been known that hypertension is an independent risk factor for cardiovascular disease (CVD). CVD is the major cause of morbidity and mortality in developed and developing countries. Elevation of blood pressure (BP) increases the adverse effect for cardiovascular outcomes. Prevention of increased BP plays a crucial role in a reduction of those outcomes, leading to a decrease in mortality. Therefore, the purpose of this study was to investigate the effects of dietary black sesame meal on BP and oxidative stress in individuals with prehypertension.

METHODS

Twenty-two women and eight men (aged 49.8 ± 6.6 years) with prehypertension were randomly divided into two groups, 15 subjects per group. They ingested 2.52 g black sesame meal capsules or placebo capsules each day for 4 weeks. Blood samples were obtained after overnight fasting for measurement of plasma lipid, malondialdehyde (MDA) and vitamin E levels. Anthropometry, body composition and BP were measured before and after 4-week administration of black sesame meal or a placebo.

RESULTS

The results showed that 4-week administration of black sesame meal significantly decreased systolic BP (129.3 ± 6.8 vs. 121.0 ± 9.0 mmHg, P < 0.05) and MDA level (1.8 ± 0.6 vs. 1.2 ± 0.6 μmol/L, P < 0.05), and increased vitamin E level (29.4 ± 6.0 vs. 38.2 ± 7.8 μmol/L, P < 0.01). In the black sesame meal group, the change in SBP tended to be positively related to the change in MDA (R = 0.50, P = 0.05), while the change in DBP was negatively related to the change in vitamin E (R = -0.55, P < 0.05). There were no correlations between changes in BP and oxidative stress in the control group.

CONCLUSIONS

These results suggest the possible antihypertensive effects of black sesame meal on improving antioxidant status and decreasing oxidant stress. These data may imply a beneficial effect of black sesame meal on prevention of CVD.

The immune system in the oxidative stress conditions of aging and hypertension: favorable effects of antioxidants and physical exercise

Several studies have shown that both oxidative stress and inflammation are linked to the process of hypertension and that the immune system is also involved in this age-related process. More specifically, the oxygen stress related to immune system dysfunction seems to have a key role in senescence, in agreement with the oxidation/ inflammation theory of aging. From a practical point of view, and according to our own research, the immune functions change in a similar fashion in hypertension and aging. As antioxidant diet supplementation decreases oxidative stress, it may be useful to treat hypertension and increase longevity. Probably, these favorable effects are mediated by an antioxidant-induced improvement of the immune function. The practice of moderate physical exercise shows similar favorable effects, and indeed our studies on exercising hypertensive women demonstrate an improved immune function, probably linked to raised levels of intracellular antioxidant defenses. The present review summarizes a selection of data related to the above from other authors as well as some findings from our own work.

Chronic antioxidant treatment improves sympathetic functions and beta-adrenergic pathway in the spontaneously hypertensive rats

BACKGROUND

Correlations have been found between oxidative stress and hypertension.

OBJECTIVE

To determine whether antioxidants can normalize sympathetic dysfunction at pre- or postsynaptic levels in spontaneously hypertensive rats (SHRs).

METHODS AND RESULTS

Untreated SHRs and Wistar-Kyoto (WKY) rats were compared with rats treated with melatonin (30 mg/kg per day) or N-acetylcysteine (NAC) (4 g/kg per day) given in drinking water for 4 weeks. At the presynaptic level, SHRs had greater plasma noradrenaline concentrations (P <0.01) and an enhanced release of [3H]noradrenaline from isolated atria (P <0.001). At the postsynaptic level, they exhibited an increased proportion of beta2-adrenoceptors in the heart (P <0.001)and a decrease in the chronotropic and mean arterial pressure (MAP) responses to isoproterenol (P <0.001). Melatonin and NAC decreased MAP (P <0.001) and heart rate (P <0.05), and restored the plasma noradrenaline concentrations (P<0.01 and P <0.001, respectively), the chronotropic response to isoproterenol (P <0.05) and the proportions of beta(1)/beta(2)-adrenoceptors in the heart (P <0.05) in SHRs to the levels found in WKY rats. The same treatments decreased the release of [3H]noradrenaline from isolated atria (P <0.05), and melatonin slightly improved the relaxation in the aorta in SHRs only (P <0.05). Plasma concentrations of adrenaline, the isoproterenol-induced relaxation in mesenteric arteries, the total density and affinity of beta-adrenoceptors in the heart, and the adenylate cyclase reactivity of cardiac membranes to isoproterenol, forskolin, sodium fluoride and guanylylimidophosphate were not altered by the treatments.

CONCLUSION

These results suggest that NAC and melatonin decreased the MAP and heart rate and improved the chronotropic response to isoproterenol in SHRs, in association with an inhibition of sympathetic activity and the restoration of cardiac beta-adrenoceptor function.

The effects of melatonin on Ca(2+) homeostasis in endothelial cells

The effect of melatonin on the Ca(2+) signaling process in bovine aortic endothelial cells (BAE) and in primary cultured vascular endothelial cells from normotensive Sprague Dawley (SDR) and genetically hypertensive (SHR) rats was investigated using the Ca(2+) indicator Fura-2. Acute applications of melatonin failed to initiate a Ca(2+) response in the three cell types considered. However, preincubating SHR aortic endothelial cells with exposure to melatonin increased the internal Ca(2+) release triggered by bradykinin (BK) and ATP while stimulating the related agonist-evoked Ca(2+) entry. This effect appeared specific for SHR cells, as a similar incubation period failed to alter the Ca(2+) responses in BAE and SDR cells. Because of the known overproduction of free radicals in SHR cells, the effect of melatonin on Ca(2+) signaling was also tested in SDR and BAE cells exposed to the superoxide anion radical. Melatonin reversed the deleterious action of free radicals on Ca(2+) signaling in both cases, suggesting that its stimulatory effect in SHR was linked to its antioxidative properties. Finally, experiments where melatonin was applied between successive BK stimulation periods showed an enhancement of the agonist-evoked Ca(2+) entry in BAE and SDR cells. This effect appeared to be independent of the production of second messengers as no specific binding sites for melatonin, including MT1, MT2 and MT3 receptors, could be detected in BAE cells. We conclude that melatonin improves Ca(2+) signaling in dysfunctional endothelial cells characterized by an overproduction of free radicals while stimulating the agonist-evoked Ca(2+) entry in normal endothelial cells through a mechanism not related to its antioxidative properties.

AT1 receptor antagonist prevents brain edema without lowering blood pressure

In order to investigate the role of Angiotensin II (AII) for the vasogenic cerebral edema, the AT1 receptor antagonist (TCV-116) was administered to 19-week-old stroke-prone spontaneously hypertensive rats (SHRSP) for 2 weeks at a dosage which did not decrease the blood pressure. Although no remarkable changes were found in blood pressure after treatment, the average brain weight of the treated group was relatively lower as compared to that of control SHRSP and no edematous changes were found in any brains. The immunohistochemical expression of intercellular adhesion molecule-1 (ICAM-1) was less and the glucose transporter-1 (GLUT-1) expression was much more intense in the endothelial cells of the micro vessels in the cerebral cortex of the treated group. Fibrinogen expression around micro-vessels was also remarkably reduced in the treated group. A decreased expression of ICAM-1 in the treated group was confirmed by RT-PCR analysis. These results indicate that the AT1 receptor blockade ameliorates hypertensive cerebral injury in a blood pressure-independent manner and suggest that AII may have an important role for endothelial injury in severe hypertension.

The spontaneously hypertensive rat as a model of human cardiovascular disease: evidence of exacerbated cardiopulmonary injury and oxidative stress from inhaled emission particulate matter

Cardiovascular disease is considered a probable risk factor of particulate matter (PM)-related mortality and morbidity. It was hypothesized that rats with hereditary systemic hypertension and underlying cardiac disease would be more susceptible than healthy normotensive rats to pulmonary injury from inhaled residual oil fly ash (ROFA) PM. Eight spontaneously hypertensive (SH) and eight normotensive Wistar-Kyoto (WKY) rats (12-13 weeks old) were implanted with radiotelemetry transmitters on Day -10 for measurement of electrocardiographic (ECG) waveforms. These and other nonimplanted rats were exposed to filtered air or ROFA (containing leachable toxic levels of metals) on Day 0 by nose-only inhalation (ROFA, 15 mg/m(3) x 6 h/day x 3 days). ECGs were monitored during both exposure and nonexposure periods. At 0 or 18 h post-ROFA exposure, rats were assessed for airway hyperreactivity, pulmonary and cardiac histological lesions, bronchoalveolar lavage fluid (BALF) markers of lung injury, oxidative stress, and cytokine gene expression. Comparisons were made in two areas: (1) underlying cardiopulmonary complications of control SH rats in comparison to control WKY rats; and (2) ROFA-induced cardiopulmonary injury/inflammation and oxidative burden. With respect to the first area, control air-exposed SH rats had higher lung and left ventricular weights when compared to age-matched WKY rats. SH rats had hyporeactive airways to acetylcholine challenge. Lung histology revealed the presence of activated macrophages, neutrophils, and hemorrhage in control SHrats. Consistently, levels of BALF protein, macrophages, neutrophils, and red blood cells were also higher in SH rats. Thiobarbituric acid-reactive material in the BALF of air-exposed SH rats was significantly higher than that of WKY rats. Lung inflammation and lesions were mirrored in the higher basal levels of pulmonary cytokine mRNA expression. Cardiomyopathy and monocytic cell infiltration were apparent in the left ventricle of SH rats, along with increased cytokine expression. ECG demonstrated a depressed ST segment area in SH rats. With regard to the second area of comparison (ROFA-exposed rats), pulmonary histology indicated a slightly exacerbated pulmonary lesions including inflammatory response to ROFA in SH rats compared to WKY rats and ROFA-induced increases in BALF protein and albumin were significantly higher in SH rats than in WKY rats. In addition, ROFA caused an increase in BALF red blood cells in SH rats, indicating increased hemorrhage in the alveolar parenchyma. The number of alveolar macrophages increased more dramatically in SH rats following ROFA exposure, whereas neutrophils increased similarly in both strains. Despite greater pulmonary injury in SH rats, ROFA-induced increases in BALF GSH, ascorbate, and uric acid were attenuated when compared to WKY rats. ROFA inhalation exposure was associated with similar increases in pulmonary mRNA expression of IL-6, cellular fibronectin, and glucose-6-phosphate dehydrogenase (relative to that of beta-actin) in both rat strains. The expression of MIP-2 was increased in WKY but attenuated in SH rats. Thus, SH rats have underlying cardiac and pulmonary complications. When exposed to ROFA, SH rats exhibited exacerbated pulmonary injury, an attenuated antioxidant response, and acute depression in ST segment area of ECG, which is consistent with a greater susceptibility to adverse health effects of fugitive combustion PM. This study shows that the SH rat is a potentially useful model of genetically determined susceptibility with pulmonary and cardiovascular complications.

Myocardial damage due to ischemia and reperfusion in hypertriglyceridemic and hypertensive rats: participation of free radicals and calcium overload

OBJECTIVE

In a model of hypertriglyceridemia and hypertension in rats (HTG), induced by adding refined sugar to the animals' drinking water, we investigated the response to an acute stress, such as ischemia and reperfusion. In addition, we examined the contribution of calcium overload and free radical release to the injury caused by the post-ischemic reperfusion in a pathological state compared with the normal state.

METHODS

Ischemia was induced in the whole anaesthetized animal, by occlusion of the left coronary artery for 4 min, followed by reperfusion for 6 min. To prevent either calcium overload or lipid oxidative processes during reperfusion, either Ketorolac (KET), a calcium ionophore-like drug, or alpha-Phenyl-N-ter-butyl nitrone (PBN), a spin-trapping agent, was administered beforehand.

RESULTS

Ketorolac failed to protect the HTG animals from heart damage, as seen by the incidence of reperfusion dysrhythmias, release of lactate dehydrogenase and creatine kinase to the plasma, and non-recovery of the sinus rhythm. On the other hand, PBN was able to prevent these harmful events in the HTG heart by diminishing lipoperoxidation.

CONCLUSIONS

The results suggest that, in HTG animals, the oxidative processes make a major contribution to the reperfusion injury and that the sole protection from calcium overload provided by KET is not sufficient to avoid damage compared with control rats.