Protective Effect of Caffeine Administration on Myocardial Ischemia/Reperfusion Injury in Rats

Chlorogenic acid rich in coffee pulp extract suppresses inflammatory status by inhibiting the p38, MAPK, and NF-κB pathways

Coffee pulp (CP) is a coffee byproduct that contains various active ingredients, namely, chlorogenic acid (CGA) and caffeine. These active compounds show several benefits, including antihyperlipidemia, antioxidants, and anti-inflammation. However, the anti-inflammatory properties of Coffea pulp extract (CPE) are unknown. This work determined the impact of CPE on lipopolysaccharide (LPS)-activated murine macrophage cells and the molecular mechanism behind this action. RAW 264.7 cells were exposed to varying doses of CPE with or without LPS. Inflammatory markers and their mechanism were studied. CPE therapy has been shown to suppress the synthesis of inflammatory cytokines and mediators, namely, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), IL-1β, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and nitric oxide (NO), as well as prostaglandin E2 (PGE₂). Finally, CPE inactivated the nuclear factor-kappa B (NF-κB) and MAPK signaling pathways. Consequently, CPE might be used as a nutraceutical to treat inflammation and its related disorders.

Caffeine and bronchopulmonary dysplasia: Clinical benefits and the mechanisms involved

Bronchopulmonary dysplasia (BPD) is a chronic respiratory disease that occurs during the neonatal period and is commonly associated with prematurity. This condition results in a severe economic burden on society and the families involved. Caffeine is used not only for the treatment of apnea in prematurity, but also for the prevention of BPD. There are multiple clinical benefits of caffeine treatment, including improved extubation success, a reduced duration of mechanical ventilation, improved lung function, and a reduction of patent ductus arteriosus requiring treatment. These clinical benefits of caffeine for the treatment of BPD are supported by both clinical trials and evidence from animal models. However, the mechanism by which caffeine protects against BPD remains unclear. Here, we review the clinical value of caffeine in the prevention of BPD and its potential mechanisms of action, including anti-inflammatory, antioxidant, antifibrotic, and antiapoptotic properties, the regulation of angiogenesis, and diuretic effects. Our aim is to provide a new theoretical basis for the clinical treatment of BPD.

Caffeine: cardiorespiratory effects and tissue protection in animal models

The aim of this review is to analyze the cardiorespiratory and tissue-protective effects of caffeine in animal models. Peer-reviewed literature published between 1975 and 2021 was retrieved from CAB Abstracts, PubMed, ISI Web of Knowledge, and Scopus. Extracted data were analyzed to address the mechanism of action of caffeine on cardiorespiratory parameters (heart rate and rhythm), vasopressor effects, and some indices of respiratory function; we close this review by discussing the current debate on the research carried out on the effects of caffeine on tissue protection. Adenosine acts through specific receptors and is a negative inotropic and chronotropic agent. Blockage of its cardiac receptors can cause tachycardia (with arrhythmogenic potential) due to the intense activity of β1 receptors. In terms of tissue protection, caffeine inhibits hyperoxia-induced pulmonary inflammation by decreasing proinflammatory cytokine expression in animal models. The protection that caffeine provides to tissues is not limited to the CNS, as studies have demonstrated that it generates attenuation of inflammatory effects in pulmonary tissue. It inhibits the effects of some pro-inflammatory cytokines and prevents functional and structural changes.

Efficacy of Alkaloids in Alleviating Myocardial Ischemia-Reperfusion Injury in Rats: A Meta-Analysis of Animal Studies

Background

Animal models are well established for studying the effects of alkaloids in preventing myocardial ischemia-reperfusion injury. However, few studies have investigated the therapeutic effects of alkaloids in humans. This meta-analysis and systematic review assessed the efficacy of alkaloids in attenuating infarct size in rats with myocardial ischemia-reperfusion injury.

Methods

An integrated literature search including the PubMed, Embase, and Cochrane Library databases was performed to identify studies that evaluated the therapeutic effects of alkaloids on myocardial ischemia-reperfusion injury in rats. The main outcome was infarct size, and SYRCLE's risk of bias tool was used to assess the quality of the studies.

Results

22 studies were brought into the meta-analysis. Compared with the effects of vehicle, alkaloids significantly reduced infarct size (standardized mean difference (SMD) = -0.45; 95% confidence interval (CI) = -0.64 to - 0.26). In subgroup analyses, isoquinoline alkaloids (SMD = -0.43; 95%CI = -0.70 to - 0.16) significantly reduced infarct size versus the control.

Conclusion

Isoquinoline alkaloids can potentially alleviate myocardial ischemia-reperfusion injury. This meta-analysis and systematic review supply a reference for research programs aiming to develop alkaloid-based clinical drugs. This trial is registered with CRD42019135489.

Caloric restriction mimetics for the treatment of cardiovascular diseases

Caloric restriction mimetics (CRMs) are emerging as potential therapeutic agents for the treatment of cardiovascular diseases. CRMs include natural and synthetic compounds able to inhibit protein acetyltransferases, to interfere with acetyl coenzyme A biosynthesis, or to activate (de)acetyltransferase proteins. These modifications mimic the effects of caloric restriction, which is associated with the activation of autophagy. Previous evidence demonstrated the ability of CRMs to ameliorate cardiac function and reduce cardiac hypertrophy and maladaptive remodelling in animal models of ageing, mechanical overload, chronic myocardial ischaemia, and in genetic and metabolic cardiomyopathies. In addition, CRMs were found to reduce acute ischaemia-reperfusion injury. In many cases, these beneficial effects of CRMs appeared to be mediated by autophagy activation. In the present review, we discuss the relevant literature about the role of different CRMs in animal models of cardiac diseases, emphasizing the molecular mechanisms underlying the beneficial effects of these compounds and their potential future clinical application.

QiShenYiQi Pills® ameliorates ischemia/reperfusion-induced myocardial fibrosis involving RP S19-mediated TGFβ1/Smads signaling pathway

QiShenYiQi Pills (QSYQ) is a compound Chinese medicine widely used in China for treatment of cardiovascular disease. However, limited data are available regarding the anti-fibrotic role of QSYQ after ischemia/reperfusion (I/R) injury. This study aimed to investigate the effect of post-treatment with QSYQ on myocardial fibrosis after I/R-induced myocardium injury, and the role of different compounds of QSYQ, focusing especially on the involvement of chemokine ribosomal protein S19 (RP S19) dimer and monocyte migration. Male Sprague-Dawley rats were subjected to left anterior descending coronary artery occlusion for 30 min followed by reperfusion with or without administration of QSYQ (0.6, 1.2, or 1.8 g/kg) once daily by gavage for 6 days. Post-treatment with QSYQ diminished I/R-induced infarct size, alleviated myocardium injury, attenuated myocardial fibrosis after 6 days of reperfusion, and restored heart function and myocardial blood flow after I/R. In addition, the drug significantly inhibited monocyte infiltration and macrophage polarization towards M2, which was attributable to chemokine RP S19 dimer. Moreover, Western blots revealed that QSYQ blocked I/R-induced increase in TGFβ1 and TGFβRⅡ and reversed its relevant gene expression, such as Smad3,4,6,7, and inhibited the increase of MMP 2,9 expression. As the major components of QSYQ, astragaloside IV (AsIV), 3,4-dihydroxy-phenyl lactic acid (DLA), and notoginsenoside R1 (R1) were assessed as to the contribution of each of them to the expression of the proteins concerned. The results showed that the effect of AsIV was similar to QSYQ, while DLA and R1 only partly simulated the effect of QSYQ. The results provide evidence for the potential role of QSYQ in treating myocardial fibrosis following I/R injury. This effect may be associated with QSYQ's inhibition effect on monocyte chemotaxis and TGFβ1/Smads signaling pathway with different component targeting distinct link (s) of the signaling.

Molecular Docking for Active Compounds of Scurrula Atropurpurea as Anti-inflammatory Candidate in Endometriosis

INTRODUCTION

Endometriosis is still a problem for women all over the world. There are no studies that apply herbs, especially Scurrula atropurpurea to inhibit the development of inflammation in endometriosis.

AIM

The purpose of this study was to analyze the docking of active ingredient of Scurrula atropurpurea on NFkB-IkB complex with IKK in silico way.

MATERIAL AND METHODS

The nine active ingredients of Scurrula atropurpurea analyzed here were including aviculin (CID 10391477), caffeine (CID 2519), catechin (CID: 9064), epicatechin (CID: 72276), kaempferol (CID 5280863), quercetin (CID 5280343), quercitrin (CID 5280459)), rutin (CID 5280805), and theobromine (CID 5429). The sequence of study procedures included searching for amino acid sequences and active plant component structures, protein 3D structure modeling, docking and analysis of protein-ligand interaction.

RESULTS

Regarding the NFkB-IkB complex, it was found that all active ingredients can interact where the strongest interaction sequence was rutin (-314.35 kJ/mol). Regarding the interaction between IKK and NFkB-IkB, the nine active ingredients can reduce bond energy, except rutin.

CONCLUSIONS

the active ingredients of Scurrula atropurpurea having the potential effect as anti-inflammatory is rutin so that it can be isolated and used as an alternative ingredient in inhibiting inflammation in endometriosis.

Coffee consumption and risk of myocardial infarction: a dose-response meta-analysis of observational studies

Background

Previous epidemiological studies have provided inconsistent conclusions on the effect of coffee consumption in the development of myocardial infarction (MI). The aim of the study was to evaluate the influence of coffee consumption and its potential dose-response patterns on the risk of developing MI.

Materials and Methods

Three databases were searched for evidence of eligible studies. A random-effects model was used to pool the fully adjusted odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). Dose-response analysis was performed to show the effect of each cup increased in daily coffee drinking on the risk of MI.

Results

Seventeen studies involving 233,617 participants were included in our study. The association between coffee consumption and risk of MI did not show statistical significance when pooling the outcome data for the coffee consumption categories of 1~2 vs. < 1 cup per day (OR = 1.06, 95% CI: 0.94–1.19) and 2~3 vs. < 1 cup per day (OR = 1.07, 95% CI: 0.94–1.23). Compared with < 1 cup, daily drinking of 3~4 cups and > 4 cups of coffee were significantly associated with the risk of MI, and the pooled ORs (95% CIs) were 1.40 (1.11–1.77) and 1.48 (1.22–1.79), respectively. The dose–response analysis showed a “J–shaped” curve relationship of the risk of MI with coffee consumption.

Conclusions

Daily drinking of more than three cups of coffee was associated with a significantly increased risk of MI. This positive association was only found in men but not in women. The impact of gender on this association should be further evaluated.

Caffeine Improves Heart Rate Without Improving Sepsis Survival

INTRODUCTION

Caffeine is consumed on a daily basis for its nervous system stimulant properties and is a global adenosine receptor antagonist. Because adenosine receptors have been found to play a major role in regulating the immune response to a septic insult, we investigated if caffeine consumption prior to a septic insult would alter immunological and physiological responses, as well as survival.

METHODS

Two separate experimental designs were used, both using outbred female ICR mice. In the first experiment, mice were administered 20 mg/kg of caffeine (equal to 2-3 cups of coffee for a human) or normal saline intraperitoneally at the time of cecal ligation and puncture (CLP). Immunological parameters including cytokines and local cell recruitment were measured. In the second experiment, caffeine (10 mg/kg per hour) was delivered continuously for 24 h via a subcutaneous infusion pump placed the day prior to CLP, and hemodynamic parameters were examined. In both experiments, survival was followed for 5 days.

RESULTS

A single dose of caffeine at the initiation of sepsis did not alter survival. This single dose of caffeine did significantly increase in plasma levels of the chemokine KC 6 h after the onset of sepsis compared with septic mice given normal saline. There were no changes in interleukin 6 (IL-6) or IL-10 levels in the caffeine groups. Peritoneal lavages performed 24 h after CLP showed no difference in the levels of IL-6, tumor necrosis factor, KC, macrophage inflammatory protein 1, IL-10, or the IL-1 receptor antagonist between caffeine- and normal saline-treated mice. In addition, the lavages yielded similar numbers of cells (4.1 × 10 vehicle vs. 6.9 × 10 caffeine) and bacterial colony-forming units (CFUs, 4.1 million CFUs vehicle vs. 2.8 million CFUs caffeine). In the infusion group, caffeine also did not alter survival. However, caffeine infusion did increase the heart rate prior to CLP and prevented the decline in heart rate after CLP.

CONCLUSION

Caffeine increased the heart rate in mice but does not impact cytokine responses or survival during the acute phase of a polymicrobial sepsis challenge. These data indicate that patients consuming caffeine will not be at risk for increased sepsis mortality.

Caffeine and cardiovascular diseases: critical review of current research

Caffeine is a most widely consumed physiological stimulant worldwide, which is consumed via natural sources, such as coffee and tea, and now marketed sources such as energy drinks and other dietary supplements. This wide use has led to concerns regarding the safety of caffeine and its proposed beneficial role in alertness, performance and energy expenditure and side effects in the cardiovascular system. The question remains "Which dose is safe?", as the population does not appear to adhere to the strict guidelines listed on caffeine consumption. Studies in humans and animal models yield controversial results, which can be explained by population, type and dose of caffeine and low statistical power. This review will focus on comprehensive and critical review of the current literature and provide an avenue for further study.

Caffeine Mitigates Lung Inflammation Induced by Ischemia-Reperfusion of Lower Limbs in Rats

Reperfusion of ischemic limbs can induce inflammation and subsequently cause acute lung injury. Caffeine, a widely used psychostimulant, possesses potent anti-inflammatory capacity. We elucidated whether caffeine can mitigate lung inflammation caused by ischemia-reperfusion (IR) of the lower limbs. Adult male Sprague-Dawley rats were randomly allocated to receive IR, IR plus caffeine (IR + Caf group), sham-operation (Sham), or sham plus caffeine (n = 12 in each group). To induce IR, lower limbs were bilaterally tied by rubber bands high around each thigh for 3 hours followed by reperfusion for 3 hours. Caffeine (50 mg/kg, intraperitoneal injection) was administered immediately after reperfusion. Our histological assay data revealed characteristics of severe lung inflammation in the IR group and mild to moderate characteristic of lung inflammation in the IR + Caf group. Total cells number and protein concentration in bronchoalveolar lavage fluid of the IR group were significantly higher than those of the IR + Caf group (P < 0.001 and P = 0.008, resp.). Similarly, pulmonary concentrations of inflammatory mediators (tumor necrosis factor-α, interleukin-1β, and macrophage inflammatory protein-2) and pulmonary myeloperoxidase activity of the IR group were significantly higher than those of the IR + Caf group (all P < 0.05). These data clearly demonstrate that caffeine could mitigate lung inflammation induced by ischemia-reperfusion of the lower limbs.

Effects of apocynin, an NADPH oxidase inhibitor, on levels of ADMA, MPO, iNOS and TLR4 induced by myocardial ischemia reperfusion

PURPOSE

In this study, the effects of apocynin, an NADPH oxidase inhibitor, on the levels of inducible nitric oxide synthase (iNOS) and the toll-like receptor 4 (TLR4), which are inflammatory mediators in myocardial ischemia-reperfusion (MIR) injury, and myeloperoxidase (MPO), which is the indicator of neutrophil infiltration and the endogenous nitric oxide synthase inhibitor asymmetric dimethyl arginine (ADMA) increasing with oxidative stress were investigated.

METHODS

MIR injury was accomplished by the application of occlusion for 30 minutes and reperfusion for 120 minutes in the left anterior descending artery (LAD). In the study, 21 Sprague-Dawley male rats were divided into three groups: a sham group (n = 7); a MIR group (n = 7); and a MIR + apocynin treatment group (n = 7, before the procedure, an intraperitoneal administration of 10 mg/kg of apocynin for 15 days). After reperfusion, iNOS, TLR4, MPO and ADMA levels in myocardial tissue were measured by ELISA.

RESULTS

While myocardial TLR4, MPO and ADMA levels increased in the MIR group, these parameters were found to be decreased significantly in the group treated with apocynin. Although iNOS levels showed an increase in the MIR group compared to the sham group and a reduction in the MIR+apocynin group, there was no statistically significant difference between the groups.

DISCUSSION

In our study, the effect of the treatment of apocynin in MIR on ADMA, MPO, iNOS and TLR4 levels in myocardial tissue was shown for the first time. It is thought that apocynin treatment may show a protective effect in MIR injury by affecting oxidative stress (ADMA) and inflammatory parameters (iNOS, MPO).

Cardiovascular effects of long-term caffeine administration in aged rats

AIM

To evaluate the possible beneficial effect of long-term caffeine administration on cardiovascular system in aged rats.

METHODS

This study was carried out on 20 senile male albino rats, aged 18-20 months. Rats were divided into caffeine-treated group, which received 25 mg/kg caffeine by gavage daily for 6 weeks, and control group. All rats were subjected to the following in vivo measurements: body weight, arterial blood pressure, heart rate and ECG recording. In vitro measurements included studying isolated hearts in a Langendorff apparatus for their intrinsic properties as well as plasma levels of lipids, malondialdehyde and nitrate.

RESULTS

Caffeine administration to aged rats significantly enhanced the baseline and maximum values achieved in response to isoproterenol infusion in isolated heart preparation for both maximum rate of tension development (dT/dt max) and time to peak tension (TPT). The responses of hearts isolated from caffeine group to the three doses of isoproterenol infusion also showed a significantly higher dT/dt max with shorter TPT and half relaxation time (1/2 RT) compared to controls. Plasma nitrate was significantly increased and ECG recording was nonsignificantly affected in caffeine group. The plasma levels of total cholesterol, LDL cholesterol as well as in vivo heart rate and systolic, diastolic and mean arterial blood pressures were all significantly increased associated with a significant decrease in HDL cholesterol in caffeine group.

CONCLUSION

Long-term caffeine administration in aged rats increased cardiac inotropy, lusitropy and preserved NO level, which points to a promising potential favorable effect on cardiac intrinsic properties.

Coffee consumption and periodontal disease in males

BACKGROUND

Coffee is a major dietary source of antioxidants as well as of other anti-inflammatory factors. Given the beneficial role of such factors in periodontal disease, whether coffee intake is associated with periodontal disease in adult males was explored.

METHODS

Existing data collected by a prospective, closed-panel cohort study of aging and oral health in adult males was used. Participants included the 1,152 dentate males in the Veterans Affairs (VA) Dental Longitudinal Study who presented for comprehensive medical and dental examinations from 1968 to 1998. Mean age at baseline was 48 years; males were followed for up to 30 years. Participants are not VA patients; rather, they receive their medical and dental care in the private sector. Periodontal status was assessed by probing depth (PD), bleeding on probing, and radiographic alveolar bone loss (ABL), measured on intraoral periapical radiographs with a modified Schei ruler method. Moderate-to-severe periodontal disease was defined as cumulative numbers of teeth exhibiting PD ≥4 mm or ABL ≥40%. Coffee intake was obtained from participant self-reports using the Cornell Medical Index and food frequency questionnaires. Multivariate repeated-measures generalized linear models estimated mean number of teeth with moderate-to-severe disease at each examination by coffee intake level.

RESULTS

It was found that higher coffee consumption was associated with a small but significant reduction in number of teeth with periodontal bone loss. No evidence was found that coffee consumption was harmful to periodontal health.

CONCLUSION

Coffee consumption may be protective against periodontal bone loss in adult males.

Increased poly(ADP-ribosyl)ation in peripheral leukocytes and the reperfused myocardium tissue of rats with ischemia/reperfusion injury: prevention by 3-aminobenzamide treatment

The overactivation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP) is considered a final common effector in ischemia/reperfusion (I/R) injury. The aim of the current study was to examine the precise time course of the activation of PARP in peripheral leukocytes and the reperfused myocardium tissue on myocardial I/R injury from the same rat and to identify the relationship between myocardial infarct size and the degree of PARP activation in circulating leukocytes. Another aim of the study was to test the effect of 3-aminobenzamide (a well-known and widely used PARP inhibitor) on the activation of PARP in the reperfused myocardium and peripheral leukocytes. Poly(ADP-ribose) polymerase activation was measured by Western blotting for its product, poly(ADP-ribose) (PAR). The localization of PARP activation was determined by PAR immunohistochemistry. The results showed that poly(ADP-ribosyl)ation was detected 15 min, peaked 2 to 6 h, and remained markedly detectable 24 h in the reperfused heart after I/R model. Similarly, PAR content of the leukocytes increased in cells isolated just after reperfusion from the same rat. Immunohistochemical studies localized the staining of PAR primarily to the cardiac myocytes and vascular endothelial cells. At 6 h, there was a significant linear correlation between infarct size and PARP activity, whereas at 2 and 24 h, no relationship was found. The PARP inhibitor 3-aminobenzamide (3-AB, 20 mg kg⁻¹ i.v. injection 15 min before reperfusion, and every 2 h thereafter for 6 h) markedly reduced infarct size through depressing the activation of the enzyme in myocytes and peripheral leukocytes even when the treatment is initiated at 2 h after reperfusion.