The Cardioprotective Effect of Protocatechuic Acid on Myocardial Ischemia/Reperfusion Injury

Protocatechuic aldehyde increases pericyte coverage and mitigates pericyte damage to enhance the atherosclerotic plaque stability

Pericyte dysfunction and loss contribute substantially to the destabilization and rupture of atherosclerotic plaques. Protocatechuic aldehyde (PCAD), a natural polyphenol, exerts anti-atherosclerotic effects. However, the effects and mechanisms of this polyphenol on pericyte recruitment, coverage, and pericyte function remain unknown. We here treated apolipoprotein E-deficient mice having high-fat diet-induced atherosclerosis with PCAD. PCAD achieved therapeutic effects similar to rosuvastatin in lowering lipid levels and thus preventing atherosclerosis progression. With PCAD administration, plaque phenotype exhibited higher stability with markedly reduced lesion vulnerability, which is characterized by reduced lipid content and macrophage accumulation, and a consequent increase in collagen deposition. PCAD therapy increased pericyte coverage in the plaques, reduced VEGF-A production, and inhibited intraplaque neovascularization. PCAD promoted pericyte proliferation, adhesion, and migration to mitigate ox-LDL-induced pericyte dysfunction, which thus maintained the capillary network structure and stability. Furthermore, TGFBR1 silencing partially reversed the protective effect exerted by PCAD on human microvascular pericytes. PCAD increased pericyte coverage and impeded ox-LDL-induced damages through TGF-β1/TGFBR1/Smad2/3 signaling. All these novel findings indicated that PCAD increases pericyte coverage and alleviates pericyte damage to improve the stability of atherosclerotic plaques, which is accomplished by regulating TGF-β1/TGFBR1/Smad2/3 signaling in pericytes.

Leonurine pretreatment protects the heart from myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion (I/R), an important complication of reperfusion therapy for myocardial infarction, is characterized by hyperactive oxidative stress and inflammatory response. Leonurine (4-guanidino-n-butyl syringate, SCM-198), an alkaloid extracted from Herbaleonuri, was previously found to be highly cardioprotective both in vitro and in vivo. Our current study aimed to investigate the effect of SCM-198 preconditioning on myocardial I/R injury in vitro and in vivo, respectively, as well as to decipher the mechanism involved. Rats were pretreated with SCM-198 before subjected to 45 min of myocardial ischemia, which was followed by 24 h of reperfusion. Primary neonatal rat cardiac ventricular myocytes (NRCMs) were exposed to hypoxia (95% N2 + 5% CO2) for 12 h, and then to 12 h reoxygenation so as to mimic I/R. The enzymatic measurements demonstrated that SCM-198 reduced the release of infarction-related enzymes, and the hemodynamic and echocardiography measurements showed that SCM-198 restored cardiac functions, which suggested that SCM-198 could significantly reduce infarct size, maintaining cardiomyocyte morphology, and that SCM-198 pretreatment could significantly reduce cardiomyocytes apoptosis. Moreover, we demonstrated that SCM-198 could exert a cardioprotective effect by reducing reactive oxygen species (ROS) level and Akt phosphorylation while reducing the phosphorylation of p38 and JNK. In addition, the upregulation of p-Akt, Bcl-2/Bax induced by SCM-198 treatment were blocked by PI3K inhibitor LY294002, and the total protein level of Akt was not affected by SCM-198 pretreatment. Our experimental results indicated that SCM-198 could have a cardioprotective effect on I/R injury, which confirmed the utility of SCM-198 preconditioning as a strategy to prevent I/R injury.

Protective effects of protocatechuic acid against doxorubicin- and arsenic trioxide-induced toxicity in cardiomyocytes

Background and purpose

Some chemotherapeutic drugs are associated with an increased risk of cardiotoxicity in patients. Protocatechuic acid (PCA) is a phenolic acid with valuable cardiovascular, chemo-preventive, and anticancer activities. Recent studies have shown the cardioprotective effects of PCA in several pathological conditions. This investigation aimed to assess the possible protective effects of PCA on cardiomyocytes against toxicities caused by anti-neoplastic agents, doxorubicin (DOX), and arsenic trioxide (ATO).

Experimental approach

H9C2 cells were exposed to DOX (1 μM) or ATO (35 μM) after 24 h pretreatment with PCA (1-100 μM). MTT and lactate dehydrogenase (LDH) tests were used to define cell viability or cytotoxicity. Total oxidant and antioxidant capacities were evaluated by measuring hydroperoxides and ferric-reducing antioxidant power (FRAP) levels. Expression of the TLR4 gene was also quantitatively estimated by real-time polymerase chain reaction.

Findings/Results

PCA showed a proliferative effect on cardiomyocytes and significantly enhanced cell viability and reduced cytotoxicity of DOX and ATO during MTT and LDH assays. Pretreatment of cardiomyocytes with PCA significantly decreased hydroperoxide levels and elevated FRAP value. Moreover, PCA meaningfully decreased TLR4 expression in DOX-and ATO-treated cardiomyocytes.

Conclusions and implications

In conclusion, antioxidant and cytoprotective activities were found for PCA versus toxicities caused by DOX and ATO in cardiomyocytes. However, further in vivo investigations are recommended to assess its clinical value for the prevention and treatment of cardiotoxicity induced by chemotherapeutic agents.

Protocatechuic acid reverses myocardial infarction mediated by β-adrenergic agonist via regulation of Nrf2/HO-1 pathway, inflammatory, apoptotic, and fibrotic events

Myocardial infarction (MI) is an instant ischemic death of cardiomyocytes that remains a major global cause of mortalities. MI is accompanied by oxidative, inflammatory, apoptotic, and fibrotic insults. Protocatechuic acid (PCA) is a polyphenolic compound with various potent biological activities. In this study, we explored the possible cardioprotective role of PCA against isoproterenol (ISO)-mediated MI. Rats were either injected with ISO (85 mg/kg, subcutaneously) or pretreated with PCA (100 or 200 mg/kg, orally). PCA supplementation markedly normalized ISO-induced disturbed cardiac function markers (creatine kinase-MB, lactate dehydrogenase, and troponin T). Notably, PCA administration exerted remarkable increases in glutathione and its derived enzymes, superoxide dismutase, and catalase, as well as decreases in malondialdehyde and nitric oxide levels in the injured cardiac tissue. The molecular findings validated the augmented cellular antioxidative capacity by PCA via increasing the gene expressions of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1. The cardioprotective efficacy of PCA extended to suppress cardiac inflammation as demonstrated by the decreased levels of tumor necrosis factor-alpha, interleukin-1 beta, and nuclear factor kappa B. Additionally, PCA prevented cardiomyocyte loss and fibrosis by decreasing Bax, caspase-3, transforming growth factor-β1 and matrix metalloproteinase-9, and enhancing B-cell lymphoma 2 and tissue inhibitors of metalloproteinase-3. The cardiac histological screening further confirmed the PCA's protective action. The obtained data recommend PCA as an alternative therapeutic agent to attenuate the molecular, biochemical, and histological alterations associated with MI development.

Bioactive Compounds (BACs): A Novel Approach to Treat and Prevent Cardiovascular Diseases

Cardiovascular diseases (CVDs) are one of the leading disorders of serious death and cause huge economic loss to patients and society. It is estimated that about 18 million people have a high death ratio due to the incidence of CVDs such as (stroke, coronary heart disease, and non-ischemic heart failure). Bioactive compounds (BACs) are healthy nutritional ingredients providing beneficial effects and nutritional value to the human body. Epidemiological studies strongly shed light on several bioactive compounds that are favorable candidates for CVDs treatment. Globally, the high risk of CVDs and related results on human body parts made them a serious scenario in all communities. In this present review, we intend to collect previously published data concerned over the years concerning green-colored foods and their BACs that aim to work in the prevention, diagnosis, and/or systematic treating CVDs. We also comprehensively discussed the oral delivery of several bioactive compounds derived from fruits and vegetables and their bioavailability and physiological effects on human health. Moreover, their important characteristics, such as anti-inflammatory, lowering blood pressure, anti-obesity, antioxidant, anti-diabetics, lipid-lowering responses, improving atherosclerosis, and cardioprotective properties, will be elaborated further. More precisely, medicinal plants' advantages and multifaceted applications have been reported in this literature to treat CVDs. To the best of our knowledge, this is our first attempt that will open a new window in the area of CVDs with the opportunity to achieve a better prognosis and effective treatment for CVDs.

Cardioprotective Effects of Vitex negundo: A Review of Bioactive Extracts and Compounds

There has been accumulating interest in the application of medicinal plants as alternative medicine to treat various diseases and/or to develop modern medicines. Vitex negundo is one of such medicinal plants that has been of interest to many researchers and has been of use in traditional medicine. V. negundo is found in Sri Lanka, Madagascar, Malaysia, India, China, The Philippines and East Africa. Therapeutic properties of V. negundo have previously been reviewed. Different parts, preparations and bioactive components of V. negundo possess potential protective and therapeutic effects against cardiovascular disease and related conditions as demonstrated in previous studies. We review the present state of scientific knowledge on the potential use of V. negundo and some of its bioactive components in protecting against cardiovascular diseases and related pathologies. Previous studies in animal and non-animal experimental models, although limited in number and vary in design, seem to support the cardioprotective effect of V. negundo and some of its active components. However, there is need for further preclinical and clinical studies to validate the use of V. negundo and its active constituents in protection and treatment of cardiovascular diseases. Additionally, since only a few V. negundo compounds have been evaluated, specific cardioprotective effects or mechanisms and possible side effects of other V. negundo compounds need to be extensively evaluated.

In Vitro Antithrombotic, Hematological Toxicity, and Inhibitor Studies of Protocatechuic, Isovanillic, and p-Hydroxybenzoic Acids from Maclura Tricuspidata (Carr.) Bur

In blood coagulation, circulating platelets and coagulation factors are crucial for the primary process because thrombi are generated by fibrin clotting with fibrinogen, thrombin, FXIIIa, and platelet activation. Therefore, strategies to reduce the activity of key coagulation factors, or interfere with their functions and delay the activation of platelets can be used as important tools to suppress excessive blood clot formation and platelet hyperactivation. This study examined the antithrombotic activity and hematological toxicity of PA, IVA, and 4-HA isolated from M. tricuspidata (Carr.) Bur in several in vitro experiments and inhibitor assays. We found that PA, IVA, and 4-HA attenuated the formation of fibrin polymers/clots and degraded the blood clots. These compounds inhibited the activities of procoagulant proteases and fibrinoligase, and prolonged the coagulation time. There was a significant reduction in platelet function and ATP or serotonin levels in thrombin-activated platelets. An inhibitor study showed that PA exhibited a mixed inhibition type for thrombin, an uncompetitive inhibition type for FXa, and a non-competitive inhibition type for FXIIIa and IVA, while 4-HA exhibited an uncompetitive inhibition type for thrombin and non-competitive inhibition type for FXa and FXIIIa. These three compounds (up to 50 μg/mL) were not toxic to blood cells.

Insight into the Role of the PI3K/Akt Pathway in Ischemic Injury and Post-Infarct Left Ventricular Remodeling in Normal and Diabetic Heart

Despite the significant decline in mortality, cardiovascular diseases are still the leading cause of death worldwide. Among them, myocardial infarction (MI) seems to be the most important. A further decline in the death rate may be achieved by the introduction of molecularly targeted drugs. It seems that the components of the PI3K/Akt signaling pathway are good candidates for this. The PI3K/Akt pathway plays a key role in the regulation of the growth and survival of cells, such as cardiomyocytes. In addition, it has been shown that the activation of the PI3K/Akt pathway results in the alleviation of the negative post-infarct changes in the myocardium and is impaired in the state of diabetes. In this article, the role of this pathway was described in each step of ischemia and subsequent left ventricular remodeling. In addition, we point out the most promising substances which need more investigation before introduction into clinical practice. Moreover, we present the impact of diabetes and widely used cardiac and antidiabetic drugs on the PI3K/Akt pathway and discuss the molecular mechanism of its effects on myocardial ischemia and left ventricular remodeling.

Physiological Effects of Green-Colored Food-Derived Bioactive Compounds on Cardiovascular and Metabolic Diseases

Cardiovascular and metabolic diseases are a leading cause of death worldwide. Epidemiological studies strongly highlight various benefits of consuming colorful fruits and vegetables in everyday life. In this review, we aimed to revisit previous studies conducted in the last few decades regarding green-colored foods and their bioactive compounds in consideration of treating and/or preventing cardiovascular and metabolic diseases. This review draws a comprehensive summary and assessment of research on the physiological effects of various bioactive compounds, mainly polyphenols, derived from green-colored fruits and vegetables. In particular, their health-beneficial effects, including antioxidant, anti-inflammatory, anti-diabetic, anti-obesity, cardioprotective, and lipid-lowering properties, will be discussed. Furthermore, the bioavailability and significance of action of these bioactive compounds on cardiovascular and metabolic diseases will be discussed in detail.

Role of Phaseolus vulgaris L. in the Prevention of Cardiovascular Diseases-Cardioprotective Potential of Bioactive Compounds

In terms of safe and healthy food, beans play a relevant role. This crop belongs to the species of Phaseolusvulgaris L., being the most consumed legume worldwide, both for poor and developed countries, the latter seek to direct their diet to healthy feeding, mainly low in fat. Phaseolus vulgaris L. stands out in this area-an important source of protein, vitamins, essential minerals, soluble fiber, starch, phytochemicals, and low in fat from foods. This species has been attributed many beneficial properties for health; it has effects on the circulatory system, immune system, digestive system, among others. It has been suggested that Phaseolus vulgaris L. has a relevant role in the prevention of cardiovascular events, the main cause of mortality and morbidity worldwide. Conversely, the decrease in the consumption of this legume has been related to an increase in the prevalence of cardiovascular diseases. This review will allow us to relate the nutritional level of this species with cardiovascular events, based on the correlation of the main bioactive compounds and their role as cardiovascular protectors, in addition to revealing the main mechanisms that explain the cardioprotective effects regulated by the bioactive components.

Antioxidant Effects of Protocatechuic Acid and Protocatechuic Aldehyde: Old Wine in a New Bottle

Phenolic compounds are naturally present as secondary metabolites in plant-based sources such as fruits, vegetables, and spices. They have received considerable attention for their antioxidant, anti-inflammatory, and anti-carcinogenic properties for protection against many chronic disorders such as neurodegenerative diseases, diabetes, cardiovascular diseases, and cancer. They are categorized into various groups based on their chemical structure and include phenolic acids, flavonoids, curcumins, tannins, and quinolones. Their structural variations contribute to their specific beneficial effects on human health. The antioxidant property of phenolic compounds protects against oxidative stress by up-regulation of endogenous antioxidants, scavenging free radicals, and anti-apoptotic activity. Protocatechuic acid (PCA; 3,4-dihydroxy benzoic acid) and protocatechuic aldehyde (PAL; 3,4-dihydroxybenzaldehyde) are naturally occurring polyphenols found in vegetables, fruits, and herbs. PCA and PAL are the primary metabolites of anthocyanins and proanthocyanidins, which have been shown to possess pharmacological actions including antioxidant activity in vitro and in vivo. This review aims to explore the therapeutic potential of PCA and PAL by comprehensively summarizing their pharmacological properties reported to date, with an emphasis on their mechanisms of action and biological properties.

Novel Co-crystal of Pentoxifylline and Protocatechuic Acid Relieves Allodynia in Rat Models of Peripheral Neuropathic Pain and CRPS by Alleviating Local Tissue Hypoxia

Local tissue ischemic hypoxia is a peripheral process that can be targeted with topical treatment to alleviate pain under chronic pain conditions such as complex regional pain syndrome (CRPS) and peripheral neuropathic pain. We recently reported three novel salts and a co-crystal composed of vasoactive agents and antioxidant nutraceuticals, all of which produced potent topical anti-allodynic effects in the chronic postischemic pain (CPIP) rat model of CRPS. One of the products, pentx-pca, is a co-crystal synthesized from pentoxifylline (pentx) and protocatechuic acid (pca). Pentx-pca exhibited potent topical anti-allodynic effects in CPIP and rats with chronic constriction injury of the sciatic nerve exceeding effects produced individually by pentx and pca. We hypothesized that the anti-allodynic effects of pentx-pca in CPIP rats were due to its impact on local tissue oxygenation and subsequent oxygen-dependent mitochondrial respiration. Percutaneous tissue oxygen saturation (SaO₂) measurements taken from the hind paw of the CPIP rats revealed that anti-allodynic doses of topical pentx-pca increased local tissue SaO₂. Moreover, assessment of the oxygen-dependent mitochondrial function using a triphenyl tetrazolium chloride assay revealed that mitochondrial dysfunction significantly declined in the plantar muscle collected from CPIP rats topically treated with anti-allodynic doses of pentx-pca as compared to vehicle-treated CPIP rats. Furthermore, time-dependent resolution of plantar muscle mitochondrial dysfunction, that occurred in the CPIP rats at 6-week post procedure, paralleled the loss of the anti-allodynic response to topical treatment with pentx-pca. Our results indicated that pentx-pca produced potent anti-allodynic effects in the CPIP rat model of CRPS by alleviating peripheral tissue ischemia/hypoxia and downstream hypoxia-driven mitochondrial dysfunction.

Protective Effects Induced by a Hydroalcoholic Allium sativum Extract in Isolated Mouse Heart

The aim of the present study was to investigate the possible protective effects of a garlic hydroalcoholic extract on the burden of oxidative stress and inflammation occurring on mouse heart specimens exposed to E. coli lipopolysaccharide (LPS), which is a well-established inflammatory stimulus. Headspace solid-phase microextraction combined with the gas chromatography-mass spectrometry (HS-SPME/GC-MS) technique was applied to determine the volatile fraction of the garlic powder, and the HS-SPME conditions were optimized for each of the most representative classes of compounds. CIEL*a*b* colorimetric analyses were performed on the powder sample at the time of delivery, after four and after eight months of storage at room temperature in the dark, to evaluate the color changing. Freshly prepared hydroalcoholic extract was also evaluated in its color character. Furthermore, the hydroalcoholic extract was analyzed through GC-MS. The extract was found to be able to significantly inhibit LPS-induced prostaglandin (PG) E₂ and 8-iso-PGF_2α levels, as well as mRNA levels of cyclooxygenase (COX)-2, interleukin (IL)-6, and nuclear factor-kB (NF-kB), in heart specimens. Concluding, our findings showed that the garlic hydroalcoholic extract exhibited cardioprotective effects on multiple inflammatory and oxidative stress pathways.

Protocatechuic Acid Prevents Early Hour Ischemic Reperfusion Brain Damage by Restoring Imbalance of Neuronal Cell Death and Survival Proteins

OBJECTIVE

To investigate the neuroprotective effect of protocatechuic acid (PCA) on cell death/survival protein imbalance in a rat model of middle cerebral artery occlusion and reperfusion.

METHODS

Focal ischemia was induced by middle cerebral artery occlusion in adult male Wistar rats and confirmed by measuring infarction of brain by 2,3,5-Triphenyltetrazolium chloride (TTC) staining. Rats were treated with vehicle or PCA at 10, 30 or 50 mg/kg dose intraperitoneally and subjected to neurological deficits or beam walk assessment at 24 h of reperfusion. Effective dose of PCA (50 mg/kg) was administered at 1, 2 and 3 h time point of post-ictus ischemia. Cellular damage and nuclear condensation was observed by haematoxylin and eosin (H and E) staining and Hoechst 33342 staining respectively. Additionally, immunohistochemical expression of caspase 3 and cAMP-response element binding protein (CREB) and their mRNA's were observed.

RESULTS

PCA at 30 and 50 mg/kg significantly improved behavioural performance and reduced infarction. Maximum neuroprotective effect of PCA (50 mg/kg) was found at 1 h (early hours) post-ictus ischemia along with reduction in cellular damage and nuclear condensation. PCA increased CREB protein and it's mRNA, while suppressed caspase-3 protein and mRNA at 1 h of reperfusion injury.

CONCLUSION

PCA exhibit the potential to prevent early hour (1h) reperfusion injury restoring balance of survival and death protein may offer a cost effective adjuvant therapy in stroke.

A review of myocardial ischaemia/reperfusion injury: Pathophysiology, experimental models, biomarkers, genetics and pharmacological treatment

Cardiovascular diseases are known to be the most fatal diseases worldwide. Ischaemia/reperfusion (I/R) injury is at the centre of the pathology of the most common cardiovascular diseases. According to the World Health Organization estimates, ischaemic heart disease is the leading global cause of death, causing more than 9 million deaths in 2016. After cardiovascular events, thrombolysis, percutaneous transluminal coronary angioplasty or coronary bypass surgery are applied as treatment. However, after restoring coronary blood flow, myocardial I/R injury may occur. It is known that this damage occurs due to many pathophysiological mechanisms, especially increasing reactive oxygen types. Besides causing cardiomyocyte death through multiple mechanisms, it may be an important reason for affecting other cell types such as platelets, fibroblasts, endothelial and smooth muscle cells and immune cells. Also, polymorphonuclear leukocytes are associated with myocardial I/R damage during reperfusion. This damage may be insufficient in patients with co-morbidity, as it is demonstrated that it can be prevented by various endogenous antioxidant systems. In this context, the resulting data suggest that optimal cardioprotection may require a combination of additional or synergistic multi-target treatments. In this review, we discussed the pathophysiology, experimental models, biomarkers, treatment and its relationship with genetics in myocardial I/R injury. SIGNIFICANCE OF THE STUDY: This review summarized current information on myocardial ischaemia/reperfusion injury (pathophysiology, experimental models, biomarkers, genetics and pharmacological therapy) for researchers and reveals guiding data for researchers, especially in the field of cardiovascular system and pharmacology.

Protocatechuic Acid Inhibits Vulnerable Atherosclerotic Lesion Progression in Older Apoe-/- Mice

BACKGROUND

Normalization of arterial inflammation inhibits atherosclerosis. The preventive role for protocatechuic acid (PCA) in early-stage atherosclerosis is well recognized; however, its therapeutic role in late-stage atherosclerosis remains unexplored.

OBJECTIVE

We investigated whether PCA inhibits vulnerable atherosclerosis progression by normalizing arterial inflammation.

METHODS

Thirty-wk-old male apolipoprotein E-deficient (Apoe-/-) mice with vulnerable atherosclerotic lesions in the brachiocephalic artery were fed the AIN-93G diet alone (control) or supplemented with 0.003% PCA (wt:wt) for 20 wk. Lesion size and composition, IL-1β, and NF-κB in the brachiocephalic arteries, and serum lipid profiles, oxidative status, and proinflammatory cytokines (e.g., IL-1β, monocyte chemoattractant protein-1, and serum amyloid A) were measured. Moreover, the effect of PCA on the inflammation response was evaluated in efferocytic macrophages from C57BL/6J mice.

RESULTS

Compared with the control treatment, dietary PCA supplementation significantly reduced lesion size (27.5%; P < 0.05) and also improved lesion stability (P < 0.05) as evidenced by increased thin fibrous cap thickness (31.7%) and collagen accumulation (58.3%), reduced necrotic core size (37.6%) and cellular apoptosis (73.9%), reduced macrophage accumulation (45.1%), and increased vascular smooth muscle cell accumulation (51.5%). Moreover, PCA supplementation inhibited IL-1β expression (53.7%) and NF-κB activation (64.4%) in lesions. However, PCA supplementation did not change serum lipid profiles, total antioxidant capacity, and inflammatory cytokines. In efferocytic macrophages, PCA at 0.5 and 1 μmol/L inhibited Il1b/IL-1β mRNA (27.2-46.5%) and protein (29.2-49.6%) expression and NF-κB activation (67.0-80.3%) by upregulation of MER proto-oncogene tyrosine kinase (MERTK) and inhibition of mitogen-activated protein kinase 3/1 (MAPK3/1). Strikingly, the similar pattern of the MERTK and MAPK3/1 changes in lesional macrophages of mice after PCA intervention in vivo was recapitulated.

CONCLUSION

PCA inhibits vulnerable lesion progression in mice, which might partially be caused by normalization of arterial inflammation by upregulation of MERTK and inhibition of MAPK3/1 in lesional macrophages.

Screening of cardioprotective diseases bioactive components from Danshen extracts and LC-MS analysis

A rapid and efficient analysis and screening method is adopted for cell affinity capture coupled with HPLC-MS (CAC-HPLC-MS) analysis of bioactive components that have possible efficiency against cardiovascular diseases. This method involves affinity capture, concentration, and separation of bioactive components from Danshen library using oxidatively damaged endothelial cells induced by H₂ O₂ , as well as analysis and identification of targeted compounds with HPLC and MS. It combines the specific interaction between cell membrane receptors and bioactive components with the powerful analysis and identification function of HPLC-MS. The CAC-HPLC-MS method was also used for analysis and screening of bioactive components from crude extracts of Danshen. A total of 19 components were found to be bound to oxidatively damaged endothelial cells with seven of these identified. Existing literature confirms that these seven components have many activities related to cardioprotective diseases. Therefore, the combination of biological affinity capture with HPLC-MS should be regarded as an attractive method with great potential for rapid and efficient screening of bioactive components related to anti-cardiovascular diseases from natural product libraries.

Protocatechuic acid attenuates β‑secretase activity and okadaic acid‑induced autophagy via the Akt/GSK‑3β/MEF2D pathway in PC12 cells

Okadaic acid (OA) can be used to induce an Alzheimer's disease (AD) model characterized by tau hyperphosphorylation, the formation of neurofibrillary tangles formation and β‑amyloid (Aβ) deposition. Previous studies have shown that the upregulation of Beclin‑1‑dependent autophagy may contribute to the elimination of aggregated Aβ. However, the effects of protocatechuic acid (PA) on the levels of Aβ42, phosphorylated (p)‑tau and β‑secretase in OA‑induced cell injury are unclear, and little is known concerning the role of the PA signaling pathway in the regulation of autophagy. The present study aimed to determine whether PA protects cells from OA‑induced cytotoxicity via the regulation of Beclin‑1‑dependent autophagy and its regulatory signaling pathway. PC12 cells were treated with OA with or without PA for 24 h. Enzymatic assays were performed to measure p‑tau, Aβ42 and β‑secretase activity. Western blotting was performed to detect p‑Akt, p‑glycogen synthase kinase‑3β (p‑GSK‑3β), Akt, GSK‑3β, myocyte enhancer factor 2D (MEF2D) and Beclin‑1 protein expression levels. Immunofluorescence and immunocytochemistry were used to measure Beclin‑1 expression levels. The results from this study showed that PA could increase cell viability and significantly decrease the levels of Aβ42, p‑tau, β‑secretase and Beclin‑1. PA can also promote the expression of p‑Akt and MEF2D while suppressing the expression of p‑GSK‑3β. These results indicated that PA protects PC12 cells from OA‑induced cytotoxicity, and attenuates autophagy via regulation of the Akt/GSK‑3β/MEF2D pathway, therefore potentially contributing to the neuroprotective effects of PA against OA toxicity. These findings suggested that PA may have potential as a drug candidate in preventative AD therapy.

miR-208b targets Bax to protect H9c2 cells against hypoxia-induced apoptosis

BACKGROUND

miR-208 family members have been considered as promising biomarkers in myocardial infarction (MI). Among which, miR-208a and miR-499 are reported to function as ischemic injury promoting miRNAs. This study aimed to explore the in vitro function of miR-208b in MI, which has not been widely studied.

METHODS

RT-qPCR was conducted to measure the expression changes of miR-208b in MI patients, MI mouse model and H9c2 cells stimulated by hypoxia. H9c2 cells were subjected to hypoxia before which miR-208b expression was altered by transfection. CCK-8, flow cytometry and Western blot were performed to detect cell survival. Besides, the regulatory relationship between miR-208b, Bax, and PI3K/AKT was tested by luciferase reporter, RT-qPCR and Western blot.

RESULTS

Serum levels of miR-208b in MI patients were significantly higher than those in the healthy controls. Also, miR-208b was up-regulated in mouse model and cell model of MI. Overexpression of miR-208b protected H9c2 cells against hypoxia-induced apoptosis, as the viability was increased, apoptosis rate was decreased, Bax and Cytochrome c were down-regulated, and Bcl-2 was up-regulated. Bax was a target gene of miR-208b. And miR-208b could not protect H9c2 cells when Bax was overexpressed. More interestingly, miR-208b activated PI3K/AKT pathway via targeting Bax, and the activated PI3K/AKT pathway could further repress Bax expression. Finally, blocking PI3K/AKT pathway by using LY294002 eliminated the myocardioprotective effects of miR-208b.

CONCLUSION

miR-208b is highly expressed during MI, and miR-208b protects H9c2 cells against hypoxia-induced apoptosis. miR-208b exerts myocardioprotective effect via targeting Bax and activating PI3K/AKT pathway.

Salvia miltiorrhizaBurge (Danshen): a golden herbal medicine in cardiovascular therapeutics

Salvia miltiorrhiza Burge (Danshen) is an eminent medicinal herb that possesses broad cardiovascular and cerebrovascular protective actions and has been used in Asian countries for many centuries. Accumulating evidence suggests that Danshen and its components prevent vascular diseases, in particular, atherosclerosis and cardiac diseases, including myocardial infarction, myocardial ischemia/reperfusion injury, arrhythmia, cardiac hypertrophy and cardiac fibrosis. The published literature indicates that lipophilic constituents (tanshinone I, tanshinone IIa, tanshinone IIb, cryptotanshinone, dihydrotanshinone, etc) as well as hydrophilic constituents (danshensu, salvianolic acid A and B, protocatechuic aldehyde, etc) contribute to the cardiovascular protective actions of Danshen, suggesting a potential synergism among these constituents. Herein, we provide a systematic up-to-date review on the cardiovascular actions and therapeutic potential of major pharmacologically active constituents of Danshen. These bioactive compounds will serve as excellent drug candidates in small-molecule cardiovascular drug discovery. This article also provides a scientific rationale for understanding the traditional use of Danshen in cardiovascular therapeutics.

The Role of the Gut Microbiota in the Metabolism of Polyphenols as Characterized by Gnotobiotic Mice

A growing body of experimental data suggests that microbes in the gut influence behavior and can alter brain physiology and neurochemistry. Although promising, researchers are only starting to understand the potential of the gut microbiota for use in neurological disease. Recent evidence demonstrated that gastrointestinal activities are linked to mood disorders such as anxiety, depression, and most recently, cognitive functions in age-related neurodegenerative disorders. Studies from our group and others are uncovering new evidence suggesting that the gut microbiota plays a crucial role in the metabolism and bioavailability of certain dietary compounds and synthetic drugs. Based on this evidence, this review article will discuss the implications of the gut microbiota in mechanisms of bioavailability and biotransformation with an emphasis on dietary polyphenol compounds. This will be followed by a survey of ongoing innovative research identifying the ability of individual gut bacteria to enhance the bioavailability of gut-derived, brain-penetrating, bioactive polyphenol metabolites that ultimately influence mechanisms associated with the promotion of resilience against psychological and cognitive impairment in response to stress. Lastly, current research initiatives aimed at promoting the generation of brain bioactive polyphenol metabolites by specialized gut microbes will be discussed, specifically the use of gnotobiotic mice to develop bioengineered second generation probiotics. We propose that leveraging the gut microbial ecosystem to generate brain targeted bioactive metabolites from dietary polyphenols can attenuate lifestyle risk factors and promote resilience against age-related cognitive decline.

Acacetin protects against cardiac remodeling after myocardial infarction by mediating MAPK and PI3K/Akt signal pathway

Since inhibiting cardiac remodeling is a critical treatment goal after myocardial infarction (MI), many drugs have been evaluated for this purpose. Acacetin is a flavonoid compound that has been shown to have anti-cancer, anti-mutagenic, anti-inflammatory and anti-peroxidative effects. In this study, we investigated whether acacetin is able to exert a protective effect against MI. One week after anterior wall standard MI surgeries or sham surgeries were performed in mice, acacetin was administered via gavage for two weeks. The results of echocardiographic and hemodynamic evaluation revealed that cardiac dysfunction significantly improved after acacetin treatment. H&E staining indicated that the ratio of the infarct size and the cardiomyocyte cross-sectional area was decreased by acacetin. Masson's staining detected that the fibrotic area ratio was evidently lower in the acacetin-treated MI group. TUNEL assays showed that acacetin ameliorated cardiomyocyte apoptosis after MI. RT-qPCR analysis showed that levels of hypertrophic and fibrotic markers were significantly decreased after acacetin treatment. Western blot analysis of various signaling pathway proteins showed that acacetin targets the MAPK and PI3K/Akt signaling pathways. Collectively, acacetin improves mouse left ventricular function and attenuates cardiac remodeling by inhibiting of the MAPK and PI3K/Akt signaling pathway.

Luteolin Exerts Cardioprotective Effects through Improving Sarcoplasmic Reticulum Ca(2+)-ATPase Activity in Rats during Ischemia/Reperfusion In Vivo

The flavonoid luteolin exists in many types of fruits, vegetables, and medicinal herbs. Our previous studies have demonstrated that luteolin reduced ischemia/reperfusion (I/R) injury in vitro, which was related with sarcoplasmic reticulum Ca²⁺-ATPase (SERCA2a) activity. However, the effects of luteolin on SERCA2a activity during I/R in vivo remain unclear. To investigate whether luteolin exerts cardioprotective effects and to monitor changes in SERCA2a expression and activity levels in vivo during I/R, we created a myocardial I/R rat model by ligating the coronary artery. We demonstrated that luteolin could reduce the myocardial infarct size, lactate dehydrogenase release, and apoptosis during I/R injury in vivo. Furthermore, we found that luteolin inhibited the I/R-induced decrease in SERCA2a activity in vivo. However, neither I/R nor luteolin altered SERCA2a expression levels in myocardiocytes. Moreover, the PI3K/Akt signaling pathway played a vital role in this mechanism. In conclusion, the present study has confirmed for the first time that luteolin yields cardioprotective effects against I/R injury by inhibiting the I/R-induced decrease in SERCA2a activity partially via the PI3K/Akt signaling pathway in vivo, independent of SERCA2a protein level regulation. SERCA2a activity presents a novel biomarker to assess the progress of I/R injury in experimental research and clinical applications.

Protocatechuic acid ameliorates neurocognitive functions impairment induced by chronic intermittent hypoxia

Chronic intermittent hypoxia (CIH) is a serious consequence of obstructive sleep apnoea (OSA) and has deleterious effects on central neurons and neurocognitive functions. This study examined if protocatechuic acid (PCA) could improve learning and memory functions of rats exposed to CIH conditions and explore potential mechanisms. Neurocognitive functions were evaluated in male SD rats by step-through passive avoidance test and Morris water maze assay following exposure to CIH or room air conditions. Ultrastructure changes were investigated with transmission electron microscopy, and neuron apoptosis was confirmed by TUNEL assays. Ultrastructure changes were investigated with transmission electron microscope and neuron apoptosis was confirmed by TUNEL assays. The effects of PCA on oxidative stress, apoptosis, and brain IL-1β levels were investigated. Expression of Bcl-2, Bax, Cleaved Caspase-3, c-fos, SYN, BDNF and pro-BDNF were also studied along with JNK, P38 and ERK phosphorylation to elucidate the molecular mechanisms of PCA action. PCA was seen to enhance learning and memory ability, and alleviate oxidative stress, apoptosis and glial proliferation following CIH exposure in rats. In addition, PCA administration also decreased the level of IL-1β in brain and increased the expression of BDNF and SYN. We conclude that PCA administration will ameliorate CIH-induced cognitive dysfunctions.

Silymarin Constituent 2,3-Dehydrosilybin Triggers Reserpine-Sensitive Positive Inotropic Effect in Perfused Rat Heart

2,3-dehydrosilybin (DHS) is a minor flavonolignan component of Silybum marianum seed extract known for its hepatoprotective activity. Recently we identified DHS as a potentially cardioprotective substance during hypoxia/reoxygenation in isolated neonatal rat cardiomyocytes. This is the first report of positive inotropic effect of DHS on perfused adult rat heart. When applied to perfused adult rat heart, DHS caused a dose-dependent inotropic effect resembling that of catecholamines. The effect was apparent with DHS concentration as low as 10 nM. Suspecting direct interaction with β-adrenergic receptors, we tested whether DHS can trigger β agonist-dependent gene transcription in a model cell line. While DHS alone was unable to trigger β agonist-dependent gene transcription, it enhanced the effect of isoproterenol, a known unspecific β agonist. Further tests confirmed that DHS could not induce cAMP accumulation in isolated neonatal rat cardiomyocytes even though high concentrations (≥ 10 μM) of DHS were capable of decreasing phosphodiesterase activity. Pre-treatment of rats with reserpine, an indole alkaloid which depletes catecholamines from peripheral sympathetic nerve endings, abolished the DHS inotropic effect in perfused hearts. Our data suggest that DHS causes the inotropic effect without acting as a β agonist. Hence we identify DHS as a novel inotropic agent.

Therapeutic and Prophylactic Potential of Morama (Tylosema esculentum): A Review

Tylosema esculentum (morama) is a highly valued traditional food and source of medicine for the San and other indigenous populations that inhabit the arid to semi-arid parts of Southern Africa. Morama beans are a rich source of phenolic acids, flavonoids, certain fatty acids, non-essential amino acids, certain phytosterols, tannins and minerals. The plant's tuber contains griffonilide, behenic acid and starch. Concoctions of extracts from morama bean, tuber and other local plants are frequently used to treat diarrhoea and digestive disorders by the San and other indigenous populations. Information on composition and bioactivity of phytochemical components of T. esculentum suggests that the polyphenol-rich extracts of the bean testae and cotyledons have great potential as sources of chemicals that inhibit infectious microorganisms (viral, bacterial and fungal, including drug-resistant strains), offer protection against certain non-communicable diseases and promote wound healing and gut health. The potential antinutritional properties of a few morama components are also highlighted. More research is necessary to reveal the full prophylactic and therapeutic potential of the plant against diseases of the current century. Research on domestication and conservation of the plant offers new hope for sustainable utilisation of the plant.

Identification of schisandrin as a vascular endothelium protective component in YiQiFuMai Powder Injection using HUVECs binding and HPLC-DAD-Q-TOF-MS/MS analysis

YiQiFuMai Powder Injection (YQFM) is a re-developed preparation based on the well-known traditional Chinese medicine formula Sheng-mai-san. It has been widely used for the treatment of cardiovascular disease with definite clinical efficacy in China, but its bioactive molecules remain obscure. In this study, an effective method has been employed as a tool for screening active components in YQFM, using human umbilical vein endothelial cells (HUVECs) extraction and liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS). Nine compounds, which could interact with HUVECs, were identified as ginsenosides Rb1, Rc, Rb2, Rd, 20(S)-Rg3, 20(R)-Rg3, Rk1/Rg5 and schisandrin by comparing with reference substances or literature. In vitro assays showed that schisandrin at concentrations of 10-100 μM protected HUVECs from hypoxia/reoxygenation (H/R) injury, increased cell viability, nitric oxide (NO) content and decreased lactate dehydrogenase (LDH) leakage, malonaldehyde (MDA) content and ROS generation. Moreover, schisandrin pretreatment inhibited cell apoptosis, as evidenced by inhibiting activation of caspase-3 and increasing the Bcl-2/Bax ratio. These data indicate that HUVECs biospecific extraction coupled with HPLC-ESI-Q-TOF-MS/MS analysis is a reliable method for screening potential bioactive components from traditional Chinese medicines. Meanwhile, the vascular endothelium protective property of schisandrin might be beneficial for the treatment of cardiovascular disease.