lignans and Stroke

Polyphenols are an important family of molecules of vegetal origin present in many medicinal and edible plants, which represent important alimentary sources in the human diet. Polyphenols are known for their beneficial health effects and have been investigated for their potential protective role against various pathologies, including cancer, brain dysfunctions, cardiovascular diseases and stroke. The prevention of stroke promoted by polyphenols relies mainly on their effect on cardio- and cerebrovascular systems. However, a growing body of evidence from preclinical models of stroke points out a neuroprotective role of these molecules. Notably, in many preclinical studies, the polyphenolic compounds were effective also when administered after the stroke onset, suggesting their possible use in promoting recovery of patients suffering from stroke. Here, we review the effects of the major polyphenols in cellular and in vivo models of both ischemic and hemorrhagic stroke in immature and adult brains. The results from human studies are also reported.

Topics: Animals; Brain Ischemia; Cerebral Hemorrhage; Diarylheptanoids; Ellagic Acid; Flavonoids; Gastrointestinal Microbiome; Humans; Hydrolyzable Tannins; Hydroxybenzoates; Lignans; Polyphenols; Stilbenes; Stroke; Subarachnoid Hemorrhage

Epidemiologic and biological evidence supports an inverse association between polyphenol consumption and the risk of cardiovascular disease (CVD). However, no previous studies have prospectively evaluated the relationship between polyphenol intake and the incidence of CVD in such a comprehensive way. The aim was to evaluate the association between intakes of total polyphenol and polyphenol subgroups, and the risk of major cardiovascular events (myocardial infarction, stroke or death from cardiovascular causes) in the PREDIMED study.. The present work is an observational study within the PREDIMED trial. Over an average of 4.3 years of follow-up, there were 273 confirmed cases of CVD among the 7172 participants (96.3%) who completed a validated 137-item food frequency questionnaire (FFQ) at baseline. Polyphenol consumption was calculated by matching food consumption data from the FFQ with the Phenol-Explorer database on polyphenol content of each reported food. After multivariate adjustment, a 46% reduction in risk of CVD risk was observed comparing Q5 vs. Q1 of total polyphenol intake (HR = 0.54; 95% confidence interval [CI] = 0.33-0.91; P-trend = 0.04). The polyphenols with the strongest inverse associations were flavanols (HR = 0.40; CI 0.23-0.72; P-trend = 0.003), lignans (HR = 0.51; CI 0.30-0.86; P-trend = 0.007), and hydroxybenzoic acids (HR = 0.47; CI 0.26-0.86; P-trend 0.02).. Greater intake of polyphenols, especially from lignans, flavanols, and hydroxybenzoic acids, was associated with decreased CVD risk. Clinical trials are needed to confirm this effect and establish accurate dietary recommendations.

Topics: Age Factors; Aged; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Cardiovascular Diseases; Cohort Studies; Diet, Mediterranean; Female; Flavonols; Follow-Up Studies; Humans; Hydroxybenzoates; Incidence; Lignans; Male; Middle Aged; Myocardial Infarction; Nuts; Olive Oil; Plant Oils; Risk Factors; Spain; Stroke

The neuroprotective role of schizandrin (SA) in cerebral ischemia-reperfusion (I/R) was recently highlighted. However, whether SA plays a regulatory role on autophagy in cerebral I/R injury is still unclear. This study aimed to explore whether the neuroprotective mechanisms of SA were linked to its regulation of AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/autophagy pathway in vivo and in vitro. The present study confirmed that SA significantly improved oxygen-glucose deprivation/re-oxygenation (OGD/R)-induced PC12 cells injury. The results of immunoblotting and confocal microscope showed that SA decreased autophagy in OGD/R-injured PC12 cells, which was reflected by the decreased Beclin-1 and LC3-II expression, autophagy flux level, and LC3 puncta formation. In addition, the autophagy inducer rapamycin partially prevented the effects of SA on cell viability and autophagy after OGD/R, whereas the autophagy inhibitor 3-methyladenine (3-MA) exerted the opposite effect. The results of Western blotting showed that SA markedly decreased the phosphorylation of AMPK (p-AMPK), whereas the phosphor-mTOR (p-mTOR) levels increased in the presence of OGD/R insult. Furthermore, pretreatment with the AMPK inducer AICAR partially reversed the protective effects and autophagy inhibition of SA. However, AMPK inhibitor Compound C pretreatment further promoted the inhibition of SA on autophagy induction and cell damage induced by OGD/R. Taken together, these findings demonstrate that SA protects against OGD/R insult by inhibiting autophagy through the regulation of the AMPK-mTOR pathway and that SA may have therapeutic value for protecting neurons from cerebral ischemia.

Topics: AMP-Activated Protein Kinases; Animals; Autophagy; Cyclooctanes; Disease Models, Animal; Glucose; Lignans; Mice; Models, Biological; Molecular Structure; Neurons; Neuroprotective Agents; Oxidation-Reduction; Oxygen; Polycyclic Compounds; Rats; Reperfusion Injury; Signal Transduction; Stroke; TOR Serine-Threonine Kinases

Intracerebral haemorrhage (ICH) induces inflammation, which can cause severe secondary injury. Recent evidence has suggested that magnolol (MG) has a protective effect against ischaemic stroke through the inhibition of inflammation. However, the anti-inflammatory effect of MG in intracerebral haemorrhage (ICH) remains unclear. Here, we report that the protective effect of MG in a rat model of ICH can be achieved by anti-inflammatory processes. We found that MG administration significantly reduced the brain water content, restored the blood-brain barrier (BBB) and subsequently attenuated neurological deficits via decreasing the activation of glial cells, decreasing the infiltration of neutrophils and reducing the production of pro-inflammation factors (IL-1β, TNF-α and MMP-9) in a rat model of ICH. These results suggest that MG reduced inflammatory injury and improved neurological outcomes in ICH model.

Topics: Animals; Anti-Inflammatory Agents; Astrocytes; Biphenyl Compounds; Blood-Brain Barrier; Brain; Brain Edema; Brain Ischemia; Cerebral Hemorrhage; Cytokines; Disease Models, Animal; Inflammation; Lignans; Male; Neuroglia; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Stroke

Silent information regulator 1 (SIRT1), a histone deacetylase, plays a protective role in ischemic brain injury. Previous studies have shown that magnolol has a beneficial effect on ischemic stroke; however, the role of SIRT1 in the protective effect of magnolol against cerebral ischemia has not been investigated.. We used a middle cerebral artery occlusion model of stroke in rats. Before stroke induction, the rats received intraperitoneal injections of magnolol with or without the SIRT1 inhibitor, EX527. Brain water content, neurological score, and infarct volume were measured. Moreover, the levels of the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were measured. Western blot analysis was performed to detect Ac-FOXO1, SIRT1, bax, and Bcl-2 expression.. Magnolol exerted a beneficial effect on cerebral ischemia, as indicated by reduced brain edema, decreased infarct volume, and improved neurological score. Magnolol had an anti-inflammatory effect mediated by a decrease in the expression of IL-1β and TNF-α in the brain tissue. Additionally, magnolol down-regulated bax and Ac-FOXO1 expression and up-regulated Bcl-2 and SIRT1 expression. This effect of magnolol was abolished by EX527 treatment.. In conclusion, our data clearly indicate that magnolol modulates brain injury caused by ischemic stroke by inhibiting inflammatory cytokines and apoptosis through SIRT1 activation.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Biphenyl Compounds; Gene Expression Regulation; Hypoxia, Brain; Inflammation; Lignans; Nerve Tissue Proteins; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Sirtuin 1; Stroke

Arctigenin (ARC), a phenylpropanoid dibenzylbutyrolactone lignan derived from Arctium lappa L, has been reported to protect against cerebral ischemia injury in rats, but the underlying mechanism is unclear. In this study, we investigated whether ARC ameliorated ischemic stroke by inhibiting NLRP3 inflammasome-derived neuroinflammation and whether SIRT1 signaling was involved in this process. ARC (20 mg/kg) or vehicle were intraperitoneally injected to Sprague-Dawley rats for 3 days before middle cerebral artery occlusion (MCAO) surgery performed. The infarct volume, neurological score, brain water content, neuroinflammation, NLRP3 inflammasome activation and SIRT1 protein expression were assessed. Furthermore, we also investigated whether ARC protected against cerebral ischemia via SIRT1-dependent inhibition of NLRP3 inflammasome by administrating EX527, a specific SIRT1 inhibitor, under oxygen-glucose deprivation (OGD) condition. We found that ARC pretreatment decreased infarct volume, neurological score and brain water content. Moreover, ARC treatment effectively inhibited cerebral ischemia induced NLRP3 inflammasome activation and IL-1β, IL-18 secretion both in vivo and in vitro. Futhermore, ARC treatment activated Silent information regulator 1 (SIRT1) singnaling in the brain. Importantly, suppress of SIRT1 reversed the inhibitory effect of ARC on NLRP3 inflammasome activation. Taken together our results demonstrated that ARC may confer protection against ischemic stroke by inhibiting NLRP3 inflammasome activation. The activation of SIRT1 signaling pathway may contribute to the neuroprotection of ARC in MCAO.

Topics: Animals; Dose-Response Relationship, Drug; Down-Regulation; Encephalitis; Furans; Inflammasomes; Lignans; Male; Neuroprotective Agents; NLR Family, Pyrin Domain-Containing 3 Protein; Rats; Rats, Sprague-Dawley; Sirtuin 1; Stroke; Treatment Outcome

Magnolol is isolated from the herb Magnolia officinalis, which has been demonstrated to exert pharmacological effects. Our aim was to investigate whether magnolol is able to act as an anti-inflammatory agent that brings about neuroprotection using a global ischemic stroke model and to determine the mechanisms involved. Rats were treated with and without magnolol after ischemia reperfusion brain injury by occlusion of the two common carotid arteries. The inflammatory cytokine production in serum and the volume of infarction in the brain were measured. The proteins present in the brains obtained from the stroke animal model (SAM) and control animal groups with and without magnolol treatment were compared. Magnolol reduces the total infarcted volume by 15% and 30% at dosages of 10 and 30mg/kg, respectively, compared to the untreated SAM group. The levels of acute inflammatory cytokines, including interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 were attenuated by magnolol. Magnolol was also able to suppress the production of nitrotyrosine, 4-hydroxy-2-nonenal (4-HNE), inducible NO synthase (iNOS), various phosphorylated p38 mitogen-activated protein kinases and various C/EBP homologues. Furthermore, this modulation of ischemia injury factors in the SAM model group treated with magnolol seems to result from a suppression of reactive oxygen species production and the upregulation of p-Akt and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). These findings confirm the anti-oxidative properties of magnolol, including the inhibition of ischemic injury to neurons; this protective effect seems to involve changes in the in vivo activity of Akt, GSK3β and NF-κB.

Topics: Animals; Biphenyl Compounds; Blotting, Western; Brain; Brain Ischemia; Cell Death; Endoplasmic Reticulum Stress; Immunohistochemistry; Indicators and Reagents; Ischemic Attack, Transient; Lignans; Male; Neurons; Neuroprotective Agents; NF-kappa B; Nitric Oxide Synthase Type II; Oncogene Protein v-akt; p38 Mitogen-Activated Protein Kinases; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Stroke; Transcription Factor CHOP; Tyrosine

Stroke is a severe neurological disorder characterized by the abrupt loss of blood circulation into the brain resulting into wide ranging brain and behavior abnormalities. The present study was designed to evaluate molecular mechanism by which sesamin (SES) induces neuroprotection in mouse model of ischemic stroke. The results of this study demonstrate that SES treatment (30 mg/kg bwt) significantly reduced infarction volume, lipid per-oxidation, cleaved-caspase-3 activation, and increased GSH activity following MCAO in adult male mouse. SES treatment also diminished iNOS and COX-2 protein expression, and significantly restored SOD activity and protein expression level in the ischemic cortex of the MCAO animals. Furthermore, SES treatment also significantly reduced inflammatory and oxidative stress markers including Iba1, Nox-2, Cox-2, peroxynitrite compared to placebo MCAO animals. Superoxide radical production, as studied by DHE staining method, was also significantly reduced in the ischemic cortex of SES treated compared to placebo MCAO animals. Likewise, downstream effects of superoxide free radicals i.e. MAPK/ERK and P38 activation was also significantly attenuated in SES treated compared to placebo MCAO animals. In conclusion, these results suggest that SES induces significant neuroprotection, by ameliorating many signaling pathways activated/deactivated following cerebral ischemia in adult mouse.

Topics: Animals; Brain Ischemia; Dioxoles; Disease Models, Animal; Encephalitis; Infarction, Middle Cerebral Artery; Lignans; Male; Mice; Mice, Inbred C57BL; Microglia; Neuroprotective Agents; Oxidative Stress; Signal Transduction; Stroke

Topics: Animals; Brain Ischemia; Disease Models, Animal; Disease Progression; Electrophysiology; Evoked Potentials, Somatosensory; Guaiacol; Lignans; Neuroprotective Agents; Prospective Studies; Rats; Stroke; Treatment Outcome

Phytoestrogens have been suggested to lower cardiovascular disease risk, but existing research focused on non-Western high intake levels and on risk factors. We investigated whether habitual low phytoestrogen intake is associated with manifest cardiovascular disease risk.. Between 1993 and 1997, 16,165 women 49 to 70 years old and free from cardiovascular disease were enrolled in the Dutch Prospect-EPIC cohort (European Prospective study Into Cancer and nutrition) and followed up for a median period of 75 months. At enrollment, women filled in questionnaires on chronic disease risk factors and nutrition. Intake of phytoestrogens was estimated using the food frequency questionnaire covering regular dietary intake of 178 food items in the year before enrollment. Cox regression analysis was used to estimate hazard ratios of cardiovascular disease for quartiles of phytoestrogen intake adjusted for age at intake, body mass index, smoking, physical activity, hypertension, hypercholesterolemia, use of hormone replacement therapy, menopausal status, and intake of total energy, total fiber, vegetables, fruit, and alcohol. In total, 372 women experienced a coronary event (CHD) (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9], 410 to 414, 427.5) and 147 women a cerebrovascular event (CVD) (ICD-9, 430 to 438) during follow-up. Overall, neither isoflavones nor lignans were associated with decreased cardiovascular disease risk. When stratifying for ever versus never smokers, CHD risk decreased with increasing lignan intake for ever smokers.. Our results do not support the presence of a protective effect of higher intake of phytoestrogens in low doses on cardiovascular disease risk, although a small risk reduction with higher lignan intake cannot be excluded for smokers.

Topics: Aged; Alcohol Drinking; Body Mass Index; Cardiovascular Diseases; Cohort Studies; Coronary Disease; Dietary Fiber; Energy Intake; Feeding Behavior; Female; Follow-Up Studies; Fruit; Hormone Replacement Therapy; Humans; Hypercholesterolemia; Hypertension; Isoflavones; Lignans; Menopause; Middle Aged; Netherlands; Nutrition Surveys; Phytoestrogens; Proportional Hazards Models; Prospective Studies; Risk; Smoking; Stroke; Surveys and Questionnaires; Vegetables

The preventive effects of sesamin, a lignan from sesame oil and vitamin E on hypertension and thrombosis were examined using stroke-prone spontaneously hypertensive rats (SHRSP). Animals at 5 weeks of age were separated into four groups: (i) control group; (ii) vitamin E group, which was given 1000 mg alpha-tocopherol/kg diet; (iii) sesamin group, given 1000 mg sesamin/kg diet; and (iv) vitamin E plus sesamin group, given 1000 mg alpha-tocopherol plus 1000 mg sesamin/kg diet for 5 weeks from 5 to 10 weeks of age. Resting blood pressure was measured by the tail-cuff method once weekly. A closed cranial window was created in the right parietal bone of the rat and platelet-rich thrombi were induced in vivo using a helium-neon laser technique. The number of laser pulses required for formation of an occlusive thrombus was used as an index of thrombotic tendency. In control rats, systolic blood pressure and the amount of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) became significantly elevated with age. However, the elevation in blood pressure and 8-OHdG were significantly suppressed in rats administered vitamin E, sesamin, or vitamin E plus sesamin. At 10 weeks, the number of laser pulses required to induce an occlusive thrombus in arterioles of the control group was significantly lower than in the other groups (P < 0.05). These results indicate that chronic ingestion of vitamin E and sesamin attenuated both elevation in blood pressure, oxidative stress and thrombotic tendency, suggesting that these treatments might be beneficial in the prevention of hypertension and stroke.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antihypertensive Agents; Antioxidants; Blood Pressure; Deoxyguanosine; Dioxoles; Fibrinolytic Agents; Hypertension; Intracranial Thrombosis; Lignans; Rats; Rats, Inbred SHR; Stroke; Vitamin E

The preventive effects of sesamin, a lignan from sesame oil, and vitamin E on hypertension and thrombosis were examined using stroke-prone spontaneously hypertensive rats (SHRSP). At 5 weeks of age the animals were separated into four groups: (i) a control group; (ii) a vitamin E group, which was given a 1,000 mg alpha-tocopherol/kg diet; (iii) a sesamin group, given a 1,000 mg sesamin/kg diet; and (iv) a vitamin E plus sesamin group, given a 1,000 mg alpha-tocopherol plus 1,000 mg sesamin/kg diet for 5 weeks from 5 to 10 weeks of age. Resting blood pressure was measured by the tail-cuff method once weekly. A closed cranial window was created and platelet-rich thrombi were induced in vivo using a helium-neon laser technique. The number of laser pulses required for formation of an occlusive thrombus was used as an index of thrombotic tendency. In control rats, systolic blood pressure and the amount of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) became significantly elevated with age. However, the elevation in blood pressure and 8-OHdG were significantly suppressed in rats administrated vitamin E, sesamin, or vitamin E plus sesamin. At 10 weeks, the number of laser pulses required to induce an occlusive thrombus in arterioles of the control group was significantly lower than in the other groups (p<0.05). These results indicate that chronic ingestion of vitamin E and sesamin attenuated each of elevation in blood pressure, oxidative stress and thrombotic tendency, suggesting that these treatments might be beneficial in the prevention of hypertension and stroke.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Blood Pressure; Blood Vessels; Body Weight; Cerebrovascular Circulation; Cerebrovascular Disorders; Deoxyguanosine; Dioxoles; Disease Susceptibility; Drug Combinations; Genetic Predisposition to Disease; Hypertension; Lignans; Male; Microcirculation; Rats; Rats, Inbred SHR; Stroke; Thrombosis; Vasomotor System; Vitamin E