PMID: 

Behav Brain Res. 2016 10 1 ;312:321-32. Epub 2016 Jun 25. PMID: 27353856

Abstract Title: 

Neuroinflammatory response to experimental stroke is inhibited by eriodictyol.

Abstract: 

BACKGROUND: Cerebral ischemia is a common disease and one of the most common causes of death and disability worldwide. The lack of glucose and oxygen in neuronal tissue leads to a series of inflammatory events, culminating in neuronal death. Eriodictyol is a flavonoid isolated from the Chinese herb Dracocephalum rupestre that has been proven to have anti-inflammatory properties.HYPOTHESIS/PURPOSE: Thus, the present study was designed to explore whether eriodictyol has neuroprotective effects against the neuronal damage, motor and memory deficits induced by permanent middle cerebral artery occlusion (pMCAO) in mice.STUDY DESIGN: Animals were orally treated with eriodictyol (1, 2 and 4mg/kg) or vehicle (saline) 30min before pMCAO, 2h after, and then once daily for the following five days.METHODS: The parameters studied were neuronal viability, brain infarcted area; sensorimotor deficits; exploratory activity; working and aversive memory; myeloperoxidase (MPO) activity; TNFα, iNOS and GFAP immunoreactivity.RESULTS: The treatment with eriodictyol prevented neuronal death, reduced infarct area and improved neurological and memory deficits induced by brain ischemia. The increase of MPO activity and TNF-α, iNOS and GFAP expression were also reduced by eriodictyol treatment.CONCLUSION: These findings demonstrate that eriodictyol exhibit promising neuroprotection effects against the permanent focal ischemia cerebral injury in the mice experimental model and the underlying mechanisms might be mediated through inhibition of neuroinflammation.

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PMID: 

J Nutr Sci Vitaminol (Tokyo). 2016 ;62(4):249-256. PMID: 27725410

Abstract Title: 

The Combination of Green Tea Extract and Eriodictyol Inhibited High-Fat/High-Sucrose Diet-Induced Cholesterol Upregulation Is Accompanied by Suppression of Cholesterol Synthesis Enzymes.

Abstract: 

Western diets induce obesity associated with an increased risk of hypercholesterolaemia. Indeed, obesity-induced hypercholesterolaemia is correlated with increased coronary cardiovascular disease (CVD) risk. Male C57BL/6J mice were fed a normal diet, high-fat and high-sucrose diet (HF/HS), HF/HS with green tea extract powder diet (HF/HS+GT), HF/HS with eriodictyol diet (HF/HS+Eri), or HF/HS with green tea extract powder and eriodictyol diet (HF/HS+GT+Eri) for 8 wk. Body weight was lower in the HF/HS+GT+Eri group than in the HF/HS group (-8.3%, p

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PMID: 

Toxicol Res (Camb). 2017 Sep 1 ;6(5):678-692. Epub 2017 Jun 19. PMID: 30090535

Abstract Title: 

Effect of eriodictyol on preneoplastic lesions, oxidative stress and bacterial enzymes in 1,2-dimethyl hydrazine-induced colon carcinogenesis.

Abstract: 

Eriodictyol, one of the strong flavonoids extracted from, is known for its antioxidant and anticarcinogenic properties. We estimated the chemopreventive effect of eriodictyol on 1,2 dimethylhydrazine (DMH)-induced experimental colon carcinogenesis in male albino Wistar rats. The rats were randomized into six groups. Our results evaluated the effect of eriodictyol supplementation (200μg per kg b.w.) on DMH (20 mg per kg b.w)-induced rats (Groups 4-6). The incidence of polyps, aberrant crypt foci (ACF) and the lipid peroxidation levels were significantly decreased as compared to those in the DMH-alone treated rats (Group 2). In eriodictyol-supplemented DMH-treated rats, we observed increased activity of enzymatic and non-enzymatic antioxidants in the circulatory system, liver, and colon. The bacterial enzymes activities of mucosa and faecal were significantly decreased in the group with treatment of eriodictyol on DMH-induced rats. Moreover, in the eriodictyol-supplementedDMH-exposed rats, we observed reduced malignant glands of a histopathological appearance in both liver and colon tissue. Furthermore, we also observed reduced AgNORs counts of eriodictyol supplemented to the DMH-exposed rats. Therefore, we can conclude that eriodictyol can be used as an effective chemopreventive agent against DMH-induced colon carcinogenesis in experimental animal models.

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PMID: 

Mol Pharm. 2017 09 5 ;14(9):2937-2951. Epub 2017 Jul 17. PMID: 28654297

Abstract Title: 

Eriodictyol, Not Its Glucuronide Metabolites, Attenuates Acetaminophen-Induced Hepatotoxicity.

Abstract: 

Acetaminophen (APAP) is one of the most commonly used oral analgesics and antipyretics, but hepatotoxicity including liver failure may occur after overdose. The therapeutic options for treating APAP hepatotoxicity are limited. Eriodictyol, a dietary flavonoid with anti-inflammatory and antioxidant properties, was used here to determine its protective effects against APAP-induced hepatotoxicity in mice. Various administration routes and pharmacokinetics-pharmacodynamics (PK-PD) analyses were used to determine these effects. Protective effects were observed in intravenously and intraperitoneally but not in intragastrically administered eriodictyol. LC-MS/MS analysis revealed two monoglucuronide metabolites of eriodictyol in liver and intestine microsomes. Recombinant human uridine-5'-diphospho -glucuronosyltransferase (UGT) isoforms and chemical inhibition studies demonstrated that UGT1As (mainly UGT1A1, UGT1A9, UGT1A10) and UGT2B7 were likely the main contributors to eriodictyol glucuronidation. Intragastric administration of eriodictyol, which displayed lower parent and higher metabolite concentrations in the plasma, did not elicit protective effects against APAP hepatotoxicity, when compared to the intraperitoneal injection of eriodictyol. The relative bioavailability of eriodictyol was increased to 216.84% with the coadministration of glycyrrhetinic acid (GA), an inhibitor of UGT1As. Intragastric administration of eriodictyol in combination with GA also induced protective effects against APAP hepatotoxicity. Furthermore, intragastric administration of eriodictyol attenuated APAP hepatotoxicity in heterozygous Ugt1 (Ugt1) mice but not in its wild-type littermates. Thus, UGT1A-mediated metabolic inactivation reduced the protective effect of eriodictyol. Eriodictyol attenuated APAP hepatotoxicity via inhibition of hepatic cytochrome P450 (cyp) 2e1 and cyp3a11 activities; reserve of glutathione (GSH) by improvement of glutathione peroxidase (GSH-Px), glutathione reductase (GR), and glutathione S-transferase (GST) activities; elevation of superoxide dismutase (SOD) activity; and reduction of malondialdehyde (MDA) level. Our findings indicate that parenterally administered eriodictyol may be used to treat APAP-induced hepatotoxicity, and its efficacy can be enhanced by UGT1As down-regulation.

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PMID: 

Microb Pathog. 2019 Feb ;127:85-90. Epub 2018 Nov 20. PMID: 30468853

Abstract Title: 

Inhibition of alpha-hemolysin expression by resveratrol attenuates Staphylococcus aureus virulence.

Abstract: 

Staphylococcus aureus is an important zoonotic pathogen that causes a variety of life-threatening diseases. The increasing emergence of drug resistance further complicates the treatment of S. aureus infections. The critical role of alpha-hemolysin (Hla) in virulence renders this toxin an ideal target for the development of anti-infective agents for S. aureus. Here, We found that resveratrol, a natural compound widely found in fruits without antibacterial activity, could effectively inhibit Hla expression via down-regulating the transcription of hla, the gene that encodes Hla, and RNAIII, the effector molecule of the agr system. The addition of resveratrol to a co-culture system of S. aureus and A549 cells significantly alleviated bacteria-mediated cellular injury. Furthermore, treatment with resveratrol effectively protected mice from S. aureus pneumonia. Our results established resveratrol as an effective Hla inhibitor that reduces Hla expression without antimicrobial activity and can be further developed into novel therapeutics against S. aureus infections.

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PMID: 

Front Pharmacol. 2018 ;9:33. Epub 2018 Jan 30. PMID: 29441020

Abstract Title: 

Eriodictyol Attenuates Myocardial Ischemia-Reperfusion Injury through the Activation of JAK2.

Abstract: 

Myocardial ischemia-reperfusion (I/R) injury remains the leading risk factor of disability and mortality worldwide. In this study, the myocardial protective effect of eriodictyol (EDT) and the underlying mechanism in anmodel of global myocardial I/R was investigated. After treatment with different concentrations of EDT, the decreased hemodynamic parameters induced by myocardial I/R injury were significantly attenuated by EDT. The elevated levels of IL-6, CRP, IL-8, and TNF-α were effectively reduced by EDT treatment. EDT also remarkably suppressed the levels of Bax and cleaved Caspase-3, and up-regulated the level of Bcl-2 in cardiac tissues from EDT-treated groups. Further studies showed that EDT could increase the levels of p-JAK2 and p-STAT3 in cardiac tissues. Meanwhile, treatment of AG490, a specific inhibitor of JAK2, abolished the protective effect of EDT on hemodynamic parameters, myocardial inflammation and myocardial cell apoptosis induced by I/R injury. These results demonstrated that EDT could protect against myocardial I/R injury through the activation of JAK2, providing a potential treatment with EDT during myocardial I/R injury.

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PMID: 

World J Microbiol Biotechnol. 2018 Apr 18 ;34(5):64. Epub 2018 Apr 18. PMID: 29671126

Abstract Title: 

Eriodictyol protects against Staphylococcus aureus-induced lung cell injury by inhibiting alpha-hemolysin expression.

Abstract: 

Staphylococcus aureus (S. aureus) is a common pathogenic bacterium that causes various diseases in both humans and animals. With the increased prevalence of methicillin-resistant S. aureus, the therapeutic effects of commonly used antibiotics are limited against S. aureus infection. Novel treatment strategies and new antibiotics are needed urgently to address this concern. Many studies have shown that virulence factors secreted from S. aureus play vital roles in their pathogenic processes. Alpha-hemolysin (Hla), an important exotoxin in S. aureus, is one such virulence factor that increases sensitivity of multiple host cells to S. aureus resulting in various diseases. Eriodictyol is a flavonoid compound that exists in many fruits and vegetables. In this study, eriodictyol was demonstrated to inhibit the expression of Hla by hemolysis assays, western blotting, and RT-qPCR at the sub-minimal inhibitory concentration. In live/dead and cytotoxicity assays, the results showed that eriodictyol protected A549 cells against Hla-induced injury in a dose-dependent manner. The minimal inhibitory concentration of eriodictyol against S. aureus was 512 µg/mL. Eriodictyol can downregulate S. aureus Hla at both the expressional and transcriptional levels without affecting S. aureus growth. In addition, cell assays had proved that eriodictyol could protect A549 cells against Hla damage. Eriodictyol could therefore have the potential to treat S. aureus infection targeting Hla.

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PMID: 

J Agric Food Chem. 2018 Oct 3 ;66(39):10205-10214. Epub 2018 Sep 21. PMID: 30208700

Abstract Title: 

Eriodictyol Attenuates LPS-Induced Neuroinflammation, Amyloidogenesis, and Cognitive Impairments via the Inhibition of NF-κB in Male C57BL/6J Mice and BV2 Microglial Cells.

Abstract: 

Eriodictyol, a natural flavonoid mainly distributed in citrus fruits and peanut, has been well-documented with possession of excellent anti-inflammatory, antioxidant, and anticancer bioactivities. This work focus on the protective effects of eriodictyol on LPS-induced neuroinflammation, amyloidogenesis, cognitive impairment, and the potential mechanisms involved. Behavioral tests and histological examinations showed that eriodictyol significantly prevented the memory and neuronal damage triggered by LPS. Consistently, eriodictyol (100 mg/kg) reduced the formation of Aβby 28.37± 16.71 pg/mL compared to the LPS group. In addition, high dose eriodictyol (100 mg/kg) also equilibrated the cholinergic system via suppressing AChE activity (0.1996 ± 0.0831 U/mgprot) and elevating ChAT activity (41.81 ± 24.72 U/g) as well as ACh level (5.093 ± 3.531 μg/mgprot) compared to the LPS group. Western blot results indicated that compared to the LPS group, eriodictyol suppressed LPS-induced glial overactivation (84.29% ± 27.21%) and regulated inflammatory mediators and cytokines by inhibiting the NF-κB and MAPK pathways. These results indicated that eriodictyol alleviated amyloidogenesis and memory impairment triggered by LPS via inhibiting TLR4, MAPKs, and PI3K/Akt, and activating Sirt1 pathways and thus blocking downstream translocation of NF-κB, which offers a potential nutritional preventive strategy for neuroinflammation diseases such as Alzheimer's disease (AD).

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PMID: 

Biomed Pharmacother. 2018 Nov ;107:1128-1134. Epub 2018 Aug 27. PMID: 30257325

Abstract Title: 

Eriodictyol inhibits IL-1β-induced inflammatory response in human osteoarthritis chondrocytes.

Abstract: 

Osteoarthritis (OA) is a degenerative disease of joints, which is closely associated with cartilage degradation. Eriodictyol, a natural flavonoid compound, has been reported to have anti-inflammatory and anti-osteoclastogenic effects. However, the effect of eriodictyol on inflammatory response in OA has not been investigated. Our results showed that eriodictyol attenuated the inhibition of cell viability in IL-1β-stimulated chondrocytes. In addition, eriodictyol inhibited the expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the production of prostaglandin E2 (PGE2) and nitric oxide (NO), which were induced by IL-1β. The induction of inflammatory cytokines and matrixmetalloproteinases (MMPs) caused by IL-1β stimulation was also attenuated by eriodictyol. Furthermore, eriodictyol pretreatment inhibited IκBα degradation and the level of p-p65, and enhanced the up-regulation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase 1 (HO-1) in IL-1β-stimulated chondrocytes. Si-Nrf2 treatment significantly inhibited the expressions of Nrf2 and HO-1 in chondrocytes. Additionally, si-Nrf2 transfection also abolished the anti-inflammatory effects of eriodictyol in chondrocytes. These findings indicated that eriodictyol exhibited anti-inflammatory effect in IL-1β-stimulated chondrocytes. The effect was mediated by inhibiting NF-κB via activating the Nrf2/HO-1 signaling pathway.

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PMID: 

J Cell Biochem. 2019 Apr ;120(4):5644-5651. Epub 2018 Oct 14. PMID: 30317656

Abstract Title: 

Eriodictyol inhibits high glucose-induced oxidative stress and inflammation in retinal ganglial cells.

Abstract: 

Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes mellitus and is considered as a leading cause of blindness. Oxidative stress and inflammation are significant drivers for the development of DR. Eriodictyol, a flavonoid compound, was proved to possess anti-inflammatory, antioxidative, and antidiabetic activities. However, the role of eriodictyol in DR has not been unveiled. In the current study, we explored the protective effects of eriodictyol on high glucose (HG)-induced rat retinal ganglial cells (RGCs). The results suggested that eriodictyol improved cell viability of HG-induced rat RGC-5 cells in a dose-dependent manner. Eriodictyol reduced the reactive oxygen species production and increased the activities of superoxide dismutase, glutathione peroxidase and catalase in rat RGC-5 cells in response to HG stimulation. The production of proinflammatory cytokines including tumor necrosis factor alpha and interleukin-8 was diminished after eriodictyol treatment. Eriodictyol also suppressed cell apoptosis induced HG in rat RGC-5 cells. Furthermore, eriodictyol enhanced the nuclear translocation of nuclear factor erythroid-2 (E2)-related factor 2 (Nrf2) and elevated the expression of antioxidant enzyme heme-oxygenase-1 (HO-1). These findings suggested that eriodictyol protects the RGC-5 cells from HG-induced oxidative stress, inflammation, and cell apoptosis through regulating the activation of Nrf2/HO-1 pathway.

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