Effect Of Fisetin Research Articles

Fisetin Regulates Gut Microbiota and Exerts Neuroprotective Effect on Mouse Model of Parkinson's Disease.

Previous studies have reported the anti-oxidant, anti-inflammatory, and anti-cancer effects of fisetin. However, the therapeutic efficacy of fisetin in Parkinson’s disease (PD) is unclear. In this study, we demonstrated that fisetin could markedly alleviate 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neurodegeneration in mice. To confirm the reported correlation between gut microbiota and PD, the bacterial DNA in the fresh feces of mice from each group was subjected to 16S rRNA (V3 and V4 regions) sequencing. The results revealed that fisetin changed the number, diversity, and distribution of gut microbiota in MPTP-induced mice model of PD. The alpha and beta diversity analyses showed that the fisetin intervented MPTP group gut microbiota exhibited a significantly higher abundance of Lachnospiraceae and a significantly lower abundance of uncultured_bacterium_g_Escherichia-Shigella and uncultured_bacterium_g_Bacillus than the MPTP group gut microbiota. These findings indicated that fisetin exerts a neuroprotective effect on neurodegeneration by altering the composition and diversity of gut microbiota. Thus, fisetin could be a potential novel therapeutic for PD.

Modulation of the Neuroprotective and Anti-inflammatory Activities of the Flavonol Fisetin by the Transition Metals Iron and Copper.

Alterations occur in the homeostasis of the transition metals iron (Fe2+) and copper (Cu2+) during aging and these are further amplified in neurodegenerative diseases, including Alzheimer’s disease (AD). These observations suggest that the most effective drug candidates for AD might be those that can reduce these alterations. The flavonoid fisetin has both neuroprotective and anti-inflammatory activity both in vitro and in vivo and can bind both iron and copper suggesting that its chelating activity might play a role in its beneficial effects. To test this idea, the effects of iron and copper on both the neuroprotective and anti-inflammatory activities of fisetin were examined. It is shown that while fisetin can reduce the potentiation of cell death by iron and copper in response to treatments that lower glutathione levels, it is much less effective when the metals are combined with other inducers of oxidative stress. In addition, iron but not copper reduces the anti-inflammatory effects of fisetin in a dose-dependent manner. These effects correlate with the ability of iron but not copper to block the induction of the antioxidant transcription factor, Nrf2, by fisetin. In contrast, although the flavanone sterubin also binds iron, the metal has no effect on sterubin’s ability to induce Nrf2 or protect cells from toxic or pro-inflammatory insults. Together, these results suggest that while iron and copper binding could contribute to the beneficial effects of neuroprotective compounds in the context of neurodegenerative diseases, the consequences of this binding need to be fully examined for each compound.

Fisetin Inhibits Autophagy in HepG2 Cells via PI3K/Akt/mTOR and AMPK Pathway

The effect of fisetin on autophagy in hepatocellular carcinoma remains uncovered. HepG2 cells were exposed to different concentrations of fisetin (25, 50, and 100 µM) for 24 h. The cells were also treated with rapamycin and chloroquine alone or in combination with fisetin. Autophagic flux formation and ATP levels were determined. The changes in autophagic markers and AMPK signaling proteins were analyzed using qRT-PCR and Western blotting. Cyto-ID staining followed by flow cytometry showed that fisetin decreased autophagic flux formation in a dose-dependent manner. In gene expression analysis, the mRNA levels of mTOR, Atg5, Atg16L, and LC3A were elevated, whereas the mRNA levels of Atg7 and Beclin1 were downregulated in a dose-dependent manner compared to control. In the Western blotting analysis, fisetin treatment inhibited the expression of Atg7, Atg16L, mTOR, and pACC and elevated the expression of Atg5, AMPKα, AMPKβ1/2, ACC and Akt. Taken together, the results revealed that fisetin inhibited autophagy by the activation of PI3K/Akt/mTOR and modulation of AMPK signaling pathways. Our findings indicate that suppression of autophagy by fisetin may serve as an effective therapeutic strategy against HCC.

Protective Effects of Fisetin on Hepatic Ischemia-reperfusion Injury Through Alleviation of Apoptosis and Oxidative Stress

Hepatic ischemia-reperfusion injury (IRI) is the main leading cause of morbidity and mortality of patients after liver surgery and transplantation. Fisetin, a kind of flavonoid, has been reported to protect against myocardial and cerebral IRI. However, the effects of fisetin on liver IRI were poorly investigated. C57BL/6 mice were used to establish the liver IRI model invivo. Intraperitoneal injection of fisetin was performed one hour before IR treatment (1h ischemia and 6h reperfusion). Invitro experimental study was conducted using AML-12 hepatocytes with 1h hypoxia and 12h reoxygenation (HR) treatment. Tissue damage was evaluated through serum AST and ALT levels and hematoxylin-eosin (HE) staining. Cell apoptosis was assessed by TUNEL staining and protein levels of Bax, Bcl-2, cleaved-caspase-3, and cleaved-PARP. Oxidative stress was evaluated by ROS and MDA levels and the activity of SOD and GSH-Px. Immunohistochemistry and immunofluorescence assay were performed to observe the translocation of Nrf2 from the cytoplasm into the nucleus. The histopathological assessment showed that fisetin attenuated IR-induced liver damage obviously. Besides, fisetin served a protective role in IR liver to alleviate cell apoptosis and oxidative stress invivo and invitro. Introduction of high concentration of fisetin promoted the translocation of Nrf2 from the cytoplasm into the nucleus, increasing protein expression of its downstream elements, at least HO-1 in IR liver tissues and hepatocytes after HR. Inhibition of Nrf2 could reverse the effects of fisetin on cell viability, cell apoptosis, and also oxidative stress of HR hepatocytes, suggesting that Nrf2 signaling was necessary in fisetin-mediated regulations of liver IRI. Fisetin alleviates liver damage, cell apoptosis, and oxidative stress induced by liver IRI, at least through Nrf2/HO-1 signaling pathway, suggesting that fisetin could be considered as a targeted drug for liver IRI treatment.

Fisetin Suppresses Pulmonary Inflammatory Responses Through Heme Oxygenase-1 Mediated Downregulation of Inducible Nitric Oxide Synthase.

The effects of a mixture of fisetin on cytokine-mediated pulmonary damages have not been studied, despite its known antiviral, neuroprotective, and anti-inflammatory activities. Using lipopolysaccharide (LPS)-activated human pulmonary artery endothelial cells (HPAECs), we determined the effects of fisetin on the induction of heme oxygenase-1 (HO-1), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). In the lung tissue of LPS-treated mice, fisetin was also evaluated for its effect on the regulation of iNOS and tumor necrosis factor (TNF)-α. In LPS-activated HPAECs, fisetin increased nuclear factor erythrocyte 2-related factor 2-antioxidant response element (Nrf2-ARE) reporter activity through the nuclear translocation of Nrf2, and the expression of HO-1, and decreased IL-1β and iNOS/NO production. In particular, the suppression of iNOS/NO expression by the administration of fisetin was dependent on HO-1. Current findings indicate that the anti-inflammatory activity of fisetin was due to its HO-1 dependent downregulation of p-STAT-1 and nuclear factor kappa B (NF-κB) and the resultant inhibition of iNOS, and also suggest TNF-α as a potential target for HO-1. We propose that administration of fisetin may be a novel approach, ideal for the treatment of inflammatory pulmonary disease.

Fisetin inhibits proliferation of pancreatic adenocarcinoma by inducing DNA damage via RFXAP/KDM4A-dependent histone H3K36 demethylation

Pancreatic adenocarcinoma (PDAC) is an extremely malignant tumor that is associated with low survival rates. Fisetin is a natural flavonoid that shows diverse antitumor effects, including DNA damage, in various cancers. Increasing studies have demonstrated that epigenetic modifications play critical roles in DNA-damage response. However, the epigenetic regulation mechanism of fisetin in cancers is hardly studied. RFXAP is a critical transcription factor for MHC II molecules, however, its transcriptional role in PDAC is poorly understood. The anti-PDAC effect of fisetin was measured by CCK-8, flow cytometry, xenograft tumor nude mice model. DNA-damage levels were examined by immunofluorescence. Bioinformatics analysis was used to examine the expression of RFXAP and other genes involved in DNA-damage response. ChIP sequencing was used to explore the transcriptional role of RFXAP. The expression of target gene KDM4A was measured by qRT-PCR and western blots. KDM4A promoter activity was analyzed using dual-luciferase reporter assay. RFXAP overexpressing or silencing of PDAC cells was used to explore the effect of RFXAP in DNA damage induced by fisetin. We found that fisetin inhibited cell proliferation and induced DNA damage and S-phase arrest in PDAC. Expression of RFXAP and other DNA-damage response genes were upregulated by fisetin. We revealed that RFXAP expression was relatively low in PDAC and correlated with tumor stage and poor prognosis. Then we explored the transcriptional role of RFXAP and found that RFXAP targeted KDM4A, a special demethylase specific for tri- and dimethylated histone H3K36. We found that overexpression of RFXAP upregulated KDM4A and attenuated methylation of H3K36, thereby impairing DNA repair and enhancing the DNA damage induced by fisetin, while RFXAP silencing showed the opposite effect. We also found the function of fisetin in enhancing the effect of chemotherapy on pancreatic cancer cells. Our findings revealed that fisetin induced DNA damage via RFXAP/KDM4A-dependent histone H3K36 demethylation, thus causing inhibition of proliferation in PDAC.

The molecular mechanism involved in cardioprotection by the dietary flavonoid fisetin as an agonist of PPAR-γ in a murine model of myocardial infarction

The methodology exploring the cardioprotective potential of the flavonoid Fisetin through its ability to modulate PPAR-γ was unraveled in the present study. Computational modelling through molecular docking based binding study of interactions between Fiestin and PPAR-γ revealed the potential role of Fisetin as an agonist of PPAR-γ. A murine model of cardiac ischemia-reperfusion injury was used to explore this further. Male Wistar Rats were randomly assigned to five groups. Fisetin (20 mg/kg; p. o) was administered for 28 days. Ischemia was induced for 45 min on the 29th day followed by 60 min of reperfusion. Fisetin pretreatment upregulated the expression of PPAR-γ in heart tissue significantly Cardioprotection was assessed by measurement of hemodynamic parameters, infarct size, ELISA for oxidative stress, immunohistochemistry and TUNEL assay for apoptosis, and western blot analysis for MAPK proteins and inflammation. PPAR-γ activation by fisetin led to significantly reduced infarct size, suppression of oxidative stress, reduction of cardiac injury markers, alleviation of inflammation, and inhibition of apoptosis The MAPK-based molecular mechanism showed a rise in a key prosurvival kinase, ERK1/ERK2 and suppression of JNK and p38 proteins. The aforementioned beneficial findings of fisetin were reversed on the administration of a specific antagonist of PPAR-γ. In conclusion, through our experiments, we have proved that fisetin protects the heart against ischemia-reperfusion injury and the evident cardioprotection is PPAR-γ dependant. In conclusion, our study has revealed a prime mechanism involved in the cardioprotective effects of fisetin. Hence, Fisetin may be evaluated in further clinical studies as a cardioprotective agent in patients undergoing reperfusion interventions.

Enhanced oral bioavailability and neuroprotective effect of fisetin through its SNEDDS against rotenone-induced Parkinson's disease rat model

Fisetin (FS) was reported to have various pharmacological activities. But due to its lower aqueous solubility and oral bioavailability, it is not in much use. As solubility and bioavailability plays and important role in the pharmacological activity, in this research work we tried to improve the oral bioavailability of fisetin. In this research work, we developed self-nanoemulsifying drug delivery system (SNEDDS) of fisetin. Developed SNEDDS were subjected for pharmacokinetic and pharmacodynamics studies against rotenone-induced Parkinson's disease (PD) model in rats. Higher Cmax and area under the curve during pharmacokinetic study indicated that SNEDDS improved the oral bioavailability of FS and also increased the mean residence time of drug in plasma. Results of behavior parameters (locomotor, muscle co-ordination and catalepsy), biochemical estimation (TBARS, nitrite, GSH, SOD and CAT) and ELISA (soluble alfa synuclein, BDNF, TNF-α and IL-6) confirmed the significantly improved (p < 0.05) neuroprotection in rats treated with FS loaded SNEDDS as compared to rats treated with naïve FS. This study suggests that SNEDDS improved the oral bioavailability of FS which further helped in improving its neuroprotective activity in rat model of PD. It further suggests the potential use of FS-SNEDDS in effective management of PD condition.

Protective effect of fisetin against subchronic chlorpyrifos-induced toxicity on oxidative stress biomarkers and neurobehavioral parameters in adult male albino mice.

Chlorpyrifos (CPF), a chlorinated organophosphate insecticide that is widely used in agriculture and public health, has neurotoxic effects in animals. In addition to acetylcholinesterase inhibition, CPF has been shown to induce alterations such as oxidative stress and lipid peroxidation. Fisetin is a dietary flavonol that protects the brain tissue against oxidative stress by modulating the activity of antioxidant enzymes. This study was designed to investigate the protective role of fisetin against brain oxidative damages and neurobehavioral parameters induced by subchronic oral exposure to CPF in albino mice. Adult albino mice (males, n = 32, weighing 20 ~ 25g) were assigned randomly into 4 groups and treated accordingly for 7weeks as follows: Group 1(S/OIL): served as the control group and were given 2ml/kg of soya oil; Group 2 (CPF): received CPF (6.6mg/kg; 1/5th of the LD50); Group 3 (FIS): fisetin (15mg/kg) and Group 4 (FIS + CPF): received fisetin at 15mg/kg, followed by CPF (6.6mg/kg) 30min later. Co-treatment with FIS + CPF mitigated the increase in brain malondialdehyde concentration (0.28 ± 0.02nmol/mg) and orchestrated the increase in the activities of catalase (81.35 ± 7.26 µ/mg), superoxide dismutase (93.03 ± 6.63IU/mL), glutathione peroxidase (68.76 ± 3.554nmol/mL) and acetylcholinesterase (11.59 ± 0.72nmol/min/mL) when compared to the CPF group. The result showed that deficits in motor strength and excitability scores induced by subchronic CPF were mitigated by fisetin administration. It was concluded that fisetin has a protective potential in mitigating against oxidative stress and damages in the brain tissues, induced by subchronic exposure to CPF in adult male albino mice.

Pharmacological study on the possible involvement of a Nrf2 -Heme oxygenase pathways in anti-cataract activity of fisetin

DM otherwise diabetes is now a days an epidemic with the percentage of patient population rising to almost 10% of the world population. Out of all the DM complications, cataract leads the way contributing to disabilities to about 60% of diabetic population. But the pathogenesis of DM cataract is still a half-understood area of medicine there by posing a problem in the therapy. The data that we have till now gives us enough evidence to advocate the oxidative stress has a major role for the pathogenesis of DM complications like DMnephropathy, DMneuropathy, and cardiac hypertrophy, which suggests the oxidative stress is a central feature of diabetes. In the current research, the pharmacological evaluation of Fisetin for its DM based anti-cataract property was performed. This research concentrates to estimate the possible involvement of Nrf-2 / heme oxygenase (HO)-pathway in the observed therapeutic effect, if any. The data obtained in this study also indicate that the observed beneficial effects mainly due to activation of Nrf2/HO-1 pathway. These effects probably result in increased tissue anti-oxidant status as well as decreased free radical production, which ultimately responsible for the observed beneficial effects of Fisetin against hyperglycemia-induced cataract.

P0700FLAVONOID FISETIN ALLEVIETES RENAL DYSFUNCTION IN A SEVERE MOUSE MODEL OF HYPERURECEMIC NEPHROPATHY

Abstract Background and Aims Flavonoid Fisetin is a natural product that has a wide distribution in many fruits and vegetables and exerts anti-cancer, anti-oxidant, anti-inflammatory and anti-mitotic effects. The renal protective effects of fisetin have been confirmed in models of diabetic nephropathy, cisplatin-induced AKI, ischemia reperfusion kidney injury and lupus nephritis. The current study instigates the protective effect of fisetin in a severe mouse model of hyperuricemic nephropathy (HN) and explores its underlying mechanisms. Method Twenty-four C57BL6 mice were randomly divided into four groups: Control, Model, Allopurinol and fisetin. HN was established by oral administration of mixture of adenine (160 mg/kg/d)/potassium oxonate (2400 mg/kg/d) every other day for 28 days. Fisetin (100 mg/kg/d) and allopurinol (10 mg/kg/d) was given by gavage simultaneously. At the end of the treatment, serum uric acid, kidney functions (serum creatinine and BUN) kidney pathological changes, as well as underlying mechanisms were investigated by biochemical assay, histopathological score, RT-PCR, and western blotting analysis. Results Oral administration of fisetin to HN mice lowered serum uric acid and improved renal functions. Renal fibrosis and inflammation in HN mice were attenuated by fisetin treatment. fisetin alleviated extracellular matrix deposition and reduced the release of pro-inflammatory cytokine IL-6, IL-1β, TNF-α and in the kidneys of HN mice. Furthermore, fisetin inhibited the activation of TGF-β and STAT3 signaling pathways in the kidneys of HN mice Conclusion These data demonstrated that fiseitn exhibited renoprotective effect in a severe mouse model of hyperuricemic nephropathy (HN). Fisetin exerted anti-inflammatory and antifibrotic effects in HN mice, which might be associated with its inhibition on TGF-β /Smad3 and STAT3 pathways.

Fisetin Inhibits Cell Proliferation and Induces Apoptosis via JAK/STAT3 Signaling Pathways in Human Thyroid TPC 1 Cancer Cells

Thyroid cancer is the most important malignant tumor reported in human populations where, its treatment remains undeveloped. Fisetin, a plant flavonoid exhibits several pharmacological properties like antioxidant, anti-inflammatory, and anticancer function. In the existing study, we assessed fisetin mediated cytotoxic effects and action potential of fisetin on cell proliferation in TPC-1 human cancer cells. Also, examined the apoptosis in TPC-1 cells by reactive oxygen species (ROS) generation, the mitochondrial membrane potential (MMP) and apoptotic morphological changes through AO/EtBr staining. Additionally, we analyzed the effects of fisetin through ELISA analysis to evaluate the caspases expression and studied JAK 1 and STAT3 signaling molecule in TPC1 cells. Our results demonstrated that fisetin stimulated apoptosis, which confirmed through reduced cell viability, improved ROS generation, altered MMP and cell cycle phases in TPC-1 cells. Further, the fisetin up-regulated the expression of caspase (3, 8, and 9) expressions in TPC-1 cells. Also, we observed the fisetin down-regulated the JAK 1 and STAT3 expression in TPC1 cells. Thus, the fisetin induced apoptosis in TPC-1 cells by the induction of oxidative damage and enhanced caspases expression by down-regulating JAK 1 and STAT3 signaling molecules. Hence, the fisetin would be considered as a beneficial therapeutic agent for the thyroid cancer treatment.

Fisetin Prevents HT22 Cells From High Glucose-Induced Neurotoxicity via PI3K/Akt/CREB Signaling Pathway.

Hyperglycemia has been widely considered as a key risk factor for diabetic encephalopathy which can cause neuronal apoptosis and cognitive deficits. The flavonoid compound, fisetin, possesses potential neuroprotective effects and also enhances learning and memory. However, the role of fisetin in hyperglycemia-induced neuronal cytotoxicity has not been fully elucidated. In the present study, HT22 murine hippocampal neuronal cell line was used to establish the injured cell model. Cell proliferation and cytotoxicity assay, Hoechst 33258 staining, qRT-PCR, western blot analysis, and specific inhibitor were used to investigate the effect and molecular mechanisms of fisetin on high glucose (HG)-induced neurotoxicity in HT22 cells. Our results showed that 125 μM and 48 h of treatment was identified as optimal damage parameter of HG. Fisetin significantly improved HG-inhibited cell viability. The levels of LDH, malondialdehyde (MDA), and superoxide dismutase (SOD) were noticeably modulated by fisetin, which alleviated HG-induced HT22 cell oxidative damage. Besides, the apoptosis of HT22 cells was rescued by fisetin pretreatment. In addition, fisetin also prevented HG-induced downregulation of the mRNA expression of Bdnf, Gdnf, synaptophysin (Syp), and glutamate ionotropic receptor AMPA type subunit 1 (Gria1) in cells. More importantly, the decreased phosphorylation of phosphoinositide 3 kinase (PI3K), Akt, and cAMP-response element binding protein (CREB) was rescued by fisetin treatment and that neuroprotective effect of fisetin was partially blocked by PI3K inhibitor, LY294002. These findings indicate that fisetin has potent neuroprotective effect and prevents HG-induced neurotoxicity by activation of PI3K/Akt/CREB pathway.

Protective effects of fisetin against myocardial ischemia/reperfusion injury.

The underlying mechanism of the myocardial protective effect of fisetin was studied in a rat ischemia/reperfusion injury model. Sprague-Dawley rats were randomly assigned to seven groups and pretreated with different solutions by gavage administration. A rat model of cardiac ischemia/reperfusion injury was established. Plasma levels of Von Willebrand factor (vWF) were determined by ELISA, flow cytometry was used to determine the level of cardiomyocyte apoptosis and 2,3,5-triphenyltetrazolium staining was used to determine the size of myocardial infarcts. Hematoxylin and eosin-stained sections of myocardial tissues were examined for pathological changes. Expressions of nuclear factor (NF)-κB and matrix metallopeptidase 9 (MMP-9) were measured by immunohistochemistry. Compared with the model group, rats pretreated with fisetin, quercetin and aspirin showed significant prolongation of clotting time, prothrombin time, thrombin time and activated partial thromboplastin time. Fisetin treatment better maintained the integrity of myocardial fibers and nuclear integrity, reduced the percentage of apoptotic myocardial cells, inhibited expression of NF-κB, decreased the loss of MMP-9 and reduced nuclear translocation of NF-kB. Rats pretreated with fisetin also demonstrated a significant decrease in plasma levels of vWF. In addition, the protective effect of fisetin on myocardial cells was found to be dose dependent.

Fisetin Improved Rotenone-Induced Behavioral Deficits, Oxidative Changes, and Mitochondrial Dysfunctions in Rat Model of Parkinson’s Disease

Oxidative stress plays an important role in the pathogenesis of Parkinson’s disease (PD), particularly the inhibition of mitochondrial complex-I. This study aimed to evaluate the effect of fisetin in the rotenone-induced rat model of PD. Rotenone was administered (2 mg/kg s.c.) for 35 days to induce PD in animals. Fisetin was administered at two doses (10 mg/kg and 20 mg/kg p.o.) for 25 days to the animals that were given rotenone. Behavioral experiment, i.e. cylinder test, was performed to assess the motor asymmetry. Animals were euthanized, and mid brains were isolated for the estimation of tricarboxylic acid cycle enzymes, oxidative measures (lipid peroxidation (LPO), glutathione (GSH) and catalase) and complex-I activity. In addition, histopathological studies were conducted. Fisetin treatment improved motor function in the cylinder test and reversed the rotenone-induced changes in mitochondrial enzymes, striatal dopamine levels, antioxidant enzyme levels and histological changes. An important finding of this study was both the doses of fisetin significantly (p < 0.05) enhanced rotenone-induced behavioral and biochemical changes and the effects were found to be dose dependent. Based on the present results, we hypothesize that fisetin may improve the mitochondrial enzyme activity, thereby preventing the pathogenesis of PD.

Phytochemicals inhibit migration of triple negative breast cancer cells by targeting kinase signaling

BackgroundCell migration and invasion are essential processes for metastatic dissemination of cancer cells. Significant progress has been made in developing new therapies against oncogenic signaling to eliminate cancer cells and shrink tumors. However, inherent heterogeneity and treatment-induced adaptation to drugs commonly enable subsets of cancer cells to survive therapy. In addition to local recurrence, these cells escape a primary tumor and migrate through the stroma to access the circulation and metastasize to different organs, leading to an incurable disease. As such, therapeutics that block migration and invasion of cancer cells may inhibit or reduce metastasis and significantly improve cancer therapy. This is particularly more important for cancers, such as triple negative breast cancer, that currently lack targeted drugs.MethodsWe used cell migration, 3D invasion, zebrafish metastasis model, and phosphorylation analysis of 43 protein kinases in nine triple negative breast cancer (TNBC) cell lines to study effects of fisetin and quercetin on inhibition of TNBC cell migration, invasion, and metastasis.ResultsFisetin and quercetin were highly effective against migration of all nine TNBC cell lines with up to 76 and 74% inhibitory effects, respectively. In addition, treatments significantly reduced 3D invasion of highly motile TNBC cells from spheroids into a collagen matrix and their metastasis in vivo. Fisetin and quercetin commonly targeted different components and substrates of the oncogenic PI3K/AKT pathway and significantly reduced their activities. Additionally, both compounds disrupted activities of several protein kinases in MAPK and STAT pathways. We used molecular inhibitors specific to these signaling proteins to establish the migration-inhibitory role of the two phytochemicals against TNBC cells.ConclusionsWe established that fisetin and quercetin potently inhibit migration of metastatic TNBC cells by interfering with activities of oncogenic protein kinases in multiple pathways.

GSK-3β-Targeting Fisetin Promotes Melanogenesis in B16F10 Melanoma Cells and Zebrafish Larvae through β-Catenin Activation.

Fisetin is found in many fruits and plants such as grapes and onions, and exerts anti-inflammatory, anti-proliferative, and anticancer activity. However, whether fisetin regulates melanogenesis has been rarely studied. Therefore, we evaluated the effects of fisetin on melanogenesis in B16F10 melanoma cell and zebrafish larvae. The current study revealed that fisetin slightly suppressed in vitro mushroom tyrosinase activity; however, molecular docking data showed that fisetin did not directly bind to mushroom tyrosinase. Unexpectedly, fisetin significantly increased intracellular and extracellular melanin production in B16F10 melanoma cells regardless of the presence or absence of α-melanocyte stimulating hormone (α-MSH). We also found that the expression of melanogenesis-related genes such as tyrosinase and microphthalmia-associated transcription factor (MITF), were highly increased 48 h after fisetin treatment. Pigmentation of zebrafish larvae by fisetin treatment also increased at the concentrations up to 200 µM and then slightly decreased at 400 µM, with no alteration in the heart rates. Molecular docking data also revealed that fisetin binds to glycogen synthase kinase-3β (GSK-3β). Therefore, we evaluated whether fisetin negatively regulated GSK-3β, which subsequently activates β-catenin, resulting in melanogenesis. As expected, fisetin increased the expression of β-catenin, which was subsequently translocated into the nucleus. In the functional assay, FH535, a Wnt/β-catenin inhibitor, significantly inhibited fisetin-mediated melanogenesis in zebrafish larvae. Our data suggested that fisetin inhibits GSK-3β, which activates β-catenin, resulting in melanogenesis through the revitalization of MITF and tyrosinase.

Fisetin Attenuates Cartilage Destruction in Adjuvant-Induced Arthritis by Modulating Cartilage Cytokine Expression Correlated with Oxidative Status in the Early Phase in Experimental Animals

The present study was designed to evaluate the effect of Fisetin on the progression of adjuvant-induced arthritis in rats and explore the mechanisms underlying fisetin mediated immunomodulation. Adjuvant-induced arthritis (AIA) was induced by a single subcutaneous injection of Freund's complete adjuvant (FCA). AIA rats were treated with Fisetin daily via oral gavage, for a period of 28 days. Paw swelling changes were assessed and histopathological and radiographic analysis was conducted to evaluate the antiarthritic effect. Lipid peroxidation and antioxidant enzyme activities in the joint tissue homogenate were performed to observe the modulation of the antioxidant status along the expression of different pro-inflammatory cartilage cytokines, such as TNF-á and IL-6. Fisetin promotes both the antiarthritic and the antioxidant effect, as well as the suppression of lipid peroxidation. Fisetin significantly inhibited the development phase of arthritis, as supported by histopathological and radiographical observations, and reduced overexpression of cartilage cytokines. Fisetin not only suppressed the arthritic progression and tissue destruction, but it also demonstrated a pronounced anti-inflammatory and immunomodulatory action against the immunosuppressive properties of AIA and provided a superior effect against inflammation. Furthermore, fisetin therapy restored the BMD loss and acts as a potent antioxidant and immunomodulator, suggesting that oral administration can suppress arthritic progression in rats.

Flavonoid fisetin alleviates kidney inflammation and apoptosis via inhibiting Src-mediated NF-κB p65 and MAPK signaling pathways in septic AKI mice

BackgroundSepsis is defined as end-organ dysfunction resulting from the host’s inflammatory response to infection. One of the most common sepsis-injured organs is the kidneys, resulting in acute kidney injury (AKI) that contributes to the high morbidity and mortality, especially patients in the intensive care unit. Fisetin, a naturally occurring flavonoid, has been reported to protect against the rat of lipopolysaccharide (LPS)-induced acute lung injury. However, the effect of fisetin on septic AKI remains unknown. PurposeThe current study proposed to systematically investigate the renoprotective effects and the underlying mechanisms of fisetin in septic AKI mice. MethodsThe model of septic AKI was established on male C57BL/6 J mice by a single intraperitoneal injection of LPS (10 mg/kg). Fisetin was administrated by gavage at 100 mg/kg for 3 consecutive days before LPS injection and the mice were sacrificed at 16 h after LPS injection. The serum and kidney samples were evaluated for biochemical analysis, histopathological examinations as well as inflammation and apoptosis related gene/protein expression. ResultsPretreatment with fisetin significantly alleviated the elevated levels of serum creatinine and blood urea nitrogen in LPS-treated mice. Consistently, LPS induced renal damage as implied by histopathological score and the increased injury markers NGAL and KIM-1, which was attenuated by fisetin. Meanwhile, LPS injection triggered proinflammatory cytokine production and inflammation related proteins in the kidneys. However, fisetin inhibited renal expression of IL-6, IL-1β, TNF-α, HMGB1, iNOS and COX-2 to improve inflammatory response. Furthermore, fisetin effectively reduced the number of TUNEL positive apoptotic cells and suppressed apoptotic protein of Bcl-2, BAX and cleaved caspase-3 in the kidneys of LPS-induced septic AKI. Mechanistically, LPS stimulated the expression of TLR4 and the phosphorylation of NF-κB p65, MAPK (p38, ERK1/2 and JNK), Src and AKT in the injured kidneys, while fisetin notably suppressed the corresponding protein expression. ConclusionFisetin alleviated kidney inflammation and apoptosis to protect against LPS-induced septic AKI mice via inhibiting Src-mediated NF-κB p65 and MAPK signaling pathways

Oral flavonoid fisetin treatment protects against prolonged high-fat-diet-induced cardiac dysfunction by regulation of multicombined signaling

Excess high-fat diet (HFD) intake predisposes the occurrence of obesity-associated heart injury, but the mechanism is elusive. Fisetin (FIS), as a natural flavonoid, has potential activities to alleviate obesity-induced metabolic syndrome. However, the underlying molecular mechanisms of FIS against HFD-induced cardiac injury remain unclear. The present study was to explore the protective effects of FIS on cardiac dysfunction in HFD-fed mice. We found that FIS alleviated HFD-triggered metabolic disorder by reducing body weight, fasting blood glucose and insulin levels, and insulin resistance. Moreover, FIS supplements significantly alleviated dyslipidemia in both mouse hearts and cardiomyocytes stimulated by metabolic stress. FIS treatment abolished HFD-induced inflammatory response in heart tissues through suppressing TNF receptor-1/TNF receptor-associated factor-2 (Tnfr-1/Traf-2) signaling. Furthermore, FIS induced a strong reduction in the expression of fibrosis-related genes, contributing to the inhibition of fibrosis by inactivating transforming growth factor (Tgf)-β1/Smads/Erk1/2 signaling. Collectively, these results demonstrated that FIS could be a promising therapeutic strategy for the treatment of obesity-associated cardiac injury.