PMID: 

J Med Food. 2015 Dec ;18(12):1327-32. Epub 2015 Sep 1. PMID: 26325006

Abstract Title: 

Flavonol Intake and Cognitive Decline in Middle-Aged Adults.

Abstract: 

Cognitive decline occurs with age and may be slowed by dietary measures, including increased intake of dietary phytochemicals. However, evidence from large and long-term studies of flavonol intake is limited. Dietary intakes of flavonols were assessed from a large biracial study of 10,041 subjects, aged 45-64, by analysis of a food frequency questionnaire administered at visit 1 of triennial visits. Cognitive function was assessed at visits 2 and 4 with the following three cognitive performance tests: the delayed word recall test, the revised Wechsler Adult Intelligence Scale digit symbol subtest, and the word fluency test of the Multilingual Aphasia Examination. The change in each score over 6 years was calculated, and a combined standardized change score was calculated. Generalized linear models controlled for age, ethnicity, gender, education level, energy intake, current smoking, physical activity, body mass index, diabetes, and vitamin C intake. Total flavonols across quintiles of intake were positively associated with preserved combined cognitive function (P

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PMID: 

Dig Dis Sci. 2012 Feb ;57(2):355-63. Epub 2011 Sep 8. PMID: 21901258

Abstract Title: 

Dietary kaempferol suppresses inflammation of dextran sulfate sodium-induced colitis in mice.

Abstract: 

BACKGROUND: In ulcerative colitis (UC), reduction of inflammation may represent a key mechanism in UC therapy, and anti-inflammatory agents would be good candidates for preventing UC. Kaempferol, a natural flavonoid, is believed to have anti-inflammatory activities and has been shown to be potentially immune-modulatory.AIMS: The aim of this study was to determine whether kaempferol alleviates the inflammatory responses of dextran sulfate sodium (DSS)-induced colitis in mice.METHODS: Female C57BL/6J mice were divided into six groups: a negative control group, a DSS control group, and DSS + 0.1% or 0.3% kaempferol pre- or post-fed groups. At the end of the experimental period, clinical and biochemical markers were evaluated.RESULTS: Plasma levels of NO and PGE(2) were significantly decreased in both the 0.3% kaempferol pre- and post-fed groups. The plasma LTB(4) level was profoundly decreased in all animals fed kaempferol. Colonic mucosa MPO activity was also suppressed in both the 0.3% kaempferol pre- or post-fed groups. TFF3 mRNA, a marker for goblet cell function, was up-regulated in kaempferol pre-fed animals.CONCLUSIONS: These results indicate that kaempferol is an effective anti-inflammatory agent that protects colonic mucosa from DSS-induced UC. Dietary kaempferol fed prior to colitis induction was more effective to suppress some of the colitis-associated markers.

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PMID: 

Toxicology. 2012 Feb 6 ;292(1):53-62. Epub 2011 Dec 6. PMID: 22155320

Abstract Title: 

Kaempferol protects against doxorubicin-induced cardiotoxicity in vivo and in vitro.

Abstract: 

The long-term clinical usefulness of doxorubicin (DOX), an anthracycline with potent antitumor activity, is limited by DOX-induced cardiotoxicity. Kaempferol, one of the most common dietary flavonoids, is known to have anti-apoptotic, anti-oxidative, and anti-inflammatory properties. The current study aimed to investigate the possible protective effect of kaempferol against DOX-induced cardiotoxicity and the underlying mechanisms. Rats were intraperitoneally (i.p.) treated with DOX (3 mg/kg) every other day for a cumulative dose of 9 mg/kg. After 28 days, DOX caused retarded body and heart growth, oxidative stress, apoptotic damage, mitochondrial dysfunction, and Bcl-2 expression disturbance. In contrast, kaempferol pretreatment (10 mg/kg i.p. before DOX administration) attenuated the DOX-induced apoptotic damage in heart tissues. In vitro studies also indicated that kaempferol may have used the mitochondrion-dependent pathway to counteract the DOX-induced cardiotoxicity. This counteraction was achieved by inhibiting p53 expression and its binding to the promoter region of the Bax proapoptotic gene, but not to the Bcl-2 antiapoptotic gene. Kaempferol also effectively suppressed DOX-induced extracellular signal-regulated kinase (ERK) 1/2 activation, but had no effect on p38 and JNK. Therefore, kaempferol protected against DOX-induced cardiotoxicity, at least, partially, by inhibiting the activation of p53-mediated, mitochondrion-dependent apoptotic signaling, and by being involved in an ERK-dependent mitogen-activated protein kinase pathway. These findings elucidated the potential of kaempferol as a promising reagent for treating DOX-induced cardiotoxicity, and may have implications in the long-term clinical usefulness of DOX.

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PMID: 

J Diabetes Res. 2015 ;2015:532984. Epub 2015 May 7. PMID: 26064984

Abstract Title: 

Small Molecule Kaempferol Promotes Insulin Sensitivity and Preserved Pancreaticβ -Cell Mass in Middle-Aged Obese Diabetic Mice.

Abstract: 

Insulin resistance and a progressive decline in functionalβ-cell mass are hallmarks of developing type 2 diabetes (T2D). Thus, searching for natural, low-cost compounds to target these two defects could be a promising strategy to prevent the pathogenesis of T2D. Here, we show that dietary intake of flavonol kaempferol (0.05% in the diet) significantly ameliorated hyperglycemia, hyperinsulinemia, and circulating lipid profile, which were associated with the improved peripheral insulin sensitivity in middle-aged obese mice fed a high-fat (HF) diet. Kaempferol treatment reversed HF diet impaired glucose transport-4 (Glut4) and AMP-dependent protein kinase (AMPK) expression in both muscle and adipose tissues from obese mice. In vitro, kaempferol increased lipolysis and prevented high fatty acid-impaired glucose uptake, glycogen synthesis, AMPK activity, and Glut4 expression in skeletal muscle cells. Using another mouse model of T2D generated by HFdiet feeding and low doses of streptozotocin injection, we found that kaempferol treatment significantly improved hyperglycemia, glucose tolerance, and blood insulin levels in obese diabetic mice, which are associated with the improved islet β-cell mass. These results demonstrate that kaempferol may be a naturally occurring anti-diabetic agent by improving peripheral insulin sensitivity and protecting against pancreatic β-cell dysfunction.

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PMID: 

Redox Rep. 2015 Sep ;20(5):198-209. Epub 2014 Dec 12. PMID: 25494817

Abstract Title: 

Ameliorative effect of kaempferol, a flavonoid, on oxidative stress in streptozotocin-induced diabetic rats.

Abstract: 

OBJECTIVE: The aim of the present study was to evaluate the protective effect of kaempferol against oxidative stress in streptozotocin (STZ)-induced diabetic rats.METHODS: Diabetes was induced in male, adult albino rats of the Wistar strain, by intraperitoneal administration of STZ (40 mg/kg body weight (BW)). Kaempferol (100 mg/kg BW) or glibenclamide (600µg/kg BW) was administered orally once daily for 45 days to normal and STZ-induced diabetic rats.RESULTS: The STZ-induced diabetic rats showed significantly increased levels of plasma glucose, thiobarbituric acid reactive substances, lipid hydroperoxides, and conjugated dienes in plasma, liver, kidney, and heart whereas they showed significantly decreased level of plasma insulin. The levels of non-enzymic antioxidants (vitamin C, vitamin E, reduced glutathione) in plasma, liver, kidney, and heart and the activities of enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase) in liver, kidney, and heart were significantly decreased in diabetic rats. Administration of kaempferol to diabetic rats was showed brought back in plasma glucose, insulin, lipid peroxidation products, enzymatic, and non-enzymatic antioxidants to near normal.CONCLUSION: The present study indicates that kaempferol has a good antioxidant property, as evidenced by its increase of antioxidant status and decrease of lipid peroxidation markers, thus providing protection from the risks of diabetic complications.

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PMID: 

Oncol Rep. 2014 Mar ;31(3):1350-6. Epub 2014 Jan 7. PMID: 24399193

Abstract Title: 

Kaempferol induces cell cycle arrest and apoptosis in renal cell carcinoma through EGFR/p38 signaling.

Abstract: 

Kaempferol has been shown to inhibit cell growth, induce apoptosis and cell cycle arrest in several tumors, but not in renal cell carcinoma (RCC). In the present study, we investigated the effects of kaempferol and the underlying mechanism(s) on the cell growth of RCC cells. MTT assay and colony formation assay were used to study cell growth, and flow cytometry was used to study apoptosis and cell cycles in different RCC cells treated with various doses of kaempferol. A significant inhibition on cell growth, induction of apoptosis and cell cycle arrest were observed in 786-O and 769-P cells after kaempferol treatment compared with the control group. Moreover, the results clearly showed that kaempferol causes a strong inhibition of the activation of the EGFR/p38 signaling pathways, upregulation of p21 expression and downregulation of cyclin B1 expression in human RCC cells, together with activation of PARP cleavages, induction of apoptotic death and inhibition of cell growth. Collectively, our results suggest that kaempferol may serve as a candidate for chemo-preventive or chemotherapeutic agents for RCC.

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PMID: 

Int Immunopharmacol. 2015 Sep ;28(1):744-50. Epub 2015 Aug 9. PMID: 26263168

Abstract Title: 

Kaempferol alleviates insulin resistance via hepatic IKK/NF-κB signal in type 2 diabetic rats.

Abstract: 

Recent studies show that inflammation underlies the metabolic disorders of insulin resistance and type 2 diabetes mellitus. Since kaempferol, a naturally occurring flavonoid, has been described to have potent anti-inflammatory properties, we investigated whether kaempferol could ameliorate insulin resistance through inhibiting inflammatory responses. The model of diabetic rat was induced by 6-week high-fat diet plus streptozotocin. Animals were orally treated with kaempferol (50 or 150 mg/kg) and aspirin (100mg/kg) for 10 weeks. The results showed that kaempferol ameliorated blood lipids and insulin in an dose-dependent manner. Kaempferol effectively restored insulin resistance induced alteration of glucose disposal by using an insulin tolerance test and the euglycemic-hyperinsulinemic clamp method. Western blotting results showed that KPF inhibited the phosphorylation of insulin receptor substrate-1 (IRS-1), IkB kinaseα (IKKα) and IkB kinase β (IKKβ). These effects were accompanied with reduction in nucleic and cytosol levels of nuclear factor kappa-β (NF-κB), and further tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels. Aspirin had similar effects. These results provide in vivo evidence that kaempferol-mediated down-regulation of IKK and subsequent inhibition of NF-κB pathway activation may be associated with the reduction of hepatic inflammatory lesions, which is contributing to the improvement of insulin signaling defect in diabetes.

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PMID: 

Pharm Biol. 2016 ;54(6):984-92. Epub 2015 Oct 12. PMID: 26459663

Abstract Title: 

The roles of CDR1, CDR2, and MDR1 in kaempferol-induced suppression with fluconazole-resistant Candida albicans.

Abstract: 

CONTEXT: Fungal infections caused by fluconazole-resistant Candida albicans are an intractable clinical problem, calling for new efficient antifungal drugs. Kaempferol, an active flavonoid, has been considered a potential candidate against Candida species.OBJECTIVE: This work investigates the resistance reversion of kaempferol in fluconazole-resistant C. albicans and the underlying mechanism.MATERIALS AND METHODS: The antifungal activities of fluconazole and/or kaempferol were assessed by a series of standard procedures including broth microdilution method, checkerboard assay and time-kill (T-K) test in nine clinical strains as well as a standard reference isolate of C. albicans. Subsequently, the morphological changes, the efflux of rhodamine 6G, and the expressions of CDR 1, CDR 2, and MDR 1 were analysed by scanning electron microscope (SEM), inverted fluorescence microscope and quantitative reverse transcription polymerase chain reaction (qRT-PCR) in C. albicans z2003.RESULTS: For all the tested C. albicans strains, the minimum inhibitory concentrations (MICs) of fluconazole and kaempferol ranged 0.25-32 and 128-256 μg/mL with a range of fractional inhibitory concentration index of 0.257-0.531. In C. albicans z2003, the expression of both CDR 1 and CDR 2 were decreased after exposure to kaempferol alone with negligible rhodamine 6G accumulation, while the expression of CDR 1, CDR 2 and MDR 1 were all decreased when fluconazole and kaempferol were used concomitantly with notable fluorescence of rhodamine 6G observed.DISCUSSION AND CONCLUSION: Kaempferol-induced reversion in fluconazole-resistant C. albicans might be likely due to the suppression of the expression of CDR1, CDR2 and MDR1.

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PMID: 

Am J Chin Med. 2015 ;43(2):241-54. Epub 2015 Mar 19. PMID: 25787296

Abstract Title: 

Hepatoprotective effect of kaempferol against alcoholic liver injury in mice.

Abstract: 

Kaempferol is a biologically active component present in various plants. The hepatoprotective effect of kaempferol in drug-induced liver injury has been proven, while its effect against alcoholic liver injury (ALI) remains unclear. Hence, the present study aimed to evaluate the effect of kaempferol against ALI in mice. The experimental ALI mice model was developed and the mice were treated with different doses of kaempferol for 4 weeks. The liver functions were observed by monitoring the following parameters: Aspartate aminotransferase (AST/GOT) and alanine aminotransferase (ALT/GPT) levels in serum; histopathological studies of liver tissue; oxidative stress by hydrogen peroxide (H2O2), superoxide dismutase (SOD) and glutathione (GSH); the lipid peroxidation status by malondialdehyde (MDA) and lipid accumulation by triglyceride (TG) level in serum; and the expression levels and activities of a key microsomal enzyme cytochrome 2E1 (CYP2E1), by both in vitro and in vivo methods. The ALI mice (untreated) showed clear symptoms of liver injury, such as significantly increased levels of oxidative stress, lipid peroxidation and excessive CYP2E1 expression and activity. The mice treated with different kaempferol dosages exhibited a significant decrease in the oxidative stress as well as lipid peroxidation, and increased anti-oxidative defense activity. The kaempferol treatment has significantly reduced the expression level and activity of hepatic CYP2E1, thus indicating that kaempferol could down regulate CYP2E1. These findings show the hepatoprotective properties of kaempferol against alcohol-induced liver injury by attenuating the activity and expression of CYP2E1 and by enhancing the protective role of anti-oxidative defense system.

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PMID: 

Endocrine. 2018 04 ;60(1):83-94. Epub 2018 Feb 1. PMID: 29392616

Abstract Title: 

Kaempferol attenuates hyperglycemia-induced cardiac injuries by inhibiting inflammatory responses and oxidative stress.

Abstract: 

PURPOSE: Suppression of inflammation and oxidative stress is an attractive strategy to against diabetic cardiomyopathy (DCM). Kaempferol (KPF) exerts both anti-inflammatory and antioxidant pharmacological properties. However, little is known about the effect of KPF on protecting myocardial injury in diabetes. The present study aimed to investigate the effect of KPF on DCM and underlying mechanism.METHODS: Anti-inflammation and anti-oxidative stress activities of KPF were evaluated in H9c2 cells or primary cardiomyocytes by real-time quantitate PCR, immunoblotting, immunofluorescence, ELISA, and FACS. Streptozotocin (STZ)-induced type 1 diabetes mellitus mice were constructed. Corresponding to experiments in vitro, the therapeutic effect of KPF was also assessed using heart tissues from mice.RESULTS: KPF significantly inhibited high glocose (HG) induced expression of inflammatory cytokines and generation of ROS, leading to reduced fibrotic responses and cell apoptosis in vitro. KPF mediated DCM protective effects through inhibiting nuclear factor-κB (NF-κB) nucleus translocation and activating nuclear factor-erythroid 2 p45-related factor-2 (Nrf-2). In STZ-induced type 1 diabetic mouse model, KPF prevented diabetes-induced cardiac fibrosis and apoptosis. These changes were also accompanied by reducing inflammation and oxidative stress in diabetic mice hearts.CONCLUSION: KPF is a potential therapeutic agent for the treatment of DCM, mechanically linked to inhibition of NF-κB and Nrf-2 activation.

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