||Chrysoeriol has antioxidant, antiinflammatory, antitumor, antimicrobial, antiviral, and free radical scavenging activities, it also shows selective bronchodilator effect. Chrysoeriol can potently inhibit the induction of nitric oxide synthase by blocking activator protein 1 (AP-1) activation and its anti-inflammatory effects; it can potentially serve as a novel cardioprotective agent against doxorubicin (DOX)-induced cardiotoxicity without affecting the antitumor activity of DOX. Chrysoeriol may be used for the prevention and treatment of vascular diseases and during restenosis after coronary angioplasty, it can inhibit the downstream signal transduction pathways of platelet-derived growth factor (PDGF)-Rbeta, including ERK1/2, p38, and Akt phosphorylation.|
|J Pharmacol Sci. 2009 May;110(1):105-10. |
|An inhibitory effect of chrysoeriol on platelet-derived growth factor (PDGF)-induced proliferation and PDGF receptor signaling in human aortic smooth muscle cells.[Pubmed: 19423953]|
|Platelet-derived growth factor (PDGF)-BB is one of the most potent factors in the development and progression of various vascular disorders such as restenosis and atherosclerosis. Chrysoeriol is a flavonoid with antioxidant and anti-inflammatory activities. |
METHODS AND RESULTS:
In this study, we investigated the effect of Chrysoeriol on the proliferation of human aortic smooth muscle cells (HASMC). Chrysoeriol significantly inhibited PDGF (20 ng/mL)-induced migration and [(3)H]-thymidine incorporation into DNA at concentrations of 5 and 10 microM without any cytotoxicity. Chrysoeriol also blocked PDGF-stimulated dissociation of actin filament and inhibited PDGF beta-receptor (Rbeta) phosphorylation in a concentration-dependent manner. As a result, the downstream signal transduction pathways of PDGF-Rbeta, including ERK1/2, p38, and Akt phosphorylation, were also inhibited by Chrysoeriol in the same pattern.
These findings suggest that in addition to its antioxidant and anti-inflammatory activities, Chrysoeriol may be used for the prevention and treatment of vascular diseases and during restenosis after coronary angioplasty.
|Toxicology. 2010 Jul-Aug;274(1-3):42-8. |
|Inhibitory effects of chrysoeriol on DNA adduct formation with benzo[a]pyrene in MCF-7 breast cancer cells.[Pubmed: 20553787]|
|Cytochrome P450 (CYP) 1 families including CYP1A1, 1A2 and 1B1 are well known to be deeply involved in the initiation of several cancers, due to the fact that they activate environmental pro-carcinogens to form ultimate carcinogens. Benzo[a]pyrene (BaP) is one of the major classes of prototypical pro-carcinogen.
It is activated by the CYP1 family to its ultimate carcinogenic forms, mainly BaP-7,8-diol-9,10-epoxide (BPDE), and it forms adducts with DNA. This has been recognized to be a major initiation pathway for cancer. Our previous study demonstrated that Chrysoeriol, which is a dietary methoxyflavonoid, selectively inhibited CYP1B1 enzymatic activity and might protect the CYP1B1 related-diseases such as breast cancer.
METHODS AND RESULTS:
In the present study, we further examined the effects of Chrysoeriol on the other initiation pathway of cancer relating to the CYP1 family with BaP in human breast cancer MCF-7 cells. The effects of Chrysoeriol on the formation of BPDE-DNA adducts were analyzed specifically using the liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. When MCF-7 cells were incubated with 2 microM BaP for 24h, three types of BPDE-dG adducts, especially (+)-trans-BPDE-dG as the dominant adduct, were detected. Co-treatment of MCF-7 cells with 10 microM Chrysoeriol and BaP remarkably reduced (+)-trans-BPDE-dG formation. Chrysoeriol (1-10 microM) dose-dependently inhibited both EROD activity and the gene expressions of CYP1A1, 1B1 and 1A2 stimulated by treatment with BaP. In addition, the same amounts of Chrysoeriol significantly inhibited the binding of BaP to the aryl hydrocarbon receptor (AhR), which is the key factor concerning the induction of the CYP1 families.
In conclusion, our results clearly indicate that Chrysoeriol inhibited the formation of BPDE-DNA adducts via regulation of the AhR pathway stimulated by BaP. As a consequence Chrysoeriol may be involved in the chemoprevention of environmental pro-carcinogens such as BaP.
|J Biomed Sci. 2005 Dec;12(6):949-59. |
|Chrysoeriol potently inhibits the induction of nitric oxide synthase by blocking AP-1 activation.[Pubmed: 16228289 ]|
|Chrysoeriol is a flavonoid with antioxidant and anti-inflammatory activities. Despite the large number of studies performed on its biological activities, no clear picture of its mode of action has emerged.
METHODS AND RESULTS:
In the present study, we isolated Chrysoeriol from the leaves of Digitalis purpurea (foxglove), and studied its effect on the induction of the inducible nitric oxide synthase (iNOS) gene, and the mechanism of this induction in Raw264.7 macrophages. Chrysoeriol pretreatment potently inhibited the release of NO in the cells treated with lipopolysaccharide (LPS), and Western blot and RT-PCR analyses revealed that Chrysoeriol inhibited the LPS-induced inductions of iNOS gene. Moreover, it is known that the activations of nuclear factor-kappaB (NF-kappaB) and activator protein 1 (AP-1) are crucial steps in the transcriptional activation of the iNOS gene. Here, we found that Chrysoeriol selectively suppressed AP-1 activation, and that activation of AP-1 is likely to be essential for iNOS induction in LPS-treated macrophages.
This presumed inhibitory effect on AP-1 activation by Chrysoeriol may be associated with its potent NO blocking and anti-inflammatory effects.
|Eur J Nutr. 2006 Dec;45(8):463-9. |
|Selective bronchodilatory effect of Rooibos tea (Aspalathus linearis) and its flavonoid, chrysoeriol.[Pubmed: 17080260]|
|Rooibos tea (Aspalathus linearis) is commonly used for hyperactive gastrointestinal, respiratory and cardiovascular disorders.
The aqueous extract of Rooibos tea (RT) was studied for the possible bronchodilator, antispasmodic and blood pressure lowering activities in an attempt to rationalize some of its medicinal uses.
METHODS AND RESULTS:
Isolated tissue preparations, such as rabbit jejunum, aorta and guinea-pig trachea and atria were set up in appropriate physiological salt solutions and aerated with carbogen. For in vivo studies rats were anesthetized with pentothal sodium and blood pressure was measured through carotid artery cannulation.In jejunum, RT caused a concentration-dependent relaxation of low K(+) (25 mM)-induced contractions, with mild effect on the contractions induced by high K(+) (80 mM). In presence of glibenclamide, the relaxation of low K(+)-induced contractions was prevented. Similarly, cromakalim caused glibenclamide-sensitive inhibition of low K(+), but not of high K(+), while verapamil did not differentiate in its inhibitory effect on contractions produced by the two concentrations of K(+). Like in jejunum, RT caused glibenclamide-sensitive relaxation of low K(+)-induced contractions in trachea and aorta, but with a 20 times higher potency in trachea. In atria, RT was least potent with weak inhibitory effect on atrial force and rate of contractions. RT caused a dose-dependent fall in arterial blood pressure in rats under anesthesia. Among the tested pure compounds of Rooibos, Chrysoeriol showed selective bronchodilator effect.
Chrysoeriol (luteolin 3'-methyl ether) is a bioactive flavonoid known for antioxidant, antiinflammatory, antitumor, antimicrobial, antiviral, and free radical scavenging activities.