• Preventive Nutrition and Food Science
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• v.15 no.2
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• pp.92-97
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• 2010

Luteolin and chicoric acid are the most abundant phytochemicals in dandelion (Taraxacum officinale) leaf. In this study, four kinds of extraction methods [hot water, ambient temperature (AT) water, ethanol, and methanol] were applied to analyze the contents of both phytochemicals and verify their anti-inflammatory and antioxidative activities. The methanol extract showed the most potent nitric oxide (NO) inhibitory effect. The luteolin and chicoric acid concentrations were 3.42 and $12.86\;{\mu}g/g$ dandelion leaf in the methanol extract. The NO-suppressive effect of luteolin and chicoric acid was identified in a dose-dependent manner with $IC_{50}$ values of $21.2\;{\mu}M$ and $283.6\;{\mu}M$, respectively, in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells without cytotoxicity. Malondialdehyde (MDA) concentration, as an index for free radical injury on cell membrane, was also dose-dependently inhibited by the two compounds. The suppressive effect was further examined using mRNA and protein expression levels, which were attributable to the inhibition of inducible nitric oxide synthase (iNOS). These results suggest that two phytochemicals in dandelion leaf, luteolin and chicoric acid, may play an important role in the amelioration of LPS-induced oxidative stress and inflammation.

• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.590-594
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• 2008

The inclusion complexes of cyclodextrins (CDs) with flavones in aqueous solution were investigated by phase solubility measurements. The effect of b -cyclodextrin (b -CD), heptakis (2,6-di-O-methyl) b -cyclodextrin (DM-b -CD) and 2-hydroxypropyl-b -cyclodextrin (HP-b -CD) on the aqueous solubility of three flavones, namely, chrysin, apigenin and luteolin was investigated, respectively. Solubility enhancements of all flavones obtained with three CDs followed the rank order: HP-b -CD > DM-b -CD > b -CD, and besides, CDs show higher stability constant on luteolin than that on others flavones. 1H-nuclear magnetic resonance (NMR) spectroscopy and molecular modeling was used to help establish the model of interaction of the CDs with luteolin. NMR spectroscopic analysis suggested that A-C ring, and part of the B ring of luteolin display favorable interaction with the CDs, which was also confirmed by docking studies based on the molecular simulation. The observed augmentation of solubility of luteolin by three CDs was explained by the difference of electrostatic interaction of each complex, especially hydrogen bonding.

• Biomolecules & Therapeutics
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• v.31 no.2
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• pp.193-199
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• 2023

In this investigation, we made a study of the efficacy of luteolin (a flavonoid found in plants such as vegetables, herbs and fruits) on vascular contractibility and to elucidate the mechanism underlying the relaxation. Isometric contractions of denuded muscles were stored and combined with western blot analysis which was conducted to assess the phosphorylation of myosin phosphatase targeting subunit 1 (MYPT1) and phosphorylation-dependent inhibitory protein for myosin phosphatase (CPI-17) and to examine the effect of luteolin on the RhoA/ROCK/CPI-17 pathway. Luteolin significantly alleviated phorbol ester-, fluoride- and thromboxane mimetic-elicited contractions regardless of endothelial nitric oxide synthesis, implying its direct effect on smooth muscle. It also significantly alleviated the fluoride-elicited elevation in pCPI-17 and pMYPT1 levels and phorbol 12,13-dibutyrate-elicited increase in pERK1/2 level, suggesting depression of ROCK and PKC/MEK activity and ensuing phosphorylation of MYPT1, CPI-17 and ERK1/2. Taken together, these results suggest that luteolin-elicited relaxation includes myosin phosphatase reactivation and calcium desensitization, which seems to be arbitrated by CPI-17 dephosphorylation via ROCK/PKC inhibition.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.986-992
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• 2009

Type I interferons (IFNs) are critical mediators of the innate immune system to defend viral infection. Interferon regulatory factor (IRF) and signal transducer and activator of transcription (STAT) play critical roles in type I IFN production in response to viral infection. Luteolin is natural polyphenolic compounds that have anti-inflammatory, cytoprotective and anti-carcinogenic effects. However, the mechanism of action and impact of luteolin on innate immunity is still unknown. In this study, we examined the effects of luteolin on the lipopolysacchride (LPS)-induced inflammatory responses. Luteolin inhibited Type I IFNs expression of mRNA and increased interleukin(IL)-10 expression of mRNA. Next, we examined the protective effects of IL-10 using IL-10 neutralizing antibody (IL-10NA). Blockade of IL-10 action didn't cause a significant reduction of Type I IFNs than LPS-induced luteolin pretreatment. Pretreatment of luteolin inhibited the level of IRF-1, and IRF-7 mRNA and the nuclear translocation of IRF-3. Also, luteolin reduced the activation of STAT - 1, 3. Theses results suggest that luteolin inhibits LPS-induced the production of Type I IFNS by both IRFs and STATs not IL-10 and may be a beneficial drug for the treatment of inflammatory disease.

• The Korean Journal of Food And Nutrition
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• v.34 no.2
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• pp.233-241
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• 2021

The purpose of this study was to investigate the contents of apigenin and luteolin in vegetables mainly distributed and consumed in Korea. In this study, the contents of apigenin, apigenin-7-O-glucoside, luteolin, and luteolin-7-O-glucoside in vegetables were surveyed by using liquid chromatography coupled to mass spectrometry (LC-MS/MS). According to the analysis of 27 items (91 samples) in vegetables, the content of total apigenin (the sum of apigenin and apigenin-7-O-glucoside) was quantified in 8 out of the 27 items in vegetables, followed by pepper leaves, parsley, celery, chamnamul, foremost mugwort, and perilla leaves. The content of total luteolin (the sum of luteolin and luteolin-7-O-glucoside) was found in 11 of the 27 items in vegetables, followed by pepper leaves, dandelion, celery, red lettuce, foremost mugwort, and perilla leaves. Celery was divided into stalks and leaves for comparing the contents of apigenin and luteolin. Celery showed higher contents of apigenin and luteolin in leaves than in stalks.

• Journal of Life Science
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• v.19 no.4
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• pp.514-519
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• 2009

Monocyte chemoattractant protein 1 (MCP1) plays a key role in monocyte /macrophage infiltration to the sub-endothelial space of the blood vessel wall, which is a critical initial step in atherosclerosis. In this study, we examined $interleukin-1{\bate}$ ($IL-1{\beta}$) induced MCP1 expressions via activation of transcription factor $NF-{\kappa}B$ in primary human aorta smooth muscle cells. We determined the effect of several anti-inflammatory agents on $IL-1{\beta}-induced$ MCP1 expression. The pretreatment of luteolin significantly suppressed $IL-1{\beta}-induced$ MCP1 expressions through blocking activation and translocation of $NF-{\kappa}B$ to the nucleus.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.15-26
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• 2022

Luteolin is a common dietary flavone possessing potent anti-inflammatory activities. However, when administrated in vivo, luteolin becomes methylated by catechol-O-methyltransferases (COMT) owing to the catechol ring in the chemical structure, which largely diminishes its anti-inflammatory effect. In this study, we made a modification on luteolin, named LUA, which was generated by the chemical reaction between luteolin and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). Without a catechol ring in the chemical structure, this new flavone could escape from the COMT-catalyzed methylation, thus affording the potential to exert its functions in the original form when administrated in the organism. Moreover, an LPS-stimulated RAW cell model was applied to detect the anti-inflammatory properties. LUA showed much more superior inhibitory effect on LPS-induced production of NO than diosmetin (a major methylated form of luteolin) and significantly suppressed upregulation of iNOS and COX-2 in macrophages. LUA treatment dramatically reduced LPS-stimulated reactive oxygen species (ROS) and mRNA levels of pro-inflammatory mediators such as IL-1β, IL-6, IL-8 and IFN-β. Furthermore, LUA significantly reduced the phosphorylation of JNK and p38 without affecting that of ERK. LUA also inhibited the activation of NF-κB through suppression of p65 phosphorylation and nuclear translocation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5311-5316
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• 2014

Nuclear factor erythroid 2-related factor 2 (Nrf2) has been recognized as a transcription factor that controls mechanisms of cellular defense response by regulation of three classes of genes, including endogenous antioxidants, phase II detoxifying enzymes and transporters. Previous studies have revealed roles of Nrf2 in resistance to chemotherapeutic agents and high level expression of Nrf2 has been found in many types of cancer. At physiological concentrations, luteolin as a flavonoid compound can inhibit Nrf2 and sensitize cancer cells to chemotherapeutic agents. We reported luteolin loaded in phytosomes as an advanced nanoparticle carrier sensitized MDA-MB 231 cells to doxorubicin. In this study, we prepared nano phytosomes of luteolin to enhance the bioavailability of luteolin and improve passive targeting in breast cancer cells. Our results showed that cotreatment of cells with nano particles containing luteolin and doxorubicin resulted in the highest percentage cell death in MDA-MB 231cells (p<0.05). Furthermore, luteolin-loaded nanoparticles reduced Nrf2 gene expression at the mRNA level in cells to a greater extent than luteolin alone (p<0.05). Similarly, expression of downstream genes for Nrf2 including Ho1 and MDR1 were reduced significantly (p<0.05). Inhibition of Nrf-2 expression caused a marked increase in cancer cell death (p<0.05). Taken together, these results suggest that phytosome technology can improve the efficacy of chemotherapy by overcoming resistance and enhancing permeability of cancer cells to chemical agents and may thus be considered as a potential delivery system to improve therapeutic protocols for cancer patients.

• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.7-11
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• 2016

The aerial part of Trichosanthes kirilowii Maxim. (Cucurbitaceae), has long been used in traditional Korean and Chinese medicines for the treatment of heatstroke. We isolated and identified three flavones, luteolin-7-O-${\beta}$-D-glucopyranoside(1), luteolin-4'-O-${\beta}$-D-glucopyranoside(2), luteolin(3) from its methanolic extract. In the present study, we found that luteolin attenuates the lipopolysaccharide(LPS)-induced inflammation in BV2 microglial cells. Luteolin significantly inhibited LPS-induced production of pro-inflammatory mediators such as nitric oxide(NO) and prostaglandin $E_2(PGE_2)$ in BV2 microglia in a concentration-dependent manner without cytotoxic effect. Luteolin dose-dependently suppressed the protein expression of inducible nitric oxide synthase(iNOS) and cyclooxygenase-2(COX-2). In addition, luteolin also showed significant induction of heme oxygenase(HO)-1. These results suggest that both the aerial part of T. kirilowii and luteolin may be good candidates to regulate LPS-induced inflammatory response.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.260-266
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• 2021

This study aimed to identify the hepatoprotective effects of a fermented Chrysanthemum indicum L. water extract. The extraction yield, antioxidant activities (ABTS and DPPH), and content of luteolin and luteolin-7-glucoside were significantly higher in the fermented C. indicum L. water extract (FCI) than in the C. indicum L. water extract. Treatment with FCI (200 ㎍/mL) significantly reduced the activities of gamma(γ)-glutamyl transferase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in HepG2 cells treated with 3% ethanol. Furthermore, FCI did not affect the viability of the HepG2 cells. These results suggest that FCI can be useful for the development of an effective hepatoprotective agent.