Flavonoids의 약리작용(I) -Flavonoies 구조와 과민반응 억제작용과의 상관성-

김창종(Chang Johng Kim),정진모(Jin Mo Chung) 대한약학회 1990 약학회지 Vol.34 No.5

The activities of twenty-one flavonoids and their related compounds on the hypersensitivity reaction against various antigens were studied in vitro and in vivo. 1.Generally flavonoids inhibited significantly the homologous passive cutaneous anaphylaxis (PCA) induced by reaginic antibody as compared as anaphylaxis by compound 48/80-induced mast cell degranulation, and so more strongly active in the IgE-mediated anaphylaxis than non-IgE-mediated anaphylaxis. 2.Flavonoids inhibited remarkably Arths reaction, hemolysin titer, delayed hypersensitivity, haemaggltitinin titer, rosette forming cells and plague forming cells against sheep red blood cells, and so it exhibited that flavonoids inhibited type 2, 3 and 4 hypersensitivity. 3.Quercetin, kaempferol, hesperetin, disodium cromoglycate, malvin and baicalein were active dose-dependently in the all types of hypersensitivity. Fisetin, daidzein, morin, narigin, flavone, catechin, rutin, hesperidin, neophsperidin, apigenin and chrysin were significantly active in the various types of hypersensitivity, but apigenin, rutin and catechin were less active in the delayed hypersensitivity. Taxifolin was significantly active in PCA and histamine-induced anaphylaxis except other types of hypersensitivity. Rotenone and cyanin also inhibited all types of hypersensitivity, but they are toxic. 4.Based on these results from hypersensitivity, the following flavonoid structure-activity relationships became apparent. 1)Flavonoids with C2-3 double bond in C-ring were more active than that of C2-3 saturation. 2)Flavonoids with C4 ketone group in C-ring were more active than absence of them except catechin and malvin. 3)Flavonoids with benzene ring at positions 2 or 3 in C-ring exhibited same activities. 4)Flavonoids with opening of the C-ring does not abolish their activities. 5)The glycosylated flavonoids in position 3 or 7 was less active than their aglycone. 6)Flavonoids with the more hydroxy group in A and B-ring were more active. 7)Flavonoids with or without C3-OH did not change their activities.

Flavonoids와 근류균의 상호작용

강상재,박우철,서상현,Kang, Sang-Jae,Park, Woo-Churl,Seo, Sang-Hyun 한국응용생명화학회 1997 Applied Biological Chemistry (Appl Biol Chem) Vol.44 No.4

본 연구는 숙주특이적인 근류형성에 두과작물의 뿌리분비물에 포함된 기주특이적인 flavonoids와 근류균의 상호작용에 대해 실험하였다. Flavonoid 화합물에 대한 근류균의 생물학적 활성은 B. japonocum의 경우 대두의 뿌리분비물에 포함된 flavonoid화합물인 daidzein과 genistein에서는 생장 증진 효과가 나타났으며, alfalfa의 뿌리분비물에 포함된 flavonoid인 luteolin에서는 생장 저해 효과가 나타났으며, R. meliloti의 경우 luteolin의 경우 생장증진 효과가 나타났으며, daidzein과 genistein의 경우 생장저해효과가 나타났다. 각 근류균의 흡수 특이성은 B. japonicum에서 daidzein과 genistein이 각각 $14.95\;{\mu}g/g$와 $14.20\;{\mu}g/g$로 가장 높고 luteolin이 가장 낮게 나타났으며, R. meliloti의 경우 luteolin이 $18.31\;{\mu}g/g$으로 가장 높고 daidzein과 genistein이 가장 낮게 나타났다. 이와 같은 사실로 숙주특이적인 flavonoids가 근류균의 숙주특이성에 깊은 관련이 있을 것으로 사료된다. This experiment was carried out to elucidate the biological activity and absorption characteristics of flavonoids in Rhizobium and Bradyrhizobium and to obtain basic information on host specific nodulation by flavonoids in rhizobium-legume symbiosis. The purpose of the present study was to explore the biological activity and the flavonoid absorption indicates that host-specificity is induced by flavonoids in symbiotic nitrogen fixation. Biological activity increased by daidzein and genistein treatment on B. japonicum KCTC 1539 whereas decreased by luteolin treatment but increased by luteolin treatment on R. meliloti whereas decreased by daidzein and genistein treatment. Daidzein and genistein are absorbed by B. japonicum, KCTC 1539 at higher rate than other flavonoids. Especially, luteolin was absorbed at a least rate. Luteolin are absorbed by R. meliloti KCTC 2353 at higher rate than other flavonoids. Especially, daidzein and genistein was absorbed at a least rate.

가금 생산에서 천연 항산화제로서 식물성 Flavonoids의 적용

서문강민,장인석 한국가금학회 2022 韓國家禽學會誌 Vol.49 No.4

Poultry are exposed to extremely high levels of oxidative stress as a consequence of the excessive production of reactive oxygen species (ROS) induced by endogenous and exogenous stressors, such as high-stocking densities, thermal stress, environmental and feed contamination, along with factors associated with intensive breeding systems. Oxidative stress promotes lipid peroxidation, DNA damage, and inflammation, which can have detrimental effects on the health of birds. During the course of evolution, birds have developed antioxidant defense mechanisms that contribute to maintaining homeostasis when exposed to endogenous and exogenous stressors. The primary antioxidant defense systems are enzymatic and non-enzymatic in nature and play roles in protecting cells from ROS attack. Recently, plant flavonoids, which have been established to reduce oxidative stress, have been attracting considerable attention as potential feed additives. Flavonoids are a group of polyphenolic compounds that can be stabilized by binding structural compounds with ROS, and can promote the elimination of ROS by inducing the expression of antioxidant enzymes. However, although flavonoids can contribute to reducing lipid peroxidation and thereby enhance the antioxidant capacity of birds, they have low solubility in the gastrointestinal tract, and consequently, it is necessary to develop a delivery technology that can facilitate the effect intestinal absorption of these compounds. Furthermore, it is important to determine the dietary levels of flavonoids by assessing the exact antioxidant effects in the gastrointestinal tract wherein the concentrations of dietary flavonoids are highest. It is also necessary to examine the expression of transcriptional factors and vitagenes associated with the efficient antioxidant effects induced by flavonoids. It is anticipated that the application of flavonoids as natural antioxidants will become a particularly important field in the poultry industry. 최근 닭은 고도화된 육종개량과 함께 고밀도 사육, 열 스트레스, 환경 및 사료 오염 등과 같은 내외적 스트레스 요인에 의해 체 조직에서 과도한 활성산소(ROS) 발생으로 산화적 스트레스가 매우 높다. 산화적 스트레스는 지질과산화 작용으로 DNA 손상, 세포사 등을 유발하여 닭의 건강과 복지에 심각한 문제를 유발한다. 닭은 이러한 내외적 산화적 스트레스에 따라 항산화 효소와 비효소적 항산화 물질에 의해 활성산소를 제거하는 방어 작용을 한다. 최근 영양학적 방법으로서 산화적 스트레스를 억제하는 식물성 flavonoids 사료첨가제 개발에 주목하고 있다. Favonoid를 닭에게 급여 시 소화기관 및 근육에서 지질과산화도 감소, 항산화력 및 항산화 효소 활성도가 증가하는 것으로 항산화제로서 가치가 높다. Flavonoids는 구조화합물이 활성산소와 결합하여 안정화할 수 있는 구조로서 ROS를 소거 또는 항산화 효소의 발현을 통해 ROS를 제거한다. 또한 금속 이온과 결합하는 킬레이트화 작용, 산화효소 및 NO 생성 억제 등 다양한 항산화 작용이 있다. 그러나 문제점으로 flavonoid 화합물은 용해도가 낮아 소장 흡수세포에서 흡수율이 저하됨으로 이를 극복할 수 있는 체내 운반 기술의 개발이 필요하다. 또한 사료 섭취 시 flavonoid 농도가 가장 높은 곳이 위장관으로 이곳에서 명확한 항산화 효과를 나타내는 용량을 구명하여 첨가 수준을 결정하여야 한다. 항산화 작용기전은 스트레스에 따라 다양한 전사인자들(transcrptional factors)을 통해 스트레스 반응 유전자(vitagenes)의 발현을 유도한다. Flavonoid의 항산화 작용기전으로 Nrf-2와 Nf-kB 등과 같은 전사인사의 발현 과정과 vitagenes을 통해 효율적 항산화 효과를 나타내는 방법에 관한 연구도 중요하다. 닭에서 육종 및 사육 환경 요인에 따라 발생하는 산화 스트레스는 경제성과 더불어 동물복지 측면에서도 심각한 문제를 유발한다. Flavonoid 함유 천연 항산화제 개발과 적용은 가금 산업에서 향후 중요한 분야가 될 것으로 전망된다.

Modulation of Activator Protein-1 (AP-1) and MAPK Pathway by Flavonoids in Human Prostate Cancer PC3 Cells

Avanthika Gopalakrishnan,Chang-Jiang Xu,Sujit S Nair,Chi Chen,Vidya Hebbar,Ah-Ng Tony Kong 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.8

In last couple of decades the use of natural compounds like flavonoids as chemopreventive agents has gained much attention. Our current study focuses on identifying chemopreventive flavonoids and their mechanism of action on human prostate cancer cells. Human prostate cancer cells (PC3), stably transfected with activator protein 1 (AP-1) luciferase reporter gene were treated with four main classes of flavonoids namely flavonols, flavones, flavonones, and isoflavones. The maximum AP-1 luciferase induction of about 3 fold over control was observed with 20 μM concentrations of quercetin, chrysin and genistein and 50 μM concentration of kaempferol. At higher concentrations, most of the flavonoids demonstrated inhibition of AP-1 activity. The MTS assay for cell viability at 24 h showed that even at a very high concentration (500 μM), cell death was minimal for most of the flavonoids. To determine the role of MAPK pathway in the induction of AP-1 by flavonoids, Western blot of phospho MAPK proteins was performed. Four out of the eight flavonoids namely kaempferol, apigenin, genistein and naringenin were used for the Western Blot analysis. Induction of phospho-JNK and phospho-ERK activity was observed after two hour incubation of PC3-AP1 cells with flavonoids. However no induction of phospho-p38 activity was observed. Furthermore, pretreating the cells with specific inhibitors of JNK reduced the AP-1 luciferase activity that was induced by genistein while pretreatment with MEK inhibitor reduced the AP-1 luciferase activity induced by kaempferol. The pharmacological inhibitors did not affect the AP-1 luciferase activity induced by apigenin and naringenin. These results suggest the possible involvement of JNK pathway in genistein induced AP-1 activity while the ERK pathway seems to play an important role in kaempferol induced AP-1 activity.

Modulation of Activator Protein-1 (AP-1) and MAPK Pathway by Flavonoids in Human Prostate Cancer PC3 Cells

Gopalakrishnan, Avanthika,Xu, Chang-Jiang,Nair, Sujit S.,Chen, Chi,Hebbar, Vidya,Kong, Ah-Ng Tony The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.8

In last couple of decades the use of natural compounds like flavonoids as chemopreventive agents has gained much attention. Our current study focuses on identifying chemopreventive flavonoids and their mechanism of action on human prostate cancer cells. Human prostate cancer cells (PC3), stably transfected with activator protein 1 (AP-1) luciferase reporter gene were treated with four main classes of flavonoids namely flavonols, flavones, flavonones, and isoflavones. The maximum AP-1 luciferase induction of about 3 fold over control was observed with $20\;{\mu}M$ concentrations of quercetin, chrysin and genistein and $50\;{\mu}M$ concentration of kaempferol. At higher concentrations, most of the flavonoids demonstrated inhibition of AP-1 activity. The MTS assay for cell viability at 24 h showed that even at a very high concentration $(500\;{\mu}M)$, cell death was minimal for most of the flavonoids. To determine the role of MAPK pathway in the induction of AP-1 by flavonoids, Western blot of phospho MAPK proteins was performed. Four out of the eight flavonoids namely kaempferol, apigenin, genistein and naringenin were used for the Western Blot analysis. Induction of phospho-JNK and phospho-ERK activity was observed after two hour incubation of PC3-AP1 cells with flavonoids. However no induction of phospho-p38 activity was observed. Furthermore, pretreating the cells with specific inhibitors of JNK reduced the AP-1 luciferase activity that was induced by genistein while pretreatment with MEK inhibitor reduced the AP-1 luciferase activity induced by kaempferol. The pharmacological inhibitors did not affect the AP-1 luciferase activity induced by apigenin and naringenin. These results suggest the possible involvement of JNK pathway in genistein induced AP-1 activity while the ERK pathway seems to play an important role in kaempferol induced AP-1 activity.

플라보노이드의 항암 효능과 면역중재성 항암 작용 및 기작

이제형,이용규 한국식품영양과학회 2019 한국식품영양과학회지 Vol.48 No.8

The side effects resulting from chemotherapy for cancer treatment are mostly related to immunosuppression or reduced immunity. To prevent such side effects, many studies have started focusing on natural dietary substances that have immunomodulatory effects. Flavonoids have been a particular focus of such research because they are known, for over 20 years, to have outstanding antioxidant and anti-inflammatory effects. New molecular targets of anticancer activities continue to be discovered and a comprehensive overview of various anticancer immunity studies is soon expected, and so this current study reviews the recent study results on flavonoids (quercetin, hesperidin, epigallocatechin, genistein, luteolin, kaempferol, apigenin), their anticancer activities, their anticancer immunity, their anti-inflammatory cancer suppression activity, and the mechanism of these actions. In particular, immunomodulatory flavonoids activate effector cells like macrophages, NK cells, and neutrophil granulocytes, and these cells then infiltrate themselves into tumor to slay these malignant cancer cells. Immunomodulatory flavonoids also suppress the formation and growth of tumor by suppressing TR cells, activating TC and TH cells, increasing IFN-γ, and decreasing PD-L1, IL-1 and TLR. Fortunately, there were some recent clinical reports on flavonoids preventing cancer recurrence. However, the number of reports is not enough to support flavonoids’ clinical effects and adoption as a standard treatment, because their bioavailability is low. Despite the low bioavailability, flavonoids are highly effective and safe, and each flavonoid has different molecular targets in a cell. That is why more in-depth studies are needed to find the results of combined treatment of various flavonoids or flavonoids treatment combined with other pharmaceutical substances. 암 치료 시 화학요법제로 인한 부작용의 대부분은 면역 억제 또는 면역력 저하와 관련되어 있다. 이러한 부작용을 방지하기 위하여 면역중재성 식이 천연물에 많은 관심이 집중되고 있다. 플라보노이드는 2000년도 이전부터 항산화 작용과 항염증 작용이 뛰어난 물질로 알려져 오면서 이 물질의 항암 효능에 관하여 여러 연구들이 이루어졌다. 항암 작용의 연구를 위한 여러 분자 타깃이 새로이 발견되고 면역중재성 항암 작용에 대한 포괄적인 분석이 요구됨에 따라서 본 연구는 최근에 보고된 결과를 중심으로 플라보노이드(퀘르세틴, 헤스페리딘, 에피갈로카테친, 제니스타인, 루테올린, 켐페롤, 아피게닌)의 항암 효능, 면역중재성 항암 작용, 항염증성 종양 억제 작용과 그의 작용 기전을 확인하였다. 특히 면역중재성 플라보노이드는 종양에 대항하기 위하여 마크로파지, NK 세포, 호중구와 같은 효과 세포(effector cell)를 활성화시켜 이를 종양에 침투시키고 대항할 뿐 아니라, TR 세포 억제, TC와 TH 세포 활성화, IFN-γ 증가, PD-L1 감소, IL-1 감소 및 TLR 감소를 통하여 종양 생성 및 증식을 억제하는 것으로 보고되고 있다. 이러한 플라보노이드의 탁월한 효능과 함께 최근에는 암의 재발을 억제한다는 임상적 사례도 보고되고 있지만, 임상적 효능과 적용에 관한 사례는 부족하다. 이는 플라보노이드의 생체이용률이 약하기 때문으로 알려졌는데, 이러한 문제점들을 극복하기 위하여 플라보노이드 구조의 활성기 보존 및 임상적 적용에 대한 여러 연구도 진행되고 있다. 플라보노이드는 생체이용률은 낮지만, 효능과 안전성이 뛰어나며 각각의 플라보노이드는 세포 내의 작용점이 다르다는 장점을 고려할 때 여러 플라보노이드와의 병용 또는 다른 치료 약물과의 병용으로 나타나는 반응 또는 상승 효능에 대해 많은 연구 결과가 요구된다.

Anti-adipogenic effect of the flavonoids through the activation of AMPK in palmitate (PA)-treated HepG2 cells

Priyanka Rajan,Premkumar Natraj,Sachithra S. Ranaweera,Lakshi A. Dayarathne,Young Jae Lee,Chang-Hoon Han 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.1

Background: Flavonoids are natural polyphenols found widely in citrus fruit and peel that possess anti-adipogenic effects. On the other hand, the detailed mechanisms for the anti-adipogenic effects of flavonoids are unclear. Objectives: The present study observed the anti-adipogenic effects of five major citrus flavonoids, including hesperidin (HES), narirutin (NAR), nobiletin (NOB), sinensetin (SIN), and tangeretin (TAN), on AMP-activated protein kinase (AMPK) activation in palmitate (PA)-treated HepG2 cells. Methods: The intracellular lipid accumulation and triglyceride (TG) contents were quantified by Oil-red O staining and TG assay, respectively. The glucose uptake was assessed using 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) assay. The levels of AMPK, acetyl-CoA carboxylase (ACC), and glycogen synthase kinase 3 beta (GSK3β) phosphorylation, and levels of sterol regulatory element-binding protein 2 (SREBP-2) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) expression were analyzed by Western blot analysis. The potential interaction between the flavonoids and the γ-subunit of AMPK was investigated by molecular docking analysis. Results: The flavonoid treatment reduced both intracellular lipid accumulation and TG content in PA-treated HepG2 cells significantly. In addition, the flavonoids showed increased 2-NBDG uptake in an insulin-independent manner in PA-treated HepG2 cells. The flavonoids increased the AMPK, ACC, and GSK3β phosphorylation levels and decreased the SREBP-2 and HMGCR expression levels in PA-treated HepG2 cells. Molecular docking analysis showed that the flavonoids bind to the CBS domains in the regulatory γ-subunit of AMPK with high binding affinities and could serve as potential AMPK activators. Conclusion: The overall results suggest that the anti-adipogenic effect of flavonoids on PA-treated HepG2 cells results from the activation of AMPK by flavonoids.

In Vitro 에서 Phosphatidate Phosphohydrolase 활성과 HepG2 세포증식에 미치는 Hesperidine, Naringin 및 그 Aglycone Flavonoid의 영향

차재영,조영수,Cha, Jae-Young,Cho, Young-Su 한국응용생명화학회 1997 Applied Biological Chemistry (Appl Biol Chem) Vol.44 No.4

Effects of four citrus flavonoids, hesperidin, naringin and their aglycones on phosphatidate phosphohydrolase(PAP, EC 3.1.3.3) activity were examined using isolated rat microsomes as an enzyme source. In addition, these flavonoids were tested to see whether they exert any influence on the proliferation and growth in cultured human hepatocytes HepG2 cells. Flavonoids at concentration up to $10{-4}M$ had no significant effect on the number of cells and cell proliferation by MTT cell growth assay method, whereas aglycone flavonoids, hesperetin and narigenin, at concentration of $10{-3}M$ significantly inhibited cell proliferation. Hesperetin inhibited PAP activity in a dose-dependent manner starting at concentration of $10{-5}M$. Narigenin at concentration of $10{-2}M$ inhibited PAP activity markedly, while the other flavonoids did not show any significant effect. The present study, therefore, demonstrated that aglycone flavonoids exerted portent effects on PAP activity and on cell proliferation. 감귤류에 포함되어있는 성분중, 생리활성물질로 거론되어지고 있는 citrus flavonoid 즉, hesperidin, hesperetin, naringin 및 naringenin 4종류를 가지고 간장triglyceride합성의 율속효소로 알려져 있는 phosphatidate phosphohydrolase 활성에 대하여 in vitro계에 미치는 영향과 이들 flavonoid가 HepG2 세포의 생존율 및 증식에 미치는 영향에 대해서도 함께 검토하였다. 그 결과 본 실험에 사용된 모든 flavonoid 는 $10{-4}M$ 농도까지는 세포생존율 및 증식이 최고에 도달하였으나, $10{-3}M$ 농도에서 aglycone flavonoid는 현저한 저해효과를 나타냈다. naringin 및 hesperidin의 glycoside flavonoid는 첨가한 모든 농도에서 PAP활성을 촉진시키는 경향을 나타내었다. 그러나, aglycone flavonoid인 hesperetin은 PAP활성을 농도 의존적으로 저해하였으며, naringenin은 $10{-2}M$ 농도에서 강한 저해효과를 나타내었다. 이러한 결과로 미루어 볼 때 aglycone flavonoid가 생체내에서 세포 생존율, 증식 및 지질대사에 강한 영향을 미칠 것으로 생각되어진다.

Quali-Quantitative Analysis of Flavonoids for Mulberry Leaf and Fruit of ‘Suhyang’

( Wan-taek Ju ),( O-chul Kwon ),( Min-ki Lee ),( Hyun-bok Kim ),( Gyoo-byung Sung ),( Yong-soon Kim ) 한국환경농학회 2017 한국환경농학회지 Vol.36 No.4

BACKGROUND: Globally, mulberry (Morus sp.) is exploited for feeding leaf to silkworms in order to obtain silk fiber or for animal feedstock production. Also, mulberry fruit is known to a by-product that was produced from mulberry tree after harvesting leaves for silkworm rearing, as a yield and consumption of mulberry fruit was increased, it has been fixing to a new income crop .Mulberry leaves and fruits are used for the health benefits of human beings. Mulberry contains various bioactive components, such as alkaloids and flavonoids. Mulberry flavonoids are an important part of the diet because of their effects on human nutrition. The flavonoids in mulberry leaf and fruit of ‘Suhyang’ (Morus alba L.) were determined. METHODSANDRESULTS: Flavonoids form ulberry leaf and fruit of ‘Suhyang’ were analysed using ultrahigh performance liquid chromatography coupled with diode array detection and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF/MS) technique. An UPLCDAD- QTOF/MS system was used, and identification of mulberry leaves constituents was carried out on the basis of the complementary information obtained from LC spectra, MS ions, and MS/MS fragments. The mulberry leaf (16 flavonoids) and fruit (9 flavonoids) were isolated and analyzed from Suhyang using UPLC-DAD-QTOF/MS chromatogram. To the best of our knowledge, Quercetin 3-O-(6''-O-malonyl) glucoside and quercetin 3-O-rutinoside (rutin) was detected on the highest content in leaf and fruit, respectively and further research will be devoted to evaluate their biological activity. CONCLUSION: Obtaining information about the concentration of functional materials in mulberry leaves could contribute to the development and promotion of processed, functional products and offer possible industrial use of ‘Suhyang’, holding promises to enhance the overall profitability of sericulture.

Free Radical Scavenging of Flavonoids and Their Effects on Erythrocyte Na Leak, Platelet Aggregation and TBARS Production

Kang, Jung Sook 제주대학교 방사능이용연구소 2002 연구보고 Vol.16 No.-

We compared radical scavenging activity of flavonoids and their antioxidant effcts on erythrocyte Na leak, platelet aggregation and TBARS production using Sprague Dawley rats. The concentrations of flavonoids scavenging radical by 50%(SC_50) for 0.1mMDPPH were Quercetin; 7.4μM , Catechin; 10.6μM, Morin; 22μM, Hesperidin; 400μM, Naringin; 3.95μM respectively. Morin completed its antioxidant activity in 2minutes while catechin, hesperidin and naringin have slow but long lasting antioxidant activity. Whole blood platelet aggregation when incubated with quercetin or catechin was significantly decreased (P<0.05) compared with the control. Na-leak in intact erythrocyte was significantly lower when incubated with quercetin compared with other flavonoids (P<0.05). Morin, hesperidin and naringin rather increased Na leak in intact erythrocyte. Na-leak in erythrocyte treated with phenazine methosulfate (PMS) was overall increased, but was not affected by flavonoids. Intracelluar Na and K were not affected by treatment of PMS. TBARS production in platelet rich plasma (PRP) was significantly lower (P<0.05) when incubated with quercetin or hesperidin compared with the control. PMS treatment caused an increase in TBARS production regardless of flavonoids. Physiological functions of flavonoids are known to be associated with their radical scavenging activities, possibly preventing oxidative modification in many phases. In the present study, Antioxidant effects of flavonoids were not well correlated with their radical scavenging activities although quercetin which showed the strongest radical scavenging activity had the most antioxidant effects.