Flavonoids in cardiovascular health and diseases

【金仁謙，博士，韓國藥理學(xué)會理事長，慶北國立大學(xué)藥學(xué)院藥理學(xué)系教授，慶北國立大學(xué)藥學(xué)院心血管研究所所長；主要研究方向：高血壓和心臟代謝綜合征發(fā)病機(jī)制?！?/p>

Flavonoids,which are a large,diverse group of bioactive polyphenolic compounds found in plants,are known to confer anti-inflammatory and anti-oxidant benefits.The six main classes of flavo?noids(with examples of foods that provide them to adults)are as follows:anthocyanidins(fruits,especially berries),flavan-3-ols(tea),flavanones(citrus fruits and juices),flavones(tea,peppers,and celery),flavonols(tea,onions,and potatoes),and isoflavones(soy products).【黃酮類化合物是從植物中發(fā)現(xiàn)的一大類具有多種生物活性的多酚類化合物，具有抗炎和抗氧化的功效。6類主要黃酮類化合物如下：花青素（水果，尤其是漿果）、黃烷醇（茶）、二氫黃酮（柑橘類水果和果汁）、黃酮類（茶、辣椒和芹菜）、黃酮醇（茶、洋蔥和土豆）和異黃酮（大豆制品）?！?/p>

Recently,it was also revealed that dietary flavonoid intake is inversely associated with cardio?vascular disease(CVD)risks as assessed by body mass index(BMI)and waist circumference(WC)among adult(≥20 years)participants in What We Eat in America(WWEIA),National Health and Nutrition Examination Survey(NHANES)2007-2010[1].CVD risks are classified into five categories based on BMI and WC(as in National Heart,Lung,and Blood Institute Guide?lines)as follows;average(BMI＜25.0),increased(BMI 25.0-29.9,normal WC),high(BMI 25.0-29.9,large WC;BMI 30.0-34.9,normal WC),very high(BMI 30.0-34.9,large WC;BMI 35.0-39.9),and extremely high(BMI≥40.0).Individu?als were divided into categories of intake of total flavonoids and each flavonoid class,and adjust?ed estimates of the percentages at high+CVD risk were calculated.High+CVD risk classes include high,very high,and extremely high CVD risk categories,but exclude average and increased CVD risk categories.Inverse linear relationships were found between the percentages of adults at high+CVD risk and the intake of total flavonoids,anthocyanidins,flavan-3-ols,and flavanones(P＜0.01).For individuals in the highest(versusthe lowest)intake category of anthocyanidins,flavan-3-ols,and flavanones,their relative risk was 0.86,0.88,and 0.89,respectively.【最近“在美國吃什么（WWEIA）”和“美國國家健康與營養(yǎng)調(diào)查（NHANES）”2007-2010年的研究以體質(zhì)量指數(shù)（body mass index，BMI）和腰圍作為評估指標(biāo)。結(jié)果表明，20歲以上的成年人膳食類黃酮攝入量與心血管疾病風(fēng)險(xiǎn)呈負(fù)相關(guān)［1］。國家心肺血液研究所指南（NHLBI）根據(jù)體質(zhì)量指數(shù)和腰圍，將心血管疾病風(fēng)險(xiǎn)分成以下5類：一般風(fēng)險(xiǎn)（BMI＜25.0）、發(fā)病風(fēng)險(xiǎn)增加（BMI 25.0～29.9，正常腰圍）、高風(fēng)險(xiǎn)（BMI 25.0～29.9，大腰圍；BMI 30.0～34.9，正常腰圍）、很高風(fēng)險(xiǎn)（BMI 30.0～34.9，大腰圍；BMI 35.0～39.9）和極高風(fēng)險(xiǎn)（BMI≥40.0）。將個體按照總黃酮類和各類黃酮類的攝入量分類，并計(jì)算心血管疾病高風(fēng)險(xiǎn)百分比的調(diào)整估計(jì)值。心血管疾病高風(fēng)險(xiǎn)等級包括高、很高和極高心血管疾病風(fēng)險(xiǎn)，但不包括一般風(fēng)險(xiǎn)和發(fā)病風(fēng)險(xiǎn)增加。有心血管疾病高風(fēng)險(xiǎn)的成年人的百分比與總黃酮、花青素、黃烷醇和二氫黃酮的攝入量呈負(fù)線性關(guān)系（P＜0.01）?；ㄇ嗨?、黃烷醇和二氫黃酮攝入量最高個體與最低個體比較，患心血管疾病的相對風(fēng)險(xiǎn)分別是0.86，0.88和0.89?！?/p>

Isoflavones have been a subject of intensive researches that have evaluated their possible hypo?cholesterolemic effects,antioxidant effects,and estrogen-like effects on blood vessels.Investiga?tions in regards to animals and in humans have suggested that dietary soy protein containing isofla?vones can reduce blood pressure,improve lipid profiles,and restore vascular function.The 3 major isoflavones found in soybeans are genistein(4′,5,7-trihydroxyisoflavone),daidzein(4′,7-dihydroxyi?soflavone),and glycitein (6-methoxydaidzein).Soy protein containing isoflavones has been observed to have several beneficial effects on cardiovascular health;a meta-analysis study showed that total cholesterol decreased by 9.3%,triglyc?erides by 10.5%and low-density lipoprotein choles?terol by 12.9%,when an average of 47 g of soy protein was consumed daily.Soybean isofla?vones were believed to inhibit proliferation of vascular smooth muscle and thus contribute to the prevention of atherosclerotic cardiovascular diseases.【異黃酮是重點(diǎn)研究對象，已經(jīng)評價了其可能的降膽固醇、抗氧化和對血管的雌激素樣作用。動物和人類研究均表明，食用含有異黃酮的大豆蛋白可以降低血壓、改善血脂和恢復(fù)血管功能。大豆中發(fā)現(xiàn)的3類主要異黃酮是染料木黃酮（4‘，5，7-三羥基異黃酮）、大豆苷元（4’，7-二羥基異黃酮）和大豆黃素（6-甲基大豆黃素）。含有異黃酮的大豆蛋白對心血管健康有益。一項(xiàng)薈萃分析顯示，如果每天平均攝入47 g大豆蛋白，總膽固醇可降低9.3%、甘油三酯降低10.5%、低密度脂蛋白降低12.9%。大豆異黃酮預(yù)防動脈粥樣硬化性心血管疾病與其抑制血管平滑肌增殖有關(guān)?！?/p>

A number of flavonoids have been reported to modulate vascular relaxation.Flavonoids usually induce endothelium-dependent vasorelaxation,while some of them also exert endothelium-inde?pendent vasorelaxation.We elucidated a molecular mechanism by which isoflavone attenuates vascular contraction.Genistein and daidzein prevented agonist-induced vascular contraction by inhibiting RhoA/Rho-kinase signaling pathway[2].Rat aortic rings were denuded of endothelium,mounted in organ baths,and contracted with 9,11-dideoxy-11α,9α-epoxymethanoprostaglandin F2α (U46619),a thromboxane A2 analogue or KCl 30 min after the pretreatment with genistein,daidzein or vehicle.We determined the phosphorylation level of the myosin light chain(MLC20),myosin phospha?tase targeting subunit 1(MYPT1)and protein kinase C(PKC)-potentiated inhibitory protein for hetero?trimeric myosin light chain phosphatase of 17 ku(CPI17)by means of Western blot.We also mea?sured the amount of GTP RhoA as a marker regarding RhoA activation.The cumulative addi?tions of U46619 or KCl increased vascular tension in a concentration-dependent manner,which was inhibited by pretreatment with genistein or daidzein.Both U46619(30 nmol·L-1)and KCl(50 mmol·L-1)increased MLC20 phosphorylation levels which were inhibited by genistein as well as daidzein.Furthermore,both genistein and daidzein decreased the amount of GTP RhoA activated by either U46619 or KCl.U46619(30 nmol·L-1)increased phosphorylation of the MYPT1Thr855 and CPI17Thr38,which was also inhibited by genistein or daidzein.However,neither genistein nor daidzein inhibited PDBu-induced vascular contraction and CPI17 phosphorylation.In conclu?sion,isoflavone attenuates vascular contraction through inhibition of the RhoA/Rho-kinase signaling pathway.【據(jù)報(bào)道，許多黃酮類化合物可以調(diào)節(jié)血管舒張，通常引起內(nèi)皮依賴性血管舒張，而有些也有非內(nèi)皮依賴性血管舒張作用。我們闡明了異黃酮減弱血管收縮的分子機(jī)制。染料木黃酮和大豆苷元可通過抑制RhoA/Rho激酶信號通路阻止激動劑誘導(dǎo)的血管收縮［2］。兩者預(yù)處理30 min后，去除大鼠主動脈環(huán)內(nèi)皮，放在器官浴中，用血栓素A2類似物（9，11-雙脫氧-11α，9α-環(huán)氧甲醇前列腺素F2α，U46619）或氯化鉀誘導(dǎo)主動脈環(huán)收縮。我們用Western蛋白印跡法檢測了肌球蛋白輕鏈（MLC20）的磷酸化水平，肌球蛋白磷酸酶靶向亞單位1（MYPT1）和磷酸化依賴的肌球蛋白輕鏈磷酸酶抑制蛋白-蛋白激酶C加強(qiáng)的磷酸酶抑制劑17（CPI17），還檢測了RhoA激活的標(biāo)志-GTP RhoA的含量。增加U46619或氯化鉀可濃度依賴性增加血管張力，而染料木黃酮或大豆苷元預(yù)處理可以抑制此效應(yīng)。染料木黃酮和大豆苷元均能抑制U46619（30 nmol·L-1）和氯化鉀（50 mmol·L-1）引起的MLC20磷酸化水平增加，而且均可降低由U46619或氯化鉀激活的GTP RhoA含量。U46619（30 nmol·L-1）增加了 MYPT1Thr855 和CPI17Thr38的磷酸化，染料木黃酮和大豆苷元可抑制此效應(yīng)。然而，無論染料木黃酮還是大豆苷元都不能抑制PDBu誘導(dǎo)的血管收縮和CPI17磷酸化?？傊?，異黃酮通過抑制RhoA/Rho激酶信號通路減弱血管收縮?！?/p>

3’，4’-Dihydroxyflavonol（DiOHF）is a synthetic flavonol with optimized antioxidant properties relative to naturally-occurring flavonols according to struc?ture-activity relationship studies.DiOHF enhances nitric oxide bioavailability through an antioxidant effect and improves vascular function after isch?emia and reperfusion injury or in diabetes in rats.Moreover， DiOHF administered during isch?emia，but shortly before reperfusion，significantly reduced the infarct size and reperfusion injury in anesthetized sheep and goats.In addition，DiOHF causes vascular relaxation of both endotheliumintact and-denuded rat aortas.Compared with a range of natural flavonols，flavones and synthetic flavonols，DiOHF is the most potent vasorelaxant flavonol.DiOHF and flavone decrease vascular contraction through inhibition of the RhoA/Rhokinase pathway in endothelium-denuded rat aorta［3-4］as well as Ca2+desensitization in permeabilized rat mesenteric artery［5］。【3’，4’-二羥基黃酮醇（DiOHF）是合成的黃酮醇。結(jié)構(gòu)-活性關(guān)系研究表明，與天然黃酮醇比較，其具有優(yōu)化的抗氧化性質(zhì)。DiOHF通過抗氧化作用提高了一氧化氮的生物利用度，改善缺血后血管功能和再灌注損傷或大鼠的糖尿病。而且，在缺血期間再灌注之前不久，給予DiOHF能顯著減少麻醉綿羊和山羊的梗死面積和再灌注損傷。此外，DiOHF會導(dǎo)致大鼠內(nèi)皮完整和去內(nèi)皮主動脈血管舒張。與許多天然黃酮醇、黃酮和合成黃酮醇比較，DiOHF是最強(qiáng)效的血管舒張黃酮醇。DiOHF和黃酮通過抑制大鼠去內(nèi)皮主動脈［3-4］的RhoA/Rho激酶途徑以及大鼠透化的腸系膜動脈中的鈣失敏來減輕血管收縮［5］?！?/p>

Thioflavones(2-phenyl-4H-1-benzothiopyran-4-ones)are thio analogues of flavones in which a sulfur atom is substituted for an oxygen atom and can be synthesized from thiosalicylic acid in diverse ways.They have drawn considerable atten?tion because of their profound pharmacological activities such as antimalarial,antibacterial,and antitumor effects as well as inhibitory effect of steroid sulfatase.3′,4′-Dimethoxythioflavone induces endothelium-dependent vasorelaxation through activation of epidermal growth factor receptor[6].【硫代黃酮（2-苯基-4H-1-苯并噻喃）是含硫的黃酮類似物，黃酮的硫原子被氧原子取代，可以以不同的方式由硫代水楊酸合成。由于其具有抗瘧、抑菌、抗腫瘤及抑制甾體硫酸酯酶等藥理作用，引起了廣泛關(guān)注。3′，4′-二甲氧基硫代黃酮通過激活表皮生長因子受體，誘導(dǎo)內(nèi)皮依賴性血管舒張［6］?！?/p>

［1］Sebastian RS，Wilkinson Enns C，Goldman JD，Moshfegh AJ.Dietary flavonoid intake is inversely associated with cardiovascular disease risk as assessed by body mass index and waist circumference among adults in the United States［J/OL］.Nutrients，2017，9（8）：827（2017-08-02）.https：//www.ncbi.nlm.nih.gov/pmc/articles/PMC5579620/

［2］ Seok YM，Baek I，Kim YH，Jeong YS，Lee IJ，Shin DH，et al.Isoflavone attenuates vascular contraction through inhibition of the RhoA/Rhokinase signaling pathway［J］.J Pharmacol Exp Ther,2008,326(3)：991-998.

［3］ Song MJ，Baek I，Seo M，Kim SH，Suk K，Wood OL，et al.Effects of 3′，4′-dihydroxyflavonol on vascular contraction of rat aortic rings［J］.Clin Exp Pharmacol Physiol,2010,37（8）：803-810.

［4］Baek I，Jeon SB，Song MJ，Yang E，Sohn UD，Kim IK.Flavone attenuates vascular contractions by inhibiting RhoA/Rho kinase pathway［J］.Korean J Physiol Pharmacol.2009,13（3）：201-207.

［5］ Kim HY,Seok YM,Woodman OL,Williams SJ,Kim IK.3′,4′-Dihydroxyflavonol reduces vascular contraction through Ca2+desensitization in perme?abilized rat mesenteric artery［J］.Naunyn Schmie?debergs Arch Pharmacol,2012,385(2):191-202.

［6］Jang EJ，Seok YM，Lee JI，Cho HM，Sohn UD，Kim IK.3′，4′-Dimethoxythioflavone induces endo?thelium-dependent vasorelaxation through activation of epidermal growth factor receptor［J］.Naunyn Schmiedebergs Arch Pharmacol，2013，386（3）：339-350.