Antioxidant activity and analysis of proanthocyanidins from pine (Pinus densiflora) needles

In this study, we evaluated the antioxidant activity of pine needle extracts prepared with hot water, ethanol, hexane, hot water-hexane (HWH), and hot water-ethanol (HWE), using the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical method. The hot water extract possessed superior antioxidant activity than the other extracts. We also compared the antioxidant activity of pine needle extracts through ROS inhibition activity in a cellular system using MC3T3 E-1 cells. The hot water extract exhibited the lowest ROS production. The pattern of HPLC analysis of each extract indicated that the hot water extract contained the highest proanthocyanidin level. The pine needle hot-water extract was then isolated and fractionated with Sephadex LH-20 column chromatography to determine the major contributor to its antioxidant activity. The No.7 and 12 fractions had high antioxidant activities, that is, the highest contents of proanthocyanidins and catechins, respectively. These results indicate that the antioxidant activity of procyanidins from the hot water extract of pine needles is positively related to not only polymeric proanthocyanidins but also to monomeric catechins. Moreover, the antioxidant activity of the pine needle hot water extract was similar to well-known antioxidants, such as vitamin C. This suggests that pine needle proanthocyanidins and catechins might be of interest for use as alternative antioxidants.     

原花青素B2对H2O2诱导的星形胶质细胞氧化损伤和凋亡的保护作用及机制研究[①]

摘要：目的 本研究旨在探讨原花青素B2（proanthocyanidin B2, PC-B2）对过氧化氢（H2O2）诱导的小鼠星形胶质细胞（astrocytes, AS）氧化损伤和凋亡的保护作用及其机制。方法 利用C57BL/6新生小鼠（1-3 d）分离、培养AS,通过随机数字表法分为正常组、正常+PC-B2组（100 μg·mL-1的PC-B2处理24 h）、H2O2模型组（200 μmol·L-1的H2O2处理24 h）、H2O2+PC-B2组（200 μmol·L-1的H2O2与100 μg·mL-1的PC-B2共同处理24 h）;CCK-8法检测各组细胞存活率,LDH法进行细胞毒性检测;ELISA试剂盒检测各组细胞中MDA含量以及SOD、CAT和GSH-Px活力;TUNEL染色法检测各组细胞凋亡情况;RT-PCR和Western Blot分别检测AS中Bax、Bcl-2、Caspase-3、Akt/Stat3、p-Akt、p-stat3、Nrf2/HO-1的mRNA和蛋白表达水平。结果 PC-B2能够明显增强细胞活力,抑制AS凋亡。并且与H2O2模型组相比,PC-B2干预能够显著降低AS中LDH、MDA含量,提高SOD、CAT和GSH-Px活力,抑制Bax,caspase-3的mRNA和蛋白表达,上调Akt/Stat3、Bcl-2、Nrf2/HO-1的mRNA和蛋白表达。结论 PC-B2能够通过Akt/Stat3和Nrf2/HO-1途径增强AS抗氧化能力,减轻H2O2诱导的AS氧化损伤和凋亡。     

葡萄籽原花青素对人卵巢癌裸鼠移植瘤细胞增殖和凋亡的影响

目的 探讨葡萄籽来源的原花青素对人卵巢癌裸鼠皮下移植瘤增殖和凋亡的影响和机制.方法 建立24只人卵巢癌裸鼠皮下移植瘤模型,分成3组(n=8):原花青素高浓度组(200 ms/kg)、原花青素低浓度组(100 mg/kg)、空白对照组.观察各组裸鼠皮下移植瘤生长情况,HE染色观察肿瘤细胞形态,流式细胞分析细胞凋亡,RT-PCR,Westernblot检测肿瘤细胞Bax,Caspase-3在RNA及蛋白水平的表达情况.结果 原花青素处理组皮下移植瘤抑瘤率分别为34.303%、28.594%,与对照组相比差异具有显著性(P<0.05);治疗组肿瘤细胞出现明显的凋亡形态学变化,流式细胞检测治疗组肿瘤细胞凋亡率分别为67.965%,24.650%;原花青素还可以明显增高Bax、Caspase-3 RNA和蛋白的表达,且呈浓度依赖性.结论 葡萄籽原花青素对卵巢癌皮下移植瘤生长有抑制作用,并促进其凋亡,其作用可能通过增强Bax、Caspase-3的表达而实现.     

葡萄多酚在糖尿病视网膜病变中的抗氧化作用及其机制

背景 目前认为,糖尿病视网膜病变（DR）的发病和进展可能与氧化应激有关联.研究表明,葡萄多酚（GSPE）在多种系统性疾病中发挥强大的抗氧化作用,但其在DR中的作用及其机制尚不完全清楚.目的 探讨GSPE对糖尿病的视网膜是否具有保护作用,并分析其作用机制.方法 按照随机数字表法将30只SPF级成年Wistar大鼠随机分为对照组、糖尿病组和糖尿病＋GSPE组,用100 mg/kg枸橼酸缓冲液制备链脲佐菌素（STZ）的一次性腹腔内注射法制备大鼠糖尿病模型,对照组大鼠以同样的方法注射等容量枸橼酸缓冲液.造模即日起,糖尿病＋GSPE组大鼠用GSPE溶液灌胃,每天250 mg/kg,共56 d;糖尿病组和对照组大鼠用等量蒸馏水灌胃.动物饲养至第8周处死,分离视网膜,苏木精-伊红染色法,观察各组大鼠视网膜形态学改变;部分视网膜制备组织匀浆,分别检测大鼠视网膜中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）活性及丙二醛（MDA）含量;用免疫组织化学对各组大鼠视网膜中核红细胞相关因子2（Nrf2）的表达进行定性和定位分析,用Western blot法对大鼠视网膜中Nrf2和血红素加氧酶1（HO-1）蛋白的表达进行定量分析;TUNEL法测定各组大鼠视网膜细胞的凋亡情况并进行比较.结果 实验后8周,糖尿病组和糖尿病＋GSPE组大鼠血糖水平明显高于对照组,而体质量明显低于对照组,差异均有统计学意义（P＜0.01）.对照组大鼠视网膜结构正常,糖尿病组大鼠视网膜组织疏松,各层细胞排列不规则,视网膜神经纤维层、视神经节细胞（RGCs）层以及内丛状层（IPL）变薄,而糖尿病＋GSPE组大鼠视网膜形态的异常轻于糖尿病组.3个组间SOD和GSH-Px活性及MDA含量均明显不同,差异均有统计学意义（F=11.010,P=0.001;F=12.072,P=0.000;F=25.224,P=0.000）,其中糖尿病组大鼠SOD和GSH-Px活性均明显低于对照组和糖尿病＋GSPE组,而MDA含     

葡萄籽原花青素的药理学研究进展

原花青素是一类广泛存在于植物界的多酚化合物的总称,其中以葡萄籽的含量最为丰富。研究表明,葡萄籽原花青素具有清除自由基、抗氧化、抗肿瘤、抗动脉粥样硬化、抗辐射等药理作用,对多个系统的疾病具有一定的治疗作用。作为一种天然抗氧化剂,葡萄籽原花青素符合现代人们对高效、低毒药物的需求,具有广阔的开发前景。本文就葡萄籽原花青素在心血管系统疾病、癌症、男性生殖系统疾病、眼科疾病等方面的研究进展进行综述,并讨论了其与抗氧化和清除自由基能力相关的作用机制,为葡萄籽原花青素的进一步开发和利用提供参考。     

Remineralising effects of fluoride varnishes containing calcium phosphate on artificial root caries lesions with adjunctive application of proanthocyanidin

ObjectivesTo evaluate the remineralising effects of fluoride (F) varnishes containing bioavailable calcium-phosphate compound (Ca-P) based remineralisation systems and 5000 ppm F toothpaste (FTP) on root caries lesions (RCLs) and the potential effects of proanthocyanidin (PA) for the treatments of RCLs when used as an adjunct to F regimens.MethodsDemineralised root dentine and a pH-cycling model were used to mimic RCLs and the oral environment. Remineralising effects of MI Varnish^TM (MIV) containing casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) and Clinpro? White Varnish (CPWV) containing tri-calcium phosphate (TCP) along with FTP and PA were evaluated regarding the birefringence, elemental composition, mechanical properties and mineral density of remineralised dentine with Duraphat^TM as a comparison.ResultsMIV, CPWV and Duraphat^TM promoted the incorporation of F into RCLs and increased mineral density but did not change microhardness of root dentine significantly. Surface microhardness increased significantly when MIV or CPWV was used with 5000 ppm FTP. Application of PA with F regimens significantly increased subsurface mineral density. When PA was applied with MIV or CPWV along with FTP, the highest ion uptake and relative mineral gain (%ΔZ) was achieved, and significant increase of microhardness was up to 30 μm depth. Generally, MIV was associated with a higher mineral content gain than CPWV.SignificanceTreatment of carious root surfaces remains challenging due to the complex pathological processes and difficulty in restoring the highly organised structure of root dentine. Treatment strategies targeting both remineralisation and preservation of the dentinal organic matrix have the potential to improve the fluoride-mediated remineralisation approaches.     

原花青素对慢性不可预知性应激小鼠脑内单胺递质的影响

目的 研究原花青素在慢性不可预知性应激（unpredictable chronic mild stress,UCMS）小鼠中的抗抑郁样作用以及对小鼠脑内单胺递质含量的影响。方法 随机将ICR小鼠分为6组：空白对照组,UCMS组,原花青素低、中、高剂量组（UCMS+原花青素12.5,25,50 mg·kg^-1）,氟西汀组（UCMS+氟西汀10 mg·kg^-1）。采用UCMS建立模型组评估小鼠的抑郁和焦虑样行为,采用HPLC测定小鼠海马、额叶皮层和下丘脑中单胺递质的含量。结果 与空白对照组比较,UCMS组小鼠悬尾的不动时间明显增加（P<0.05）,大理石掩埋数目显著增加（P<0.01）;小鼠海马、额叶皮层和下丘脑中的去甲肾上腺素、5-羟色胺和多巴胺的含量均减少;与UCMS组比较,原花青素组能明显逆转上述行为学以及脑内单胺递质含量的改变。结论 UCMS小鼠存在抑郁焦虑样行为学的改变,海马、额叶皮层和下丘脑中单胺递质含量表达异常。原花青素可以改善UCMS小鼠行为学的改变,并调节海马、额叶皮层和下丘脑中单胺递质的表达。     

Inhibitory effects of grape seed proanthocyanidin extract on selenite-induced cataract formation and possible mechanism

This study investigated the inhibitory effect of grape seed proanthocyanidin extract(GSPE) on selenite-induced cataract formation in rats and the possible mechanism.Eighty 8-day-old Sprague-Dawley rats were divided randomly into 5 groups:control group,model group,three GSPE groups(low dose,medium dose and high dose).Control group received subcutaneous injection of physiological saline.Model group was given subcutaneous injection of sodium selenite(20 μmol/kg body weight) on the postpartum day 10,and once every other day for consecutive three times thereafter.GSPE treated groups were respectively administered GSPE at doses of 50,100,and 200 mg/kg body weight intragastrically 2 days prior to the selenite injection(that was,on the postpartum day 8),and once daily for fourteen consecutive days thereafter.The opacity of lenses was observed,graded and photographed under the slit lamp microscopy and the maximal diameter of the nuclear cataract plaques was measured.The lenses were analyzed for superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GSH-PX),malondialdehyde(MDA),calcium(Ca 2+),nitric oxide(NO) and anti-hydroxyl radical ability(anti-OH).The histomorphology of lenses was observed with HE staining under a light microscope.The levels of calpainⅡ,and iNOS protein and mRNA expression in lenses were detected by using immunohistochemistry and real-time quantitative RT-PCR.The results showed subcutaneous injection of sodium selenite led to severe nuclear cataract in model group,and the achievement ratio of model group was 100%.As compared with model group,the degree of lenses opacity and the maximal diameter of nuclear cataract plaques were significantly reduced in GSPE-treated groups.Moreover,we observed selenite treatment caused a significant decrease in the activities of antioxidative enzymes(SOD,CAT,GSH-PX) and anti-OH ability,accompanied by a significant increase in the levels of MDA,NO,Ca 2+ as well as iNOS,and calpainⅡ protein and mRNA expression.Administration of GSPE could dose-dependently pre     

原花青素对大鼠视网膜缺血再灌注损伤后视神经的保护作用

目的探讨原花青素对大鼠高眼压视网膜缺血再灌注损伤后视神经的保护作用。方法用眼内灌注法,前房灌注林格液制成实验性高眼压视网膜缺血再灌注损伤模型。将70只Wistar大鼠随机分为正常对照组(10只)、模型对照组(30只)和原花青素干预组(30只)。模型对照组和原花青素干预组根据再灌注的时间不同分为1、3和7 d组,每组各10只。各组于造模前5 d开始用药,原花青素干预组每天用原花青素混悬液300 mg.kg-1灌胃,正常对照组、模型对照组分别给予灌注等量蒸馏水,每日分2次给药。造模后各组仍继续按原方案给药。造模后分别在1、3、7 d脱颈处死大鼠,迅速摘除眼球取出视网膜。利用双抗体夹心酶联免疫吸附法检测各组大鼠视网膜中超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、神经元型一氧化氮合酶(nNOS)的表达水平。结果再灌注1 d,模型对照组nNOS的表达水平开始增高,3 d达高峰,7 d后逐渐下降。再灌注各时间点,模型对照组视网膜内nNOS阳性表达明显增多,MDA含量持续升高,SOD活性持续下降,与正常对照组比较,差异有统计学意义(P<0.01)。各时段原花青素干预组与模型对照组比较,视网膜内nNOS阳性神经元明显减少(P<0.01),MDA含量降低(P<0.01),SOD活性升高(P<0.01);与正常对照组比较,差异无统计学意义(P>0.05)。结论原花青素可通过提高视网膜组织中SOD活性,降低MDA含量,减少视网膜组织中nNOS表达,对大鼠视网膜缺血再灌注损伤有一定的保护作用。