In vitro and in vivo antioxidant activities of three major polyphenolic compounds in pomegranate peel: Ellagic acid, punicalin, and punicalagin

Pomegranates is abundant in polyphenols and is well-known for its antioxidant activity. Punicalagin （PG） is a major poly- phenolic compound in the pomegranate peel. In certain conditions, PG can be hydrolyzed to punicallin （PL） and ellagic acid （EA）, and PL can be further hydrolyzed to EA. PG, PL, and EA all play important roles in the antioxidant activity of pomegranate peels. This study was conducted to compare the in vitro antioxidant activity and in vivo anti-oxidative stress effects of PG, PL, and EA. For the in vitro test, 2,2-diphenyl-l-picrylhydrazyl radical （DPPH.） and superoxide anion （O2~） scavenging capacities, ferric-reducing antioxidant power （FRAP）, and lipid peroxidation （LPO） inhibition capacities of PG, PL, and EA were tested. For the in vivo test, oxidatively stressed mice, which were induced by oxidized fish oil, were administrated PG, PL or EA （10 mg kg-1 d-1） for 21 days. The results showed that the in vitro antioxidant activity trends were EA〉PG〉PL〉Trolox in scavenging DPPH., PG〉PL〉EA=Trolox in scavenging O2~, EA〉PG=PL〉Trolox in FRAP, and Trolox〉PG〉EA〉PL in LPO inhibition. In the in vivo test, the EAt＇reatment increased the average daily weight gain and total antioxidant capacity （T-AOC） in the plasma （P〈0.05）, liver （P〈0.05）, and intestine （P〈0.05） in oxidatively stressed mice. It increased the superoxide dismutase （SOD） activity in the liver （P〈0.05） and intestine （P〈0.05）. It increased the glutathi- one peroxidase （GSH-Px） activity in the intestine （P〈0.05） and the intestinal villus height to crypt depth ratio （P〈0.05）. EA treatment decreased the malondialdehyde （MDA） content in the plasma （P〈0.05）, liver （P〈0.05）, and intestine （P〈0.05） and the mRNA expressions of the pro-inflammatory factors, TNF-a （P〈0.05）, IFN-y （P〈0.05） and IL-6 （P〈0.05）. PL increased the SOD （P〈0.05） and GSH-Px activities （P〈0.05） in the intestine and decreased the MDA content （P〈0.05） and the mRNA expressions of TNF-a （P〈0.05） and IL-6 （P〈0.05） in the intestine. PG increased the SOD activity （P〈0.05） and GSH-Px activity （P〈0.05） in the intestine and decreased the MDA content in the intestine （P〈0.05） and IL-6 mRNA expression in the intestine （P〈0.05）. In summary, EA, PL, and PG all had powerful in vitro antioxidant capacities, and they had different antioxidant advantages in acting against different types of radicals; EA was more effective than PL and PG in protecting against oxidative injury in vivo, especially for intestinal injury. These findings suggest that multiple polyphenol compounds in pomegranate peel may exert superior antioxidant activity than single purified polyphenols; when using pomegranate peels as health-promoting additive in animal feed, raising EA content by methods of hydrolysis or fermentation in advance could achieve better effects.

石榴皮多酚类成分——安石榴林的研究进展

安石榴林是石榴皮中一种重要的鞣花单宁,也称石榴皮鞣素,具有抗氧化、抗菌、抗病毒、抗炎等多种药理学功效。本文主要对国内外关于安石榴林的研究进行了综述,详细阐述了安石榴林的结构、提取分离方法、含量测定、药理活性及代谢方式等研究进展,以期为安石榴林的开发应用提供参考依据。

HPLC法同时测定石榴皮中4种多酚类成分的含量

建立同时测定石榴皮中没食子酸、石榴皮鞣素、安石榴苷和鞣花酸的含量的高效液相色谱法。方法:色谱柱为Thermo ODS-2 Hypersil柱(4.6 mm×250 mm,5μm),流动相为甲醇-0.2%磷酸溶液梯度洗脱,流速为1.0 m L·min-1,检测波长为272 nm,柱温为室温。结果表明:没食子酸在2.448~19.58μg·m L^(-1)(r=0.9998)的浓度范围内、石榴皮鞣素在20.80~166.4μg·m L^(-1)(r=0.9998)的浓度范围内、安石榴苷在80.00~640.0μg·m L^(-1)(r=0.9997)的浓度范围内,鞣花酸在40.10~320.8μg·m L^(-1)(r=0.9995)的浓度范围内与其峰面积呈良好的线性关系;平均回收率分别为99.8%、100.1%、99.5%、和99.9%,RSD分别为0.87%、1.2%、1.2%和1.3%。本文所建立方法快速准确,专属性强,重复性好,可为全面控制石榴皮质量提供依据。

RP-HPLC法同时测定石榴皮中4种多酚类成分的含量

目的:建立同时检测石榴皮中没食子酸、石榴皮鞣素、安石榴苷和鞣花酸含量的方法。方法:采用反相高效液相色谱法。色谱柱为ArcusEP-C18(250mm×4.6mm,5μm),流动相为甲醇-0.1%三氟乙酸(梯度洗脱),流速为1.0ml/min,检测波长为254nm(没食子酸)、377nm(石榴皮鞣素、安石榴苷和鞣花酸)。结果:没食子酸、石榴皮鞣素、安石榴苷和鞣花酸的进样量分别在0.020～0.320、0.038～0.608、0.074～1.184、0.039～0.624μg范围内与各自峰面积积分值呈良好线性关系(r分别为0.9997、0.9971、0.9978、0.9994);平均加样回收率分别为93.22%、95.35%、98.00%、99.84%,RSD分别为2.75%、2.28%、2.11%、1.82%(n均为6)。结论:本方法精密、可靠,可作为检测石榴皮中没食子酸、石榴皮鞣素、安石榴苷和鞣花酸4种有效成分的方法。

田口法优化石榴皮中3种活性成分的提取工艺

采用田口法优化乙醇回流提取石榴皮中3种酚酸——安石榴林、安石榴苷和鞣花酸,并使3种成分产率达到最大。通过单因素试验和田口法优化显著影响石榴皮提取的因素,包括乙醇体积分数、提取温度、提取时间、液料比、粒径和提取次数。结果表明,优化后取得的乙醇体积分数、提取温度、提取时间、液料比、粒径和提取次数分别为20%、70℃、2 h、50︰1(mL/g)、0.125 mm和提取2次。在这些最佳条件下,从1 g干燥的石榴皮粉末中可获得17.89±0.27 mg安石榴林、498.66±2.13 mg安石榴苷、7.30±0.05 mg鞣花酸,与预测值17.94 mg安石榴林、497.44 mg安石榴苷、7.26 mg鞣花酸符合。因此,达到利用田口法使安石榴林、安石榴苷和鞣花酸3种成分产率最大的目标。

Punica granatum果实皮甲醇提取物化学成分的分离和标准化(英文)

AIM:The present study was undertaken to isolate and standardize the various active phytochemical constituents present in the fruit rinds of Punica granatum.METHODS:Fruit rinds of Punica granatum were dried and extracted with methanol in a static extractor;the percentage yield of the methanolic extract (MEPG) was found to be 26%;the methanolic extract was partitioned using n-butanol,ethyl acetate and water;the percentage yield of the fractions were found to be 17.16%,26.88% and 47.72% respectively.HPLC was carried out for all the fractions and the markers corresponding to the major peaks in HPLC were isolated using column chromatography.The isolated markers were characterized using UV,IR,Mass and NMR spectroscopy.RESULTS & CONCLUSION:Totally four compounds were isolated and identified as punicalin,punicalagin,gallic acid and ellagic acid based on UV,IR,Mass and NMR data,they were standardized by HPLC.