Investigation of in vitro antioxidant activity of dihydromyricetin and flavonoids rich extract from vine tea(Ampelopsis grossedentata)

Background:Vine tea from fermented Ampelopsis grossedentata leaves has been used as a herbal tea and folk medicine in the southern region of China for hundreds of years.The aim of this investigation was to analyze the total flavonoids found in vine tea,including three bioactive flavonoids,and the total phenolic contents in the aqueous methanol extracts of 10 vine tea samples.In addition,this study also aimed to examine the antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract.Methods:The total flavonoids and total phenolic content assay of extracts from vine tea were performed by ultraviolet-visible spectroscopy and epoch microplate spectrophotometer,respectively.Three bioactive flavonoids were quantified simultaneously using high performance liquid chromatography.The antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract was evaluated in vitro using six different methods.Results:Vine tea contained a large number of flavonoids,with dihydromyricetin as its main constituent.The flavonoid-rich extract exhibited a significant scavenging effect on superoxide anion radicals,and on 3-ethylbenzthiazoline-6-sulphonic acid and 1,1-diphenyl-2-picrylhydrazyl radicals.It also possessed definite activity in lipid peroxidation inhibition,ferric reduction,and the moderation of Fe2+ion chelation ability.There was a significant negative correlation between dihydromyricetin content and antioxidant activity in the vine tea samples,including superoxide anion radical scavenging activity(P=−0.754,P<0.05),lipid peroxidation inhibition activity(P=−0.759,P<0.05),ferric-reducing antioxidant power(P=−0.843,P<0.01),respectively.Dihydromyricetin played a dominant role in the antioxidant activities of the flavonoid-rich extract.Conclusion:Vine tea’s flavonoid-rich extract could be used as a new antioxidant source to safeguard against oxidative stress.

Study on Extraction and Separation of Dihydromyricetin from Vine Tea [Ampelopsis grossedentata(Hand-Mazz) W. T. wang]

Ampelopsis grossedentata(Hand-Mazz) W. T. wang is a typical edible plant with important physiological health functions. Dihydromyricetin is the main active ingredient of A. grossedentata, which has good pharmacological effects such as antibacterial, anti-inflammatory, anti-oxidation, anti-tumor and liver protecting effects. This paper summarized the research progress on the extraction materials, extraction methods and separation and purification processes of dihydromyricetin in A. grossedentata to understand the best experimental method of dihydromyricetin, aiming to provide an important theoretical basis for the comprehensive development and utilization of dihydromyricetin.

Effects of Dihydromyricetin Extracted from Ampelopsis grossedentata on Visceral Organ Indexes and Intestinal Digestive Enzyme Activities of Chickens

To provide a reference basis for reasonable development and utilization of Ampelopsis grossedentata resource and its application in production,we added 0.025%,0.05% and 0.1% dihydromyricetin（DMY）extracted from A.grossedentata into the basal diets of Yaoshan chickens,and studied the effects of DMY on visceral organ indexes and digestive enzyme activities of 40-day-old healthy Yaoshan chickens.Supplementation of DMY in basal diets influenced visceral organ weight,organ index,length and digestive enzyme activity of small intestine of chickens.Among them,0.05% DMY was the most appropriate volume for supplementation.Compared with control group（without DMY）,0.05% DMY reduced lung weight and index（P〉0.05）,significantly reduced liver weight（P〈0.05）,extremely reduced stomach weight and stomach index（P〈0.01）,increased activity of amylase in small intestine（P〉0.05）,significantly increased length of small intestine and activity of protease（P〈0.05）.Supplementation of 0.05% DMY reduced the visceral organ weight and organ index,enhanced digestion and absorption ability of gastrointestinal tract,thereby improving feed utilization rate and promoting the growth of chickens.

藤茶复合汤汁抗大鼠血栓功效研究

采用下腔静脉结扎术构建大鼠血栓模型,以藤茶(Ampelopsis grossedentata)复合汤汁进行干预,并以二氢杨梅素及藤茶汤汁为对照。测定大鼠血栓的重量、长度及血栓抑制率,结合HE染色和免疫组化分析血栓样品的理化指标。结果表明,藤茶复合汤汁中总黄酮(1.43±0.11 mg/mL)及二氢杨梅素(0.66±0.05 mg/mL)含量均低于藤茶汤汁和二氢杨梅素溶液的含量。模型组大鼠血栓长度(10.98±1.20 mm)、湿重(70.6±15.44 mg)和干重(9.9±3.2 mg)显著高于正常组。相比于其他干预组,藤茶复合汤汁组的血栓长度(3.92±0.64 mm)和血栓面积占管腔面积百分比(32.1%±1.4%)明显降低,而血栓抑制率(64.5%±1.3%)和溶解率(54.2%±1.3%)显著升高。HE染色及免疫组化分析表明,相比模型组藤茶复合汤汁组大鼠血管细胞完整性损伤程度降低,核固缩现象程度明显减轻,阳性细胞率明显增加,血栓素1相对表达量(25.2%±2.1%)显著降低,说明藤茶复合汤汁具有较好的抗血栓作用。

油茶中幼林复合经营藤茶技术及效益分析

通过研究油茶(Camellia oleifera Abel.)林下栽培藤茶(Ampelopsis grossedentata)复合经营模式,介绍了具体栽培技术,对该模式下经济效益、社会效益和生态效益进行了分析。结果表明,油茶中幼林下套种藤茶是科学可行的,油茶中幼林复合经营藤茶的投资收益是油茶单作模式的4.27倍,可为油茶中幼林经营管理的林下经济模式提供参考。

藤茶中二氢杨梅素的研究

比较分析了不同产地藤茶(Ampelopsis grossedentata)嫩叶中二氢杨梅素(DMY)的含量,结果发现,DMY含量按照从高到低排序为云南省丽江市、广西壮族自治区金秀瑶族自治县、福建省武平县、湖南省张家界市、湖北省恩施土家族苗族自治州来凤县。云南省丽江市产藤茶DMY含量显著高于其他地区,湖北省恩施土家族苗族自治州来凤县产藤茶DMY含量显著低于其他地区,其他3个地区无显著差异。在此基础上,采用超声、微波、破壁式3种方式辅助乙醇溶剂提取藤茶中DMY成分,微波辅助乙醇使用量较少、提取时间短、料液比相对较低,可达到绿色、节能、高效的提取状态。

运用组织培养建立藤茶快速繁殖体系的研究

以带芽的藤茶(Ampelopsis grossedentata)茎段为试验材料,研究藤茶组织培养过程中各个阶段的培养基和激素配比以及炼苗的基质配比。结果表明,藤茶组培苗的快速繁殖体系中,最佳初代培养基为MS+1.5 mg/L 6-BA+0.2 mg/L NAA+2 g/L PVP;初代茎段培养愈伤组织的最佳基质配比为MS+4.0 mg/L 6-BA+2.0 mg/L ZT+1.0 mg/L NAA;藤茶芽的最佳增殖培养基为MS+2.0 mg/L 6-BA+1.0 mg/L NAA+2.0 mg/L ZT;最佳壮苗培养基为MS+1.0 mg/L 6-BA+1.0 mg/L NAA;最佳生根培养基为NAA(0.1 mg/L)+IBA(0.5mg/L),生根率可达到86.7%;炼苗阶段最佳移栽基质为泥炭+珍珠岩(2∶1),并浇以改良霍格兰营养液,炼苗和移栽成活率可达73%。

根施硒肥对藤茶二氢杨梅素含量与硒含量的影响

以藤茶(Ampelopsis grossedentata)为试验材料,采用随机区组试验,研究根施硒肥对藤茶二氢杨梅素含量与硒含量的影响。结果表明,6—10月藤茶二氢杨梅素含量呈先升后降的趋势;同一采收期内不同处理藤茶二氢杨梅素含量呈先升后降的趋势;适量硒肥对藤茶二氢杨梅素含量升高有促进作用。

藤茶转录组SSR分子标记开发与初步验证

利用MISA软件对藤茶转录组测序获得的92472条Unigene进行SSR位点信息分析,共检测到单核苷酸至六核苷酸重复类型的SSR位点34420个,分布在27096条Unigene中,出现频率为37.22%,平均分布距离为31.69 kb。SSR重复类型主要以单核苷酸重复为主,占66.11%,其次是二、三核苷酸,各占19.95%和12.52%。34420个SSR位点中共发现77种重复基序,重复次数在5~24次之间,其中出现频率高的基序有A/T、AG/CT、AT/AT、AC/GT、AAG/CTT和AAT/ATT。利用Primer 3.0共设计得到34440对SSR引物,从中随机选取40对引物进行PCR扩增检测,有30对引物扩增出预期大小的条带,其中9对引物在8份藤茶种质材料中表现出多态性。以上结果表明,基于藤茶转录组序列的SSR标记开发是有效可行的,开发的SSR标记为后续藤茶种质资源鉴定及遗传多样性分析等研究提供了科学依据。