Assessment of Intestinal Absorption of Vitexin-2″-O-Rhamnoside in Hawthorn Leaves Flavonoids in Rat Using In Situ and In Vitro Absorption Models

The purpose of this study was to investigate the absorption mechanism of vitexin-2″-O-rhamnoside, the index component in hawthorn leaves flavonoids (HLF) in the rat intestine, using two different absorption models, the in situ single-pass intestinal perfusion and the in vitro everted gut sac model. The effective permeability coefficients (P_eff) in the in situ single-pass intestinal perfusion experiments and the apparent permeability coefficients (P_app) in the in vitro everted gut sac experiments were calculated. Furthermore, the influences of the P-glycoprotein inhibitors, verapamil and digoxin, on the intestinal absorption of vitexin-2″-O- rhamnoside in HLF were studied using the above-mentioned two models. Results showed that there were no significant differences in the absorption of vitexin-2″-O-rhamnoside in HLF in four segments of the rat intestine, duodenum, jejunum, ileum, and colon, and at different concentrations of HLF ranging from 0.05 mg/ml to 0.5 mg/ml (P > 0.05). The P_eff values for vitexin-2″-O-rhamnoside in the rat jejunal perfusion at the concentration of 0.05, 0.1, 0.25, and 0.5 mg/ml were (2.48 ± 0.33) × 10^?5; (2.23 ± 0.67) × 10^?5; (2.18 ± 0.48) × 10^?5; and (2.25 ± 0.17) × 10^?5 cm/s, respectively. But there was significant difference between absence and presence of verapamil or digoxin (P < 0.05). P_eff and P_app values of vitexin-2″-O-rhamnoside in HLF were increased in the presence of verapamil or digoxin. In conclusion, vitexin-2″-O-rhamnoside can be classified into high permeability class drug according to the biopharmaceutical classification system. Passive diffusion dominates the absorptive transport behavior of vitexin-2″-O-rhamnoside in HLF. The absorption and secretion are mediated by the efflux transport system, P-gp. The absorption of vitexin-2″-O-rhamnoside in HLF can be enhanced administered together with P-gp inhibitors.     

Effects of different drying methods on the physical characteristics and flavor of dried hawthorns (Crataegus spp.)

ABSTRACT

The objective of this study was to compare the physical characteristics and flavor of dried hawthorns obtained by freeze-drying (FD), microwave freeze-drying (MFD), atmospheric freeze-drying (AFD), and heat pump drying (HPD). The parameters including moisture content, product temperature, rehydration ratio, chroma, hue angle, yellowness index, total color difference, and energy consumption were investigated. The use of fuzzy reasoning for the sensory evaluation of hawthorn quality was also performed. As expected, AFD, FD, and MFD produced better accepted dried hawthorn products than did HPD. Nevertheless, FD consumed the highest energy and had a long drying time, but its product was the best; AFD had a similar energy cost as HPD, but its drying time was the longest; and MFD had a higher energy cost and longer drying time than HPD, but its product quality was similar to that of FD products. As a result, MFD and AFD had potential to replace FD to yield dried hawthorns with high product quality and relatively low cost.     

山楂生、炒品果胶结构表征和体外降脂作用研究

目的 明确山楂生品果胶(raw hawthorn pectin, RHP)和炒品果胶(fried hawthorn pectin, FHP)的结构与其体外降脂作用的关系。方法 通过测定酯化度、半乳糖醛酸含量、分子量、特性黏度、黏均分子量、中性糖组成和比例,用扫描电镜观察微观形态,来表征RHP和FHP的结构。通过果胶对胆固醇胶束和胆酸盐的结合能力等体外实验评价其降脂作用。结果 RHP酯化度为52.19%,属于高酯果胶; FHP酯化度为31.95%,属于低酯果胶。RHP分子量有4个级分(217904、16907、8933、5104 Da),FHP分子量有4个级分(238813、16662、8770、5063 Da)。RHP特性黏度和黏均分子量分别为0.10 dL/g和2.75×10⁴ g/moL, FHP特性黏度和黏均分子量分别为0.16 dL/g和4.71×10⁴ g/moL。RHP、FHP均含有葡萄糖、鼠李糖、半乳糖、果糖和木糖等中性糖,但各糖的分子摩尔比不同。微观形态中, RHP分子间交联良好; FHP分子之间交联较少。在体外降脂实验中,R...     

山楂对果蝇抗氧化相关调控基因表达的影响

以果蝇为动物模型,研究给予不同剂量山楂提取物（0、0.8、4 mg/mL）对果蝇寿命、抗氧化酶活力及抗氧化相关调控基因表达的影响。结果表明：添加山楂提取物可以延长果蝇寿命;体内抗氧化酶活力测定结果显示,添加0.8 mg/mL山楂提取物可以显著升高铜锌超氧化物歧化酶（CuZn-superoxide dismutase,CuZn-SOD）酶活力（P＜0.05）,给予4 mg/mL山楂提取物可以极显著升高CuZn-SOD酶活力（P＜0.01）和显著升高过氧化氢酶（catalase,CAT）酶活力（P＜0.05）,且降低丙二醛（malondialdehyde,MDA）水平。实时定量PCR（real timepolymerasechain reaction,real time-PCR）,结果显示,给予4 mg/mL山楂提取物显著上调CuZn-SOD、CAT mRNA表达水平（P＜0.05）;给予0.8 mg/mL山楂提取物磷脂氢谷胱甘肽过氧化物酶（phospholipid hydroperoxideglutathione peroxidase,PHGSH-Px） mRNA表达水平显著升高（P＜0.05）,4 mg/mL组表达水平极显著升高（P＜0.01）。综上,山楂在机体内抗氧化活性可能是通过上调内源性抗氧化酶来实现的。     

山楂黄酮提取及降血脂研究

目的:研究山楂黄酮提取工艺以及山楂黄酮对降低血脂的作用。方法:采用乙醇超声波提取方法提取山楂黄酮,及山楂黄酮对大鼠降血脂作用的研究。结果:山楂黄酮提取条件:溶剂:70%乙醇;超声波频率: 40kHz;超声波作用时间:15min;料液比:1:40倍。结论:乙醇超声波提取方法具有操作简单、提取时间短、纯度高、得率高等特点;山楂黄酮能够降低高血脂大鼠血清中胆固醇、甘油三酯和低密度脂蛋白胆固醇的含量,升高大鼠血清中高密度脂蛋白胆固醇的含量。     

山楂原花青素的抗氧化活性研究

研究了山楂果实中的原花青素在溶液体系和脂质体体系中的体外抗氧化活性。在所用的实验模型中,山楂原花青素表现出较强的清除自由基和抑制脂质过氧化的能力。对.OH,山楂原花青素和Vc的IC50分别约为0.053mg/mL和0.11mg/mL;对O2-.,山楂原花青素和VC的IC50分别约为0.05mg/mL和0.17mg/mL。在脂质体体系中,山楂原花青素抑制脂质过氧化的能力远大于VE。     

气相色谱-质谱法分析山楂中的脂肪酸

为了促进山楂及山楂核在药物、精细化工领域的应用,用气相色谱-质谱联用仪,改良脂肪酸甲酯化法检测出山楂果肉中的7种脂肪酸,分别为棕榈酸、亚油酸、油酸、亚麻酸、硬脂酸、花生酸及山嵛酸。用CSASS软件进行峰识别及确定峰面积,峰面积归一化法计算每种脂肪酸的相对质量分数。分析测定了河北、安徽、山东、吉林、辽宁5个产地山楂药材中的脂肪酸相对质量分数,各产地去核山楂药材均以不饱和脂肪酸为主,其相对质量分数分别为59.10%、61.18%、63.08%、59.76%、60.76%。对河北、安徽、辽宁3个产地山楂核中的脂肪酸成分进行了较系统全面的研究,其脂肪酸以不饱和脂肪酸为主,相对质量分数分别为89.80%、61.59%、79.55%,均高于同一产地去核山楂中的不饱和脂肪酸相对质量分数。     

山楂苦荞醋发酵过程中活性成分及风味物质与抗氧化活性的相关性

该实验研究了山楂苦荞醋发酵过程总多酚、总黄酮、挥发性香气物质与抗氧化活性的相关性。结果表明,总多酚和总黄酮含量在醋酸发酵第7天分别达到2.43 mg/mL和1.29 mg/mL,酒精和醋酸发酵阶段分别检测到58和60种香气物质。羟基自由基清除率、超氧阴离子清除率和1,1-二苯基-2-三硝基苯肼（DPPH）自由基清除率在酒精发酵第5天分别达到81.4%、52.3%和99.8%,亚铁离子螯合率在醋酸发酵第1天达到90.6%。总多酚、总黄酮含量与4种抗氧化活性均呈极显著正相关（P<0.01）,多酚含量与亚铁离子螯合率相关性最高（R=0.984）。发酵过程中共有20种挥发性香气物质与抗氧化活性具有相关性,酒精发酵阶段的12种香气物质与超氧阴离子清除率的相关性较高（R均>0.85）,醋酸发酵阶段的8种香气物质与4种抗氧化能力的相关性均较高（R均>0.85）。     

山楂蒸馏酒减压蒸馏工艺优化及对风味成分的影响

以山楂为主要原料,经发酵和减压蒸馏工艺加工山楂蒸馏酒。通过单因素和响应面试验考察蒸馏温度、真空度、蒸馏时间对山楂蒸馏酒的酒精度和酸酯总量的影响,采用顶空固相微萃取-气质联用（HS-SPME-GC-MS）技术对比常压和减压蒸馏山楂酒的主要成分变化。结果表明,山楂蒸馏酒最佳减压蒸馏条件为蒸馏温度76 ℃、真空度0.02 MPa、蒸馏时间20 min。在此优化条件下山楂蒸馏酒的酒精度和酸酯总量达到最优,分别为（45.8±1.21）%vol和（49.4±2.03） mmol/L;相比常压蒸馏,减压蒸馏方式得到的山楂蒸馏酒能较好地富集风味物质。     

酵母菌发酵降低山楂汁有机酸含量的研究

山楂汁用酵母菌在溶氧25％～35％、20℃条件下进行84h发酵,采用高效液相色谱法和酸碱滴定法测定样品中的有机酸含量。结果表明,山楂汁中总酸为17.10g/L,其中柠檬酸含量为14.07g/L,苹果酸含量为1.24g/L。山楂汁发酵后总酸下降到3.52g/L,其中柠檬酸全部降解,苹果酸降解了86.6％,其它有机酸含量变化不大。柠檬酸降解速度在发酵的72h内与时间呈线性关系,苹果酸降解则发生在48～72h