南瓜中糖苷类化合物抗炎生物活性研究

采用巴豆油所致炎症模型研究了南瓜中6种糖苷类化合物的抗炎作用。结果表明,糖苷类化合物(20mg/mL)具有显著的抗炎能力(p<0.05),并呈剂量依赖关系。其中,二半乳糖亚麻酸单酰甘油(DGMG,18∶3)抗炎活性最强,而四半乳糖亚油酸单酰甘油(QGMG,18∶2)活性最弱。进一步构效关系研究发现,抗炎活性与糖苷分子中的糖基数目和脂酰基不饱和度有关。分子中半乳糖基数目一定,抗炎能力随着脂酰基不饱和程度的增加而提高;脂酰基组成相同,抗炎能力随着半乳糖基数目的增加而降低。      

RP-HPLC-ELSD检测法测定南瓜中甘油糖脂的含量

建立了用反相高效液相色谱-蒸发光散射检测器（RP-HPLC-ELSD）测定南瓜中4种甘油糖脂QGMG（18:3）、TGMG（18:3）、QGMG（18:2）和TGMG（18:2）含量的方法。RP-HPLC-ELSD条件为:WatersSymmetryC18色谱柱（4.6mm×150mm,5μm）,流动相为乙睛-水（60:40,v/v）,流速为1.0mL/min,漂移管温度为60℃,ELSD增益值7,载气为空气,压力0.35MPa。在该色谱条件下,4种甘油糖脂在0.05～0.5mg/mL浓度范围内呈良好线性关系,方法加样回收率为96.7%～101.3%。该方法简便、准确、分离效果好、无干扰,可用于南瓜中甘油糖脂的定量测定。      

南瓜中甘油糖脂分离制备及体外抗肿瘤活性研究

采用高速逆流色谱与制备型高效液相色谱相结合的方法,从南瓜中分离制备甘油糖脂,并用MTT法检测不同甘油糖脂单体对不同肿瘤细胞生长抑制作用,并阐明其构效关系.结果表明:采用高速逆流色谱-制备HPLC联合法,从南瓜中分离得到6种甘油糖脂单体,并采用电喷雾质谱(ESI-MS)以及核磁共振氢谱(1H-NMR)和碳谱(13C-NMR)对化合物结构进行了鉴定.该方法制备量大,分离效率高.6种甘油糖脂单体对人结肠癌细胞COLO205和小鼠黑色素瘤细胞B16-F103均有一定的生长抑制作用,构效关系表明,抗肿瘤能力随着脂酰基不饱和程度的增加而提高,随糖基数目的增加而降低.南瓜中糖苷类化合物作为抗肿瘤药物具有较好的开发前景.     

典型甜菊糖苷的抗氧化和抗炎活性

本文以6种代表性甜菊糖苷及其肠道代谢物甜菊醇以及甜菊醇的重排异构体异甜菊醇为对象,研究了上述甜菊化合物的抗氧化性及其对鼠巨噬细胞Raw264.7的细胞毒性和抗炎活性。结果表明,所试甜菊糖苷在100 μg/mL内对鼠巨噬细胞的Raw264.7均无细胞毒性,也不会诱导炎症反应;其中异甜菊醇抗炎效果最优,100 μg/mL时相对于脂多糖刺激后产生的NO含量降低了约30.7%。所试甜菊糖苷对DPPH·和·OH两种自由基的清除率最高分别为24.8%和13.8%,其对DPPH·的清除能力具有结构相关性,但对·OH清除率均低,无结构相关性;而甜菊酚对DPPH·和ABTS+·清除率分别为92.1%和29.6%,即甜菊提取物的自由基清除率主要由甜菊酚产生。     

生物活性肽的抗炎功能及其对氧化应激的调节作用

通过动物实验研究乳源性生物活性肽Gln-Glu-Pro-Val-Leu(QEPVL)的抗炎能力,将32只小鼠随机分成空白组、模型组、低剂量组和高剂量组4组,利用脂多糖(Lipopolysaccharides,LPS)建立急性炎症模型,测定血清一氧化氮(NO)浓度和总抗氧化能力(TAOC)及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、丙二醛(MDA)、过氧化氢酶(CAT)的浓度。结果表明,在100 mg/kg剂量下灌喂QEPVL水溶液30天可以显著降低血清NO浓度,并显著提高动物体内各种还原酶的酶活,提高机体抗氧化能力,缓解炎症引发的氧化应激状态,从而起到抗炎的功效。随着QEPVL剂量的加大,其抗炎效果加强。     

甘油糖脂生物活性最新研究进展

综述了甘油糖脂在生物活性及构效关系方面的研究进展.甘油糖脂是细胞膜的重要组成部分,具有抗氧化、抗病毒、抗菌、抗肿瘤、抗炎、抗动脉粥样硬化等多种生物活性.构效关系的研究表明甘油糖脂的活性与糖脂上脂酰基链的长短、糖环上的取代基的类型及其位置有关.     

食用菌中甾醇物质抗炎活性研究概述

近年来,在天然产物中筛选具有抗炎作用药物的研究愈加深入。食用菌分布广泛,次级代谢产物丰富,在许多方面表现出良好的生理活性,从而引起了普遍的关注。文章对食用菌中具有抗炎活性的甾醇类物质的提取、测定、分离纯化及其抗炎作用的研究方法和作用机制进行了整理,以期为以后的相关研究提供参考。     

抗炎低聚糖的制备及其抗炎机制研究进展

炎症是机体对各种致炎因素及损伤的一种防御反应,也是许多慢性疾病发生的关键因素.研究表明低聚糖具有抗炎、抗菌、抗氧化和抗癌等多种生理活性.作为新型功能性糖源,低聚糖具有低热量、高溶解度、促进双歧杆菌增殖等特点.本文对近年来具有抗炎活性低聚糖的种类和制备方法进行介绍,并从炎症介质和炎症信号通路两方面对其抗炎机制进行综述,以...     

食源性抗炎肽的制备、分离、鉴定及其抗炎机制研究进展

生物活性肽是生命和食品科学领域的研究热点之一。其抑菌、降血压、调节免疫、抗病毒、抗炎等活性已相继被证实,其中肽的抗炎作用研究相对较为薄弱。慢性炎症严重影响人体健康,而传统治疗炎症药物均有一定副作用,食源性抗炎肽的开发应用有望为机体炎性反应提供新的抗炎策略。本文综述了食源性抗炎活性肽的制备、分离纯化、鉴定以及抗炎活性与分子作用机制的研究进展,并对其研究进行了展望,为食源性抗炎肽的进一步深入研究提供参考。      

七叶莲果实的抗炎镇痛作用研究

目的:研究七叶莲果实水提物的抗炎镇痛作用。方法:采用热板法疼痛模型、醋酸诱发的小鼠扭体疼痛模型评价水提物的镇痛作用和二甲苯致小鼠耳廓肿胀模型评价水提物的抗炎作用。结果:七叶莲果实水提物对热板、醋酸导致的疼痛,二甲苯所致的耳廓肿胀均有不同程度的抑制作用。结论:七叶莲果实水提物有较强的抗炎镇痛作用。     

Oligosaccharides prepared by acid hydrolysis of polysaccharides from pumpkin (Cucurbita moschata) pulp and their prebiotic activities

As a rich source of polysaccharides, pumpkin pulp was used for the production of oligosaccharides. To investigate the prebiotic potential of the oligosaccharides, prepared by acid hydrolysis of polysaccharides from pumpkin pulp, the effect of the oligosaccharides on lactobacilli growth was studied. The oligosaccharides were composed of galactose (99.03%) and glucose (0.97%). The molecular weight distribution of the oligosaccharides showed a larger part of low molecular weight fraction in a range from 5000 to 324 Da than the polysaccharides, which gave the oligosaccharides higher solubility. The oligosaccharides showed good resistance to hydrolysis by artificial human gastric juice and α‐amylase, compared to the reference prebiotic inulin, and considerable capability to stimulate the growth of lactobacilli. In vitro studies showed that the number of lactobacilli was significantly greater than those in control medium when they were cultured in the medium supplemented with the oligosaccharides (P < 0.05), and there was no significant difference at the oligosaccharides group and the inulin group (P < 0.05).     

Anti-oxidant,anti-proliferative and anti-inflammatory activities of the extracts from black raspberry fruits and wine

The purpose of the study was to determine polyphenols, anthocyanins and ascorbic acid in the extracts of black raspberry fruits and wine, along with their anti-oxidant, anti-proliferative and anti-inflammatory activities. Black raspberry fruits without or with seeds crushed were blended in 60% ethanol (FE and FES, respectively) or in water (FW and FWS, respectively). Black raspberry wine without or with seeds crushed (W and WS, respectively) were prepared. Polyphenol content was the highest in the FES (8.25 mg/g fruit). Generally the ethanol extracts with seeds crushed showed higher anti-oxidant activities with the lowest DPPH IC₅₀ (130 μg/ml (freeze-dried extract/reaction solution)) for the FES and the lowest ABTS IC₅₀ (198 μg/ml) for the WS. Cell viabilities were reduced by 13–70% when treated with 100 μg/ml (freeze-dried extract/medium) for HT-29 cells and 1000 μg/ml for LNCaP cells. The FES most actively suppressed nitric oxide production in LPS-stimulated RAW264.7 cells (p < 0.05). Superoxide dismutase and glutathione peroxidase activities treated with the extracts were higher than the control (p < 0.05).     

南瓜叶浓缩蛋白制品的食用安全性初步评价

采用我国《食品安全性毒理学评价程序》中所规定的标准方法和实验模型,对南瓜叶浓缩蛋白制品的食用安全性进行评价。结果显示,该产品小鼠经口LD50值大于21.501g/kg·bw,属无毒级;小鼠30d喂养未显示任何毒副作用。因此,该产品对实验动物不具有急性毒性作用。      

南瓜叶浓缩蛋白制品的食用安全性初步评价

采用我国《食品安全性毒理学评价程序》中所规定的标准方法和实验模型,对南瓜叶浓缩蛋白制品的食用安全性进行评价.结果显示,该产品小鼠经口LD50值大于21.501g/kg·bw,属无毒级;小鼠30d喂养未显示任何毒副作用.因此,该产品对实验动物不具有急性毒性作用.     

Physicochemical,nutritional and functional properties of Cucurbita moschata

Cucurbita moschata is widely planted in most parts of the world, and is rich in carotenoids, vitamins, dietary fiber, minerals, and phenolic compounds. It also has important medicinal value. Some related research has proven that Cucurbita moschata has the potential ability to induce anti-obesity, anti-diabetic, antibacterial, and anticancer effects. At the same time, it has attracted more attention in the medical field. These nutrients and bioactive compounds in Cucurbita moschata have important effects on human health. In order to make better use of this crop, it still needs further study. Therefore, the purpose of this article is to summarize the physicochemical properties and nutritional components of Cucurbita moschata, and to provide a reference for further research on the benefits of on human health.     

Comparison of hot air-drying and freeze-drying on the physicochemical properties and antioxidant activities of pumpkin (Cucurbita moschata Duch.) flours

Freeze-drying and hot air-drying were applied in the preparation of pumpkin flours to investigate the effects of drying methods on the antioxidant activities and physicochemical properties. The antioxidant activities of methanol extracts from pumpkin flours were studied in terms of total antioxidant activity, reducing power, free radical scavenging, superoxide anion radical scavenging and metal chelating activities. Hot air-dried pumpkin flour showed stronger antioxidant activities than freeze-dried flour. The percentage inhibition of peroxidation in linoleic acid system by 15 mg mL⁻¹ extracts from hot air-dried and freeze-dried pumpkin flours was found to be 92.4% and 86.1% after 120 h of incubation, respectively. Hot air-dried pumpkin flour exhibited higher reducing power, free radical scavenging and metal chelating activities than freeze-dried flour. This study also indicated that freeze-drying significantly reduced the browning and preserved the redness of pumpkin flours. Hot air-drying reduced the oil absorption capacity, water absorption and porosity of pumpkin flours, while it markedly increased the water solubility and bulk density.     

南瓜中内生菌筛选及其次级代谢产物的分析

目的：为充分开发利用南瓜资源,寻找生产多酚类化合物等活性物质的内生菌。方法：采用组织块分离法、划线分离法及梯度稀释法获得南瓜果肉中的内生菌,并利用平板对峙法对其抑菌活性进行测定,再以南瓜提取液为对照,对各拮抗菌株的发酵液进行薄层层析分析,然后利用高效液相色谱法作进一步检测,从而确定活性物质的种类。结果：从南瓜果肉中共分离到54 株内生菌。通过抑菌实验发现其中12 株对一种或多种指示菌具有抑菌活性,占分离菌株数的22%,其中3 株（25、26、29号）具有较广谱抑菌活性,抑菌率较高,可达（36.73±0.52）%。薄层层析检测表明：25号菌株的发酵产物在比移值（Rf）为0.57时与标准南瓜提取液斑点Rf相同。结论：25号菌株能发酵产生多酚类或类似化合物,这为利用内生菌发酵生产多酚类成分提供了新的思路和途径。     

Characterisation and stability of quality indices on storage of pumpkin (Cucurbita moschata and Cucurbita maxima) purees

Purees of Cucurbita moschata‘Menina Brasileira’ and of Cucurbita maxima‘Exposição’ pumpkins were produced. A commercial sterilisation test confirmed the effectiveness of the thermal treatment applied in the production. The stability was monitored during storage in ambient conditions. No significant alterations in pH, titratable acidity or soluble solids were noted. Both types of puree have a good concentration of carotenoids, although a slight decrease was detected in the ‘Exposição’ pumpkin puree after 15 days of storage. In relation to the colour of the purees, there were no significant alterations in a*, b* or ΔE during storage. Decreases in L* and WI were detected after 30–60 days of storage, thus suggesting a browning in an initial period. However, the scores given by the sensory assessors remained above 7 in a 9‐point scale, thus showing no significant alterations during storage. The results showed the stability of the pumpkin purees during the 180 days of storage under the proposed conditions.