野亚麻蝇(Parasarcophaga Similis)幼虫凝集素的细胞凝集和糖抑制作用

野亚麻蝇幼虫凝集素的测定结果表明:它对人的A、B、O、AB血型红细胞,以及兔、豚鼠、大鼠、小鼠、鸽子的红细胞有凝集作用,其中对豚鼠红细胞凝集活性最高;但对牛、绵羊、鸡、鸭、龟、蛙、鳝鱼、鲤鱼、泥鳅的红细胞无凝集作用。对小鼠淋巴细胞凝集作用的浓度为18.75μg/ml,而对大鼠淋巴细胞凝集浓度则为150μg/ml,对牛的淋巴细胞无凝集活性。对肿瘤细胞的凝集作用很不相同,可凝集小鼠的S180、SP2/0、u14、LⅡ细胞,但不能凝集小鼠艾氏细胞,大鼠W256细胞、人Hela细胞和MGC80—3胃癌细胞。该凝集素对兔红细胞的凝集作用可被D—半乳糖,N—乙酰氨基半乳糖抑制。

阿托伐他汀对大鼠再狭窄血管醛糖还原酶表达及内膜增生的抑制作用

目的研究醛糖还原酶在大鼠再狭窄血管中的表达,探讨醛糖还原酶表达与内膜增生之间的关系,以及阿托伐他汀对醛糖还原酶表达及内膜增生的抑制作用。方法24只健康雄性SD大鼠,随机分成手术未干预组、假手术组及阿托伐他汀组,每组8只。用通气—干燥法损伤手术未干预组及阿托伐他汀组中的右侧颈总动脉,左侧颈总动脉作为对照。分别于第7天及14天处死动物,HE染色以观察内膜及中膜增生情况,并计算内膜和中膜面积及其比值,FISH原位杂交及免疫组织化学检测醛糖还原酶及核因子κB的表达。结果术后第7天损伤侧血管内膜增生明显,第14天内膜增生进一步加重,对照血管无明显增生。阿托伐他汀组血管内膜面积、内膜与中膜面积比值明显低于手术未干预组(P<0.05或P<0.01)。醛糖还原酶及核因子κB在损伤侧血管中的表达明显强于对照侧。阿托伐他汀组醛糖还原酶及核因子κB的表达明显低于手术未干预组(P<0.05或P<0.01)。结论醛糖还原酶可能参与了大鼠颈动脉损伤后内膜增生及再狭窄的形成。阿托伐他汀可抑制血管内膜增生及再狭窄的形成。阿托伐他汀可能是通过抑制醛糖还原酶及核因子κB而抑制再狭窄的形成。

福建10种甲壳动物凝集素的研究

10种甲壳动物凝集素提取液 ,用 11种天然或经酶修饰的动物及人红细胞进行凝血活性检测 ,同时进行凝集素的糖抑制、热稳定性、pH及Ca2 + 影响试验 .结果表明 ,每种甲壳动物提取液至少凝集 10种以上天然或经酶修饰的红细胞 .各类红细胞经酶 (蜗牛酶 )修饰后对凝集素的敏感性普遍增强 (人和家鸽红细胞对几种甲壳动物例外 ) .某些种类的凝集素对兔红细胞的凝集活性可被一种或几种糖抑制 .8种凝集素表现出对 pH值和温度的广泛适应性 ,在pH3- 11、温度为4℃ - 90℃范围内对兔血均具凝集活性 .10种凝集素的凝集活性依赖于Ca2 + .

响应面法优化辣木叶蛋白提取工艺及凝集活性研究

辣木叶中含有丰富的蛋白质,但溶解性较差,本研究采用盐析法提取新鲜辣木叶中的蛋白并对其活性进行研究。以新鲜辣木叶为原料,分析提取时间、硫酸铵饱和度、料液比3个因素对蛋白得率的影响,在单因素实验的基础上,通过响应面优化盐析法提取辣木叶蛋白的最佳工艺条件。结果表明:对蛋白得率的影响依次为提取时间>硫酸铵饱和度>料液比,确定的最佳工艺条件为提取时间7 h、硫酸铵饱和度71%、料液比1:9 g/mL,在此条件下辣木叶蛋白得率为13.49 mg/g,与预测结果13.76 mg/g基本相符。辣木叶蛋白的凝集效价为2^(8),D(+)无水葡萄糖是辣木凝集素专一性抑制糖,可以较好地抑制兔红细胞和辣木叶蛋白凝集反应。

Inhibitory effect of emodin and Astragalus polysaccharide on the replication of HBV

AIM: To evaluate the anti-viral effect of emodin plus Astragalus polysaccharide (APS) in hepatitis B virus (HBV) transgenic mice.METHODS: Sixty HBV transgenic mice (HBV TGM) whose weight varied between 18 and 24 g were randomly divided into 3 groups, with 20 mice in each group. Group A was the normal control, where the mice were treated with physiological saline; group B was the positive control where the mice were treated with lamivudine solution (100 mL/kg per day). Group C was the experimental group where the mice were treated with physiological saline containing emodin and APS (57.59 mg/kg per day and 287.95 mg/kg per day, respectively). The mice were treated daily for 3 wk. After 1 wk recovery time, the mice were sacrifi ced and serum as well as liver tissues were collected for ELISA and histological examination.RESULTS: After 21 d treatment, HBV DNA levels in group B and group C significantly declined when compared with group A (P < 0.05). However, a signif icant increase in HBV DNA content was observed in group B, whereas this phenomenon was not observed in group C. A reduction in the contents of HBsAg, HBeAg and HBcAg in the mice from group B and C was observed when compared with group A.CONCLUSION: Emodin and APS have a weak but persistent inhibitory effect on HBV replication in vivo, which may function as a supplementary modality in the treatment of hepatitis B infection.

Inhibitory effects of polysaccharides isolated from Phellinus gilvus on benzo(a)pyrene-induced forestomach carcinogenesis in mice

AIM: Although polysaccharides from Phellinus mushrooms are a well-known material with anti-tumor properties, there is no information about the effect of polysaccharides from Phellinus gilvus (PG) on tumor. The modulating effect of polysaccharides isolated from PG on the benzo(a)pyrene (BaP)-induced forestomach carcinogenesis in ICR female mice was investigated in this study.METHODS: A forestomach carcinogenesis model was established in 40 ICR female mice receiving oral administration of BaP for 4 wk. The mice were randomly assigned to 4 groups (10 each). The mice in each group were treated with sterile water or PG for 4 and 8 wk (SW4,PGW4, SW8, and PGW8 groups). Eight or 12 wk after the first dose of BaP, forestomachs were removed for histopathological and RT-PCR analysis.RESULTS: In histopathological changes and RT-PCR analysis, sterile water-treated mice showed significant hyperplasia of the gastric mucosa with a significantly increased expression of mutant p53 mRNA compared to mice treated with PG for 8 wk.CONCLUSION: Polysaccharides isolated from PG may inhibit BaP-induced forestomach carcinogenesis in mice bydown-regulating mutant p53 expression.

Crystallization inhibition of an amorphous sucrose system using raffinose

The shelf life of pure amorphous sucrose systems, such as cotton candy, can be very short. Previous studies have shown that amorphous sucrose systems held above the glass transition temperature will collapse and crystallize. One study, however, showed that adding a small percent of another type of sugar, such as trehalose, to sucrose can extend the shelf life of the amorphous system by slowing crystallization. This study explores the hypothesis that raffinose increases the stability of an amorphous sucrose system. Cotton candy at 5 wt% raffinose and 95 wt% sucrose was made and stored at room temperature and three different relative humidities (%RH) 11%RH, 33%RH, and 43%RH. XRD patterns, and glass transition temperatures were obtained to determine the stability as a function of %RH. The data collected showed that raffinose slows sucrose crystallization in a low moisture amorphous state above the glass transition temperature and therefore improves the stability of amorphous sucrose systems.

Antisense Smad2 inhibits high glucose-stimulated production of extracellular matrix in cultured rat glomerular mesangial cells

Objective：Hyperglycemia stimulates secretion of transforming growth factor-βl （TGF-βl） in cultured glomerular mesangial cells, thereby increases production of extracellular matrix （ECM）. We examined the effect of antisense mRNA for Smad2 on high glucose-induced ECM production in rat mesangial cells. Methods..A mammalian expression vector, pES2a, which expresses antisense Smad2 mRNA and green fluorescent protein （EGFP）, was transfected into mesangial cells. Following incubation in high glucose medium, EGFP expression and Smad2 mRNA level were determined by fluorescence microscopy and PCR, respectively. Secreted fibronectin and type IV collagen were assessed by enzyme-linked immunosorbent assay. Results ：Within 48 h of incubation in high glucose medium, Smad2 mRNA level significantly increased by 1.6 fold in association with increases in prodtaction of both fibronectin （from [45.86±2.73] to [84.19±6.81] ng/ml） and type IV collagen （from [16. 28±0. 90] to [55.27±4.75] ng/ml） in nontransfected cells （P〈0.05）. In pES2a-transfected cells, the high glucose-induced increase in Smad2 mRNA was abrogated completely, in parallel with significant suppression of the high glucose-indtmed increase in fibronectinproduction （[54.44±4.99] ng/ml） and type Ⅳ collagen （[20.96±2.47] ng/ml）. An empty vector was without effects. Coneluslon：These findings demonstrate that Smad2 plays a critical role in mediating high glucose-stimulated ECM production in mesangial cells, indicating that inhibition of Smad2 activity by antisense Smad2 mRNA may be an effective means to attenuate glomerular matrix accumulation in diabetic nephropathy.

Inhibition of Porcine Small Intestinal Sucrase by Validamine

As an important medicinal intermediate with broad uses, validamine, an aminocyclitol, isolated from the enzymolysis broth of validamycins, has gained more and more attention. The absolute configuration of validamine is similar to that of a-D-glucose, and it demonstrates powerful inhibition activity on glycosidase. In this paper, the inhibitory effect of validamine on porcine small intestinal sucrase was investigated. Validamine was found to be a potent, competitive inhibitor to porcine small intestinal sucrase in vitro with an IC50 value of 6.85 X 10(-4) mol center dot L-1. Validamine exhibited a dose-dependent inhibition effect on porcine small intestinal sucrase, whereby the inhibition interaction of validamine and porcine small intestinal sucrase was a fast binding process. The inhibition of validamine on porcine small intestinal sucrase was pH-dependent.

Polysaccharide sulfate 916 inhibits neutrophil-endothelial adhesion

OBJECTIVE: To study the effect of polysaccharide sulfate 916 (PS916) on neutrophil-endothelial cell adhesion. METHODS: Cell adhesion was evaluated by testing neutrophil myeloperoxidase activity. Expression of adhesion molecule in human umbilical vein endothelial cell (HUVEC) was measured by ELISA. The neutrophil activation rate induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was tested by nitroblue tetrazolium (NBT) reduction. RESULTS: Tumor necrosis factor alpha (TNFalpha, 50 - 800 U/ml) increased the adherence of neutrophil to TNFalpha-stimulated HUVEC in a concentration and time dependent manner. PS916 (0.01 - 1.0 mg/ml) dose-dependently inhibited the adherence of neutrophils to TNFalpha-stimulated HUVEC. fMLP increased the activation rate of neutrophils independent of concentration. PS916 also inhibited the adherence of fMLP-activated neutrophils to HUVEC. Moreover, PS916 inhibited adhesion molecule expression in TNFalpha-stimulated HUVEC. CONCLUSIONS: PS916 inhibited neutrophil-endothelial adhesion. The mechanism of its action was partially related to suppressing the expressions of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1).

Effect of Honghua (Flos Carthami) on nitric oxide production in RAW 264.7 cells and α-glucosidase activity

OBJECTIVE： To study the effects of extracts from Honghua （Flos Carthaml~ on lipopolysaccharide in- duced nitric oxide （NO） production in RAW 264.7 cells and the influence of the extracts on yeast a-glucosidase activity. The total flavonoid content of the extracts was also determined. METHODS： Cytotoxicity of the extracts to RAW 264.7 cells was evaluated by the ATPliteTM method. Inhibitory effects of the extracts on NO production were evaluated by Griess assay. Curcumin was used as a positive control. Screening of extracts for po- tential a-glucosidase inhibitors was done by a fiuo- rometric assay. The assay was based on the hydroly- sis of 4-methylumbelliferyl-a-D-glucopyranoside toform the fluorescent product, 4-methylumbellifer- one. Acarbose was used as a positive control. The total t3avonoid content was tested using kaempfer- ol as the standard. RESULTS： There were significant inhibitory effects on NO production when the extracts were 25-100 μg/ mL （P〈0.05） and curcumin was 2-4 μg/mL （P〈 0.001）. The extracts showed an inhibitory effect on a-glucosidase activity at the concentrations of 15.6-125 μg/mL with a half maximal （50%）inhibito- ry concentration （ICs0） of （32.8± 5.7） μg/mL, com- pared with the ICs0 of acarbose at （1.8±0.4） μg/mL. There was a significant difference between the two IC50 values （P〈0.001）. The total content of flavo- noids per gram of dried herb was 1.14 mg. CONCLUSION： Honghua （Flos Carthami） showed in- hibitory effects on NO production in activated RAW 264.7 macrophage cells and an inhibitory effect on yeast a-glucosidase. There might be a relationship between these pharmacological effects and its fla- vonoid content.