Effects of veterinary drugs on beta-hexosaminidase release from rat basophilic leukemia cells (RBL-2H3)

Little is known about the effects of residual veterinary drugs on the allergic reaction, except for the antigenicity of antibiotics and synthetic antimicrobials. Therefore, 59 kinds of veterinary drugs were investigated for their effects on the IgE receptor-mediated beta-hexosaminidase release from RBL-2H3 cells as an index of immediate allergic reaction. We found that the antibiotics chlorotetracycline, doxycycline, monensin, the synthetic antimicrobial pyrimethamine and the steroid hormone testosterone inhibited beta-hexosaminidase release. Most of the veterinary drugs showed no action, though the ionophores lasalocid, salinomycin and the steroid hormone hexestrol promoted beta-hexosaminidase release from injured cells. Based on the residual levels of these drugs and the frequencies of detection in actual food samples, it seems unlikely that these drugs have any immediate allergic effect in practice.     

Inhibitory effect of aqueous spinach extract on degranulation of RBL-2H3 cells

The inhibitory effect of an aqueous extract from spinach on degranulation of RBL-2H3 cells is herein reported. The extract significantly suppressed antigen-induced degranulation in a dose-dependent manner without affecting cell viability. Active substances in the extract were heat-stable and trypsin-resistant with molecular weights ranging from 500 Da to 14 kDa. The extract inhibited elevation of the intracellular Ca²⁺ concentration caused by stimulation by antigen, while not suppressing degranulation induced by a calcium ionophore A23187. Immunoblot analysis revealed that the inhibitory effect results from downregulation of phosphorylation of both Syk kinase and phosphatidylinositol 3-kinase in the signalling pathways involved in degranulation caused by the antigen–antibody interaction. Taken together, these findings suggest that aqueous spinach extract has an anti-allergic activity that controls degranulation.     

Effects of organonitrogen, carbamate pesticides and others on beta-hexosaminidase release from rat basophilic leukemia cells (RBL-2H3)

There have been very few reports of the effect of pesticides on immediate allergy. In the previous report, the effect of pyrethroid pesticides and organophosphorus pesticides on immediate allergic reaction was investigated. Subsequently, 12 organonitrogen pesticides, 14 carbamate pesticides and 4 other pesticides were investigated for their effects on the enzyme activity of beta-hexosaminidase as an index of chemical mediator release from rat basophilic leukemia cells (RBL-2H3). Two organonitrogen pesticides, bitertanol and pyridaben, and two organotin pesticides, cyhexatin and fenbutatin oxide, were found to promote beta-hexosaminidase release. Bitertanol non-specifically caused the promotion of chemical mediator release, while the release-promotive action of pyridaben was related to IgE antibody and those of cyhexatin and fenbutatin oxide to cell injury. On the other hand, two organonitrogen pesticides, propiconazole and triadimenol, and imazalil showed release-inhibitory action. These data suggested that some pesticides can affect immediate allergy.     

Inhibitory effect of chlorophyll c2 from brown algae,Sargassum horneri,on degranulation of RBL-2H3 cells

The anti-allergic effect of alcohol extracts from edible seaweeds was evaluated by the degranulation of a rat basophilic leukemia cell line (RBL-2H3). Extracts prepared from the brown algae Sargassum horneri, Ecklonia cava and Ecklonia kurome, inhibited the degranulation of RBL-2H3 cells, whereas those from green algae and red algae did not. The active substance in S. horneri was purified and identified as chlorophyll c2, a major pigment in brown algae. The purified chlorophyll c2 preparation also suppressed the degranulation of RBL-2H3 cells. In contrast, chlorophyll a and b did not affect cell degranulation. Therefore, chlorophyll c2 from brown algae might be useful for the prevention or mitigation of allergic symptoms.     

Inhibitory effect of Zizania latifolia chloroform fraction on allergy-related mediator production in RBL-2H3 cells

Food Science and Biotechnology - Zizania latifolia exhibits anti-inflammatory and anti-allergic effects; however, the mechanisms behind these effects are unknown. Here the ethanol extract of Z....     

Anti-allergic activity of grapeseed extract (GSE) on RBL-2H3 mast cells

Grapeseed extract (GSE) is a rich source of natural phenolic compounds and possesses various pharmacological activities, including antioxidant, anticarcinogenic and anti-inflammatory properties. However, effects of GSE on immunoglobulin (Ig) E-mediated allergic responses still remain elusive. In the present study, the effects of GSE on activation and degranulation of RBL-2H3 mast cells were investigated. GSE pretreatments (20-100 μg/ml) reduced IgE-antigen mediated release of β-hexosaminidase and histamine in RBL-2H3 cells. Additionally, GSE reversibly inhibited expression of FcεRI on RBL-2H3 cells. GSE treatments caused a significant elevation of intracellular cAMP levels, whereas the Ca²⁺ influx upon antigen stimulation was inhibited. Suppression on FcεRI expression together with decreased calcium uptake and increased cAMP level might be involved in attenuated degranulation of mast cells by GSE treatment. Our results suggest a possible pharmaceutical application of GSE in treating type I allergic diseases.     

Inhibitory effects of flavonoid glycosides isolated from the peel of Japanese persimmon (Diospyros kaki Fuyu) on antigen-stimulated degranulation in rat basophilic leukaemia RBL-2H3 cells

We found that two distinct flavonoid glycosides isolated from the peel of Japanese persimmon (Diospyros kaki Fuyu), isoquercitrin (Isq) and hyperin (Hyp), are capable of inhibiting antigen-stimulated degranulation in rat basophilic leukaemia RBL-2H3 cells. In order to elucidate the underlying mechanisms, we examined effects of Isq and Hyp on cellular responses induced by antigen stimulation. Treatment with both Isq and Hyp markedly inhibited antigen-stimulated elevation of intracellular free Ca²⁺ concentration and reactive oxygen species (ROS). Isq and Hyp did not affect NADPH oxidase (NOX) activity, but they possessed DPPH radical-scavenging activity similar to that of epigallocatechin gallate, a potent anti-oxidant, Finally, Isq and Hyp showed little or no effects on Ag-stimulated Syk activation or phosphorylation of signalling molecules. These results indicate that inhibition of antigen-stimulated degranulation by Isq and Hyp is mainly due to suppression of intracellular Ca²⁺ elevation, which is caused by direct scavenging of ROS that are generated by NOX. Our findings suggest that Isq and Hyp, isolated from the peel of persimmon, would be beneficial for alleviating symptoms of type I allergy.     

Inhibitory effect of the ethyl acetate fraction from astringent persimmon on H2O2-induced oxidative stress in HepG2 cells

Persimmon cv. Sangjudungsi (Diospyros kaki Thunb.) is a major astringent cultivar in Korea. A phenolic extract of cv. Sangjudungsi was obtained using acetone with homogenization, then sequentially fractionated into n-hexane, chloroform, ethyl acetate, n-butanol, and water fractions. These 5 fractions were used to evaluate levels of total phenolics and total flavonoids, and the antioxidant capacities, and to investigate whether the fractions protected human hepatoma HepG2 cells from deleterious oxidative stress. The ethyl acetate fraction had the highest levels of total phenolics and total flavonoids, and the greatest antioxidant capacity. Under oxidative stress caused by H₂O₂, the ethyl acetate fraction at non-toxic concentrations significantly (p<0.05) restored the viability of HepG2 cells in a dose-dependent manner, compared with a control. The ethyl acetate fraction also alleviated intracellular oxidative stress, possibly due to effective antioxidant activities in cells. Astringent persimmons are a good source of antioxidants for reduction of oxidative stress.     

中草药提取物抑制H_2O_2诱导人皮肤细胞凋亡的初步研究

建立了过氧化氢(H2O2)诱导人皮肤成纤维细胞损伤及凋亡模型,并研究几种具有抗氧化作用的复方中草药提取物对细胞损伤及凋亡的影响。采用MTT、Hoechst染色及TUNEL等方法检测过氧化氢诱导细胞后以及加入中草药提取物后细胞的存活率、细胞形态以及细胞凋亡的状况。实验结果显示:在浓度为0.8 mmol/L,作用时间6 h,过氧化氢能诱导人皮肤成纤维细胞损伤和凋亡(p<0.05);而抗氧化类中草药复方提取物等物质能够显著提高过氧化氢诱导的细胞存活率的降低,并能明显减少凋亡细胞的数量(p<0.05),表明其对过氧化氢导致的细胞损伤和凋亡作用具有一定的抑制和防护作用。     

Inhibitory effect of adrenaline on oxytocin release in the ewe during the milk-ejection reflex.

Milk-ejection activity was determined in the blood plasma of ewes during normal milking and during milking when adrenaline was injected intravenously before or after udder stimulation. It was found that administration of adrenaline either before or after udder washing, decreased the oxytocin concentration and milk yield but increased the yield by hand-stripping. Adrenaline also retards the average time for peak oxytocin concentration. These results and the use of a beta-receptor blocker to inhibit the effect of adrenaline at the myoepithelial cell level indicate that in ewes adrenaline can prevent the release of oxytocin from neurohypophysis.     

海藻酸纤维吸附及释放锌离子的性能

为深入了解海藻酸纤维吸附及释放锌离子的性能,通过湿法纺丝方法制备纯海藻酸锌纤维,并通过盐酸处理海藻酸钙纤维制备海藻酸纤维。在不同时间、温度及锌离子浓度的条件下研究海藻酸纤维吸附锌离子的性能。结果显示,通过控制硫酸锌及海藻酸纤维的质量比可制备锌离子含量不同的海藻酸纤维。采用生理盐水及不同浓度的蛋白质水溶液处理海藻酸锌纤维,并测试接触液中锌离子的浓度发现,低温时比高温下的锌离子释放量大,溶液中的蛋白质可促进锌离子的释放。     

紫娟茶提取物对酪氨酸酶活性的抑制作用

首先对从蘑菇中提取的酪氨酸酶的反应条件进行了探讨。采用单因素和正交实验确定了酪氨酸酶单酚酶和二酚酶活性的最适反应条件。结果显示单酚酶最适反应条件为:底物L-酪氨酸为10.0mmol/L,酪氨酸酶为0.30g/mL,反应时间为15min,反应温度为30℃;二酚酶最适反应条件为:底物邻苯二酚为7.5mmol/L,酪氨酸酶为0.035g/mL,反应时间为15min,反应温度为15℃。然后对紫娟茶的3种提取物的酪氨酸酶活性的抑制作用进行了探讨。结果表明,3种提取物对酪氨酸酶单酚酶和二酚酶活性均有较好的抑制作用,特别是含有花青素和茶多酚混合物的提取物I的抑制作用最强;3种提取物对单酚酶和二酚酶的半抑制浓度IC50分别为6.85×10-4、8.21×10-4、16.29×10-4g/mL和6.37×10-4、7.62×10-4、13.53×10-4g/mL。      

香乳菇多糖对Hela细胞凋亡及对RAW264.7细胞免疫活性的影响

为研究香乳菇多糖(LC-1)的抗肿瘤和免疫调控活性,将人的宫颈癌Hela细胞和小鼠巨噬细胞RAW264.7体外培养,分别通过CCK-8法、流式细胞术和ELISA技术检测不同浓度LC-1对Hela细胞增殖和凋亡周期的影响,对RAW264.7细胞增殖、吞噬的影响,及对RAW264.7细胞分泌NO、IL-6和TNF-α的影响。结果表明:香乳菇多糖对体外培养的Hela细胞有明显的抑制作用,且影响Hela细胞的形态及凋亡周期,当LC-1浓度为10μg/mL时,Sub峰含量可达19.4%;同时,LC-1能调控巨噬细胞的免疫活性,当LC-1浓度为10μg/mL时,巨噬细胞增值率和吞噬活性分别为67.48%和87.09%,亦能促进巨噬细胞从G0/G1期向G2期和S期转化,同时刺激巨噬细胞产生IL-6和TNF-α,且呈现出明显的剂量依赖性,但对NO生成没有明显的促进作用。综上,在体外试验中,香乳菇多糖LC-1能抑制宫颈癌Hela细胞生长,促进RAW264.7细胞增殖和吞噬活性,刺激巨噬细胞产生免疫因子。     

虫草素对脂多糖诱导巨噬细胞过度活化的抑制作用研究

目的:研究虫草素对脂多糖（LPS）诱导巨噬细胞过度活化的抑制作用。方法:培养RAW264.7小鼠巨噬细胞,采用LPS（1μg/m L）激活巨噬细胞,同时给予0.1¹0μmol/L的虫草素处理细胞,采用四甲基偶氮唑盐（MTT）法测定细胞存活率,Griess法检测细胞一氧化氮（NO）释放量,酶联免疫吸附分析实验（ELISA）分别检测三种细胞炎症因子肿瘤坏死因子α（TNF-α）、白介素-1β（IL-1β）和白介素-6（IL-6）的释放水平,采用Fluo-3/AM染色法以流式细胞仪测定胞浆游离钙离子浓度([Ca²⁺]i)的变化,采用水杨酸法考察虫草素对羟自由基（·OH）清除作用,L-酪氨酸法检测其对过氧亚硝酸根离子自由基（ONOO-）清除作用,邻苯三酚自氧化法检测其对超氧阴离子自由基（O₂^-·）清除作用。结果:虫草素在0.1¹0μmol/L浓度范围内可显著抑制LPS激活的RAW264.7巨噬细胞释放NO及3种炎症因子（IL-1β、IL-6和TNF-α）,同时对细胞存活率无显著影响;虫草素（10μmol/L）可显著抑制LPS诱导的巨噬细胞内[Ca²⁺]i水平异常升高;此外,虫草素对·OH、ONOO-和O₂^-·自由基具有显著清除作用。结论:虫草素可抑制LPS激活的RAW264.7巨噬细胞释放NO及炎症因子TNF-α、IL-1β和IL-6,这可能与其抑制了细胞内[Ca²⁺]i的增高及清除·OH、ONOO-和O₂^-·自由基有关。虫草素可能对巨噬细胞过度激活引起的炎症相关疾病具有一定的防治作用。      

花椒精油挥发性物质分析及其对红白血病HEL细胞分化和凋亡的影响

目的 研究余庆花椒精油(Yuqing Zanthoxylum bungeanum Essential Oil,YZBO)的挥发性化学物质及其对红白血病HEL细胞分化和凋亡的影响。方法 采用HS-SPME-GC-MS检测分析YZBO的挥发性风味,并以不同质量浓度(1 μg/mL、5 μg/mL和10 μg/mL)YZBO处理HEL细胞24h后,采用MTT和台酚蓝计数分析细胞存活,流式细胞仪检测HEL细胞CD71、CD235a、CD41的分化以及ROS情况,流式细胞仪和Hoechst33258染色法检测HEL细胞凋亡情况。结果 YZBO含有99种化学成分,包括28种醇类物质、7种酯类物质、1种醛类物质、6种酸类物质、4种酮类物质、37种烯烃类、7种烷烃类物质、2种炔烃类物质、2种酚类物质和5种其他物质。橙花叔醇、榄香醇和τ-杜松醇是主要的醇类物质,乙酸苯乙酯和异乔木萜醇乙酸酯是其的主要酯类物质。YZBO对HEL细胞的IC50值为2.94386 μg/mL,促进CD71(45.6%)和CD235a(38.8%)的分化,而对CD41的分化不明显,诱导HEL细胞程序性凋亡,凋亡数目呈剂量和时间依赖性,镜下和染色观察发现细胞体积变小,核固缩以及呈高亮蓝色等典型细胞凋亡形态学改变。结论 YZBO的化合物主要是烷类、醇类和烯类化合物,具有抗红白血病HEL细胞的生物活性,促进分化未成熟的HEL细胞向成熟细胞方向分化,抑制向巨核细胞方向分化,并诱导其凋亡。