Development of an in vivo bioassay method for allergy-preventive substances using hen-egg white lysozyme (HEL)-induced blood flow decrease

We discovered a phenomenon in which the blood flow in vein microcirculation markedly decreases in response to hen-egg white lysozyme (HEL)-sensitization without any change in blood pressure. Using this blood flow decrease as a guide, we developed an in vivo assay method to search for substances, which can prevent allergies. Antagonists of histamine, serotonin and platelet activating factor (PAF) did not affect the blood flow decrease in response to HEL-sensitization. On the other hand, cyclooxygenase (COX)-1, COX-2, thromboxane (TX) A(2), endothelin-1 (ET-1), prostacyclin (PGI(2)) and granulocytic elastase (GE) as well as nitric oxide (NO) from inducible NO synthase (iNOS) were involved in the blood flow decrease. Thus, these substances might injure vascular endothelial cells, and cause a decrease in blood flow in vein microcirculation. Our method can be used to search for preventive agents against allergies involving NO, COX-1, 2 and PGI(2). This is the first report to applying to an assay method the specific blood flow decrease to occur in the promotion stage of allergy.     

Essential elements content of hen egg-white in Markazi province (Iran)

Eggs are among the nutrient-rich food in the human daily diet. Knowledge of the essential element content of hen eggs is required for different purposes for the nutritional value for human consumption. Within the current study, content of elements in hen egg-white from 32 industrial poultry farms was investigated by inductively coupled plasma optical emission spectrometry. Eggs were sampled in the Markazi province (Iran), in autumn 2014. The results of our study show that, except about P, egg-whites produced in Markazi province are poor sources for supply essential trace element. Thus, nutritionists have focused their research on the impact of supplementing the diet of the hen with different levels of trace elements.     

凤仙花化学成分及药理作用研究进展

目的介绍凤仙花的化学成分及药理作用的研究进展。方法根据近年来的29篇文献,对凤仙花的主要化学成分及药理药效进行综述。结果凤仙花含有大量黄酮类、萘醌类、香豆素类、甾醇类等成分,有些为首次从凤仙花中得到的全新化合物;具有较好的抗过敏、抗炎、抗真菌等作用。结论凤仙花有待进一步研究开发。     

Effects on blood pressure decrease in response to PAF of Impatiens textori MIQ

A 35% EtOH extract of flowers of Impatiens textori MIQ. showed an inhibitory effect on blood pressure decrease in response to platelet activating factor (PAF) measured with a blood pressure monitoring system. Bioassay-guided fractionation of the 35% EtOH extract (IT) led to isolation of the flavones apigenin (1) and luteolin (3), which significantly inhibited blood pressure decrease in response to PAF. Their compounds and apigenin 7-glucoside (2), chrysoeriol (4), quercetin (5), quercetin 3-glucoside (6), kaempferol (7), kaempferol 3-glucoside (8) and kaempferol 3-rhamnosyldiglucoside (9) were also isolated from the flowers of I. textori for the first time. This study revealed that the flowers of I. textori might be a possible anti-allergy agent.     

Involvement of inducible nitric oxide synthase in blood flow decrease in vein induced by hen-egg white lysozyme

Our in vivo assay system developed to search for allergy-preventive substances, assesses the blood flow decrease in tail vein microcirculation of mice subjected to sensitization with hen-egg white lysozyme (HEL). The blood flow decrease appears to be regulated by various factors such as nitric oxide (NO), thromboxane (TX) A(2), prostacyclin (PGI(2)) and endothelin (ET)-1 together with cyclooxygenase (COX)-1, COX-2, inducible nitric oxide synthase (iNOS), and constitutive nitric oxide synthase (cNOS). In this study, we examined in detail the roles of iNOS in this assay system using an iNOS knockout (KO) mouse. We found that the blood flow decrease in the HEL-sensitized iNOS KO mice was slightly weaker than that in their wild type (WT) mice. This blood flow decrease was not affected by a selective COX-1 inhibitor, a selective COX-2 inhibitor and a PGI(2) agonist unlike the case of the WT mice. However, it was inhibited by a nonselective NOS inhibitor, a specific TXA(2) synthase inhibitor and a specific ET-1 receptor blocker as in the case of the WT mice. The present results indicate that the blood flow decrease occurs via two pathways; one is an iNOS-independent response involving TXA(2) and ET-1, and the other is an iNOS-dependent response involving COX-1, COX-2 and PGI(2). cNOS appears to play some roles in the blood flow decrease and iNOS acts as an exacerbation factor. Our method using HEL-sensitized should be useful for searching for agents that can prevent allergy via new mechanisms.     

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-induced decrease in the fluidity of rat liver membranes

1. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCCD)-induced lipid peroxidation has previously been demonstrated by assessing the hepatic content of thiobarbituric acid reactive substances (TBARS) as well as the NADPH-dependent microsomal formation of TBARS as well as the NADPH-dependent microsomal formation of TBARS using malondialdehyde as the standard. 2. Changes in membrane fluidity as a result of lipid peroxidation may occur. Therefore the dose- and time-dependent effects of TCDD on lipid peroxidation in mitochondrial, microsomal, and plasma membranes, and changes in membrane fluidity in these subcellular fractions, were examined. Animals were treated with either 50 or 100 micrograms TCDD/kg orally, and killed 3, 6, or 9 days post-treatment. 3. Time-dependent increases occurred in TBARS content and formation following TCDD administration for all three membranes. Similar results were observed after 50 and 100 micrograms TCDD/kg. 4. Following TCDD administration, fluorescence polarization measurements as determined by the fluorescence polarization (r) and anisotropy parameter (a.p.) values demonstrated significant decreases in membrane fluidity in all membrane fractions, indicative of membrane structural alterations. 5. Excellent inverse correlations between lipid peroxidation and membrane fluidity were observed. Thus, decreased membrane fluidity and increased membrane damage may contribute to the toxic manifestations of TCDD as a consequence of an oxidative stress.     

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-induced decrease in the fluidity of rat liver membranes

1. 2,3,7,8-Tetrachlorodibenzo-ρ-dioxin (TCCD)-induced lipid peroxidation has previously been demonstrated by assessing the hepatic content of thiobarbituric acid reactive substances (TBARS) as well as the NADPH-dependent microsomal formation of TBARS as well as the NADPH-dependent microsomal formation of TBARS using malondialde-hyde as the standard.

2. Changes in membrane fluidity as a result of lipid peroxidation may occur. Therefore the dose- and time-dependent effects of TCDD on lipid peroxidation in mitochondrial, microsomal, and plasma membranes, and changes in membrane fluidity in these subcellular fractions, were examined. Animals were treated with either 50 or 100 μg TCDD/kg orally, and killed 3, 6, or 9 days post-treatment.

3. Time-dependent increases occurred in TBARS content and formation following TCDD administration for all three membranes. Similar results were observed after 50 and 100 μg TCDD/kg.

4. Following TCDD administration, fluorescence polarization measurements as determined by the fluorescence polarization (r) and anisotropy parameter (a.p.) values demonstrated significant decreases in membrane fluidity in all membrane fractions, indicative of membrane structural alterations.

5. Excellent inverse correlations between lipid peroxidation and membrane fluidity were observed. Thus, decreased membrane fluidity and increased membrane damage may contribute to the toxic manifestations of TCDD as a consequence of an oxidative stress.     

凤仙花治疗痛经的药效学及其机制的实验研究

目的：探讨凤仙花对痛经的作用效果及可能作用机制。方法将大鼠随机分为5组,正常组（洛氏液）,高、中、低3个剂量（1,2,4 mg? L－1凤仙花提取液）实验组,对照组（1 mg? L－1布洛芬）,考察凤仙花醇提物对大鼠离体子宫平滑肌的影响。小鼠随机分为6组,正常组,模型组（痛经模型）,凤仙花水提物高、中、低3个浓度（200,100,50 mg? kg－1）实验组,对照组（布洛芬）,观察各给药组对痛经模型小鼠的扭体反应以及子宫组织匀浆中钙离子（ Ca2＋）与一氧化氮（ NO）水平的影响。结果与模型组相比,凤仙花提取物可以明显降低大鼠的离体子宫平滑肌的收缩幅度与收缩频率。凤仙花醇提物能明显减少痛经模型小鼠的扭体反应次数,延长潜伏期;同时,可以明显降低小鼠的子宫组织中Ca2＋含量,提高NO水平。结论凤仙花提取物能有效降低大鼠离体子宫的收缩频率和振幅。同时,凤仙花醇提物能有效改善痛经,其机制可能为凤仙花能增加小鼠子宫组织中NO浓度、减少Ca2＋浓度有关。     

Nigral-induced decrease in striatal blood flow and the influence on this decrease of several drugs in reserpinized and non-reserpinized cats

The effect of nigral electrical stimulation on regional blood flow in the caudate nucleus and the cerebral cortex, and the influence of several drugs on these effects were examined in reserpinized or non-reserpinized cats. A double-thermistor element was inserted into the left caudate nucleus, and a plate-type thermocouple element was put on the left cerebral cortex. The left substantia nigra was electrically stimulated for 10 sec through a concentric bipolar electrode with a diameter of 0.3 mm (30 Hz, 1 msec, 10-30 V). In non-reserpinized cats, the nigral stimulation caused a decrease in striatal blood flow, increase in cortical blood flow and rise in mean blood pressure. Hexamethonium (3 mg/kg, i.v.) blocked completely the rise in mean blood pressure following nigral stimulation, but did not affect a decrease in striatal blood flow, indicating that a decrease in striatal blood flow following nigral stimulation was not due to the activation of the peripheral sympathetic nervous system. Nigral-induced decrease in striatal blood flow in non-reserpinized cats was blocked by haloperidol (0.1 mg/kg, i.v.), methysergide (1 mg/kg, i.v.) and reserpine (2 mg/kg, i.v.), but not by phentolamine (7 mg/kg, i.v.). In reserpinized cats, nigral stimulation caused an increase in striatal blood flow in contrast to a decrease in non-reserpinized cats. After administration of 5-HTP (50 mg/kg, i.v.) in reserpinized cats, nigral stimulation decreased the striatal blood flow. On the other hand, after administration of L-DOPA (30 mg/kg, i.v.) in reserpinized cats, nigral stimulation increased striatal blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preventive and curative effects of Artemisia absinthium on acetaminophen and CCl4-induced hepatotoxicity

• 1.1. Effect of aqueous-methanolic extract of Artemisia absinthium (Compositae) was investigated against acetaminophen- and CCl₄-induced hepatic damage.
• 2.2. Acetaminophen produced 100% mortality at the dose of 1 g/kg in mice while pretreatment of animals with plant extract (500 mg/kg) reduced the death rate to 20%.
• 3.3. Pretreatment of rats with plant extract (500 mg/kg, orally twice daily for two days) prevented (P < 0.01) the acetaminophen (640 mg/kg) as well as CCl₄ (1.5 ml/kg)-induced rise in serum transaminases (GOT and GPT).
• 4.4. Post-treatment with three successive doses of extract (500 mg/kg, 6 hr) restricted the hepatic damage induced by acetaminophen (P < 0.01) but CCl₄-induced hepatotoxicity was not altered (P > 0.05).
• 5.5. Plant extract (500 mg/kg) caused significant prolongation (P < 0.05) in pentobarbital (75 mg/kg)-induced sleep as well as increased strychnine-induced lethality in mice suggestive of inhibitory effect on microsomal drug metabolizing enzymes (MDME).
• 6.6. These results indicate that the crude extract of Artemisia absinthium exhibits hepatoprotective action partly through MDME inhibitory action and validates the traditional use of plant in hepatic damage.

     

有机铬对实验性糖尿病大鼠降血糖作用的观察

目的 :观察有机铬对实验性糖尿病大鼠的降血糖作用。方法 :用葡萄糖氧化酶法观察了口服有机铬 4 0 0μg/ kg.d及80 0μg/ kg.d连续 84 d的四氧嘧啶所致糖尿病大鼠血糖水平。结果 :每日 80 0μg/ kg体重组和 4 0 0μg/ kg体重组血糖与糖尿病模型组相比较均有明显下降 ,有显著性差异 (P <0 .0 5 )。每日 80 0μg/ kg体重组血糖浓度虽仍比正常组高 ,但已无显著差异(P>0 .0 5 ) ,每日 4 0 0μg/ kg体重组血糖浓度虽比糖尿病模型组有明显下降但与正常组相比较仍有显著性差异 (P >0 .0 5 )。结论 :有机铬可明显降低实验性糖尿病大鼠血糖水平     

Possible non-involvement of lipoxygenase pathway in the cerebral blood flow decrease due to indomethacin

Indomethacin (10n mg/kg i.p.) induced a marked decrease in local cerebral blood flow (l.CBF), which was measured in the frontal cortex of unanesthetized rats by the hydrogen clearance technique. Brain prostaglandins (PGD2, PGE2, PGF2 alpha,) and 6kPGF1 alpha the stable metabolite of prostacyclin, were significantly decreased. Treatments with inhibitors of lipoxygenase (BW 755C and nordihydroguaiaretic acid) and with FPL 55712, a leukotriene receptor antagonist, did not influence the effect of indomethacin on 1.CBF. The results suggest that the release of vasoconstrictory leukotrienes does not play a major role in the lowering of 1.CBF by indomethacin.     

Antineoplastic action of egg-white lysozyme on the growth of MCa mammary carcinoma and TLX5 lymphoma in the CBA mouse

The antitumor effects of egg-white lysozyme, at dosages between 25 and 100 mg/kg/day given for 5 to 14 days, was examined in CBA mice bearing MCa mammary carcinoma or TLX5 lymphoma. At early stages of tumor growth the antitumor action of lysozyme is statistically significant, independently from the route of administration (e.g., i.v. and oral admixed with food). With larger tumor masses, oral administration of lysozyme is effective on s.c. tumor growth but not on i.m. tumors. The effects of lysozyme in mice bearing TLX5 lymphoma consist of reduction of the capacity of tumor cells to form brain metastases: the effect is mediated by spleen cells. Dietary intake of lysozyme is also active in prolonging the survival time of animals treated with surgery and postsurgical cisplatin treatment. These effects indicate lysozyme to be an active substance, effective on the growth of malignant tumors and capable of synergizing with conventional therapies such as surgery plus cisplatin for the control of disseminated tumors in mice.     

Adrenomedullin inhibits the pressor effects and decrease in renal blood flow induced by norepinephrine or angiotensin II in anesthetized rats.

Adrenomedullin (AM), a hypotensive peptide originally isolated from human pheochromocytoma, has been reported to regulate renal functions. In patients with glomerulonephritis, the serum levels of AM are elevated as well as hypertensive agents norepinephrine (NE) and angiotensin II (AII). The effects of AM on the NE- or AII-induced pressor effects and renal blood flow responses, however, are not well clarified. We examined the effects of AM on blood pressure and renal blood flow induced by NE or AII in anesthetized rats. Arterial blood pressure and renal blood flow were measured using a calibrated pressure transducer and a laser Doppler flowmeter, respectively. Drugs were injected into the tail vein with a syringe. Intravenous administration of AM (1-3 nmol/kg) decreased the arterial blood pressure in anesthetized rats in a dose-dependent manner, whereas it did not affect the renal blood flow. NE or AII administration in anesthetized rats caused both increases in blood pressure and decreases in renal blood flow. Simultaneous administration of AM with NE or All prevented the increasing effects of blood pressure and inhibited the decreases in renal blood flow caused by NE or AII. These findings suggest that AM may have a protective role against the pressor effects and decrease in renal blood flow caused by NE or AII.     

The effect of blood decrease on (67)Ga uptake by the liver in partially hepatectomized rats

As (67)Ga is injected into the blood, (67)Ga is immediately bound to transferrin (Tf) and transported to various tissues and the Tf-(67)Ga complex binds to Tf receptor on various tissues. In partial hepatectomy (PH) a part of blood in circulation is lost together with removed liver tissues, consequently the amounts of blood cells and Tf in circulation decrease. In order to investigate the effect of those decreases on (67)Ga uptake by the liver, we compared the uptake in partially hepatectomized rats with that in venesectioned rats in which only a part of blood in circulation decreased. A two-thirds PH was performed. Two milliliters of blood was venesectioned. Each treated rat was intraveneously injected with (67)Ga. The changes of erythrocyte and reticulocyte contents after PH did not differ from those after venesection (VS) at all. But (67)Ga uptake by reticulocytes significantly increased after VS but did not after PH. On the other hand, (67)Ga uptake by the liver significantly increased after PH but did not after VS. These differences must be related to the different expression of Tf receptors on the liver after PH and VS.     

Preventive effect of D-psicose, one of rare ketohexoses, on di-(2-ethylhexyl) phthalate (DEHP)-induced testicular injury in rat

To investigate the preventive effects of d-psicose, one of rare ketohexoses, on di-(2-ethylhexyl) phthalate (DEHP)-induced testicular injury, prepubertal male Sprague-Dawley rats were exposed to DEHP via their diet or orally, while under treatment with d-psicose. The rats given a diet-containing 1% DEHP alone for 7-14 days showed severe testicular atrophy accompanied by aspermatogenesis. On the other hand, those given the diet plus 2% but not 1% d-psicose-supplemented water for 14 days did not develop testicular atrophy, and exhibited an almost complete spermatogenesis. There was no significant difference in plasma mono-(2-ethylhexyl) phthalate (MEHP) levels between the d-psicose-free and d-psicose-treated groups. The testicular malondialdehyde (MDA) level after a single oral administration of 2g/kg of DEHP showed a similar pattern of increase to the plasma MEHP level and peaked in 24h suggesting a close and dose-dependent relation between plasma MEHP and testicular reactive oxygen species (ROS) levels. Pretreatment with d-psicose at a concentration of 2% and 4% resulted in an almost complete but not absolute suppression of testicular MDA production among rats administered 2g/kg of DEHP. The microarray analysis showed the induction of oxidative stress related genes including the thioredoxin, glutathione peroxidase 1 and 2, glutaredoixn 1 after 24h of the DEHP treatment in the testis. These results show that d-psicose prevents DEHP-induced testicular injury by suppressing the generation of ROS in the rat testis. This effect may be due to the direct scavenging by d-psicose of ROS generated in the testis.     

金丝桃苷对内毒素(LPS)诱导的小鼠急性肾损伤的保护作用

目的考察金丝桃苷对内毒素(LPS)诱导的小鼠急性肾损伤的保护作用。方法通过采用腹腔注射7 mg·kg-1LPS建立小鼠急性肾损伤模型,通过检测血清尿素氮(BUN)和肌酐(Cr)水平,HE染色法观察肾脏病理组织学改变,Western blot法检测p50、p65、IκB-α和TLR4的蛋白表达,考察金丝桃苷对小鼠急性肾损伤保护作用。结果与模型组相比,金丝桃苷降低小鼠血清中BUN、Cr水平及肾组织p50、p65、和TLR4的蛋白表达量,升高IκB-α的蛋白表达量,组织切片观察发现其可缓解肾组织损伤,且具有一定的剂量依赖关系。结论金丝桃苷对内毒素所致的小鼠急性肾损伤具有一定的保护作用,其机制可能与抑制NF-κB炎症通路有关。     

Evaluation of teniposide (VM-26)-induced toxicity on mouse spermatogenesis by flow cytometry

Alteration in the testicular weight and various germ cell populations was studied in male mice treated with different doses (0.05, 0.25, 0.5, 1.0 and 2.0 mg/kg b. wt.) of teniposide (VM-26) at various post-treatment time periods. Treatment of mice with different doses of teniposide did not significantly alter the testicular weights, irrespective of the drug dose used. Flow-cytometric analysis of germ cells of the untreated control mice testes revealed four distinct DNA peaks corresponding to elongated spermatids (HC), round spermatids (1C), spermatogonia and non-germ cells (2C) and primary spermatocytes (4C). The region between 2C and 4C peaks represents cells that are actively synthesizing DNA (S-phase cells). Treatment of mice with different doses of teniposide resulted in a significant depletion in the relative percentage of spermatogonia from day 2 to 35 post-treatment depending on the drug dose. DNA-synthesizing, i.e. S-phase, cells declined significantly at day 1 post-treatment and continued to decline up to day 70 post-treatment for all the drug doses studied, except 2 mg/kg drug dose at day 28 post-treatment. A significant decline in the relative percentage of primary spermatocytes (4C) was observed at day 7 that continued up to day 70 post-treatment depending on the drug dose. Round spermatids (1C) declined significantly at day 21 post-treatment after administration of 0.25--2.0 mg/kg VM-26. The relative percentage of elongated spermatids showed a significant decline at day 28 after 1 and 2 mg/kg drug treatment. These alterations in different germ-cell populations are reflected in the various germ-cell ratios. The 4C:2C ratio showed a significant decline at day 7 and 14 post-treatment after 1 and 2 mg/kg VM-26 treatment, while the 1C:2C ratio declined significantly at day 21 post-treatment in the mice treated with 0.5 and 2.0 mg/kg of VM-26. 4C:S-phase and 1C:4C ratios increased significantly from day 1 to 70 post-treatment, depending on the drug dose. Our study demonstrates that the treatment of mice with low doses of VM-26 exerts cytotoxic effects on various germ-cell populations.