瓜蒌皮提取物对大鼠主动脉PDC Ca2+内流的影响

为了研究瓜蒌皮治疗冠心病的有效成分,用醚醇法和水煎醇沉法提取瓜蒌皮的有效成分,并用＾４５Ｃａ跨膜测量方法研究各提取物对大鼠主动脉ＰＤＣ钙通道Ｃａ＾２＋内流的影响。发现氯仿和醇溶物能阻滞Ｃａ＾２＋内流,水溶物具有相反的作用,其中氯信提取物浓度为３０ｍｇ／ｍＬ时,使Ｃａ＾２＋内流量比对照下降３１．５７％,实验结果表明瓜蒌皮中可能有７种组分具有治疗冠心病的活性。     

双参通冠方药物血清抗缺氧复氧损伤心肌细胞Ca2+超载的机制研究

目的:探讨双参通冠方药物血清对培养心肌细胞缺氧复氧损伤Ca²⁺超载的影响及其机制。方法:培养心肌细胞,建立缺氧复氧损伤模型。运用血清药理学方法研究双参通冠方药物血清对缺氧复氧损伤心肌Ca²⁺超载的影响。荧光分光光度法测定心肌细胞胞浆[Ca²⁺]i,激光扫描共聚焦显微法观察高K+及Thapsigargin诱导的细胞内Ca²⁺变化。结果:正常心肌细胞[Ca²⁺]i值较低,缺氧复氧后显著增高,高K⁺及Thapsigargin可诱导细胞内Ca²⁺的快速增多,双参通冠方药物血清能降低缺氧复氧心肌细胞Ca²⁺升高,并能抑制高K⁺及Thapsigargin所致的细胞内Ca²⁺荧光升高。结论:缺氧复氧损伤、高K⁺及Thapsigargin均可导致心肌细胞Ca²⁺增高,双参通冠方药物血清可抗心肌细胞Ca²⁺超载,其机制可能与其抑制细胞外Ca²⁺内流和促进内Ca²⁺吸收有关。     

益心酮调控细胞膜钙通道的实验研究

目的 :观察中药益心酮片调控细胞膜钙通道的特性 ,从细胞和亚细胞水平探讨其改善心肌缺血再灌注损伤的作用机理。方法 :采用大鼠主动脉平滑肌细胞模型 ,用放射性⁴⁵Ca跨膜流动测定技术分别观察益心酮片对溢流钙通道 (LC)、受体调控钙通道 (ROC)和电压依赖钙通道 (PDC)Ca²⁺ 内流的影响。结果 :益心酮片对LCCa²⁺ 内流无明显影响 ,对ROC和PDCCa²⁺ 内流有明显抑制作用。结论 :益心酮可以抑制慢通道Ca²⁺ 内流 ,且抑制作用呈现剂量依赖关系。     

JAK,PTPs抑制剂钙拮抗剂对As2O3引起的[Ca2+]i变化的影响

 目的　研究蛋白酪氨酸激酶 (JAK)、蛋白酪氨酸磷酸酶 (PTPs)抑制剂和Ca²⁺通道阻滞剂对As₂O₃致人脑皮层神经元和白血病细胞的胞浆 [Ca²⁺]_i变化的影响。方法　Fluo-3/AM荧光探针标记胞浆游离Ca²⁺,激光共聚焦显微镜实时测定不同浓度As₂O₃干预后胞浆[Ca²⁺]_i 的变化及JAK PTPs抑制剂和Ca²⁺通道阻滞剂对As₂O₃引起的胞浆[Ca²⁺]_i 变化的影响。结果　As₂O₃升高胞浆[Ca²⁺]_i,并被Ca²⁺通道阻滞剂不完全抑制。1μmol·L^-1的As₂O₃使NB4胞浆[Ca²⁺]_i明显增高,而对神经元胞浆[Ca²⁺]_i 影响不明显。JAK抑制剂genistein能浓度依赖性抑制As₂O₃触发的[Ca²⁺]_i 升高。给药后 280s的总抑制率均值分别为NB4:(6.7± 2.9)%,(25.6±2.5) %和(52.2±3.5)%;皮层神经元:(7.8±3.1)%,(18.1± 2.8) %和(51.3±3.3)%。结论　As₂O₃对不同细胞的胞浆[Ca²⁺]_i 升高程度不同。JAK,PTPs参与As₂O₃触发的钙池操纵性Ca²⁺内流。Ca²⁺通道阻滞剂参与了As₂O₃触发的电压门控性Ca²⁺内流。     

野西瓜正丁醇萃取物对HepG2细胞线粒体膜电位和［Ca2+］i的影响

目的 研究野西瓜正丁醇萃取物诱导人肝癌细胞 HepG2 细胞凋亡的机制,观察其对 HepG2 线粒体膜电位和细胞内 Ca²⁺ 浓度［Ca²⁺］_i 的影响。方法 经流式细胞仪观察野西瓜正丁醇萃取物对线粒体膜电位的影响;激光共聚焦显微镜检测野西瓜正丁醇萃取物作用前后,HepG2 细胞［Ca²⁺］_i 的变化。结果 野西瓜正丁醇萃取物可不同程度降低 HepG2 细胞线粒体跨膜电位,此外,中、高剂量的野西瓜正丁醇萃取物还可以显著升高［Ca²⁺］_i,造成钙稳态平衡。结论 野西瓜正丁醇萃取物降低线粒体膜电位,开放 MPTP 孔道,造成细胞内 Ca²⁺ 超载,诱导 HepG2 细胞凋亡。     

微毛诃子对家兔胸主动脉环的作用及其机制

目的： 研究微毛诃子甲醇提取物和乙醇提取物对家兔离体胸主动脉环的作用并探讨其可能的作用机制。 方法： 采用累积加药法,观察0.01~0.08 g·mL^-1微毛诃子对家兔离体胸主动脉环血管张力的影响;观察乙酰胆碱、酚妥拉明预处理对0.01 g·mL^-1微毛诃子缩血管作用的影响;采用Ca²⁺剥夺和复加法,观察0.01 g·mL^-1微毛诃子对细胞内钙释放和外钙内流动脉收缩作用的影响。 结果： 微毛诃子甲醇提取物浓度依赖性对内皮完整的家兔胸主动脉环收缩幅度低于内皮不完整的收缩幅度（P<0.05）,乙醇提取物对内皮完整的家兔胸主动脉环收缩幅度高于内皮不完整的收缩幅度（P<0.05）,且具有浓度依赖性;0.01 g·mL^-1的微毛诃子的甲醇提取物或乙醇提取物均可使乙酰胆碱（Ach,1×10^-5mol·L^-1）、酚妥拉明（10 mg·L^-1）预舒张的血管条收缩;维拉帕米（1×10^-7 mol·L^-1）预处理可消除0.01 g·mL^-1微毛诃子甲醇提取物的缩血管作用;在无Ca²⁺液中,0.01 g·mL^-1的微毛诃子甲醇提取物对去内皮主动脉环的收缩幅度显著低于有Ca²⁺液中的收缩幅度（P<0.05）。 结论： 微毛诃子甲醇提取物和乙醇提取物对家兔离体胸主动脉均有收缩作用;其缩血管作用可能与M受体及α受体有关;微毛诃子甲醇提取物的收缩作用具有内皮依赖性,可能与其促使血管平滑肌细胞外Ca²⁺内流进入细胞有关。     

银杏叶提取物对大鼠急性肾缺血再灌注损伤保护作用的实验研究

目的:研究银杏叶提取物对大鼠急性肾缺血再灌注损伤的保护作用。方法:肾缺血45 min再灌注4 h建立大鼠急性肾缺血再灌注损伤模型,用银杏叶提取物预处理,测定肾皮质丙二醛含量、超氧化物歧化酶活性、Na⁺-K⁺-ATP酶和Ca²⁺-ATP酶的活性,血浆肌酐和尿素氮的水平,并观察肾脏病理学改变。结果:缺血再灌注损伤后,肾皮质MDA含量升高,SOD,Na⁺-K⁺-ATP酶和Ca²⁺-ATP酶的活性下降;血浆BUN和Cr水平升高;肾组织出现明显的病理改变。银杏叶提取物预处理能降低肾皮质丙二醛含量;提高超氧化物歧化酶、Na⁺-K⁺-ATP酶和Ca²⁺-ATP酶的活性;降低血浆肌酐和尿素氮水平;肾组织病理改变明显减轻。结论:银杏叶提取物对大鼠急性肾缺血再灌注损伤具有保护作用。     

灵芝抗癌活性及放化疗对HL-7702细胞的保护作用

目的：研究灵芝精粉（灵芝醇提物+水提物）、灵芝精粉氯仿提取物、氯仿提取后的醋酸乙酯提取物、2次提取后的剩余物对肝癌BEL-7402和胃癌MGC-803细胞的抑制效果及其对HL-7702细胞顺铂损伤、⁶⁰Coγ射线辐射损伤的修复与保护作用。方法: 采用MTT法检测灵芝抗癌活性及放化疗时对HL-7702细胞保护作用。结果: 灵芝氯仿提取物的抗癌活性为最强：在0.125 mg·mL^-1时,对癌细胞的抑制率已超过50％。对已受顺铂损伤的HL-7702细胞,4种提取物未能显示出修复作用,但氯仿提取物预处理可显著降低其损伤程度。对受辐射的HL-7702细胞,仅氯仿提取物对中、高剂量照射下的辐射损伤体现一定的修复作用；但4种提取物预处理均可降低其辐射损伤的程度。结论: 灵芝氯仿提取物对癌细胞的抑制作用,对正常细胞放化疗损伤的保护作用,均体现了显著的效果。     

参附注射液对戊巴比妥钠致心衰模型心肌细胞膜ATP酶和相关离子的影响

目的: 通过探讨参附注射液对新生大鼠心力衰竭心肌细胞Ca²⁺-ATP酶,Ca²⁺-Mg²⁺-ATP酶、Na⁺-K⁺-ATP酶活性及细胞内Na⁺,Mg²⁺,K⁺,Ca²⁺浓度的影响,揭示参附注射液强心作用的机制。 方法: 通过胰蛋白酶消化法和差速贴壁法获得心肌细胞,经0.8%戊巴比妥钠作用5min后,分别给予1.5, 3, 6 mg·L^-1(5,10,20 mL·L^-1)3个不同浓度的参附注射液,作用1 h,检测心肌细胞Ca²⁺-ATP酶,Ca²⁺-Mg²⁺-ATP酶,Na⁺-K⁺-ATP酶的活性和细胞内Na⁺,Mg²⁺,K⁺,Ca²⁺的浓度。 结果: 参附注射液能增加心衰模型心肌细胞的搏动强度,提高Ca²⁺-ATP酶和Ca²⁺-Mg²⁺-ATP酶的活性,抑制Na⁺-K⁺-ATP酶的活性,降低细胞内K⁺,Ca²⁺的浓度,升高细胞内Na⁺,Mg²⁺的浓度。 结论: 参附注射液对戊巴比妥钠致心衰细胞有明显的保护作用,且作用的发挥与调节心肌细胞Ca²⁺-ATP酶,Ca²⁺-Mg²⁺-ATP酶,Na⁺-K⁺-ATP酶的活性和细胞内Na⁺,Mg²⁺,K⁺,Ca²⁺的浓度有关。     

马桑内酯对大鼠脑突触膜Ca2+,Mg2+-ATP酶作用的研究

 目的:探讨致痫剂马桑内酯(coriaria lactone)对大鼠大脑皮层突触膜Cat²⁺ , Mg²⁺ -ATP酶的作用。方法:酶底 物动力学分析(Hanes作图法)。结果:马桑内酯对Ca²⁺ , Mg²⁺-ATP酶具有抑制作用，在1.2 x 10^-9～6.0 X 10^-7mol · L^-1范围内，随浓度增加其抑制作用增强。此作用有明显的时效关系，抑制作用随作用时间延长而增强。酶底物动力学分析表明，马桑内酯对该酶的抑制属非竞争性抑制。结论:马桑内酯是Ca²⁺ , Mg²⁺-ATP酶的强力抑制剂。本文对Ca²⁺ , Mg²⁺-ATP酶与胞内游离钙之间的关系及该酶抑制在癫痫发病机制中的意义进行了讨论。     

大黄素和大黄多糖对小鼠脾淋巴细胞内游离钙浓度的影响

应用最新一代钙离子荧光指示剂ｕｒａ－２／ＡＭ测定小鼠脾淋巴细胞内游离钙浓度，探讨大黄有效成分蒽醌类中大黄素和大黄多糖对脾淋巴细胞内游离钙的影响。实验表明：大黄素（终浓度１８．５μｍｏｌ／Ｌ）对淋巴细胞外钙内流有明显促进作用（Ｐ＜０．０１）；大黄多糖则有抑制内钙释放和外钙内流（Ｐ＜０．０１），且抑制程度与剂量相关。本文为大黄双向调节作用提供理论依据。     

Phytochemical study guided by the myorelaxant activity of the crude extract,fractions and constituent from stem bark of Hymenaea courbaril L.

Ethnopharmacological relevance

Hymenaea courbaril L. (Caesalpinoideae) is used in Brazilian folk medicine to treat anemia, kidney problems, sore throat and other dysfunctions of the respiratory system, such as bronchitis and asthma, although such properties are yet to be scientifically validated.

Aim of the study

In order to give a scientific basis to support the traditional use of Hymenaea courbaril, this study was designed to evaluate antioxidant, myorelaxant and anti-inflammatory properties of the ethanol extract from stem bark and its fractions. The myorelaxant effect of astilbin, a flavonoid isolated from the bioactive ethyl acetate fraction (EAF), has also been evaluated.

Material and methods

In the present study ethanol extract from stem bark (EEHC) and fractions were analyzed using bioassay-guided fractionation. The following activities were investigated: antioxidant by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, myorelaxant on rat tracheal smooth muscle, and anti-inflammatory using ovalbumin-induced leukocytosis and airway hyperresponsiveness in rats.

Results

The results of the present investigation show that the whole extract of Hymenaea courbaril and some of its fractions strongly scavenged DPPH radical. The extract showed myorelaxant activity on rat trachea, being EAF its highest efficient fraction. Bio-guided study allowed the isolation of astilbin, a well-known flavonoid. The activity induced by this compound indicates that it may be partly responsible for the myorelaxant effect of EAF. EAF reduced contractions that depended on divalent cation inflow through voltage-operated Ca²⁺ channels (VOCCs) or receptor-operated Ca²⁺ channels (ROCCs), but it was more potent to inhibit VOCC- than ROCC-dependent contraction induced by Ca²⁺ addition in ACh-enriched Ca²⁺-free medium. Oral pretreatment of antigen-challenged animals with EAF prevented airway hyperresponsiveness on KCl-induced contraction and reduced the number of total white cells, particularly eosinophils and neutrophils in bronchoalveolar lavage.

Conclusions

This study provided scientific basis that Hymenaea courbaril presents potential antioxidant, myorelaxant and anti-inflammatory actions, which support its use in folk medicine to treat inflammatory airway diseases.     

Relaxant effect of flavonoid naringenin on contractile activity of rat colonic smooth muscle

Ethnopharmacological relevance

Disturbed gastrointestinal (GI) motility can be associated with smooth muscle abnormalities and dysfunction. Exploring innovative approaches that can modulate the disturbed colonic motility are of great importance for clinical therapeutics. Naringenin, a flavonoid presented in many traditional Chinese herbal medicines, has been shown to have a relaxant effect on different smooth muscles. The aim of the present study was to investigate the effect of naringenin on regulation of GI motility.

Material and methods

Mechanical recording was used to investigate the effect of naringenin on isolated rat colonic smooth muscle spontaneous contractions. Whole cell patch clamp, intracellular [Ca²⁺] concentration ([Ca²⁺]_i) and membrane potential measurements were examined on primary cultures of colonic smooth muscle cells (SMCs). A neostigmine-stimulated rat model was utilized to investigate the effect of naringenin in vivo.

Results

Naringenin induced a concentration-dependent inhibition (1–1000 μM) on rat colonic spontaneous contraction, which was reversible after wash out. The external Ca²⁺ influx induced contraction and [Ca²⁺]_i increase were inhibited by naringenin (100 μM). In rat colonic SMCs, naringenin-induced membrane potential hyperpolarization was sensitive to TEA and selective large-conductance calcium-activated K⁺ (BK_Ca) channel inhibitor iberiotoxin. Under whole cell patch-clamp condition, naringenin stimulated an iberiotoxin-sensitive BK_Ca current, which was insensitive to changes in the [Ca²⁺]_i concentration. Furthermore, naringenin significantly suppressed neostigmine-enhanced rat colon transit in vivo.

Conclusion

Our results for the first time demonstrated the relaxant effect of flavonoid naringenin on colon smooth muscle both in vitro and in vivo. The relaxant effect of naringenin was attributed to direct activation of BK_Ca channels, which subsequently hyperpolarized the colonic SMCs and decreased Ca²⁺ influx through VDCC. Naringenin might be of therapeutic value in the treatment of GI motility disorders.     

大黄素对小鼠腹腔巨噬细胞内游离钙浓度的影响

用钙敏感的荧光指示剂Fura－2／Am定量分析大黄素对小鼠腹腔巨噬细胞内（Ca2 ）i的影响。结果显示：在巨噬细胞悬液中相继加入不同剂量的CaCl2后，（Ca2 ）i明显增高（P＜0．01）。巨噬细胞用适当剂量大黄素予处理10min，使用上述不同剂量的CaCl2后，（Ca2 ）i水平明显增高，该实验进一步提示；大黄素可促进细胞内Ca2 释放，也可促进细胞外Ca2 内流。而且大黄素对［Ca2 ］i的作用呈剂量依赖性。     

胡颓子叶对豚鼠离体气管平滑肌收缩功能的影响

目的 研究胡颓子叶乙醇提取物正丁醇部位(胡颓子叶正丁醇部位)对正常及多种致痉剂诱导的豚鼠气管平滑肌收缩功能的影响.方法 制备豚鼠离体气管平滑肌螺旋条,在其正常状态下以及用乙酰胆碱、组胺、氯化钾、无钙下乙酰胆碱诱导细胞内钙释放和高钙下诱发细胞外钙内流条件下,观察胡颓子叶正丁醇部位对离体气管张力的影响.结果 胡颓子叶正丁醇部位对静息状态下的豚鼠离体气管平滑肌有明显的舒张作用,使乙酰胆碱和组胺的量效曲线发生明显右移,抑制加入高钾或高钙后引发细胞外钙内流导致的收缩.结论 胡颓子叶正丁醇部位能明显抑制正常状态及多种致痉剂诱发的豚鼠气管平滑肌收缩.     

葛根素对氧糖剥夺大鼠海马神经细胞Ca2+和NO的影响

 目的研究葛根素(puerarin,Pur)对缺氧缺糖状态下海马神经细胞内Ca²⁺和NO水平的影响。方法选用新生大鼠体外培养8 d的海马神经细胞,进行3 h的氧糖剥夺(oxygen/glucose deprivation,OGD)或30 min的L-谷氨酸(0.5mmol·L^-1)处理后再正常培养24 h,Pur处理组在OGD或谷氨酸处理的同时和以后24 h给予不同剂量(40,100μmol·L^-1)Pur,Annexin V联合流式细胞仪检测细胞的凋亡率和坏死率;以Fluo-3或DAF-2为荧光标记,用激光共聚焦显微镜观测30 min的OGD过程中海马神经细胞Ca²⁺和NO的动态变化以及Pur的影响。结果OGD诱导海马神经细胞Ca²⁺和NO水平快速升高,其最高值分别达正常对照组的2.9和1.9倍;Pur明显减缓OGD期间神经细胞Ca²⁺内流和NO合成,与OGD组相比,40和100μmol·L^-1的Pur分别使细胞Ca²⁺峰值降低29.2%和37.1%(P<0.05和P<0.01),NO峰值降低23%和33%(P<0.05和P<0.01),显著抑制细胞内Ca²⁺和NO水平的升高;同时Pur可有效抑制OGD和谷氨酸引起的神经细胞死亡。结论Pur可通过抑制神经细胞谷氨酸/Ca²⁺/NO通路的活动而有效保护缺氧缺糖对神经细胞的损伤作用。     

Contractile effect of some extracts from the leaves of Musanga cecropioides (Cecropiaceae) on uterine smooth muscle of the rat

Portions of the hot water extract, chloroform and n-butanol fractions of the leaves of Musanga cecropioïdes were used to challenge uterine strips from nonpregnant and early stage pregnant (3–8 days) female Wistar rats. Uterine strips were obtained from oestrogenized females. The aqueous and n-butanol extracts (10 mg/L showed very marked uterotonic effects which were more pronounced in the pregnant females. These contractile effects were dose-dependent and comparable to oxytocin and acetylcholine (100 μg/mL) but were all antagonized by ethanol, a potent Ca^2t channel antagonist. These effects may account for the abortifacient properties of the extracts observed in previous in vivo trials.