左旋多巴对偏侧帕金森病大鼠纹状体多巴胺D2受体表达数及多巴胺含量的影响

 目的了解左旋多巴(L-dopa)在抗帕金森病(PD)治疗中对纹状体区多巴胺D₂受体表达数及多巴胺含量的影响。方法采用6-羟基多巴胺(6-OHDA)制备偏侧PD大鼠模型。用免疫组化染色法和高效液相色谱法分别检测PD模型大鼠在L-dopa100mg·kg^-1·dkg^-1)腹腔注射15d前后纹状体部位的多巴胺D₂受体表达数、多巴胺及其代谢物含量变化。结果与L-dopa治疗前组相比,L-dopa治疗后PD大鼠模型纹状体中D2受体阳性表达细胞数明显减少(P<0.01),而多巴胺和代谢物含量明显增高。结论偏侧PD大鼠模型损毁侧纹状体区多巴胺D₂受体因代偿作用出现明显上调,而L-dopa干预能很大程度逆转了这种上调作用。     

绞股蓝皂苷脑干缺血性损伤保护作用及机制探讨

 目的：探讨绞股蓝皂苷对脑干缺血性损伤的保护作用及其作用机制。方法：建立犬脑干缺血模型。在缺血前3h，经十二指肠灌注给予绞股蓝皂苷0．15g·kg－1。观察脑干听觉诱发电位（BAEP）及病理（光镜及电镜）恢复率、磷脂酶A₂（PLA₂）和SOD活性的动态变化。结果：在基底动脉夹闭后1，3，6及12h，绞股蓝皂苷组BAEP及病理恢复率逐渐升高，PLA₂活性逐渐降低（晚期突出），SOD活性逐渐升高（早期明显），与缺血组比较，均有显著性差异（P＜0．01）。结论：绞股蓝皂苷对犬脑干缺血有较好的保护作用，其机制可能与升高SOD活性及降低PLA₂活性有关，早期以升高SOD活性为主，晚期以降低PLA₂活性为主     

氧化苦参碱对感染性休克大鼠肾组织JAK2/STAT3信号通路的影响

目的: 观察氧化苦参碱(oxymatrine,OMT)对感染性休克大鼠肾组织JAK₂/STAT₃信号通路的影响。方法: 采用大鼠盲肠结扎穿孔法(cecal ligation and puncture,CLP)复制大鼠感染性休克模型,随机将56只SD大鼠分为假手术组、OMT对照组、模型组(CLP)、CLP+OMT高、中、低剂量组(52,26,13 mg·kg^-1)、阳性对照组(CLP+地塞米松10 mg·kg^-1)。光镜下观察大鼠肾组织病理学改变,采用尿酶法测定血清尿素氮(BUN)含量,RT-PCR法测定肾组织肿瘤坏死因子-α(TNF-α),白细胞介素-1β(IL-1β) mRNA的表达;Western blot测定肾组织JAK₂,STAT₃的表达;放射免疫分析法测定肾组织匀浆中TNF-α及IL-1β蛋白含量的改变。结果: 不同剂量的OMT能抑制肾组织JAK₂,STAT₃的活化(P<0.05),减少JAK₂,STAT₃的蛋白表达(P<0.05)及TNF-α,IL-1β mRNA的表达(P<0.05),降低肾组织匀浆中TNF-α及IL-1β的含量(P<0.05),降低血清BUN含量(P<0.05),改善肾组织充血、水肿和炎性细胞浸润等病变,并且该作用在OMT高、中剂量组与阳性对照组的结果相一致。结论: OMT能通过抑制JAK₂/STAT₃信号通路的活化,减少肾组织TNF-α,IL-1β等促炎因子的表达,进而对感染性休克大鼠肾损伤性病变发挥治疗作用。     

丹参酮ⅡA抑制大鼠血管平滑肌细胞增殖及其机制研究

目的：观察丹参酮Ⅱ_A(tanshinone Ⅱ_A，TA)对10％胎牛血清诱导的大鼠血管平滑肌细胞(RVSMC)增殖的抑制作用，并探讨其可能的作用机制。方法：体外培养大鼠主动脉平滑肌细胞A7r5细胞株，以终浓度为10％的胎牛血清(FBS)作为刺激因素，用细胞计数法、噻唑蓝(MTT)比色法和5-溴脱氧尿嘧啶(BrdU)掺入法测定TA对细胞增殖的影响，用流式细胞术(FCM)分析细胞周期分布特征，用Western blot实验测定细胞外信号调节激酶1/2(ERK1/2)磷酸化活性，用RT-PCR测定c-fos的表达水平。结果：细胞计数、MTT比色法和BrdU掺入实验表明丹参酮Ⅱ_A能抑制10％FBS所诱导的VSMC增殖，作用强度呈剂量依赖性；细胞周期分析显示，TA处理组G₀/G₁期细胞百分比高于10％FBS组，而S期比例低于10％FBS组，表明TA可阻止10％FBS所诱导的细胞周期由G₀/G₁期向S期推进；Western blot结果显示与10％FBS组相比，TA处理组ERK1/2磷酸化活性降低；RT-PCR结果显示TA处理组c-fos表达水平降低。结论：丹参酮可抑制10％FBS诱导的体外培养大鼠动脉平滑肌细胞增殖，此作用可能与其阻止细胞周期由G₀/G₁期向S期推进，抑制MAPK信号转导通路激活，进而下调c-fos表达有关。     

基于配伍理论的芪麝方对神经根压迫模型大鼠背根节神经元磷脂酶A2及前列腺素E2表达的影响

目的：观察芪麝方拆方后不同配伍组别不同给药时长对神经根压迫模型大鼠背根节神经元（DRG）内磷脂酶A₂（PLA₂）、前列腺素E₂（PGE₂）含量表达的影响,并进一步探讨芪麝方的配伍规律。方法：选用3月龄SPF级SD雄性大鼠352只,随机分为11组,,根据芪麝方及阳性对照药成人每日常用剂量及芪麝方处方配比并按“动物体表面积比率换算等剂量方法”换算给药剂量,每天灌服1次,各组别分别于给药1,2,3,4周取背根节,应用ELISA法检测神经根组织中PLA₂和PGE₂的含量。测定结果应用SPSS 18.0进行统计学比较,通过差异对比找出引起炎症变化的敏感组分。从而揭示芪麝方各配伍组分抑制炎症的相互作用规律。结果：模型组与正常组比较,两炎症因子水平显著高于正常组,并在4周内变化趋势稳定,进一步验证了该模型的稳定性。不同给药时长不同配伍组别相对于模型组均能显著降低模型大鼠背根节中PLA₂,PGE₂含量（P<0.01）,其中不同组别之间抑制炎症的程度各有不同（P<0.05）,说明各配伍组分间存在协同作用。结论：统计结果显示复方中君药起到主导药效的作用,臣、佐、使对君药有协同增强疗效的作用,其他各组别虽作用效果明显,但尤以全方配伍效果最佳,说明全方配伍的科学性和合理性。为制剂的科学配伍提供了数据依据。     

坤宁颗粒对痛经模型大鼠的抗炎镇痛作用研究

[目的]研究坤宁颗粒对痛经模型大鼠COX-2/PGF_2α通路、内分泌激素、炎症因子和氧化应激水平的影响,探讨其保护作用及机制。[方法]取SD雌性大鼠,随机分为6组,正常对照组、模型组、益母草颗粒(3.5 g/kg)阳性对照组、坤宁颗粒低(1.4 g/kg)、中(2.8 g/kg)、高(5.6 g/kg)剂量组,除正常对照组外,其余组建立痛经模型,第1、10天灌胃戊酸雌二醇每只0.2 mg,第2~9天每只0.1 mg,从第5天各给药组灌胃给药,正常对照组和模型组灌胃蒸馏水,每日1次,第10天正常对照组大鼠腹腔注射生理盐水,其余各组大鼠腹腔注射缩宫素每只10 U。观察各组大鼠扭体反应次数;采用酶联免疫吸附实验(ELISA)检测大鼠血清前列腺素F_2α(PGF_2α)、前列腺素E₂(PGE₂)、β-内啡肽(β-EP)、雌二醇(E₂)、孕酮(PROG)、白介素-1β(IL-1β)、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)含量;比色法检测大鼠血清超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)水平;蛋白免疫印迹法(Western Blot)检测大鼠子宫组织环氧合酶-2(COX-2)、前列腺素E₂受体(PTGER₂)、雌激素受体α(ER_α)蛋白表达;苏木精-伊红(HE)染色观察子宫组织病理形态。[结果]与正常对照组相比,模型组大鼠扭体反应次数显著增加,大鼠血清中PGF_2α、E₂、IL-1β、IL-6、TNF-α、MDA水平和子宫组织COX-2、ER_α蛋白表达显著升高,而血清PGE₂、β-EP、PROG、SOD、GSH-Px水平显著降低,子宫PTGER₂蛋白表达显著降低,子宫组织可见明显充血、水肿。与模型组相比,坤宁颗粒可以显著降低大鼠扭体反应次数和血清中PGF_2α、E₂、IL-1β、IL-6、TNF-α、MDA水平,升高PGE₂、β-EP、PROG、SOD、GSH-Px水平,显著抑制子宫组织COX-2、ERα蛋白表达,升高PTGER₂蛋白表达,组织病理学明显改善。[结论]坤宁颗粒对痛经模型大鼠具有显著的改善作用,其机制可能与调节COX-2/PGF_2α通路和PGE₂、β-EP、E₂、PROG等内分泌激素、降低炎症因子水平、改善氧化应激水平有关。     

三七皂苷Rg1对失血性休克大鼠肠上皮细胞线粒体损伤保护作用的研究

 目的观察大鼠失血性休克后肠上皮细胞线粒体编码基因细胞色素氧化酶(COXⅠ，COXⅡ，COXⅢ)mRNA的表达变化，并探讨三七皂苷Rg1(Rg₁)对其保护作用的分子机制，为休克的防治提供实验依据。方法采用失血性休克模型，分离肠上皮细胞后进行RNA的提取，应用RT-PCR检测大鼠失血性休克后及用Rg₁治疗后COXⅠ，COXⅡ，COXⅢ mRNA的表达变化情况。结果大鼠失血性休克1h，COXⅠ，COXⅡ基因表达开始增强，2h表达最强，以后随着休克时间延长，表达又逐渐减弱，失血性休克晚期5 h表达显著低于正常对照鼠(P＜0.01)；Rg1(5 mg·kg^-1)治疗后，可使COXⅠ，COXⅡ mRNA表达显著增强(P＜0.01)。结论失血性休克可引起大鼠肠上皮细胞线粒体编码基因COXⅠ，COXⅡ mRNA的明显改变，Rg1可提高其表达,对失血性休克肠上皮细胞线粒体损伤有明显的保护作用。     

丹参酮ⅡA对大鼠肥厚心肌NO产生及eNOS基因表达的影响

目的：研究丹参酮Ⅱ_A(TSN)对腹主动脉缩窄大鼠肥厚心肌一氧化氮合酶及蛋白激酶C的影响，探讨丹参酮Ⅱ_A逆转高血压左心室肥厚的分子生物学机制。方法：SD大鼠行腹主动脉缩窄术建立高血压左室心肌肥厚模型，术后4周将手术大鼠随机分为手术组、TSN低、高剂量组(10，20 mg·kg^-1·d^-1，腹腔注射)、缬沙坦组(10 mg·kg^-1·d^-1，灌胃)，每组8只；另有8只作为假手术组。用药8周后检测各组尾动脉压，取左心室组织检测左心室质量指数(LVMI)、心肌纤维直径(MFD)；硝酸还原法测定心肌组织NO的含量，逆转录-聚合酶链式反应(RT-PCR)、免疫印迹法(Western blotting)分别检测eNOS的基因表达水平和蛋白激酶C(PKC)的活性。结果：①TSN低、高剂量组的血压仍显著高于假手术组和缬沙坦组(P<0.01)。②TSN低、高剂量组和缬沙坦组的LVMI，MFD虽然高于假手术组(P<0.05)，却显著低于手术组(P<0.01)。③ TSN低、高剂量组和缬沙坦组的NO含量以及eNOS蛋白、mRNA表达水平明显高于手术组(P<0.01)，TSN两组的eNOS上调超过缬沙坦组(P<0.05)。④ 手术组的PKC蛋白水平显著升高(P<0.01)，TSN低、高剂量组PKC水平明显低于缬沙坦组(P<0.05)。结论：丹参酮Ⅱ_A对心肌肥厚的逆转作用是非血压依从性的，丹参酮Ⅱ_A通过抑制PKC蛋白的表达、促进心肌局部NO的产生及eNOS基因表达，起到阻止、逆转高血压心肌肥厚的发展。     

人ⅡA型磷脂酶A2衍生多肽M17杀菌作用的研究

目的: 研究和比较人ⅡA型磷脂酶A₂(phospholipase A₂,PLA₂)衍生多肽M17,P26和N_1-11对不同细菌在体外的杀菌效应。方法: 根据人ⅡA型PLA₂氨基酸顺序分别设计合成3个肽分子M17(p_51-67),P26(p_99-124),N_1-11(p_1-11)。采用琼脂铺板计数法测定杀菌活性,将不同浓度衍生肽分别与革兰阳性菌(G⁺)金黄色葡萄球菌、枯草杆菌、屎肠球菌和革兰阴性菌(G^-)大肠杆菌、绿脓杆菌、鲍曼不动杆菌在37℃孵育2.5 h,然后铺板并置于37℃恒温箱培养18~24 h,记录每一琼脂板上的菌落数(CFU),并计算多肽作用后的杀菌率。结果: ⅡA型PLA₂M17对枯草杆菌、金黄色葡萄球菌、屎肠球菌的杀菌回归方程分别为:Y=1.464X+3.795(ED₅₀ 6.65 mg·L^-1),Y=1.152X+3.419(ED₅₀ 23.57 mg·L^-1),Y 0.836X+3.832 (ED₅₀ 24.95 mg·L^-1);对大肠杆菌、鲍曼不动杆菌、绿脓杆菌的杀菌回归方程分别为:Y=0.877X+4.054(ED₅₀ 12.00 mg·L^-1),Y=1.094X+3.371(ED₅₀ 30.83 mg·L^-1),Y=1.027X+3.626(ED₅₀ 21.77 mg·L^-1);M17肽分子对G⁺菌与G^-菌均有较强的杀菌活性。P26和N_1-11对金黄色葡萄球菌的杀菌回归曲方程分别为:Y=0.915X+2.766(ED₅₀ 276.39 mg·L^-1),Y=1.389X+1.668(ED₅₀ 250.52 mg·L^-1), P26和 N_1-11对大肠杆菌的杀菌回归方程为:Y=1.327X+1.437(ED₅₀ 484.18 mg·L^-1), Y=0.881X+2.903(ED₅₀ 240.02 mg·L^-1);N_1-11和P26对G⁺菌有较强的杀菌活性,但对G^-菌杀菌活性较弱。M17肽分子对金黄色葡萄球菌的杀菌活性强于P26及N_1-11,M17肽分子对大肠杆菌的杀菌活性明显强于P26及N_1-11。结论: 衍生自人ⅡA型PLA₂保守区域17个氨基酸残基的肽M17对G⁺菌和G^-菌均有较强的杀菌活性,这可能与M17肽分子更易于与细菌结合并发挥作用有关。     

补阳还五汤对肺纤维化大鼠肺组织TGF-β1/Smad3表达的影响

目的： 观察补阳还五汤对博莱霉素致肺纤维化大鼠肺组织病理及转化生长因子β₁（TGF-β₁）_mRNA,Smad3 mRNA表达的影响。方法： 将144只健康雄性SD大鼠随机分成6组,即假手术（NS）组、模型（BLM）组、强的松（P）组、补阳还五汤高、中、低（A,B,C）组,每组各24只。除NS组外,其余各组采用一次性气管滴注博莱霉素复制肺纤维化大鼠模型,NS组气管内滴注等量NS,造模第2天起,A,B,C组用补阳还五汤（剂量分别为18.48,9.24,4.62 g·kg^-1）灌胃,P组用强的松混悬液（4.2 mg·kg^-1）灌胃,NS组及BLM组用NS（10 mL·kg^-1）灌胃,于造模后第7,14,28 d分3批处死动物,每次8只,取左肺制备病理切片,行HE,Masson染色观察肺泡炎及肺纤维化程度改变情况;取右肺上中叶组织,采用逆转录-聚合酶链反应（RT-PCR）法检测各组大鼠肺组织TGF-β₁mRNA,Smad3 mRNA的表达。结果： ①BLM组大鼠肺泡炎及肺纤维化程度在不同时间点均明显高于同期NS组,差异明显（P<0.01）;②与BLM组相比,补阳还五汤各剂量组肺泡炎及肺纤维化程度有不同程度的改善（P<0.01 或 P<0.05）;③与NS组相比,BLM组肺组织TGF-β₁,Smad3表达水平在不同时间点均明显增高（P<0.01）,尤以第7天最为明显,并随时间推移有逐渐下降的趋势;④补阳还五汤各剂量组TGF-β₁,Smad3表达水平与同期BLM组相有不同程度的降低（P<0.01或P<0.05）,其中B组在7,14,28 d,C组在14,28 d下降较明显（P<0.01）,A组与同期BLM组相比虽有所降低,但早期不如B,C组明显。结论： 补阳还五汤可以明显改善模型大鼠肺组织肺泡炎和肺纤维化程度,抑制博莱霉素诱导的肺纤维化大鼠肺组织TGF-β₁mRNA、Smad3mRNA的表达上调,从而减轻肺纤维化程度。     

荧光脂质体法研究芍药甘草汤对磷脂酶A2的抑制效应及其配伍作用

目的 采用荧光脂质体研究芍药甘草汤对磷脂酶A2(PLA2)的抑制效应及其配伍作用.方法 以磷脂酰胆碱和胆固醇等为主要材料,采用薄膜分散法-超声-膜挤出-葡聚糖凝胶柱色谱分离-冷冻干燥的联用技术制备包封羧基荧光素的脂质体;利用PLA2能水解磷脂破坏脂质体造成羧基荧光素渗漏的原理,将药物、PLA2和荧光脂质体共同温孵,检测从脂质体渗漏的羧基荧光索的荧光强度,该强度反映药物对PLA2的抑制强度.结果 芍药甘草汤、甘草、甘草酸和对照药氯丙嗪对PLA2活性均具有较强的抑制作用,白芍抑制作用较弱,而芍药苷几乎无抑制作用;芍药甘草汤复方对PLA2的抑制作用强于单味甘草和白芍.结论 芍药甘草汤对PLA2具有较强的抑制活性,白芍与甘草具有协同作用.     

Anti‐inflammatory activity of Rhodiola rosea – “a second‐generation adaptogen”

Rhodiola rosea (golden root), a unique phytoadaptogen grown in high‐altitude regions has gained attention for its various therapeutic properties. In India, this plant is found in the Himalayan belt and has not been completely explored for its beneficial health effects. The present study was undertaken to evaluate the anti‐inflammatory efficacy of the tincture extract of Rhodiola rosea roots (RTE). The anti‐inflammatory activity was determined through carrageenan‐induced paw oedema, formaldehyde‐induced arthritis and nystatin‐induced paw oedema in rat model. The tincture extract exhibited inhibitory effect against acute and subacute inflammation at a dose of 250 mg/kg body weight. Inhibition of nystatin‐induced oedema was also observed in a dose‐dependent manner. The in vitro inhibitory effects of the tincture extract from R. rosea roots was evaluated against the enzymes relating to inflammation. The enzymes include cyclooxygenase‐1 (COX‐1), cyclooxygenase‐2 (COX‐2) and Phospholipase A₂ (PLA₂). The extract showed varying inhibitory activities against these enzymes depending on the concentrations. A potent inhibition was observed against Cox‐2 and PLA₂. Inhibition of nystatin induced oedema and phospholipase A₂ suggested that membrane stabilization could be the most probable mechanism of action of RTE in anti‐inflammation. The findings in this study may provide the use of R. rosea root extract in the treatment of inflammatory conditions. Copyright © 2009 John Wiley & Sons, Ltd.     

Screening of antiinflammatory medicinal plants used in traditional medicine against skin diseases

The antiinflammatory activity of twelve medicinal plants used against skin disorders were tested in different experimental models of topical inflammation and one in vitro inhibitory test against phospholipase A₂ (PLA₂) from Naja naja venom. Forsythia suspensa was the most active species on the arachidonic acid (AA) topical test. This last species together with Astragalus membranaceus and Ranunculus sceleratus were the most active on the 12-O-tetradecanoylphorbol-13-acetate (TPA) acute ear oedema test. Scrophularia auriculata was the most active on multiple topical applications of TPA and on the oxazolone-induced delayed type hypersensitivity (DTH). Santolina chamaecyparissus was the only species that inhibited PLA₂ in vitro. © 1998 John Wiley & Sons, Ltd.     

虎杖提取物中虎杖苷及白藜芦醇在大鼠胃肠道吸收的动力学分析

目的:研究虎杖提取物在大鼠胃及小肠中的吸收特性。方法:采用大鼠在体单向肠灌流法,以虎杖苷和白藜芦醇含量作为评价指标,采用HPLC测定灌流高、中、低剂量虎杖提取物后指标成分的含量变化,研究二者在胃、小肠中的吸收动力学。结果:虎杖提取物在胃内吸收量与药物浓度成正比,经SPSS 17.0软件分析,低剂量组虎杖提取物中虎杖苷的吸收速率与中、高剂量组比较具有显著性差异(P0.05),中剂量组与高剂量组比较则无显著性差异;不同组别之间白藜芦醇吸收速率分析结果为F=609.724,P0.05。当虎杖提取物给药剂量为600 mg·L~(-1)时,虎杖苷和白藜芦醇在大鼠肠道的吸收速率常数(Ka)分别为0.925,0.575 h-1;不同剂量组中虎杖苷和白藜芦醇的Ka及吸收率均无显著性差异。结论:虎杖提取物中虎杖苷在胃内吸收具有浓度饱和现象,可能是主动吸收或易化扩散机制;而白藜芦醇在胃内的吸收率随着提取物浓度的增加而增大,提示其吸收机制可能是被动转运;不同质量浓度虎杖提取物对虎杖苷和白藜芦醇的肠吸收没有影响,吸收无浓度饱和现象,提示其在肠道内的吸收可能是被动扩散机制。     

虎杖苷抑制肝星状细胞活化研究

目的：研究虎杖苷的抗肝纤维化药理作用。方法：采用转化生长因子-β1（TGF-β1）刺激人肝星状细胞株（LX-2）诱导肝纤维化细胞模型,采用虎杖苷（20μM）进行干预。Western blot法检测α-平滑肌肌动蛋白（α-SMA）的表达。结果：虎杖苷能显著抑制TGF-β1诱导的LX-2细胞α-SMA的表达。结论：虎杖苷具有显著改善肝纤维化的作用,有望成为新型的抗肝纤维化药物。     

The Chinese herbal medicine,Shinpi-To,inhibits IgE-mediated leukotriene synthesis in rat basophilic leukemia-2H3 cells

We examined the action of Shinpi-To (Formula divinita; TJ-85), a granular extract of seven Chinese medicinal herbs that is used in treating childhood asthma, on the leukotriene synthesis in rat basophilic leukemia-2H3 cells (RBL-2H3 cells). IgE-loaded cells were stimulated with anti-IgE serum in the presence or absence of Shinpi-To. Released LTC₄ and LTB₄ were measured by radioimmunoassay (RIA). Shinpi-To significantly inhibited IgE-mediated synthesis of leukotriene (LT)C₄ and LTB₄. To identify the inhibitory sites, we investigated the action of this extract on four synthetic enzymes, phospholipase A₂ (PLA₂), 5-lipoxygenase (5-LO), LTC₄ synthase, and LTA₄ hydrolase. Shinpi-To inhibited the A23187-stimulated release of [³H]arachidonic acid (AA) from the cell membrane, reflecting an effect on PLA₂ activity. It also suppressed production of LTC₄ and LTB₄ when cell lysates were incubated with AA as substrate. It did not inhibit the production of LTC₄ and LTB₄ when LTA₄-free acid was used as the substrate. Shinpi-To did not inhibit the IgE-mediated increase of intracellular Ca²⁺ ([Ca²⁺]_i) concentration. Results indicate that Shinpi-To inhibits LT synthesis by inhibiting PLA₂ and 5-LO activities without affecting the mobilization of [Ca²⁺]_i.     

Neutralization of snake venom phospholipase A2 toxins by aqueous extract of Casearia sylvestris (Flacourtiaceae) in mouse neuromuscular preparation

Aqueous extract of Casearia sylvestris (Flacourtiaceae) has been shown to inhibit enzymatic and biological properties of some Bothrops and Crotalus venoms and their purified phospholipase A₂ (PLA₂) toxins. In this work we evaluated the influence of C. sylvestris aqueous extract upon neuromuscular blocking and muscle damaging activities of some PLA₂s (crotoxin from C. durissus terrificus, bothropstoxin-I from B. jararacussu, piratoxin-I from B. pirajai and myotoxin-II from B. moojeni) in mouse phrenic-diaphragm preparations. Crotoxin (0.5 μM) and all other PLA₂ toxins (1.0 μM) induced irreversible and time-dependent blockade of twitches. Except for crotoxin, all PLA₂ toxins induced significant muscle damage indices, assessed by microscopic analysis. Preincubation of bothropstoxin-I, piratoxin-I or myotoxin-II with C. sylvestris extract (1:5 (w/w), 30 min, 37 °C) significantly prevented the neuromuscular blockade of preparations exposed to the mixtures for 90 min; the extent of protection ranged from 93% to 97%. The vegetal extract also neutralized the muscle damage (protection of 80–95%). Higher concentration of the C. sylvestris extract (1:10, w/w) was necessary to neutralize by 90% the neuromuscular blockade induced by crotoxin. These findings expanded the spectrum of C. sylvestris antivenom activities, evidencing that it may be a good source of potentially useful PLA₂ inhibitors.     

Antiasthmatic action of dibenzylbutyrolactone lignans from fruits of Forsythia viridissima on asthmatic responses to ovalbumin challenge in conscious guinea‐pigs

It was reported previously that dibenzylbutyrolactone lignans from Forsythia viridissima fruits, which are traditional medicines for the treatment of inflammatory diseases, have antiinflammatory effects. In this study, the effects on the immediate‐phase response (IAR) and late‐phase response (LAR) following aerosolized‐ovalbumin challenge in ovalbumin‐sensitized guinea‐pigs were evaluated by measuring the specific airway resistance (sRaw), recruitment of leukocytes and chemical mediators in the bronchoalveolar lavage fluids (BALF) as well as a histopathological survey. Arctiin and matairesinol at 12.5 mg/kg significantly (p < 0.05) decreased sRaw by 51.83% and 43.15% in IAR and by 47.41% and 35.43% in LAR, respectively, whereas arctigenin at 25 mg/kg was significantly active, compared with the controls. Furthermore, arctiin and arctigenin dose‐dependently inhibited histamine, and the activities of phospholipase A₂ (PLA₂) and eosinophil peroxidase (EPO) in BALF, respectively, whereas matairesinol inhibited EPO and PLA₂ at 12.5 mg/kg and histamine at 50 mg/kg, in addition, they moderately improved the infiltration of eosinophils, compared with controls. Dexamethasone, cromolyn and salbutamol significantly inhibited sRaw in both IAR and LAR, and the recruitment of leukocytes and chemical mediators, whereas salbutamol did not alter chemical mediators, in BALF. These results indicate the three lignans have antiasthmatic effects which were less active than those of the reference drugs. Copyright © 2010 John Wiley & Sons, Ltd.