老龄化对家兔左心房心律失常发生的电生理特征影响

目的:探讨老龄化易于家兔左心房(LA)心律失常发生的电生理特征及其机制。方法:实验由青龄兔[年龄6个月,分为青龄对照组(青龄组)和青龄+异丙肾上腺素(ISO)组(青龄药物组)]和老龄兔[年龄26个月,分为老龄对照组(老龄组)和老龄+ISO组(老龄药物组)]雄性新西兰大耳白兔参与。利用常规微电极记录LA组织的跨膜动作电位(tAP),观察静息膜电位(RMP)、动作电位幅度(APA)、动作电位最大上升速率(Vmax)、动作电位复极化到20%和50%以及90%时程(APD20、APD50、APD90)以及延迟后除极(DADs),酶解法分离单个LA细胞,全细胞膜片钳技术记录LA细胞L-型钙电流(ICa-L)在使用ISO前后反应。结果:与青龄组比较,老龄组动作电位形态明显增宽,传导减慢,APD20、APD50和APD90均显著延长,APA、Vmax和RMP都明显减少或降低(P<0.05或0.01);在ISO作用下,青龄和老龄药物组tAP都明显变窄,传导增快,但与青龄药物组比较,老龄药物组APD各值缩短更加明显,APA、Vmax、RMP幅度都显著增大(P均<0.05),动作电位之后出现更大幅度的延迟后除极(DADs);在电压钳制方式下,与青龄组比较,老龄组ICa-L均明显减少,当钳制电压为+10mV时,老龄组ICa-L电流密度由青龄组的(9.5±1.3)pA/pF减少为(6.3±0.8)pA/pF(P<0.01),老龄组ICa-L的电流-电压(I-V)曲线明显上抬。在ISO作用下,青龄和老龄药物组ICa-L电流密度均明显高于各自对照组(P<0.01),但与青龄药物组比较,老龄药物组ICa-L电流密度增加更加明显(P<0.05),老龄药物组ICa-L的I-V处于其他各组LA细胞ICa-L的I-V曲线最下部。结论:老龄化LAs电生理特性在ISO的作用前后均发生了明显电重构,它为折返和触发性房性心律失常发生提供了易损条件和病理生理基础,其电生理机制是老龄LA细胞ICa-L在ISO干扰前后发生离子通道重构,引发细胞内Ca2+异常调控,使老龄化房性心律失常具有非常显著的易感性。     

葱白提取物对充血性心力衰竭家兔心室相关电生理指标的影响

目的：探讨葱白提取物(FOB)对充血性心力衰竭(CHF)引起室性心律失常相关电生理的影响。方法健康成年雄性新西兰大耳白兔分为正常对照组(Control组,n=15)、CHF模型组(CHF,n=15)和CHF+FOB干预组(FOB组,n=15)。CHF模型制备经兔耳缘静脉注射异丙肾上腺素(0.3 mg· kg-1· d-1,连续注射3周)诱导,后继续喂养6个月成功完成。利用记录在体心脏左心室单相动作电位（MAP）相关静息膜电位（RMP）,动作电位幅度(APA)、最大上升速率(Maxdv/dt)、动作电位复极化恢复10%、20%、50%、90%(APD10、APD20、APD50、APD90)和短阵快速刺激观察心律失常刺激周长(BCL)、诱发率和持续时间在各组变化。酶解法分离单个心室肌细胞,全细胞膜片钳技术观察心室肌细胞L-型钙电流(ICa-L)在用药前后改变。结果与Control组比较,CHF组RMP、APA、Maxdv/dt显著减小, APD10、APD20、APD50和APD90明显延长,并且BCL、诱发率明显增加,持续时间更长(P均<0.01);与CHF组比较, FOB组RMP、APA、Maxdv/dt明显增加,各APD显著缩短,且BCL严重缩短,诱发率和持续时间均降低(P均<0.01)。FOB能明显抑制CHF心室肌细胞ICa-L电流密度(P<0.01),当钳制电压为+20 mV时,与Control组比较,CHF组ICa-L电流密度由(7.1±0.3) pA/pF增加为(10.9±0.5）pA/pF (P<0.01);当加入FOB作用CHF组心室肌细胞后,ICa-L减小为(6.4±0.2) pA/pF (P<0.01)。FOB能使CHF组ICa-L的I-V曲线明显上调,超过Control组。结论 FOB能显著改善CHF心室肌电生理易损性和室性心律失常的易感性,起到抗CHF室性心律失常作用。其机制可能与FOB抑制CHF心室肌细胞ICa-L有关。     

试用自然衰老大鼠建立中风后遗症肾虚痰瘀病证模型

目的 探讨利用自然衰老大鼠建立中风后遗症肾虚痰瘀病证模型的可行性.方法 按中医肾虚痰瘀证标准从老龄鼠中进行筛选纳入老龄组,并设青龄组作对照.经检测部分老龄鼠相关指标、确定肾虚痰瘀证存在之后建立中风后遗症模型,于造模前后进行证候观察及相关指标检测并作反证治疗.结果 老龄大鼠可见毛稀竖立、黯淡无泽、弓背、懒动、精神萎靡、反应迟钝、采食饮水减少、睡眠增多、阴囊皱缩、睾丸回升、舌质及尾部皮色暗或紫、眼球暗红等肾虚痰瘀证候,青龄大鼠未见上述证候;同时老龄鼠性功能、睾酮、红细胞SOD活性均低于青龄组(P＜0.01),血浆MDA、血脂及血液流变学指标均高于青龄组(P＜0.01).造模后:老龄模型组出现了典型的偏瘫症状和肾虚痰瘀证候,经反证治疗明显改善;神经功能缺失评分:老龄模型组[(2.41±0.31)分]高于假手术组[(0.00±0.00)分](P＜0.01),反证组[(1.50±0.33)分]低于老龄模型组[(2.41±0.31)分](P＜0.05);红细胞SOD活性:老龄模型组低于老龄假手术组(P＜0.01)和青龄模型组(P＜0.05),反证组高于老龄模型组(P＜0.01);血浆MDA:老龄模型组高于老龄假手术组(P＜0.01)和青龄模型组(P＜0.05),反证组低于老龄模型组(P＜0.01);血清睾酮:反证组高于老龄模型组(P＜0.01);血脂及血液流变学指标:反证组低于老龄模型组(P＜0.05);脑组织SOD活性:老龄模型组低于老龄假手术组(P＜0.01)和青龄模型组(P＜0.05),反证组高于老龄模型组(P＜0.01);脑组织MDA:老龄模型组高于老龄假手术组(P＜0.01)和青龄模型组(P＜0.05),反证组低于老龄模型组(P＜0.01).结论 经按肾虚痰瘀证标准筛选的自然衰老大鼠基本具备肾虚痰瘀证的生物学特点,以此类大鼠建立的中风后遗症模型可作为中风后遗症肾虚痰瘀病证模型.     

丹参制剂对豚鼠心室乳头肌电生理活动的影响(英文)

本实验通过标准玻璃微电极技术和微机系统的实时应用,利用异丙肾上腺素(ISO)制备心肌损伤的动物模型,观察丹参制剂对正常和异丙肾损伤性豚鼠心室乳头肌动作电位的影响。结果表明:①ISO使RP、APA、OS显著降低,APD明显延长,Vmax略有下降,但变化不明显。②丹参可使受损伤心肌动作电位的APD缩短而其它指标不变。③丹参在最大有效浓度(0.25mg/ml)时,可使正常豚鼠乳头肌快反应动作电位的APD缩短,而对RP、APA、Vmax基本无影响。④丹参使慢反应动作电位的APA、APD和Vmax减小。提示:丹参可能为钙桔抗剂,并能对抗ISO引起的心肌钙超载性损伤。     

3，6—[二甲氨基]—二苯骈碘杂六环葡萄糖酸盐对豚鼠心肌电生理特性的影响

目的：研究3,6－[二甲氨基]－二苯骈碘杂六环葡萄糖酸盐对豚鼠乳头肌动作电位的影响。方法：采用玻璃微电极细胞内记录技术。结果：IHC－93低度（≤30μmol/L)时对快反应动作电位的动作电位幅度（APA）,0相最大除极速率（Vmax)无影响,但可缩短动作电位时程（APD）;高浓度（90μmol/L)时使快反应动作电位的APA,Vmax降低,PAD进一步缩短,三相时程APD50－90（APD50－90＝APD90－APD50）在用药前后变化不大。IHC－93对异丙肾上腺素诱发的豚鼠左心房早期后除极有明显抑制作用,可完全或部分消除哇巴因诱发的延迟后除极和触发激动。结论：IHC－93为一钙通道阻滞剂,具有IV类抗心律失常药物的特性。     

H2S对豚鼠左心室流出道自律细胞电活动的影响※

目的:探讨硫化氢(H2S)对豚鼠左心室流出道自律细胞电生理特性的影响.方法:用标准微电极细胞内记录技术,观测硫化氢对左心室流出道自发慢反应电位的影响.观测指标:最大舒张电位(MDP)、动作电位幅度(APA)、0相最大去极速度(Vmax)、4相自动去极速度(VDD)、复极80%和90%时间(APD80and APD90)以及自发放电频率(RPF).结果:①50μmol/LNaHS灌流后,RPF和VDD减慢(P＜0.05).②100μmol/LnaHS与对照组比较,除使RPF和VDD减慢(P＜0.01)外,APA显著减小(P＜0.01).③200μmol/L NaHS与对照组比较,除使RPF和VDD减慢(P＜0.01)外,APA显著减小(P＜0.01)、MDP的绝对值显著减小(P＜0.05)、APA显著减小(P＜0.01).200μmol/L与50μmol/LNaHS比较,RPF、VDD显著减慢(P＜0.01)、APA显著减小(P＜0.01)、MDP的绝对值显著减小(P＜0.05).④400μmol/L NaHS与对照组比较,除使RPF和VDD减慢(P＜0.01)外,APA显著减小(P＜0.01)、MDP的绝对值显著减小(P＜0.01)、APA显著减小(P＜0.01).400μmol/L与50μmol/LNaHS比较,RPF、VDD显著减慢(P＜0.01)、APA和MDP的绝对值显著减小(P＜0.01).400μmol/L NaHS与100μmol/LNaHS比较,APA和MDP的绝对值显著减小(P＜0.01).结论:H2S可降低左心室流出道组织的自律性.     

左归丸对老龄大鼠海马糖皮质激素受体位点及其基因表达的影响

目的　观察左归丸 (ZGW)对老龄大鼠海马糖皮质激素受体 (GR)位点及其基因表达的影响。方法　以2 4月龄大鼠为自然老化模型 ,随机分为老龄组、左归丸组 ,并以 3月龄大鼠为青龄组 ,各组处理 3个月。采用放射配基饱和分析技术及RT PCR方法检测大鼠海马GR位点及GRmRNA表达。结果　老龄组、青龄组及左归丸组海马GR位点分别为 (439.6 4± 4 8.0 9)、(85 0 .32± 34.96 )和 (1171.5 7± 5 4 .85 )fmol/mg蛋白 ,老龄组明显低于青龄组 (P <0 .0 5 ) ,左归丸组较老龄组明显上调 (P <0 .0 1) ;3组GRmRNA表达量分别为 0 .2 74 9± 0 .0 6 5 9、0 .6 4 0 7± 0 .4 4 18、0 .96 0 3± 0 .32 4 9,表明老龄组GRmRNA表达量低于青龄组 (P <0 .0 5 ) ,左归丸组海马GRmRNA表达量明显高于老龄组 (P <0 .0 0 1)。结论　左归丸延缓衰老作用可能与上调海马GR位点及其基因表达有关     

糖尿病大鼠心肌电学的改变与腺苷的作用

目的:探讨糖尿病心肌病的心肌电生理改变以及腺苷(ADO)对其电生理的可能作用.方法:以SD雄性大鼠复制糖尿病模型,选择健康成年SD雄性大鼠作为对照组,6周时记录大鼠体表心电图和右心室乳头肌跨膜电位,观察ADO对跨膜电位的影响.结果:大鼠糖尿病成模后第6周,体表心电图QT间期和右室乳头肌动作电位时程(APD)各水平均明显长于对照组大鼠(P＜0.01);而静息膜电位(RP)、动作电位幅度(APA)和超射值(OS),以及0期去极化最大速率(Vmax)均无明显变化.经10～400 μmol/L ADO灌流,糖尿病组大鼠和对照组大鼠右心室乳头肌跨膜电位各参数均无明显作用,当ADO浓度增加到500 μmol/L时,对照组大鼠右心室乳头肌APD30、APD50、APD70及APD90轻度缩短(P＜0.05),而对糖尿病组大鼠APD无明显影响.结论:糖尿病大鼠右室乳头肌动作电位时程和QT间期明显延长,而ADO(10～500 μmol/L)对糖尿病大鼠过长的ADP无明显缩短作用.     

厄贝沙坦电生理作用的实验研究

目的:研究厄贝沙坦(Irbesartan)对正常豚鼠心室肌细胞L-型钙电流(ICa-L)、内向整流性钾电流(IK1)、快钠流(INa)以及跨膜动作电位的影响.方法:应用膜片钳全细胞记录方法记录各项离子流和跨膜动作电位.结果:①厄贝沙坦呈浓度依赖性阻断ICa-L,10,100和1000 nmol/L的厄贝沙坦分别使ICa-L密度 (pA/pF)从 (-9.8±1.1)减少到(-6.7±0.9),(-4.2±0.8)和(-2.1±0.4)(n=5,P<0.05或P<0.01).②厄贝沙坦可使ICa-L I-V曲线上移,但不改变其激活的电压依赖性和反转电位.③厄贝沙坦呈使用依赖性阻滞ICa-L.④厄贝沙坦对ICa-L激活曲线无明显影响,但可使钙电流稳态失活曲线左移,加速钙通道电压依赖性失活,对照组V1/2和κ值分别为(-30±5)mV,(8.2±0.7),厄贝沙坦组为(-39±7) mV,(11.6±1.3)(n=5,P均<0.05).⑤厄贝沙坦100 nmol/L使ICa-L失活后再激活的恢复时间常数(τ)从对照组(62.5±2.3) ms延长至(126.4±2.6) ms(P<0.01).⑥厄贝沙坦对IK1和INa无明显影响.⑦厄贝沙坦(100 nmol/L)可使单个心室肌细胞动作电位时程(APD30,APD50,APD90)从(106±10),(125±16),(178±23)ms缩短至(82±16),(99±6),(122±18) ms(n=5,P<0.05),对静息电位、动作电位幅度无影响. 结论:厄贝沙坦作用于L-型钙通道的失活态从而阻断ICa-L.     

小鼠急性柯萨奇B_3病毒性心肌炎电生理的表现

用常规细胞内微电极技术及实时微机数据处理系统,对柯萨奇B_3病毒(CB_3V)感染的BALB/c小鼠(早期7d、14d)作心肌电生理参数及动作电位波形研究。发现在病毒感染早期,心肌细胞的静息电位(RP)、动作电位振幅(APA)、超射(Os)、O相最大上升速率(Vmax)均数值除感染7d组Os值无差异,其余均显著低于同期正常对照组:而动作电位时程APD50和APD90均数值除感染14d组APD90无差异外,均显著延长。动作电位异常波形多达十种,占感染组的65％以上。提示CB_3V感染对心肌造成的损害,可产生多种心电活动异常,并成为形成各种形式心律失常的基础。     

肱骨远端全骺分离

肱骨远端全骺分离在5岁以下儿童中是较常见的肘部损伤,且极易误诊为肱骨髁上骨折或肘关节脱位。本组25例肱骨远端全骺分离均为向内侧移位,年龄11个月至14岁,平均5.6岁,属Salter-HarrisⅠ型或Ⅱ型。对本症骨骺损伤的解剖学和组织学,诸骨(和骨化中心)之间的对应关系以及骨骺损伤的诊治进行了简短的讨论。     

食指背侧皮瓣的临床应用

通过对右手虎口挛缩以及左拇指皮肤剥脱损伤各一例应用直指背侧皮瓣修复的成功经验,提出该手术的适应症和优点,并重点介绍其应用解剖学和手术方法。     

Investigation of hypoglycemic,hypolipidemic and antioxidant activities of aqueous extract of Terminalia paniculata bark in diabetic rats

Objective

To investigate the hypoglycemic, hypolipidemic and antioxidant activities of aqueous extract of Terminalia paniculata bark (AETPB) in streptozotocin (STZ)-induced diabetic rats.

Methods

Acute toxicity was studied in rats after the oral administration of AETPB to determine the dose to assess hypoglycemic activity. In rats, diabetes was induced by injection of STZ (60 mg/kg, i.p.) and diabetes was confirmed 72 h after induction, and then allowed for 14 days to stabilize blood glucose level. In diabetic rats, AETPB was orally given for 28 days and its effect on blood glucose and body weight was determined on a weekly basis. At the end of the experimental day, fasting blood sample was collected to estimate the haemoglobin (Hb), glycosylated haemoglobin (HbA1c), serum creatinine, urea, serum glutamate-pyruvate transaminase (SGPT), serum glutamate-oxaloacetate transaminase (SGOT) and insulin levels. The liver and kidney were collected to determine antioxidants levels in diabetic rats.

Results

Oral administration of AETPB did not exhibit toxicity and death at a dose of 2 000 mg/kg. AETPB treated diabetic rats significantly (P<0.001, P<0.01 and P<0.05) reduced elevated blood glucose, HbA1c, creatinine, urea, SGPT and SGOT levels when compared with diabetic control rats. The body weight, Hb, insulin and total protein levels were significantly (P<0.001, P<0.01 and P<0.05) increased in diabetic rats treated with AETPB compared to diabetic control rats. In diabetic rats, AETPB treatment significantly reversed abnormal status of antioxidants and lipid profile levels towards near normal levels compared to diabetic control rats.

Conclusions

Present study results confirm that AETPB possesses significant hypoglycemic, hypolipidemic and antioxidant activities in diabetic condition.     

Association of smoking,alcohol and NSAIDs use with expression of cag A and cag T genes of Helicobacter pylori in salivary samples of asymptomatic subjects

Objective

To determine the association of smoking, alcohol and nonsteroidal anti-inflammatory drugs (NSAIDs) use with presence and virulence of Helicobacter pylori (H. pylori) infection in a representative sample of a random adult population of asymptomatic subjects.

Methods

Non virulent 16S rRNA and virulent cag A and T genes from salivary samples of 854 asymptomatic subjects were determined using polymerase chain reaction. The presence and absence of virulent and non virulent infection was statistically compared with consumption of smoking, alcohol and NSAIDs.

Results

The prevalence of infection in male and female subjects was found to be 69.25% and 66.90%, respectively. The prevalence of infection in the population of asymptomatic subjects with respect to consumption of alcohol was as follows: current (31.22%), former (52.20%) and never (43.58%). The prevalence of infection in the population of asymptomatic subjects with respect to smoking of cigarettes was as follows: current (88.80%), former (57.14%) and never (33.33%). The prevalence of infection in the subject population consuming NSAIDs and not consuming NSAIDs frequently was found to be 82.75% and 21.16%, respectively. Virulence in male and female subjects was found to be 60.00% and 50.00%, respectively. The presence of virulent infection in the population of asymptomatic subjects with respect to consumption of alcohol was as follows: current (28.57%), former (40.15%) and never (50.00%). The prevalence of virulent infection in the population of asymptomatic subjects with respect to smoking of cigarettes was as follows: current (79.32%), former (75.00%) and never (50.00%). The prevalence of virulent infection in the subject population consuming NSAIDs and not consuming NSAIDs frequently was found to be 88.23% and 66.66%, respectively.

Conclusions

It can be concluded that smoking and NSAIDs consumption are aggravating factors for virulence of H. pylori and alcohol can inhibit H. pylori infection in asymptomatic subjects.     

大肠多发原发性癌:危险因素、诊治和预防(附8例报告)

综述分析1954～84年国内外文献,探讨了大肠多发原发性癌的诊断标准、发病情况、临床表现、发病危险因素、外科处理以及预防和诊断检测技术等问题,强调了大肠腺瘤,遗传基础、免疫缺陷、慢性溃疡性结肠炎等在发病上的作用,及高危险组患者应按方案进行常规检测监护之重要性。述介了大肠多发原发性癌系一种原发性大肠癌多中心发生的形式,在诊治上前者与后者有一致性,亦各有其独特性。报告宁夏医学院附属医院肿瘤科1977～84年收治的8例住院大肠多发原发性癌病例的临床资料,对诊治经过进行了初步总结。     

具有抗细菌黏附和杀菌双重功能的(HA/CHI-Van)5涂层的制备

目的：研究开发一种涂覆(HA/CHI-Van)5多层膜结构的骨科内植入物以用于预防骨内植入物感染。方法：将透明质酸（HA）和壳聚糖-万古霉素（CHI-Van）溶液进行层层自组装,制备得到(HA/CHI-Van)5多层膜结构;通过zeta电位检测组装过程,通过活细菌染色实验评价多层膜的抗细菌黏附效果,通过越狱实验和FE-SEM实验检测体外抗菌效果。SD大鼠随机分为空白组、(HA/CHI-Van)5组和假手术组,并以X线、Micro-CT、骨组织切片等方法检测该材料的体内动物实验效果。结果：每次组装不同的单层,zeta电位交替变化,证明多层膜组装成功。活细菌染色实验显示多层膜结构中的CHI具有一定的抗细菌黏附作用。越狱实验和FE-SEM实验证明(HA/CHI-Van)5多层膜结构在体外具有良好的抗菌作用。在体外实验中,(HA/CHI-Van)5组的X线评分为0.7,而空白组的评分为12.3,(HA/CHI-Van)5组在骨密度、骨小梁数量、骨体积分数、骨组织切片方面均优于空白组（均P＜0.05）,且非常接近假手术组（均P＞0.05）。结论：通过在骨科内植入物表面涂覆(HA/CHI-Van)5多层膜结构能够获得一定的抗细菌黏附功能和良好的抗菌作用,可以预防骨内植入物感染。     

Efficacy and side effects of praziquantel in the treatment of Schistosomiasis mansoni in schoolchildren in Shesha Kekele Elementary School,Wondo Genet,Southern Ethiopia

Objective

To evaluate the efficacy and side effects of praziquantel (PZQ) in the treatment of schistosomiasis in Ethiopia.

Methods

In a cross-sectional study, stool specimens were collected from randomly selected 299 school children in Shesha Kekele Elementary School, Wondo Genet, Southern Ethiopia, in April 2010. Stool specimens were examined using a single Kato-Katz thick smear for Schistosoma mansoni (S. mansoni) ova. Children who were found positive for S. mansoni were treated with a single oral dose of PZQ at 40 mg/kg bw and interviewed for treatment-related symptoms 24 hours after drug administration. Four weeks post-treatment, stool specimens were collected from the same children and examined following the same procedure as in the pre-treatment. Drug efficacy was determined based on cure and egg reduction rates.

Results

Pre-treatment prevalence of S. mansoni infection was 74.9% with geometric mean egg count of 268. The evaluated generic PZQ produced an overall cure rate of 73.6% (P<0.000 1, OR: 8.33, CI: 5.3–13.1) and egg reduction rate of 68.2% (P=0.03, F=0.64). The cure rate showed significant association with age (χ²=11, P=0.004), the highest rate being observed in the 15–22 age group. 83% of S. mansoni infected children showed various treatment-related symptoms, the most frequent being headache, nausea, and abdominal pain. These symptoms were associated with age (P<0.001) and pre-treatment intensity of infection (P<0.05).

Conclusions

The present observations revealed relatively lower cure and egg reduction rates of the PZQ evaluated as compared to previous reports for other PZQ brands in Ethiopia. Hence, in depth studies are recommended to clarify whether the present relatively lower cure rate is the actual cure rate of the praziquantel evaluated, treatment failure, or reduced susceptibility of the parasite. Treatment-related side effects observed were transient and tolerable.     

NGR修饰唑来膦酸长循环脂质体制备及其表征研究

目的:制备具有肿瘤血管靶向的NGR修饰唑来膦酸长循环脂质体,并对其进行表征研究。方法：采用薄膜分散法制备NGR修饰唑来膦酸长循环脂质体,,并对其进行表征研究,并测定包封率。结果：制备得到的NGR-PEG-ZOL-LPs平均粒径为(271.43±9.23)nm,Zeta电位为-(36.20±0.20)mv,多分散系数(PDI)为(0.15±0.03),理化性质相对稳定;NGR-PEG-ZOL-LPs包封率为8.41%;电镜下显示NGR-PEG-ZOL-LPs呈类圆形,大小分布均匀,无明显聚集。结论：采用薄膜分散法制备的NGR修饰唑来膦酸长循环脂质体具有较高的稳定性,从而为体内药效学研究奠定基础。     

Control of Tetranychus urticae Koch by extracts of three essential oils of chamomile,marjoram and Eucalyptus

Objective

To evaluate the acaricidal activity of extracts of three essential oils of chamomile, marjoram and Eucalyptus against Tetranychus urticae (T. urticae) Koch.

Methods

Extracts of three essential oils of chamomile, marjoram and Eucalyptus with different concentrations (0.5%, 1.0%, 2.0%, 3.0% and 4.0%) were used to control T. urticae Koch.

Results

The results showed that chamomile (Chamomilla recutita) represented the most potent efficient acaricidal agent against Tetranychus followed by marjoram (Marjorana hortensis) and Eucalyptus. The LC₅₀ values of chamomile, marjoram and Eucalyptus for adults were 0.65, 1.84 and 2.18, respectively and for eggs 1.17, 6.26 and 7.33, respectively. Activities of enzymes including glutathione-S-transferase, esterase (α-esterase and β-esterase) and alkaline phosphatase in susceptible mites were determined and activities of enzymes involved in the resistance of acaricides were proved. Protease enzyme was significantly decreased at LC₅₀ of both chamomile and marjoram compared with positive control. Gas chromatography-mass spectrometer (GC-MS) proved that the major compositions of Chamomilla recutita are α-bisabolol oxide A (35.251%), and trans-β-farersene (7.758%), while the main components of Marjorana hortensis are terpinene-4-ol (23.860%), p-cymene (23.404%) and sabinene (10.904%).

Conclusions

It can be concluded that extracts of three essential oils of chamomile, marjoram and Eucalyptus possess acaricidal activity against T. urticae.