β-榄香烯对体外培养恶性疟原虫生长抑制作用的实验研究

目的:研究从中药莪术中分离得到的新型非细胞毒性抗肿瘤药物β-榄香烯的体外抗疟活性,。方法:采用恶性疟原虫3D7株(氯喹敏感株)和Dd2株(氯喹抗性株)进行测试,恶性疟原虫经过同步化处理后添加β-榄香烯,40 h后涂片镜检,观察其细胞形态变化;采用SYBR Green I染料法检测两种虫株对β-榄香烯和氯喹的半数抑制浓度(IC_(50))。结果:与空白对照组相比,添加10μg/mL的β-榄香烯能抑制恶性疟原虫的生长,40μg/mL的β-榄香烯可以完全抑制恶性疟原虫的生长;3D7虫株和Dd2虫株对β-榄香烯的IC_(50)值分别为(13.60±0.540)μg/mL和(12.59±0.54)μg/mL。结论:β-榄香烯具有显著的体外抗疟活性,值得进一步深入研究。     

口服青蒿琥酯对伯氏鼠疟和诺氏猴疟的杀灭效果

目的:研究青蒿琥酯口服对伯氏鼠疟和诺氏猴疟的血液裂殖体杀灭效果。方法:分别在鼠疟和猴疟模型上采用“4-day试验法”、“28-day试验法”和“7-day试验法”检测了青蒿琥酯和氯喹的药效。结果:口服青蒿琥酯对伯氏鼠疟民K_(173)株的抑制效果低于氯喹,但其原虫血症下降50％、90％和转阴的时间比氯喹快10-15h,对抗株RC/K_(173)的疗效优于氯喹,无交叉抗性,I_(90)仅为1.4。青蒿琥酯和氯喹对诺氏猴疟在31.6,10.0和3.16mg·kg~(-1)剂量组的试验猴全部治愈。结论:口服青蒿琥酯在鼠、猴疟模型上的药效研究为临床研究提供有益参考。     

DDPH抑制豚鼠单个心室肌细胞L-钙电流和钠电流(英文)

目的:研究1-(2,6-二甲基苯氧基)-2-(3,4-二甲氧基苯乙氨基)丙烷盐酸盐(DDPH)对豚鼠心室肌细胞L-型钙电流和钠电流的作用。方法:全细胞膜片箝技术。结果:(1)DDPH(3-300μmol·L~(-1))浓度依赖性地抑制L-型钙电流,IC_(50)为28.5μmol·L~(-1)(95％可信限:14.3-42.7μmol·L~(-1))。维拉帕米0.3-30μmol/L浓度依赖性地抑制钙电流,IC_(50)为1.8μmol·L~(-1)(95％可信限:1.3-2.3μmol·L~(-1))。美西律100μmol·L~(-1)对钙电流无影响。DDPH30μmol·L~(-1)使用依赖性阻滞钙电流,1Hz时抑制率为58％±13％(n=5,P<0.01),3Hz时为76％±11％(n=5,P<0.01)。(2)DDPH(20-320μmol·L~(-1))浓度依赖性抑制钠电流,IC_(50)为89.0μmol·L~(-1)(95％可信限:68.7-109.3μmol·L~(-1))。美西律抑制钠电流的IC_(50)为32.2μmol·L~(-1)(95％可信限:11.7-52.7μmol·L~(-1))。维拉帕米10μmol·L~(-1)对钠电流无影响(P>0.05).DDPH80μmol·L~(-1)对钠电流无使用依赖性阻滞。结论:DDPH抑制豚鼠心室肌细胞L-型钙电流和钠电流,但抑制钙电流的作用弱于维拉帕米,抑制钠电流的作用弱于美西律。     

青蒿琥酯治疗在马里共和国的恶性疟疾321例

目的 :观察青蒿琥酯对恶性疟疾的疗效。方法 :96 1例恶性疟疾病人随机分成青蒿琥酯组 32 1例 (男性 152例 ,女性 16 9例 ) ,用青蒿琥酯 6 0mg +5%葡萄糖注射液 5mL ,iv ,qd ,首剂加倍 ,疗程 5d ;奎宁 雷琐辛组 32 0例 (男性 140例 ,女性 180例 ) ,用奎宁 雷琐辛 50 0mg + 5%葡萄糖注射液 50 0mL ,iv ,gtt ,qd ,疗程 3d ;氯喹组 32 0例 (男性 143例 ,女性 177例 ) ,用氯喹 50 0mg ,po ,qd ,首剂加倍 ,疗程 3d。各组经 1个疗程治疗后未愈者 ,均继续治疗 1个疗程。结果 :治愈率青蒿琥酯组为 10 0 % ,奎宁 雷琐辛组为 97.5% ,氯喹组为 6 7.2 %。青蒿琥酯组第 2疗程和第 1疗程治愈率分别为 10 0 %和82 .6 % (P <0 .0 1) ,复燃率为 2 .8% ,无不良反应。结论 :青蒿琥酯治疗恶性疟疾安全有效     

青蒿酯和青蒿素的放射免疫测定法

青蒿素是一种新型抗疟药,青蒿酯是其活性衍生物之一。药理研究和临床试验均证明二者对一般恶性疟、脑型疟和间日疟有较好疗效,且对耐氯喹株疟原虫感染也有效。为了深入进行青蒿酯的代谢和临床药理研究,我们建立了放射免疫测定法,并用此法研究了青蒿酯在狗体内的血药时程。     

有抗疟活性的丙烯酰胺类化合物的合成和三维定量构效关系研究

目的研究丙烯酰胺类化合物抗疟活性的三维构效关系。方法采用比较分子力场分析(CoMFA)方法。结果分别建立了丙烯酰胺类化合物抑制氯喹耐药疟原虫株(W2)和抑制氯喹敏感疟原虫株(D6)活性的三维构效关系。结论抗氯喹耐药疟原虫株活性主要与化合物的立体因素有关,而抗氯喹敏感疟原虫株的活性与化合物的立体因素以及电性因素同时相关。     

甲苯喹哌对培养爪蟾胚胎肌细胞和神经细胞离子通道的作用(英文)

目的:研究新型抗心律失常药甲苯喹哌对离子通道的作用.方法:通过膜片钳技术记录培养爪蟾胚胎肌细胞和神经细胞全细胞离子通道电流.结果:甲苯喹哌(0.1,1,10,100μmolL~(-1))可浓度依赖性地抑制肌细胞的钠通道,其IC_(50)为7.2μmol L~(-1)(5.3—9.8μmol L~(-1)).甲苯喹哌(10μmol L~(-1))可抑制神经细胞的高电压激活的钙通道.然而,肌细胞上的稳态外向钾电流却受到甲苯喹哌(10μmol L~(-1))的激活.结论:甲苯喹哌抑制钠、钙通道,但激活稳态外向钾通道.     

伯氏疟原虫对青蒿素抗药性的研究

仿Peters剂量递增法用伯氏疟原虫ANKA株及N株对QHS进行了抗药性的研究。经14个月的培育至第58代,QHS im注射“4日抑制性实验”的ED_(50)在RQ/ANKA系及RQ/N系分别为其亲代系的53.4及54.6倍,但经蚊传未获成功。在第40代(I_(50)=25)时,其50%的治愈剂量为其亲代系的5.4倍。停药传代其抗性会逐渐消失。该虫系对青蒿酯钠及蒿甲醚有明显的交叉抗性,其ED_(50)分别为其亲代系的13.1及11.7倍,对伯喹的抗性为2.9倍,对氯喹未见明显交叉抗性。     

抗疟药青蒿琥酯的研究

综述我国创制的抗疟新药青蒿琥酯的药理与临床应用进展,青蒿琥酯给药后在体内血浆中的浓度远大于体外对恶性疟原虫的最小抑制浓度,临床上清除疟原虫９５％所需时间仅为１６小时,临床应用数千例未见明显的毒副作用;可通过口服,静注,肌注及直肠等多种途径给药,青蒿琥酯的半衰期短,可能有利于延迟抗性的产生。该药已成为对恶性疟有快速治疗效果且耐受性好的抗疟药,现已在亚,非,拉等疟疾流行区被广泛用于治疗各种疟疾,是治疗     

口服青蒿琥酯对伯氏鼠疟和诺氏猴疟的杀灭效果

目的：研究青芒琥酯口服对伯氏鼠疟和诺氏猴疟的血液开明植体杀灭效果。方法：分别在鼠疟和猴疟模型上采用“４－ｄａｙ试验法”、“２８ｄａｙ”和“７－ｄａｙ”试验法检测了青蒿琥酯和氯喹的药效。结果：口服青蒿琥酯对伯氏鼠疟Ｋ１７３株的抑制效果低于氯喹,但其原虫血症下降５０％、９０％和有的时间比氯喹快１０－１５ｈ,对抗株ＲＣ／Ｋ１７３的疗效优于氯喹,无交叉抗性,Ｉ９０仅为１．４。青蒿琥酯和氯喹对诺氏猴疟在３１     

Antiviral activity of ganciclovir and artesunate towards human cytomegalovirus in astrocytoma cells

Antimalarial drug artesunate inhibits cytomegalovirus (HCMV) replication in human fibroblasts. Astrocytes, the major cell type of the brain, support cytomegalovirus (HCMV) replication. The aim of the study was to assess the antiviral activity of artesunate in astrocytoma cell line U373MG in comparison with ganciclovir. The antiviral concentration inhibiting by 50% (IC(50)) the synthesis of viral DNA was measured by real-time PCR in parallel in U373MG and MRC-5 cells. Reference HCMV strains susceptible and resistant to ganciclovir, and clinical isolates were tested. Ganciclovir and artesunate had similar activity in U373MG cells and MRC-5 fibroblasts. The artesunate IC(50)s in U373MG cells (1.5-2.25 μM) were at least 36-fold lower than the 50% cytotoxicity concentrations. Then, the anti-HCMV activity of artesunate was demonstrated in a cancer cell line.     

Stilbene-chalcone hybrids: design, synthesis, and evaluation as a new class of antimalarial scaffolds that trigger cell death through stage specific apoptosis

Novel stilbene-chalcone (S-C) hybrids were synthesized via a sequential Claisen-Schmidt-Knoevenagel-Heck approach and evaluated for antiplasmodial activity in in vitro red cell culture using SYBR Green I assay. The most potent hybrid (11) showed IC(50) of 2.2, 1.4, and 6.4 μM against 3D7 (chloroquine sensitive), Indo, and Dd2 (chloroquine resistant) strains of Plasmodium falciparum, respectively. Interestingly, the respective individual stilbene (IC(50) > 100 μM), chalcone (IC(50) = 11.5 μM), or an equimolar mixture of stilbene and chalcone (IC(50) = 32.5 μM) were less potent than 11. Studies done using specific stage enriched cultures and parasite in continuous culture indicate that 11 and 18 spare the schizont but block the progression of the parasite life cycle at the ring or the trophozoite stages. Further, 11 and 18 caused chromatin condensation, DNA fragmentation, and loss of mitochondrial membrane potential in Plasmodium falciparum, thereby suggesting their ability to cause apoptosis in malaria parasite.     

A comparison of oral artesunate and artemether antimalarial bioactivities in acute falciparum malaria

AIMS: Artesunate and artemether are the two most widely used artemisinin derivatives in the treatment of uncomplicated Plasmodium falciparum malaria, but there is little information on their comparative pharmacokinetics. The aim of this study was to examine the relative oral antimalarial bioavailability and pharmacokinetics of the two derivatives. METHODS: The pharmacokinetic properties of oral artesunate and artemether (4 mg kg(-1)) were compared in a randomized cross-over study of 14 adult patients in western Thailand with acute uncomplicated Plasmodium falciparum malaria. Antimalarial activity was compared using a previously validated, sensitive bioassay. RESULTS: Despite a 29% lower molar dose, oral artesunate administration resulted in significantly larger mean area under the plasma antimalarial activity time curve and median maximum plasma antimalarial activity than after oral artemether (P 相似文献   

Antiplasmodial alkaloids from the stem bark of Strychnos malacoclados

From the stem bark of Strychnos malacoclados, one new bisindole alkaloid, 3-hydroxylongicaudatine Y (1), was isolated along with the known alkaloids vomicine (2), bisnordihydrotoxiferine (3), divarine (4), longicaudatine (5), longicaudatine Y (6), and longicaudatine F (7). All the compounds were tested for their antimalarial activity against the chloroquine-sensitive 3D7 and -resistant W2 strains of Plasmodium falciparum. Longicaudatine was the most active compound with IC?? values of 0.682 and 0.573 μM, respectively. The activity of compounds 1, 3, 4, 6, and 7 against the two strains ranged from 1.191 to 6.220 μM and 0.573 to 21.848 μM, respectively. Vomicine (2), the only monomer isolated, was inactive. The alkaloids of the longicaudatine-type ( 1, 5-7) were more active than those of the caracurine-type (3- 4). The presence of the ether bridge in the molecule seems to increase the antiplasmodial activity. Compounds 1, 5, and 7 were tested against the WI-38 human fibroblast cell line. Longicaudatine was the most cytotoxic compound with an IC?? of 2.721 μM. Longicaudatine F was 40-46 times more active against the two strains of P. falciparum than against the human fibroblasts and was thus considered as the more selective alkaloid. The structures of the compounds were determined based on the analysis of their spectral data.     

Inhibitory effect of gnetin C, a resveratrol dimer from melinjo (Gnetum gnemon), on tyrosinase activity and melanin biosynthesis

Tyrosinase is the key enzyme involved in melanogenesis. The aim of this study was to investigate the in vitro inhibitory effects of gnetin C, a resveratrol dimer isolated from melinjo (Gnetum gnemon) seeds, on tyrosinase activity and melanin biosynthesis in murine B16 cells. The inhibitory activities of gnetin C and resveratrol were shown to be almost equal against tyrosinase and melanin biosynthesis in the cells. The IC(50) values of gnetin C activity against tyrosinase and melanin biosynthesis were 7.0 and 7.6 μM, respectively, whereas resveratrol demonstrated IC(50) values of 7.2 and 7.3 μM, respectively. These results indicated that gnetin C inhibited melanogenesis, in a manner similar to that of resveratrol, by inhibiting tyrosinase and may therefore function as a new skin-whitening agent. However, the direct effects of gnetin C and resveratrol on murine tyrosinase activities were not equal. The IC(50) value of resveratrol was 10.1 μM, while gnetin C only exhibited a 25.2% enzyme inhibition at 16 μM. The IC(25) values for gnetin C and resveratrol were 15.5 and 4.0 μM, respectively. Therefore, it is suggested that the effects of gnetin C may be due to mechanisms other than the direct inhibition of tyrosinase activity.     

青蒿琥酯和复方双氢青蒿素序贯治疗对南苏丹恶性疟疾的疗效

目的：观察注射用青蒿琥酯和复方双氢青蒿素片序贯治疗对南苏丹恶性疟疾病人的疗效。方法：回顾性分析2011年7月-2013年11月在南苏丹瓦乌中国二级医院住院的55例恶性疟疾病历。结果：肌注或静脉注射青蒿琥酯注射液（首剂120mg,后60mg/d）1~5d[（3.2±0.9）d],最后一次静脉注射或肌注后24、30、48、72h口服复方双氢青蒿素片2片,共8片。55例疟疾病人的总治愈率为100%,其中3d治愈52例（94.5%）,3~7d治愈3例（5.5%）。4例（7.3%）病人发生恶心、呕吐、腹泻或头晕等轻度不良反应。结论：注射用青蒿琥酯和复方双氢青蒿素片序贯治疗,对南苏丹恶性疟疾病人具有非常好的临床疗效,适合多种人群,耐受性好。     

Antiplasmodial constituents from the fruit pericarp of Pentadesma butyracea

Bioassay-guided fractionation of the fruit pericarp of Pentadesma butyracea, using the antiplasmodial test, led to the isolation of a new xanthone, named pentadexanthone (1), together with six known compounds: cratoxylone (2), α-mangostin (3), 1,3,5-trihydroxy-2-methoxyxanthone (4), garcinone E (5), (-)-epicathechin (6), and lupeol (7). The structure of 1 was elucidated by spectroscopic data analysis. An antiplasmodial assay was performed with the isolates, in which compounds 1- 3 and 5 exhibited potent activity in vitro against Plasmodium falciparum chloroquine-resistant strain W2, with IC?? values below 3 μM.     

青蒿琥酯抗人宫颈癌Hela细胞的实验研究

目的探讨青蒿琥酯的抗肿瘤作用。方法采用四甲基二氮唑蓝（MTT）法观察青蒿琥酯及其含药血清对人宫颈癌Hela细胞的体外抑制作用。结果青蒿琥酯及其含药血清均能明显抑制体外培养的人宫颈癌Hela细胞的生长，青蒿琥酯的半数抑瘤浓度（IC50）为31、21μg／mL，20％和10％的含药血清的抑制率分别为29．78％和21、91％。结论青蒿琥酯对体外培养的人宫颈癌Hela细胞有明显的抑制作用。     

In vitro screening of traditional South African malaria remedies against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum

Three hundred extracts were prepared from plants traditionally used in South Africa to treat malaria and screened in vitro for activity against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum. For the 43 extracts which inhibited the growth of one or more parasites to more than 95?% at 9.7?μg/mL, the IC?? values against all four protozoal parasites and cytotoxic IC??s against rat myoblast L6 cells were determined. Amongst the most notable results are the activities of AGATHOSMA APICULATA (IC?? of 0.3?μg/mL) against Plasmodium falciparum, as well as Salvia repens and Maytenus undata against Leishmania donovani with IC??s of 5.4?μg/mL and 5.6?μg/mL, respectively. This screening is the starting point for a HPLC-based activity profiling project in antiprotozoal lead discovery.