In vitro activity and mutagenicity of bisbenzylisoquinolines and quinones against Trypanosoma cruzi trypomastigotes

The accidental transmission of Chagas' disease by donor blood is recognized as a serious problem in the Latin America. This paper describes the screening of natural products as possible new chemoprophylactic additives in blood banks. Ten plant-derived alkaloids, three terpenes, three quinones and 14 crude plant extracts were tested against bloodstream forms of Trypanosoma cruzi Y strain in vitro at 4°C at a concentration of 250 μg/mL, using gentian violet as the baseline drug. The bisbenzylisoquinoline alkaloids, cocsuline, daphnandrine, daphnoline, isochondodendrine, gyrocarpine, limacine and pheanthine and the naphthoquinone, plumbagin completely lysed the trypomastigote forms of T. cruzi at a concentration of 250 μg/mL, this activity was verified by the subculture of the treated medium during 4 months. The active alkaloids, pheanthine, daphnoline and limacine were evaluated for mutagenicity by the sister chromatid exchange assay (SCE) in peripheral lymphocytes. Daphnoline and pheanthine elicited no significant increase of the SCE up to 50 μg/mL, while limacine significantly increased the SCE values at a concentration of 25 μg/mL, and 50 μg/mL.     

格帕沙星对500株临床分离致病菌的体外抗菌作用

目的　测定格帕沙星及对照药环丙沙星等对 5 0 0株临床分离菌的体外抗菌活性。方法　琼脂二倍稀释法和肉汤二倍稀释法。结果　格帕沙星抗革兰阳性球菌作用优于环丙沙星和氧氟沙星 ,与司巴沙星相当。尤其对于MSSA和链球菌属 ,格帕沙星的MIC90 ≤ 0 .2 5mg·L-1,除司巴沙星与之相当外 ,其它对照药均高出 4～ 16倍。格帕沙星抗厌氧菌作用优于环丙沙星和氧氟沙星。其对革兰阴性菌的抗菌作用与氧氟沙星、司巴沙星相当。格帕沙星有较强的杀菌作用。细菌接种量和培养基中人血清蛋白含量对格帕沙星的MIC值无明显影响。培养基pH值在酸性侧 (pH5 .0 )抗菌活性略有下降而在碱性侧 (pH9.0 )有所增强。结论　格帕沙星为一较强的广谱杀菌药     

没食子酸抑制白念珠菌生物膜作用的研究

目的:研究没食子酸对体外白念珠菌生物膜的影响.方法:采用XTT减低法评价没食子酸对白念珠菌的生物膜及黏附性的影响;镜下观察没食子酸对白念珠菌生物膜的形态学影响;细胞毒试验检测该药的毒副作用.结果:没食子酸抑制白念珠菌生物膜最低药物浓度SMIC_(50),SMIC_(80)分别是500,1 000 mg·L~(-1);100,1 000 mg·L~(-1) 的没食子酸对白念珠菌的早期黏附及菌丝生长有抑制作用;没食子酸对人细胞毒性较弱.结论:没食子酸对体外白念珠菌生物膜有较强的抑制作用.     

In vitro activity of an essential oil against Leishmania donovani

The in vitro antileishmanial effect of the essential oil from Chenopodium ambrosioides against Leishmania donovani was investigated. The product showed significant activity against promastigotes and amastigotes, with a 50% effective concentration of 4.45 and 5.1 microg/mL, respectively. The essential oil caused an irreversible inhibition of the growth of promastigotes after a treatment with 100 or 10 microg/mL for 1 or 24 h, respectively. The phagocytic activity of the macrophages was preserved at a concentration toxic to the parasite. The essential oil from C. ambrosioides may be a potential candidate drug to development a new agent to combat this parasitic disease.     

In vitro antiplasmodial activity of some plants used in Kisii,Kenya against malaria and their chloroquine potentiation effects

Fifty-five organic and aqueous extracts of 11 plants used in malaria therapy in Kisii District, Kenya were tested in vitro against chloroquine (CQ)-sensitive and resistant strains of Plasmodium falciparum. Of the plants tested, 73% were active (IC(50) < 100 microg/ml). Three plants, Vernonia lasiopus, Rhamnus prinoides and Ficus sur afforded extracts with IC(50) values ranging less than 30 microg/ml against both CQ-sensitive and resistant strains. Combination of some extracts with CQ against the multi-drug resistant P. falciparum isolate V1/S revealed some synergistic effect. The plant extracts with low IC(50) values may be used as sources for novel antimalarial compounds to be used alone or in combination with CQ.     

In vitro antimycotic activity of some natural products against Saprolegnia ferax

During the in vitro screening of four essential oils and six substances of vegetable origin against the test fungi Saprolegnia ferax, thyme and savory essential oils, carvacrol and thymol exhibited the best antifungal activity at the lower concentrations. The antimycotic activity of malachite green, formalin and sodium chloride was also tested.     

In vitro antifungal activity of extracts and neolignans from Piper regnellii against dermatophytes

The present study was designated to evaluate the in vitro antidermatophyte activity of extracts from leaves of Piper regnellii as well as of the bioactivity-directed isolation of neolignans. The antifungal assay was performed by microdilution techniques. The hydroalcoholic extract of Piper regnellii leaves presented a strong activity against the dermatophyte fungi Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis and Microsporum gypseum with MICs of 15.62, 15.62, 15.62 and 62.5 microg/ml, respectively. On light microscopy and scanning electron microscopy of nail fragments not exposed to hydroalcoholic extract of Piper regnelli leaves, well-formed and extensive mycelial growth was seen. On nail fragments exposed to hydroalcoholic extract at concentrations more than 1.2mg/ml and then inoculated with spore suspension, growth was not seen. The hydroalcoholic extract was fractionated on silica gel in to nine fractions. The active chloroform fraction was lyophilized and chromatographed by column chromatography on silica gel. Structures were established by comparison with literature data and identified as eupomatenoid-3 and eupomatenoid-5. The pure compounds showed strong activity on Trichophyton rubrum with MIC of 50 and 6.2 microg/ml, respectively. Comparing the activity of the active chloroform fraction obtained from hydroalcoholic crude extract with that of isolated compound eupomatenoid-5, it is clear that this showed the same results against Trichophyton rubrum. The results showed that the plant could be explored for possible antifungal agents and provides preliminary scientific validation for the traditional medicinal use of this plant.     

In vitro and In vivo anthelmintic activity of Nicotiana tabacum L. leaves against gastrointestinal nematodes of sheep

The in vitro and in vivo anthelmintic activity of Nicotiana tabacum L. leaves was studied to rationalize its traditional use. Live Haemonchus contortus were used to assess the in vitro anthelmintic effect of a crude aqueous extract (CAE) and a methanol extract (CME) of N. tabacum. The in vitro inhibitory effect of both the extracts was evident from the paralysis and/or mortality of worms noted at 6 h post-exposure. For the in vivo studies, CAE and CME were administered in increasing doses (1.0-3.0 g/kg) to sheep naturally infected with mixed species of gastrointestinal nematodes. A maximum reduction of 73.6% in eggs per gram (EPG) of faeces was recorded on day 5 post-treatment with CME (3.0 g/kg) while the same dose of CAE showed a 49.4% reduction. Levamisole (7.5 mg/kg), a standard anthelmintic agent, showed a 99.6% reduction in EPG. These data show that the aqueous and methanol extracts of Nicotiana tabacum exhibit dose-dependent anthelmintic activity both in vitro and in vivo, thus justifying its use in the traditional medicine system of Pakistan.     

In vitro and in vivo trypanocidal activity of flavonoids from Delphinium staphisagria against Chagas disease

The in vitro and in vivo trypanocidal activities of nine flavonoids (1-9) isolated from the aerial parts of Delphinium staphisagria have been studied in both the acute and chronic phases of Chagas disease. The antiproliferative activity of these substances against Trypanosoma cruzi (epimastigote, amastigote, and trypomastigote forms) in some cases exhibited more potent antitrypanosomatid activity and lower toxicity than the reference drug, benznidazole. Studies in vitro using ultrastructural analysis together with metabolism-excretion studies were also performed in order to identify the possible action mechanism of the compounds tested. Alterations mainly at the level of the mitochondria may explain metabolic changes in succinate and acetate production, perhaps due to the disturbance of the enzymes involved in sugar metabolism within the mitochondrion. In vivo studies provided results consistent with those observed in vitro. No signs of toxicity were detected in mice treated with the flavonoids tested, and the parasitic charge was significantly lower than in the control assay with benznidazole. The effects of these compounds were also demonstrated with the change in the anti-T. cruzi antibody levels during the chronic stage.     

川陈皮素的体外抑癌活性及其机制研究

目的 探讨川陈皮素对Caco-2、HeLa、HepG2、A375、SW1990 5种肿瘤细胞的增殖抑制作用及对HeLa细胞的作用机制.方法 0～200μmol/L浓度的川陈皮素作用于体外培养的肿瘤细胞,应用MTT法检测细胞存活率;流式细胞仪及Hochest33258染色检测细胞凋亡率及形态学变化;分光光度法检测凋亡蛋白酶caspase-3的变化.结果 川陈皮素可显著抑制5种肿瘤细胞的生长,且对HeLa细胞的抑制效果最好.川陈皮素可促进HeLa细胞的凋亡,并可以增加其凋亡蛋白酶caspase-3的活性.结论 川陈皮素能抑制5种肿瘤细胞尤其是HeLa细胞的生长.川陈皮素可诱导HeLa细胞发生凋亡;提高凋亡蛋白酶caspase-3的活性可能是其诱导细胞凋亡的作用机制之一.     

In vitro anti‐adhesive activity of green tea extract against pathogen adhesion

Camellia sinensis polysaccharide has been reported to possess anti‐adhesive activity against pathogens. The present study was designed to investigate whether hot water extracts obtained from green tea leaves might inhibit pathogen adhesion to human or mouse cell lines. Green tea extract‐4 (CSI‐4) with the maximum yield of 4% (w/v) is composed of a major proportion of carbohydrates containing 40% uronic acids, but lack of catechins. It showed strong inhibitory activities against hemagglutination mediated by pathogens Helicobacter pylori, Propionibacterium acnes and Staphylococcus aureus with the minimum inhibitory concentrations of 0.01‐0.5 mg/mL. CSI‐4 further demonstrated an inhibitory effect on the adhesion of these pathogens to host cell lines with the IC₅₀ values (50% inhibition of adhesion) of 0.14–2.3 mg/mL. It exhibited the highest activity against P. acnes, but no inhibitory effects were observed against Lactobacillus acidophilus, Bifidobacterium bifidum, Escherichia coli, or Staphylococcus epidermidis. Our results suggest that CSI‐4 may exert a selective anti‐adhesive effect against certain pathogenic bacteria with no adverse effects against beneficial or commensal bacteria. Copyright © 2008 John Wiley & Sons, Ltd.     

In vitro antiviral activity of Phyllanthus orbicularis extracts against herpes simplex virus type 1

The antiviral activity of butanol- and acetic acid-soluble fractions, prepared from the leaves and stems of Phyllanthus orbicularis H.B.K., has been investigated against acyclovir-sensitive or -resistant herpes simplex virus type 1 (HSV-1) strains, using human foreskin fibroblast (HFF) and green ape kidney (Vero) cell lines. Both fractions showed antiviral selectivity indexes (SI) from 10.3 to 22.8, while their extracellular virucidal activities reached SI values ranging from 371 to 1,040. Time-addition experiments suggested that the active compounds present in the studied fractions acted on early steps of the virus replication cycle.     

连翘对金黄色葡萄球菌及表皮葡萄球菌的体外抗菌活性研究

[目的]观察连翘对金黄色葡萄球菌及表皮葡萄球菌的体外抗菌活性。[方法]用新的中药抑菌实验方法进行连翘对84株金葡菌和140株表皮葡萄球菌的体外抗菌活性的测定。[结果]连翘对金葡菌和表皮葡萄球菌能抑制50%菌株的最低细菌浓度(MIC50)均为0.122g/L,而能抑制90%菌株的最低抑菌浓度(MIC90)分别为0.98和0.244g/L。[结论]连翘对金黄色葡萄球菌和表皮葡萄球菌均有较好的体外抗菌效果。     

In vitro and in vivo anthelmintic activity of crude extracts of Coriandrum sativum against Haemonchus contortus

In vitro anthelmintic activities of crude aqueous and hydro-alcoholic extracts of the seeds of Coriandrum sativum (Apiaceae) were investigated on the egg and adult nematode parasite Haemonchus contortus. The aqueous extract of Coriandrum sativum was also investigated for in vivo anthelmintic activity in sheep infected with Haemonchus contortus. Both extract types of Coriandrum sativum inhibited hatching of eggs completely at a concentration less than 0.5 mg/ml. ED₅₀ of aqueous extract of Coriandrum sativum was 0.12 mg/ml while that of hydro-alcoholic extract was 0.18 mg/ml. There was no statistically significant difference between aqueous and hydro-alcoholic extracts (p > 0.05). The hydro-alcoholic extract showed better in vitro activity against adult parasites than the aqueous one. For the in vivo study, 24 sheep artificially infected with Haemonchus contortus were randomly divided into four groups of six animals each. The first two groups were treated with crude aqueous extract of Coriandrum sativum at 0.45 and 0.9 g/kg dose levels, the third group with albendazole at 3.8 mg/kg and the last group was left untreated. Efficacy was tested by faecal egg count reduction (FECR) and total worm count reduction (TWCR). On day 2 post treatment, significant FECR was detected in groups treated with higher dose of Coriandrum sativum (p < 0.05) and albendazole (p < 0.001). On days 7 and 14 post treatment, significant FECR was not detected for both doses of Coriandrum sativum (p > 0.05). Significant (p < 0.05) TWCR was detected only for higher dose of Coriandrum sativum compared to the untreated group. Reduction in male worms was higher than female worms. Treatment with both doses of Coriandrum sativum did not help the animals improve or maintain their PCV while those treated with albendazole showed significant increase in PCV (p < 0.05).     

In vitro activity of Triclisia patens and some bisbenzylisoquinoline alkaloids against Leishmania donovani and Trypanosoma brucei brucei

In the search for antiprotozoal compounds from natural sources, Triclisia patens displayed activity against L. donovani promastigotes (IC(50) = 1.5 microg/mL) and T. b. brucei blood stream trypomastigote forms (IC(50) = 31.25 microg/mL). In addition, a total of 20 bisbenzylisoquinoline alkaloids were screened for antileishmanial and antitrypanosomal activity in vitro. Fangchinoline (IC(50) = 0.39 microM) was found to be as active as the standard pentamidine against Leishmania donovani promastigotes. Phaeanthine was three-fold more active (IC(50) = 2.41 microM; 1.5 microg/mL) than the standard drug Pentostam against L. donovani amastigotes, but at this concentration was toxic to murine macrophages. In contrast, cocsoline (IC(50) = 12.3 microM; 6.76 microg/mL) was as active as Pentostam, and was not toxic to macrophages at this concentration. Thalisopidine showed the strongest activity (IC(50) = 1.14 microM) against Trypanosoma brucei brucei blood stream form trypomastigotes, but was less active than pentamidine.     

Furfuran lignans and a flavone from Artemisia gorgonum Webb and their in vitro activity against Plasmodium falciparum

The chemical composition of the aerial parts of the Cape Verdean endemic shrub Artemisia gorgonum Webb (Asteraceae) was careful investigated, which led to the isolation and identification of six known furfuran lignans: eudesmin (1), magnolin (2), epimagnolin A (3), aschantin (4), kobusin (5), sesamin (6) and a flavone: artemetin (7). Compounds 1-7 were evaluated in vitro for their cytotoxicity in a screening panel consisting of various mammalian tumor cell lines, for their antimalarial activity against chloroquine-resistant Plasmodium falciparum (FcB1 strain) and for their cytotoxicity against murine normal cells (CFU-GM). While no promising cytotoxicity against human tumor cells were noticed, marginal potency and selectivity was found for compounds 1-5 against murine colon 38. Besides, compounds 2-7 showed mild antiplasmodial activities, 6 and 7 being the most active compounds (IC(50) 3.37 and 3.50 μg/ml respectively) without noticeable toxicity on mammalian normal cells. This is the first report of antiplasmodial activity for furfuran lignans and the first isolation of 1-7 from Artemisia gorgonum.     

In vitro activity of Paris polyphylla smith against enterovirus 71 and coxsackievirus B3 and its immune modulation

Enterovirus 71 (EV71) and coxsackievirus B3 (CVB3) have resulted in severe pathogenesis caused by the host's immune response, including the cytokine cascade. Paris polyphylla Smith is a folk medicinal plant in Asia traditionally prescribed for the reduction of pain and elimination of poisoning. In this study, we investigated the anti-EV71 and CVB3 activity of P. polyphylla Smith as well as its immune modulation. The IC(50) for the P. polyphylla Smith 95% ethanol extract against EV71 and CVB3 were 12.5-23% and 99-156% of that of ribavirin, a positive control. Prevention of viral infection, viral inactivation, and anti-viral replication effects against both EV71 and CVB3 were demonstrated by the extract, the anti-viral replication effect being dominant. The extract significantly increased IL-6 production in both EV71- and CVB3-infected cells. A high correlation was possibly demonstrated between the high amounts of IL-6 induction in the EV71 and CVB3-infected cells and the anti-viral replication activity of the extract. In conclusion, good anti-EV71 and CVB3 activity was observed in the P. polyphylla Smith 95% ethanol extract. The high amounts of IL-6 induction in the virus-infected cells played a key role in the anti-viral activity of the extract.     

直杆桉果实提取物体外抗单纯疱疹病毒和乙型肝炎病毒的实验研究

目的:研究3种不同溶剂的直杆桉果实提取物体外抗单纯疱疹病毒Ⅰ型(HSV-1)和乙型肝炎病毒(HBV)的活性。方法:采用MTT法检测药物毒性,CPE法与空斑减数实验检测药物抗HSV-1活性;采用ELISA法检测药物对HepG2.2.15细胞分泌的乙型肝炎表面抗原(HBsAg)和乙型肝炎E抗原(HBeAg)的抑制作用。结果:直杆桉叶果实的醋酸乙酯提取物(P18-E1)和甲醇提取物(P18-E2)无明显抗HSV-1的活性,水提物(P18-E3)能明显抑制HSV-1的致病变作用,其TC50为69.20 mg/mLI,C50为126.77μg/mL,治疗指数为545.87;3种不同溶剂的提取物对HepG2.2.15细胞分泌的HBsAg和HBeAg均无明显抑制作用。结论:直杆桉果实的水提物(P18-E3)具有显著的抗HSV-1活性,主要是对病毒有直接灭活作用,也能影响病毒对细胞的吸附。初步推测其抗HSV-1活性的机理是影响病毒的囊膜结构从而使之失活。     

In vitro cytotoxic activity of phenanthroindolizidine alkaloids from Cynanchum vincetoxicum and Tylophora tanakae against drug-sensitive and multidrug-resistant cancer cells

Two known phenanthroindolizidine alkaloids, (-)-(R)-13aalpha-antofine (1) and (-)-(R)-13aalpha-6-O-desmethylantofine (2), and two new natural products, (-)-(R)-13aalpha-secoantofine (3) and (-)-(R)-13aalpha-6-O-desmethylsecoantofine (4), were isolated from Cynanchum vincetoxicum. The structures of all compounds were established by means of NMR methods including COSY, NOESY, HSQC, and HMBC experiments, supported by HRMS and optical rotation data. Cytotoxic activity of the isolated alkaloids, and of three other alkaloids previously isolated from Tylophora tanakae, (-)-(R)-13aalpha-tylophorine (5), (-)-(R)-13aalpha-7-O-desmethyltylophorine (6), and (+)-(S)-13abeta-isotylocrebrine (7), was assessed in vitro using a drug-sensitive KB-3-1 and a multidrug-resistant KB-V1 cancer cell line. Structure-activity relationships in this series of alkaloids are discussed. The IC(50) values of some of the alkaloids are in the low nanomolar range, being thus comparable to the activity of clinically used cytotoxic drugs. Previously reported adverse side effects of these alkaloids could possibly be overcome by modern tissue-specific drug targeting techniques.