Evaluation of clastogenic potential of the antimalarial plant Solanum nudum

Compounds isolated from Solanum nudum have shown in vitro antimalarial activity against the FCB-2 strain of Plasmodium falciparum. Diosgenone (C27H40O3) the main component isolated from the hexane extract and an aqueous extract were evaluated to measure their clastogenic potential using the micronucleus test. Three concentrations (16, 32 and 64 g/kg of weight) of the aqueous extract were administered intraperitoneally into mice, (the highest concentration corresponded to 80% LD50) and diosgenone solubilized in olive oil was inoculated at the highest concentration possible (11.187 g/kg of weight). After administration of the compounds, no induction of micronucleus was observed either in polychromatic or normochromatic erythrocytes. Interestingly, a reduction of 51% in the young/mature erythrocytes ratio was seen in cells treated with aqueous extract. We conclude that neither diosgenone nor the aqueous extract have clastogenic activity, and that the aqueous extract showed some toxicity at the above mentioned concentrations. These results are significant since diosgenone could be a new therapeutic alternative for the treatment of malaria.     

Anticlastogenic effect in human lymphocytes by the sodium salt of 3,4-secoisopimar-4(18),7,15-trien-3-oic acid

The ability of the sodium salt of 3,4-secoisopimar-4(18),7,15-trien-3-oic acid (1), a diterpenoid obtained from Salvia cinnabarina, to inhibit the genotoxic effect of ethyl methanesulfonate (a clastogenic agent) and colcemid (an aneugenic agent), was studied using a micronucleus assay on cultured human lymphocytes. Cells were treated with 1 before (pretreatment), during (co-treatment), and after (post-treatment) treatment with the mutagens, in order to investigate the type of antimutagenic activity (desmutagenic or bioantimutagenic) manifested. In the range of concentrations tested (0.3-330 μM) 1 reduced significantly the frequency of micronuclei induced by ethyl methanesulfonate, in both pre- and co-treatment protocols (up to 74% and 70% of reduction, respectively), showing an anticlastogenic activity. Conversely, 1 did not inhibit the effect of colcemid in all treatments. The nuclear division index value of lymphocytes was not affected by treatment with 1, thus demonstrating that the anticlastogenic effect of 1 was not due to a cytotoxic effect. On the basis of the results obtained, it can be hypothesized that 1 exerts its anticlastogenic activity against ethyl methanesulfonate by a desmutagenic mechanism, possibly by chemical inactivation of the mutagen.     

In vitro and in vivo antitrypanosomal activity of Xanthium strumarium leaves

Antitrypanosomal activity of crude 50% ethanolic extract of Xanthium strumarium leaves was studied in vitro and in vivo. The extract exhibited trypanocidal activity at all the four concentrations tested i.e. 5, 50, 500 and 1000 μg/ml, in vitro. In vivo trial revealed that the extract exerted antitrypanosomal effect at dosage of 100, 300 and 1000 mg/kg, intraperitoneally. At 100 and 300 mg/kg doses the survival period of the Trypanosoma evansi infected mice was significantly prolonged. However, the extract was found to be toxic to the animals at 1000 mg/kg dose.     

Inhibition of clastogenic effects of nicotine by chlorophyllin in mice bone marrow cells in vivo

The effect of chlorophyllin in modifying the clastogenic action of nicotine was tested in vivo on mice bone marrow cells. Nicotine, when administered by gavage, induced chromosomal aberrations in frequencies directly proportional to the dose. Maximum effects were recorded at 6 h after exposure. Chlorophyllin, when given alone, was not clastogenic even at the highest concentration (1.50 mg/kg body wt). Simultaneous administration of nicotine and chlorophyllin with even lower doses (1.25 and 0.77 mg/kg body wt) reduced the frequency of chromosomal aberrations to the normal level. Chlorophyllin alone, given 2 h before nicotine, however, did not counteract the effects of nicotine. The use of green plant parts in modifying the genotoxicity of different agents may be related to the protective action of chlorophyllin.     

In vitro and in vivo Leishmanicidal activity of 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone (lapachol)

This study aims to evaluate the in vitro and in vivo leishmanicidal activity of lapachol, a naphthoquinone found in the seeds and heartwood of certain tropical plants, and to compare its efficacy with a reference drug, sodium stibogluconate (Pentostam(R)). These compounds (0.0125-4.0 mg/mL) were evaluated in vitro against intracellular amastigotes of Leishmania (Viannia) braziliensis (LVb), then tested in an animal model (hamster) to try to reproduce the leishmanicidal activity. In vitro, lapachol exhibited an anti-amastigote effect, whereas in vivo it did not prevent the development of LVb-induced lesions at an oral dose of 300 mg/kg/day for 42 days. Pentostam(R) demonstrated a significant anti-amastigote effect in vitro for LVb and apparent clinical cure in vivo (60 mg/kg/day). However, it could not completely eradicate parasites from the tissues of infected animals. The observation that lapachol exerts leishmanicidal activity in vitro without offering significant protection against LVb-infected lesions in hamsters suggests that lapachol in vivo might possibly inhibit the microbicidal functioning of macrophages. Alternatively, it might be transformed into an inactive metabolite(s) or neutralized, losing its leishmanicidal activity. It is also possible that an optimal and sustained plasma level of the drug could not be achieved at the dose used in this study.     

In vitro anti-leukemic and antiviral activities of traditionally used medicinal plants in Taiwan

Medicinal plants have been historically used as treatment for different kinds of human diseases. In this study, hot water (HW) extract of five Taiwanese traditionally used medicinal plants was evaluated for their in vitro anti-leukemic (including anti-K562, L1210, P3HR1, Raji and U937 leukemia cells) and antiviral (including HSV-1 and HSV-2) activities. Results showed that Blumea lacera exhibited broad anti-leukemic activity at magnitudes ranging from moderate to mild and Ixeris chinensis is effective at inhibiting the proliferation of K562 cells. B. lacera and Tithonia diversifolia suppressed the replication of HSV-1 and HSV-2, and had IC50 values below 100 microg/ml. The medicinal plants showed no cytotoxic effect at concentrations that inhibited HSV infection. It was, therefore, concluded that the HW extract of tested medicinal plants exhibited anti-leukemic and antiviral activities at different magnitudes of potency.     

Clastogenic effect of ginger rhizome in mice

The present study focuses on the clastogenic effect of ginger rhizome. Crude aqueous extracts of ginger were gavaged at doses of 0. 5, 1, 2, 5, 10 g/kg body weight and ginger oil (0.625, 1.250 and 2. 50 ml/kg body weight) was administered by intraperitoneal injection to male mice. Chromosome damage was studied in a preparation made from bone marrow cells following colchicine injection to all mice and examination of the cells after pretreatment in hypotonic solution, fixation, air drying and staining in Giemsa solution. Attention is drawn to the weakness of the clastogenic activity expressed by the ginger extract. In comparison ginger oil gave a higher frequency of chromosomal aberrations. It is suggested therefore, that the extract may contain substance(s) that suppress clastogenesis in the bone marrow cells of mice.     

A phytotherapeutic extract of Equisetum myriochaetum is not genotoxic either in the in vivo wing somatic test of Drosophila or in the in vitro human micronucleus test

Equisetum myriochaetum is a Mexican plant used in folk medicine to treat kidney diseases and type 2 diabetes mellitus. The main constituents of the phytoextract are flavonol glycosides (kaempferol), phytoesterols and carbohydrates. In this study, phytotherapeutic extracts from Equisetum myriochaetum were investigated for genotoxicity in the in vivo wing spot test in Drosophila melanogaster and in the in vitro human micronucleus test. No acute toxicity of the phytoextract could be determined in Drosophila or in human lymphocytes in culture, ranging from 0.78 microg/ml to 3700 microg/ml for the wing assay and between 12.5 microg/ml and 500 microg/ml for the micronucleus test. The Drosophila wing somatic mutation and recombination test (SMART) was applied in the standard version with basal biotransformation activity as well as in a variant version with increased cytochrome P450-dependent bioactivation capacity. The ranges of exposure concentrations for these genotoxicity experiments were between 0.78 microg/ml and 500 microg/ml. The human micronucleus test in vitro was performed with cultured lymphocytes obtained from four healthy donors. The concentrations assayed for these experiments ranged from 12.5 microg/ml to 500 microg/ml. No statistically significant increase was observed between treated series when compared with a concurrent negative (water solvent) control series in either assay. The results demonstrate clearly that the phytotherapeutic extract from Equisetum myriochaetum, under the experimental conditions tested, is not genotoxic in the in vivo experiments or in the in vitro studies.     

Effect of Solanum nudum Dunal (Solanaceae) steroids on hepatic trophozoites of Plasmodium vivax

Steroids isolated from the plant Solanum nudum showed antiplasmodial activity against the blood stages of Plasmodium falciparum. It has been demonstrated that these steroids are neither mutagenic in vitro nor clastogenic in vivo. This study evaluated the effect of five steroids of S. nudum (SN-1, SN-2, SN-3, SN-4 and SN-5) on hepatic trophozoites of P. vivax, using an experimental design, non-balanced, with blind determination of the effect expressed as the percentage reduction of hepatic trophozoites. The sporozoites used to inoculate human hepatoma cells HepG2-A16 were obtained from gametocytemic blood of volunteers infected only with P. vivax, and passed into laboratory-reared Anopheles albimanus mosquitoes. Steroids were added at three different doses (100, 10 and 1 microg/mL) just after inoculation of the cells with sporozoites. The effect was determined by indirect immunofluorescence assays using the monoclonal antibodies Pv210 or Pv47E-2E10 and steroid cytotoxicity on HepG2-A16 cells was assessed by the MTT method. All the steroids reduced the number of hepatic P. vivax trophozoites, SN-2 and SN-4 reduced the number of hepatic trophozoites by 47% and 39% (p < 0.05), respectively.     

Effect of a preparation from Viscum album on tumor development in vitro and in mice

The effect of Iscador, a commercial preparation made from Viscum album was studied on several cell lines using in vitro tissue culture as well as tumor-bearing animals. Iscador was found to be cytotoxic to animal tumor cells such as Dalton's lymphoma ascites cells (DLA cells) and Ehrlich ascites cells in vitro and inhibited the growth of lung fibroblasts (LB cells), Chinese hamster ovary cells (CHO cells) and human nasopharyngeal carcinoma cells (KB cells) at very low concentrations. Moreover, administration of Iscador was found to reduce ascites tumours and solid tumours produced by DLA cells and Ehrlich ascites cells. The effect of the drug could be seen when the drug was given either simultaneously, after tumour development or when given prophylactically, indicating a mechanism of action very different from other chemotherapeutic drugs. Iscador was not found to be cytotoxic to lymphocytes.     

千金子提取物抗肿瘤作用的实验研究

目的探索千金子的抗肿瘤作用。方法采用极性梯次提取与硅胶柱层析分离,并对其不同极性段的提取物和分离物进行了体内(小鼠移植性肿瘤)、外(噻唑蓝染色法)抗肿瘤活性研究。结果千金子的氯仿、丙酮段提取物对 K562,HepG_2和 U937细胞株具有抑瘤作用,对在体的 EAC、S180呈现出明显疗效;其石油醚、甲醇、水段提取物则基本上未显示有明显抗癌活性;该有效提取物的硅胶柱层析的多组分离物对K562,HL-60、Hela 细胞呈现出较强的细胞毒作用。结论除已知的千金子因子5外,千金子中还存在有多种细胞毒物质,其物质有抗肿瘤作用。     

Biological disposition of boldine: in vitro and in vivo studies

Boldine is a natural compound with well-established free radical scavenger and hepatoprotective properties. The further exploration of its actual therapeutic potential as an antioxidant is, however, partially limited by the absence of knowledge on its pharmacokinetics. In the present studies, we provide information on the in vitro and in vivo biological disposition of boldine. The addition of 200 microM boldine to an isolated rat hepatocyte suspension was followed by a time-dependent (0-60 min) disappearance of boldine from the extracellular medium. This decline was associated with an early (first 2 min) and swift accumulation (1600 microM) of boldine within the cells. Although the intracellular concentration of boldine diminished, boldine was always found to occur within the cells at concentrations substantially higher than those initially added to the preparation. Boldine was also concentration-dependently removed from the extracellular medium by isolated rat livers portally perfused with the antioxidant. In vivo studies, conducted in rats, revealed that following either its oral or its intravenous administration, plasma boldine concentrations declined rapidly and according to an apparently first order type of kinetics. After its oral administration (50 or 75 mg/kg), boldine was rapidly (within 30 min) absorbed and preferentially concentrated in the liver, with substantially lower concentrations being found in the brain and heart. Maximal hepatic concentrations of boldine were found to be equal to or greater than those needed to afford antioxidant and hepatoprotective effects in vitro.     

Crown gall -- a plant tumour with biological activities

Petroleum ether, acetone, 80% MeOH and water extracts of crown gall, a plant tumour, obtained from Eucalyptus globulus tree were screened for cytotoxic, antioxidant, antiinflammatory, embryotoxic, antitumour-promoting and antimicrobial activities.In terms of bioactivity the 80% MeOH extract was most effective followed by the acetone extract. The petroleum ether extract showed weak to moderate cytotoxic activity in dose-dependent manner against PC12 cells, mouse L fibroblasts and 1321N1 glia cells, whereas the hydroalcohol extract had no or a weak cytotoxic effect. The 80% MeOH extract exhibited strong antioxidant activity. Based on the in vitro HET-CAM assay all the extracts were effective against inflammation. The extracts did not show any embryotoxic effect at the concentrations tested. Antitumour-promoting activity (100% inhibition; 100 microg/mL) was observed in the 80% MeOH and acetone extracts. In the antimicrobial screening all extracts displayed predominantly antifungal activity against Candida sp. The extracts also showed various levels of antibacterial activity against E. faecalis, Ps. aeruginosa, Bac. subtilis and Staph. epidermidis.From the results of the investigations it can be concluded that crown gall is a valuable plant tumour tissue having interesting biological activities.     

Antimalarial activity of extracts of Abutilon grandiflorum G. Don - a traditional Tanzanian medicinal plant

The Tanzanian medicinal plant Abutilon grandiflorum G. Don was studied for its in vivo and in vitro antiplasmodial effects. The ethyl acetate extract showed prominent in vivo activity against P. vinckei vinckei in mice and in vitro against P. falciparum strains HB3 and FCB. The extract was only moderately cytotoxic if tested in vitro against the colon cell line HT29. In the in vivo study, the results were significantly influenced by the treatment schedule used, i.e. early treatment with higher doses was more successful than applying the same overall amount over a longer period. Phytochemical analysis of the extract provided no conclusive evidence for the observed parasitological effects.     

In vitro and in vivo trypanocidal effect of lipophilic extracts of medicinal plants from Mali and Burkina Faso

AIM OF THE STUDY: To determine the in vitro and in vivo antitrypanosomal activity of extracts of traditionally used plants. MATERIALS AND METHODS: 47 dichloromethane extracts were tested in vitro in the Long-term Viability Assay (LtVA) on Trypanosoma brucei brucei. The most active ones were also tested in vivo using a standardised mouse test. RESULTS: 13 extracts (28%) were active in vitro with MIC-values相似文献   

Cytotoxic flavone analogues of vitexicarpin,a constituent of the leaves of Vitex negundo

Bioassay-guided fractionation of the chloroform-soluble extract of the leaves of Vitex negundo led to the isolation of the known flavone vitexicarpin (1), which exhibited broad cytotoxicity in a human cancer cell line panel. In an attempt to increase the cytotoxic potency of 1, a series of acylation reactions was performed on this compound to obtain its methylated (2), acetylated (3), and six new acylated (4-9) derivatives. Compound 9, the previously unreported 5,3'-dihexanoyloxy-3,6,7,4'-tetramethoxyflavone, showed comparative cytotoxic potency to compound 1 and was selected for further evaluation. However, this compound was found to be inactive when evaluated in the in vivo hollow fiber assay with Lu1, KB, and LNCaP cells at the highest dose (40 mg/kg/body weight) tested, and in the in vivo P-388 leukemia model (135 mg/kg), using the ip administration route.     

The in vitro antiviral property of Azadirachta indica polysaccharides for poliovirus

Ethnopharmacological relevance

Azadirachta indica A. Juss, popularly known as neem, has been extensively used in Ayurvedic medicine by Indian population for over 2000 years. It is used traditionally for the healing of various diseases. Natural products and their derivatives provide an excellent source for new anti-viral drugs.

Aim of the study

The present study aims at evaluating the activity of two polysaccharides (P1 and P2) isolated from the leaves of Azadirachta indica and their chemical sulfated derivatives (P1S and P2S) against poliovirus type 1 (PV-1).

Materials and methods

The cytotoxicity of the compounds was analyzed by MTT and the antiviral effect was determined by plaque reduction assay in different protocols.

Results

The polysaccharides did not show any cytotoxic effects on HEp-2 cells at the highest tested concentration (200 μg/ml) and exhibited significant antiviral activity with inhibitory concentrations (IC₅₀) of 80 μg/ml, 37.5 μg/ml, 77.5 μg/ml, and 12.1 μg/ml for P1, P1S, P2 and P2S, respectively, and the selectivity indexes (SI) ranged from 18 to 131.9. The compounds demonstrated better inhibitory effect when added concomitantly with the virus infection with a dose-dependent curve inhibition. Lesser effect was observed when the compounds were added after viral infection and the least effect at pre-treatment.

Conclusions

We suggested that the polysaccharides obtained from Azadirachta indica act against PV-1 by inhibiting the initial stage of viral replication. Importantly, original polysaccharides showed better virucidal effect than their sulfated derivatives at all tested concentrations. This study provides a scientific basis for the past and present ethnomedical uses of this plant.     

Evaluation of nitric oxide scavenging activity, in vitro and ex vivo, of selected medicinal plants traditionally used in inflammatory diseases

Steroidal and non-steroidal antiinflammatory drugs, despite their various side effects, are in great demand worldwide. Alternatively, herbal formulations provide relief to a large percentage of the population suffering from inflammatory diseases. Therefore, such practices need to be rationalized through a mechanistic approach. Thus, four traditional medicinal plants, namely Ventilago madraspatana Gaertn., Rubia cordifolia Linn., Lantana camara Linn. and Morinda citrifolia Linn. were selected for a study on the inhibition of nitric oxide (NO*), a key mediator in the phenomenon of inflammation, signifying the presence of effective antiinflammatory constituents therein. Plant samples were extracted with different solvents for evaluation of their inhibitory activity on NO* produced in vitro from sodium nitroprusside, and in LPS-activated murine peritoneal macrophages, ex vivo. Further, the inhibition of NO* synthesis was correlated with the reduction of iNOS protein expression through Western blot. Notable NO* scavenging activity was exhibited in vitro by some extracts of V. madraspatana, R. cordifolia and L. camara (IC(50) < 0.2 mg/mL). Most of them showed marked inhibition (60%-80%), ex vivo, at a dose of 80 microg/mL without appreciable cytotoxic effect on the cultured macrophages. Immunoblot analysis confirmed that the modulatory effect of the samples had occurred through suppression of iNOS protein.     

In vivo and in vitro studies on the anticancer activity of Copaifera multijuga hayne and its fractions

Copaiba oil resin (COR) obtained from Copaifera multijuga Hayne has been used in popular medicine as an antinflammatory and for the treatment of bronchitis, ulcers and cancer. The aim of this study was to evaluate the action of COR and its fractions on the inhibition of lung metastasis and tumour growth induced by B16F10 melanoma cells in mice and cytotoxicity in vitro using Trypan Blue exclusion method and MTT conversion.Mice which have received subcutaneously B16F10 cells developed a solid tumour that reached a peak at 17 days. Together with the increase in tumour growth we also observed an increase in the number of lung nodules. There was a positive correlation between the in vitro cytotoxic assay and in vivo antitumour activity. The oral administration of COR (at 2 g/Kg in the days 3, 5, 7, 10, 12 and 14 after inoculation of tumoral cells) reduced tumour growth by 58% and tumour weight by 76%. At the same dose COR reduced the number of lung nodules by 47.1%. In vitro experiments showed that COR incubated with the melanoma cell line reduced cell viability in a concentration and time-dependent manner. Diterpenic and sesquiterpenic fractions or reconstituted oil induced cytotoxicity. Our results shows that COR and its fractions have tumouricidal activity in the melanoma cell line in both models in vivo and in vitro.     

Immunostimulating activity of the hot water-soluble polysaccharide extracts of Anacyclus pyrethrum,Alpinia galanga and Citrullus colocynthis

Hot water polysaccharide extracts of Anacyclus pyrethrum (L.) Link. (family Compositae) Citrullus colocynthis (L.) Schrad. (family Cucurbitaceae) and Alpinia galanga (L.) Willd. (family Zingiberaceae) were tested for their immunostimulating activity in mice. The fractions from Anacyclus pyrethrum and Alpinia galanga showed a marked stimulating effect on the reticulo-endothelial system (RES) and increased the number of peritoneal exudate cells (PEC), and spleen cells of mice. In this case, the optimum doses were 50 and 25 mg/kg for the two fractions, respectively. On the other hand, the polysaccharide extracts of both Anacyclus pyrethrum and Alpinia galanga markedly enhanced the proliferation of the murine spleen cells in vitro using two tests (in vitro and in vivo effect). The results of the in vivo effect at a doses of 50 and 25 mg/kg, showed a stimulation index better than obtained with the in vitro effect at 50 and 25 microg/ml for Anacyclus pyrethrum and Alpinia galanga, respectively. While the extract of Citrullus colocynthis showed much weaker and variable immunostimulating activity.