RESUMO
The coronavirus disease 2019, COVID-19, caused by the severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, appears as a major pandemic having adverse impact on public health and economic activities. Since viral replication in human enterocytes results in its faecal shedding, wastewater surveillance is an ideal, non-invasive, cost-effective and an early warning epidemiological approach to detect the genetic material of SARS-CoV-2. Here, we review techniques for the detection of SARS-CoV-2 in municipal wastewater, and disinfectants used to control viral spread. For detection, concentration of ribonucleic acid involves ultrafiltration, ultracentrifugation and polyethylene glycol precipitation. Identification is done by reverse transcriptase amplification, nucleic acid sequence-based amplification, helicase dependent amplification, loop-mediated isothermal amplification, recombinase polymerase amplification, high throughput screening and biosensor assays. Disinfectants include ultraviolet radiations, ozone, chlorine dioxide, hypochlorites and hydrogen peroxide. Wastewater surveillance data indicates viral presence within longer detection window, and provides transmission dynamics earlier than classical methods. This is particularly relevant for pre-symptomatic and asymptomatic COVID-19 cases.
RESUMO
Wastewater flowing in streams and nallahs across India carries several trace metals, including metalloid arsenic (As), which are considered serious environmental contaminants due to their toxicity, and recalcitrant nature. In this study, we determined the phytoremediation of As by Eichhornia crassipes (Mart.) Solms either alone or in association with plant growth-promoting rhizobacteria. Pseudomonas and Azotobacter inoculation to E. crassipes resulted in enhanced As removal compared to uninoculated control. Co-inoculation with a consortium of Pseudomonas, Azotobacter, Azospirillum, Actinomyces, and Bacillus resulted in a higher As (p < 0.05) phytoaccumulation efficiency. P. aeruginosa strain jogii was found particularly effective in augmenting As removal by E. crassipes. Our findings indicate that the synergistic association of E. crassipes and various rhizobacteria is an effective strategy to enhance removal of As and thus may be utilized as an efficient biological alternative for the removal of this metalloid from wastewaters.
Assuntos
Arsênio , Eichhornia , Poluentes Químicos da Água , Arsênio/metabolismo , Biodegradação Ambiental , Eliminação de Resíduos Líquidos , Águas Residuárias , Poluentes Químicos da Água/metabolismoRESUMO
Three Arbuscular mycorrhizal fungi (AMF) from Glomus, Acaulospora and Scutellospora, and four plant growth promoting rhizobacteria (PGPR) isolates related to genera Streptomyces, Azotobacter, Pseudomonas and Paenibacillus were found to be effective in phytoremediation of Fe(3+) contaminated soil where Pennisetum glaucum and Sorghum bicolor were growing as host plants. Co-inoculation of AMF and PGPR showed better results in comparison to either, AMF and PGPR under pot conditions. Both AMF and PGPR were able to produce siderophores. AMF and PGPR associated to P. glaucum and S. bicolor plants increased the extent of iron absorption. AMF and PGPR combination exhibited superior (p < 0.01) phytoremediation efficiency with P. glaucum compared to S. bicolor. These findings warrant further investigations of these synergistic interactions and large-scale in situ studies for bioremediation of iron-contaminated soils.
Assuntos
Bactérias/metabolismo , Ferro/metabolismo , Micorrizas/metabolismo , Pennisetum/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Sorghum/metabolismo , Biodegradação AmbientalRESUMO
Antibiotic resistance in bacteria has emerged as a serious public health threat worldwide. Aquatic environments including irrigation-purpose wastewaters facilitate the emergence and transmission of antibiotic-resistant bacteria and antibiotic resistance genes leading to detrimental effects on human health and environment sustainability. Considering the paramount threat of ever-increasing antibiotic resistance to human health, there is an urgent need for continuous environmental monitoring of antibiotic-resistant bacteria and antibiotic resistance genes in wastewater being used for irrigation in Indian agro-ecosystems. In this study, the prevalence of antibiotic resistance in Gram-negative bacteria isolated from irrigation-purpose wastewater samples from Sirmaur and Solan districts of Himachal Pradesh was determined. Bacterial isolates of genera Escherichia, Enterobacter, Hafnia, Shigella, Citrobacter, and Klebsiella obtained from 11 different geographical locations were found to exhibit resistance against ampicillin, amoxyclav, cefotaxime, co-trimoxazole, tobramycin, cefpodoxime and ceftazidime. However, all the isolates were sensitive to aminoglycoside antibiotic gentamicin. Enterobacter spp. and Escherichia coli showed predominance among all the isolates. Multidrug-resistance phenotype was observed with isolate AUK-06 (Enterobacter sp.) which exhibited resistant to five antibiotics. Isolate AUK-02 and AUK-09, both E. coli strains showed resistant phenotypes to four antibiotics each. Phenotypic detection revealed that six isolates were positive for extended-spectrum ß-lactamases which includes two isolates from Enterobacter spp. and E. coli each and one each from Shigella sp. and Citrobacter sp. Overall, the findings revealed the occurrence of antibiotic resistant and ESBL-positive bacterial isolates in wastewaters utilized for irrigation purpose in the study area and necessitate continuous monitoring and precautionary interventions. The outcomes of the study would be of significant clinical, epidemiological, and agro-environmental importance in designing effective wastewater management and environmental pollution control strategies.
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Rumen microbial community comprising of bacteria, archaea, fungi, and protozoa is characterized not only by the high population density but also by the remarkable diversity and the most complex microecological interactions existing in the biological world. This unprecedented biodiversity is quite far from full elucidation as only about 15-20 % of the rumen microbes are identified and characterized till date using conventional culturing and microscopy. However, the last two decades have witnessed a paradigm shift from cumbersome and time-consuming classical methods to nucleic acid-based molecular approaches for deciphering the rumen microbial community. These techniques are rapid, reproducible and allow both the qualitative and quantitative assessment of microbial diversity. This review describes the different molecular methods and their applications in elucidating the rumen microbial community.
Assuntos
Biota , Ecossistema , Metagenômica/métodos , Rúmen/microbiologia , Animais , Archaea/classificação , Archaea/genética , Bactérias/classificação , Bactérias/genética , Cilióforos/classificação , Cilióforos/genética , Fungos/classificação , Fungos/genéticaRESUMO
Glycosyl 1,4-dihydropyridine analogue (2,6-dimethyl-4-(3-O-benzyl-1,2-O-isopropylidene-beta-l-threo pentofuranos-4-yl)-1-phenyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid diethyl ester) synthesized in our laboratory, inhibited Leishmania donovani infection in vitro and in hamsters (Mesocricetus auratus) when administered orally. This analogue is nontoxic, cell-permeable and orally effective. This glycosyl dihydropyridine analogue functioned through arrest of cells in sub-G0/G1-phase, triggering mitochondrial membrane depolarization-mediated programmed cell death of the intracellular amastigotes.
Assuntos
Antiprotozoários/farmacologia , Di-Hidropiridinas/farmacologia , Glicosídeos/farmacologia , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Macrófagos/parasitologia , Oxirredutases/efeitos dos fármacos , Administração Oral , Animais , Antiprotozoários/administração & dosagem , Antiprotozoários/química , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Cricetinae , Di-Hidropiridinas/administração & dosagem , Di-Hidropiridinas/uso terapêutico , Citometria de Fluxo , Glicosídeos/administração & dosagem , Glicosídeos/uso terapêutico , Concentração Inibidora 50 , Leishmania donovani/citologia , Leishmania donovani/enzimologia , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mesocricetus , Camundongos , Camundongos Endogâmicos BALB C , Membranas Mitocondriais/efeitos dos fármacos , Membranas Mitocondriais/metabolismo , Fenótipo , Baço/parasitologiaRESUMO
OBJECTIVES: Several Leishmania strains with episomal expression of green fluorescent protein (GFP) require constant drug pressure for its continuous expression and hence limit its use in ex vivo or in vivo systems. The aim of this study was to alleviate this problem by stably integrating the GFP gene into the parasite genome, so as to use these transfectants for ex vivo and in vivo drug screening. METHODS: The GFP gene was integrated downstream of the 18S ribosomal promoter region of Leishmania donovani. After initial selection, GFP-expressing parasites-both sodium stibogluconate (SAG)-susceptible (2001) and -resistant (2039) isolates-were grown without adding G418. The infectivity of these transfectants to macrophages (J774.1) as well as to hamsters was checked. The ex vivo screening assay was standardized using standard antileishmanial drugs. RESULTS: A constitutive and enhanced expression of GFP in promastigote and amastigote stages was achieved for approximately 12 months without any need for drug pressure. These transfectants were highly infective to macrophage cell lines as well as to hamsters, as observed by fluorescence microscopy and flow cytometry (FACS). GFP-tagged promastigotes as well as intracellular amastigotes were found to be highly susceptible to miltefosine, amphotericin B and pentamidine, in a concentration-dependent manner. SAG was inactive against the GFP-promastigotes, as well as SAG-resistant intracellular amastigotes, correlating well with earlier reports. CONCLUSIONS: The GFP-transfectants were found to be suitable for FACS-based ex vivo screening assays. They were also infective to hamsters up to day 60 post-infection.
Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/normas , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/genética , Organismos Geneticamente Modificados/genética , Animais , Antiprotozoários/farmacologia , Cricetinae , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Leishmania donovani/patogenicidade , Leishmaniose Visceral/parasitologia , Macrófagos/parasitologia , CamundongosRESUMO
The protozoan parasite Leishmania donovani is the causative agent of visceral leishmaniasis. The enzyme pteridine reductase 1 (PTR1) of L. donovani acts as a metabolic bypass for drugs targeting dihydrofolate reductase (DHFR); therefore, for successful antifolate chemotherapy to be developed against Leishmania, it must target both enzyme activities. Leishmania cells overexpressing PTR1 tagged at the N-terminal with green fluorescent protein were established to screen for proprietary dihydropyrimidone (DHPM) derivatives of DHFR specificity synthesised in our laboratory. A cell-permeable molecule with impressive antileishmanial in vitro and in vivo oral activity was identified. Structure activity relationship based on homology model drawn on our recombinant enzyme established the highly selective inhibition of the enzyme by this analogue. It was seen that the leishmanicidal effect of this analogue is triggered by programmed cell death mediated by the loss of plasma membrane integrity as detected by binding of annexin V and propidium iodide (PI), loss of mitochondrial membrane potential culminating in cell cycle arrest at the sub-G0/G1 phase and oligonucleosomal DNA fragmentation. Hence, this DHPM analogue [(4-fluoro-phenyl)-6-methyl-2-thioxo-1, 2, 3, 4-tetrahydropyrimidine-5-carboxylic acid ethyl ester] is a potent antileishmanial agent that merits further pharmacological investigation.
Assuntos
Antiprotozoários/farmacologia , Apoptose , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/parasitologia , Oxirredutases/biossíntese , Pirimidinonas/farmacologia , Animais , Anexina A5/farmacologia , Antiprotozoários/química , Morte Celular , Sobrevivência Celular , Cricetinae , Fragmentação do DNA/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Indicadores e Reagentes/farmacologia , Leishmania donovani/enzimologia , Leishmania donovani/isolamento & purificação , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Propídio/farmacologia , Pirimidinonas/química , Relação Estrutura-AtividadeRESUMO
Pteridine reductase 1 (PTR1, EC 1.5.1.33) is a NADPH dependent short-chain reductase (SDR) responsible for the salvage of pterins in the protozoan parasite Leishmania. This enzyme acts as a metabolic bypass for drugs targeting dihydrofolate reductase, therefore, for successful antifolate chemotherapy to be developed against Leishmania, it must target both enzyme activities. Based on homology model drawn on recombinant pteridine reductase isolated from a clinical isolate of L. donovani, we carried out molecular modeling and docking studies with two compounds of dihydrofolate reductase specificity showing promising antileishmanial activity in vitro. Both the inhibitors appeared to fit well in the active pocket revealing the tight binding of the carboxylic acid ethyl ester group of pyridine moiety to pteridine reductase and identify the important interactions necessary to assist the structure based development of novel pteridine reductase inhibitors.
Assuntos
Antiprotozoários/farmacologia , Leishmania donovani/enzimologia , Modelos Moleculares , Oxirredutases/química , Sequência de Aminoácidos , Animais , Antiprotozoários/química , Biopterinas/química , Inibidores Enzimáticos/química , Citometria de Fluxo , Proteínas de Fluorescência Verde/química , Leishmania donovani/efeitos dos fármacos , Metotrexato/química , Dados de Sequência Molecular , Oxirredutases/antagonistas & inibidores , Estrutura Secundária de Proteína , Alinhamento de Sequência , Relação Estrutura-AtividadeRESUMO
We determined the prevalence and antibiotic susceptibilities patterns of bacterial isolates from pus samples collected from patients in a tertiary care hospital of Punjab, India. E. coli was the most prevalent pathogen (51.2%) followed by Staphylococcus aureus (21%), Klebsiella pneumoniae (11.6%), Pseudomonas aeruginosa (5.8%), Citrobacter spp. (3.5%), Acinetobacter baumannii (2.3%), Proteus mirabilis (2.3%), and Streptococcus spp. (2.3%). E. coli, K. pneumoniae, A. baumannii, and Citrobacter isolates were resistant to multiple antibiotics including higher generation cephalosporins. S. aureus and Streptococcus isolates were sensitive to cloxacillin and vancomycin. However, P. aeruginosa, P. mirabilis, and Streptococcus isolates were found to be less resistant to the spectrum of antibiotics tested. Overall, our findings indicate the prevalence of resistance to different classes of antibiotics in bacterial isolates from pus infections and hence highlight the need for effective surveillance, regulator reporting, and antibiogram-guided antibiotic prescription.
RESUMO
Crude ethanolic extract of Indian medicinal plant, Desmodium gangeticum (A001) and its three fractions-hexane (F002), n-butanol (F003) and aqueous (F004) were evaluated chemoprophylactically and chemotherapeutically against experimental visceral leishmaniasis in hamsters. Ethanolic extract showed 41.2+/-5.3% inhibition of parasite multiplication when administered at a dose of 250 mg/kgx2 on day -7 and +7 of Leishmania donovani challenge. Its n-butanol fraction exhibited better efficacy than the ethanolic extract to the tune of 66.7+/-6.1% inhibition when administered at similar dose schedule. But the other two fractions failed to exert any action prophylactically. F003 also imparted significant (P<0.001) non-specific resistance to peritoneal macrophages against Leishmania infection. F003 also showed moderate antileishmanial activity when tested against established infection of Leishmania donovani in hamsters but the rest three fractions failed to show any significant inhibition of parasite multiplication. These findings revealed that this plant has potential prophylactic and therapeutic efficacy against Leishmania infection and warrants detailed investigations on its possible immunopotentiatory actions.
Assuntos
Fabaceae/química , Leishmaniose Visceral/tratamento farmacológico , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , 1-Butanol/química , 1-Butanol/isolamento & purificação , 1-Butanol/farmacologia , Administração Oral , Animais , Clorofórmio , Cricetinae , Esquema de Medicação , Avaliação Pré-Clínica de Medicamentos/métodos , Etanol , Índia/etnologia , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/crescimento & desenvolvimento , Leishmania donovani/parasitologia , Leishmaniose Visceral/parasitologia , Macrófagos Peritoneais/efeitos dos fármacos , Ayurveda , Fosforilcolina/análogos & derivados , Fosforilcolina/farmacologia , Extratos Vegetais/isolamento & purificaçãoRESUMO
The characteristic feature of visceral leishmaniasis (VL) is the profound impairment of immune system of the infected host, which contributes significantly to the partial success of antileishmanial chemotherapy. Since in VL, cure is the combinatorial effect of drug and immune status of the host, the rationale approach towards antileishmanial chemotherapy would be to potentiate the immune functioning of the host to extract desired results. Towards this direction several rationally designed analogues of human beta-casein fragment (54-59) were evaluated for their ability to stimulate the non-specific resistance in hamsters against Leishmania donovani infection. By virtue of being derived from the food protein casein derivatives may be devoid of unwanted side effects associated with the substances of microbial origin, e.g. muramyl dipeptide (MDP). Out of this one peptide Val-Glu-Gly-Ile-Pro-Tyr (compound 89/215) had been reported to have such activity. In this communication, the prophylactic and therapeutic efficacy of the peptide along with its natural sequence has been evaluated in detail against experimental VL in hamsters. Their use as an adjunct to chemotherapy was also explored. Human beta-casein fragment, compound 89/215 and MDP were tested in vivo at various dose levels wherein compound 89/215 showed superiority over MDP at 3 mg/kg x 2 given intraperitoneally (i.p.). Compound 89/215 sensitized peritoneal macrophages acquired considerable resistance and only 24% of the cells were found infected in comparison to control peritoneal macrophages where 76.4% of the cells were found infected. Similarly, the efficacy of sodium antimony gluconate (SAG) in hamsters pretreated with compound 89/215 enhanced significantly (P < 0.001). This peptide also exhibited considerably good therapeutic efficacy when evaluated either alone or in combination with SAG in established infection of L. donovani.
Assuntos
Antiprotozoários/farmacologia , Caseínas/farmacologia , Leishmania donovani/efeitos dos fármacos , Mesocricetus/parasitologia , Fragmentos de Peptídeos/farmacologia , Acetilmuramil-Alanil-Isoglutamina/farmacologia , Sequência de Aminoácidos , Animais , Gluconato de Antimônio e Sódio/uso terapêutico , Caseínas/síntese química , Caseínas/química , Células Cultivadas , Cricetinae , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Ensaio de Imunoadsorção Enzimática , Interações Hospedeiro-Parasita , Humanos , Injeções Intraperitoneais , Leishmania donovani/isolamento & purificação , Leishmaniose Visceral/terapia , Macrófagos Peritoneais/efeitos dos fármacos , Masculino , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/química , Fatores de TempoRESUMO
The present study was undertaken to investigate the effect of crude seed powder (CSP) and gross saponins extract (GSE) of seeds of Albizia lebbeck on antimicrobial activity by taking two Gram-positive (Staphylococcus aureus and Bacillus cereus), two Gram-negative (Escherichia coli and Salmonella Typhi) bacteria, and two fungi species (Aspergillus niger and Candida butyric) were taken at 25, 50, 100, 250, and 500 µg levels using agar well diffusion method. Zone of inhibition was increased with increasing of concentration of CSP and saponins which indicates that Gram-negative bacteria (E. coli), Gram-positive bacteria (B. cereus), and A. niger were significantly susceptible to inhibition. Another experiment was conducted to study the effect of GSE and saponins fraction A and B of A. lebbeck supplementation at 6% on DM basis on methane production and other rumen fermentation parameters using in vitro gas production test, by taking three different type diets, that is, high fiber diet (D1, 60R : 40C), medium fiber diet (D2, 50R : 50C), and low fiber diet (D3, 40R : 60C). Significant (P ≤ 0.05) increase was seen in IVDMD, methane production; however ammonia nitrogen concentration decreased as compared to control. The methane production was reduced in a range between 12 and 49% by saponin supplemented diets except in case of GSE in D2. Sap A showed the highest methane reduction per 200 mg of truly digested substrate (TDS) than other treatment groups. Results in relation with quantification of methanogens and protozoa by qPCR indicated the decreasing trend with saponins of A. lebbek in comparison with control except total methanogen quantified using mcr-A based primer.
RESUMO
In the present study, the diversity of rumen methanogens in crossbred Karan Fries cattle was determined by constructing 16S rRNA and mcrA (methyl coenzyme-M reductase α subunit) gene libraries using specific primers. All thirteen OTUs or phylotypes from 16S rRNA library clustered with order Methanobacteriales, twelve of which aligned with Methanobrevibacter spp., whereas one OTU resemble with Methanosphaera stadtmanae. Out of eighteen OTUs identified from mcrA gene library, fifteen clustered with order Methanobacteriales, two resemble with Methanomicrobiales and remaining one grouped with Methanosarcinales. These results revealed that Methanobrevibacter phylotype was predominantly present in Karan Fries crossbred cattle fed on high fibrous diet containing wheat straw. Compared to 16S rRNA gene, mcrA gene OTUs clustered in three orders providing better insights of rumen methanogens diversity in cattle.
Assuntos
Enzimas de Restrição do DNA/genética , Methanobacteriales/genética , RNA Ribossômico 16S , Animais , Bovinos , Dieta , Masculino , Methanobacteriales/classificação , Dados de Sequência Molecular , Filogenia , Rúmen/microbiologiaRESUMO
Transfection of protozoan parasites, such as Plasmodium, Leishmania, Trypanosoma and Toxoplasma, with various reporter gene constructs, has revolutionized studies to understand the biology of the host-parasite interactions at the cellular level. It has provided impetus to the development of rapid and reliable drug screens both for established drugs and for new molecules against different parasites and other pathogens. Furthermore, reporter genes have proved to be an excellent and promising tool for studying disease progression. Here, we review the recent advances made by using reporter genes for in vitro and in vivo drug screening, high-throughput screening, whole-animal non-invasive imaging for parasites and for the study of several aspects of host-parasite interactions.
Assuntos
Antiprotozoários , Eucariotos , Genes Reporter , Interações Hospedeiro-Parasita , Animais , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Modelos Animais de Doenças , Eucariotos/classificação , Eucariotos/efeitos dos fármacos , Eucariotos/genética , Genes Reporter/genética , Genes Reporter/fisiologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Parasitária , Infecções por Protozoários/tratamento farmacológico , Infecções por Protozoários/parasitologia , Infecções Protozoárias em Animais/tratamento farmacológico , Infecções Protozoárias em Animais/parasitologia , TransfecçãoRESUMO
Two new compounds 4-methyl-heptadec-6-enoic acid ethyl ester (2) and 3-hydroxy-2,9,11-trimethoxy-5,6-dihydro isoquino[3,2-a]isoquinolinylium (7) were isolated from an ethanolic extract of the stems of Tinospora sinensis, along with six known compounds (1, 3-6 and 8). The structures of new compounds were established on the basis of detailed spectroscopic studies. Compound 7 exhibited the highest in vitro antileishmanial activity against Leishmania donovani promastigotes and intracellular amastigotes, whereas compounds 2, 4, 5 and 6 demonstrated moderate activity. Other compounds were found to be inactive.
Assuntos
Antiprotozoários/farmacologia , Leishmania donovani/efeitos dos fármacos , Extratos Vegetais/farmacologia , Tinospora/química , Animais , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificaçãoRESUMO
In the search of new antileishmanial drugs from marine resources, we have investigated Actinopyga lecanora, a coral reef sea cucumber, for its in vitro and in vivo activities. Methanol extract and n-butanol fraction of A. lecanora exhibited excellent Leishmania donovani inhibition. Among the two glycosides isolated from n-butanol fraction, holothurin B (2) displayed excellent in vitro and moderate in vivo leishmanicidal activity, whereas holothurin A (1) revealed only moderate action. These findings provide an important marine lead toward the development of new antileishmanial drugs and necessitate the further exploration of rich and diverse marine resources for more potent bioactive molecules.
Assuntos
Antiprotozoários/farmacologia , Glicosídeos/farmacologia , Holoturina/farmacologia , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Pepinos-do-Mar/metabolismo , Triterpenos/farmacologia , Animais , Antiprotozoários/uso terapêutico , Linhagem Celular , Glicosídeos/química , Glicosídeos/uso terapêutico , Holoturina/química , Holoturina/uso terapêutico , Leishmaniose Visceral/parasitologia , Camundongos , Testes de Sensibilidade Parasitária , Pepinos-do-Mar/química , Resultado do Tratamento , Triterpenos/química , Triterpenos/uso terapêuticoRESUMO
The chemotherapeutic interventions against visceral leishmaniasis (VL) are limited and facing serious concerns of toxicity, high cost, and emerging drug resistance. There is a greater interest in new drug developments from traditionally used medicinal plants which offers unprecedented diversity in structures and bioactivity. With this rationale, ethanolic extract of Tinospora sinensis Linn and its four fractions were tested in vitro against promastigotes and intracellular amastigotes and in vivo in Leishmania donovani infected hamsters. Ethanolic extract exhibited an appreciable activity against promastigotes (IC(50) 37.6+/-6.2 microg/ml) and intracellular amastigotes (IC(50) 29.8+/-3.4 microg/ml). In hamsters, it resulted in 76.2+/-9.2% inhibition at 500 mg/kg/day x 5 oral dose level. Among fractions, n-butanol imparted highest in vitro and in vivo activities. Ethanolic extract and butanol fraction also enhances reactive oxygen species (ROS) and nitric oxide (NO) release. The results indicate that T. sinensis may provide new lead molecules for the development of alternative drugs against VL.
Assuntos
Antiprotozoários/uso terapêutico , Leishmaniose Visceral/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Tinospora , Animais , Clorofórmio , Cricetinae , Modelos Animais de Doenças , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Extratos Vegetais/isolamento & purificação , SolventesRESUMO
In this study, we are reporting antileishmanial activity of a marine sponge Haliclona exigua, belonging to phylum Porifera. The crude methanol extract and its three fractions were tested both in vitro and in vivo. The crude extract exerted almost complete inhibition of promastigotes at 50 microg/ml and 76.4 +/- 6.5% inhibition of intracellular amastigotes at 100 microg/ml concentration with IC50 values of 18.6 microg/ml and 47.2 microg/ml, respectively. When administered to Leishmania donovani infected hamsters at a dose of 500 mg/kg x 5, p.o., it resulted in 72.2 +/- 10.4% inhibition of intracellular amastigotes. At a lower dose (250 mg/kg), it exhibited 43.9 +/- 5.1% inhibition. Among the fractions, highest antileishmanial activity both in vitro (>90%) and in vivo (60.9 +/- 18.3%) was observed in n-butanol (soluble) fraction with IC50 values of 8.2 mug/ml and 31.2 microg/ml against promastigotes and intracellular amastigotes, respectively. Hexane fraction also showed comparatively good activity against both the stages of parasites in vitro but was moderately active in leishmania-infected hamsters. Chloroform fraction resulted in 45 +/- 10.2% inhibition in vivo at a dose of 500 mg/kg x 5, p.o., whereas it was inactive in vitro. n-Butanol (insoluble) fraction was inactive both in vitro and in vivo. Araguspongin C, an alkaloid isolated from n-butanol (soluble) fraction exhibited moderate inhibition of promastigotes and intracellular amastigotes at 100 microg/ml but showed weak antileishmanial action in vivo. Our findings indicate that this marine sponge has the potential to provide new lead toward development of an effective antileishmanial agent and, hence, calls for more exhaustive studies for exploiting the vast world of marine resources to combat the scourge of several parasitic diseases.
Assuntos
Antiprotozoários/farmacologia , Haliclona/química , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Animais , Misturas Complexas/farmacologia , Cricetinae , Concentração Inibidora 50 , Macrófagos/parasitologia , Masculino , Quinolizinas/isolamento & purificação , Quinolizinas/farmacologiaRESUMO
Susceptibility of animals to infections depends upon various factors including sex and age of the host, which plays a pivotal role. In this communication, we have investigated the "intake" of Leishmania donovani infection in young (3-4 weeks old) and adult (15-16 weeks old) golden hamsters. The splenic parasite load in young hamsters on day 15 post infection (p.i.) was 54 +/- 4 amastigotes/100 macrophage nuclei and increased to 106.3 +/- 3.5 on day 30 p.i. However, adult group showed 2.2-(P < 0.001) and 1.75-fold (P < 0.001) lesser parasite burden on these days, respectively. But as the disease progresses further, differences in parasite burden become less significant, as revealed by comparable levels of parasite loads at 2 months p.i. Spleen weight measurements correspond to the above observations. In the young group, the levels of antileishmanial antibody rise two and 4.5 times on days 15 and 30 p.i., respectively, as compared to only 1.3 and 2.3 times increase in their respective adult counterparts. However, after 2 months of infection both groups recorded analogous (12-fold) rise in antibody levels. Both mitogenic and antigenic responses in adult hamsters were less suppressed compared to young hamsters on days 15 and 30 p.i. However, both groups exhibited highly suppressed cell-mediated immune (CMI) responses after 2 months of infection. These findings implicate that age of the host may influence the susceptibility and resistance to Leishmania infection.