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1.
PeerJ ; 8: e10034, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33240589

RESUMO

Three species of Old World vultures on the Asian peninsula are slowly recovering from the lethal consequences of diclofenac. At present the reason for species sensitivity to diclofenac is unknown. Furthermore, it has since been demonstrated that other Old World vultures like the Cape (Gyps coprotheres; CGV) and griffon (G. fulvus) vultures are also susceptible to diclofenac toxicity. Oddly, the New World Turkey vulture (Cathartes aura) and pied crow (Corvus albus) are not susceptible to diclofenac toxicity. As a result of the latter, we postulate an evolutionary link to toxicity. As a first step in understanding the susceptibility to diclofenac toxicity, we use the CGV as a model species for phylogenetic evaluations, by comparing the relatedness of various raptor species known to be susceptible, non-susceptible and suspected by their relationship to the Cape vulture mitogenome. This was achieved by next generation sequencing and assembly. The Cape vulture mitogenome had a genome size of 16,908 bp. The mitogenome phylogenetic analysis indicated a close evolutionary relationship between Old World vultures and other members of the Accipitridae as indicated by bootstrap value of 100% on the phylogenetic trees. Based on this, we postulate that the other species could also be sensitive to the toxic effects of diclofenac. This warrants further investigations.

2.
Artigo em Inglês | MEDLINE | ID: mdl-30336288

RESUMO

Asian Gyps vulture species are gradually recovering from the devastating effect of diclofenac being present in contaminated carcasses. This drug was responsible for the death of over 10 million vultures in India, Nepal and Pakistan. To prevent the extinction of vultures, meloxicam was introduced after the ban of veterinary diclofenac. Meloxicam's safety in vultures was attributed to its short elimination half-life in contrast with diclofenac. The reason for the rapid elimination of meloxicam is yet to be explained. The aim of this study was to evaluate the role of biotransformation in the elimination of meloxicam. Six Cape griffon vultures (Gyps coprotheres) were treated with 2 mg/kg meloxicam intramuscularly for faecal and plasma quantification of meloxicam concentration over time. In the plasma meloxicam was characterised by a half-life, mean residence time, clearance and volume of distribution at steady state of 0.37 ±â€¯0.10 h, 0.90 ±â€¯0.12 h, 0.02 ±â€¯0.00 l/h kg and 0.02 ±â€¯0.00 l/kg respectively (presented as geometric mean). Over the 24 h monitoring period, the total non-metabolised meloxicam in the faeces was 1.35 ±â€¯0.71% of the total concentration in the plasma. Based on the short meloxicam elimination half-life and low cumulative concentration of total faecal meloxicam over a period in excess of 10 half-lives, this study indicates that Cape griffon vultures are efficient metaboliser of meloxicam, which is suggestive of different set of cytochrome enzymes being involved in the metabolism to that for diclofenac in this species. Identification of orthologous human CYP2C9 and CYP3A4 enzyme families in vultures will be an important further step in explaining the differences in the metabolic pathway(s) of meloxicam and diclofenac for the species.


Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Espécies em Perigo de Extinção , Poluentes Ambientais/toxicidade , Falconiformes/fisiologia , Meloxicam/toxicidade , Modelos Biológicos , Drogas Veterinárias/toxicidade , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/análise , Anti-Inflamatórios não Esteroides/sangue , Biotransformação , Carnivoridade , Diclofenaco/toxicidade , Resíduos de Drogas/toxicidade , Poluentes Ambientais/administração & dosagem , Poluentes Ambientais/análise , Poluentes Ambientais/sangue , Fezes/química , Meia-Vida , Injeções Intramusculares , Eliminação Intestinal , Meloxicam/administração & dosagem , Meloxicam/análise , Meloxicam/sangue , Taxa de Depuração Metabólica , Reprodutibilidade dos Testes , África do Sul , Toxicocinética , Drogas Veterinárias/administração & dosagem , Drogas Veterinárias/análise , Drogas Veterinárias/sangue
3.
Onderstepoort J Vet Res ; 83(1): a1045, 2016 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-27247071

RESUMO

Clausena anisata is a medicinal plant used traditionally to treat myiasis and as an insect repellent by various communities. We have previously demonstrated the effects of C. anisata extracts on blowfly feeding and development in our laboratory. The impact of C. anisata leaf extracts on populations of different fly species on farms in Mpumalanga, South Africa was investigated in this study under field conditions. Flies were exposed to liver baits treated with acetone leaf extracts of C. anisata (150 mg/mL). Fly numbers and composition on two farms, with and without C. anisata treated liver, were compared during a period of 12 weeks when fly populations were expected to be high. Observations were made on fly behaviour and development, adult sizes and numbers. The flies exposed to liver treated with the leaf extract of C. anisata had a decreased rate of development, prolonged larval period, smaller body sizes and more sluggish behaviour compared to those subjected to the control treatment. No significant differences were, however, found between the numbers and sizes of flies on the treated and on the control farm, which was most likely due to the limited nature of the baiting programme we followed. The effects of C. anisata extracts on blowfly behaviour and development observed in previous laboratory studies were confirmed in this field evaluation. Although the extracts did not have a significant effect on the overall population size in this experiment, we believe that the C. anisata leaf extract could be useful in integrated pest management based on its effect on larval development. In addition, species such as Lucilia cuprina and Chrysomya marginalis seemed to have been repelled by the C. anisata treated liver; as a result, further work should explore this aspect and how it can be used for the protection of animals.


Assuntos
Doenças dos Bovinos/tratamento farmacológico , Clausena/química , Dípteros/efeitos dos fármacos , Doenças das Cabras/tratamento farmacológico , Miíase/veterinária , Extratos Vegetais , Doenças dos Ovinos/tratamento farmacológico , Acetona/química , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Dípteros/crescimento & desenvolvimento , Doenças das Cabras/parasitologia , Cabras , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Miíase/tratamento farmacológico , Miíase/parasitologia , Fitoterapia/veterinária , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Ovinos , Doenças dos Ovinos/parasitologia , África do Sul
4.
Environ Sci Pollut Res Int ; 23(11): 11257-11266, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26924698

RESUMO

Mosquitoes are rapidly developing resistance to insecticides that millions of people relied on to protect themselves from the diseases they carry, thereby creating a need to develop new insecticides. Clausena anisata is used traditionally as an insect repellent by various communities in Africa and Asia. For this study, the repellency and adulticidal activities of leaf extracts and compounds isolated from this plant species were evaluated against the yellow fever mosquito, Aedes aegypti. In the topical application assays, using total bites as an indicator, repellency was dose dependent, with the acetone crude extract (15 %) having 93 % repellence and the hexane fraction (7.5 %) 67 % repellence after 3 h. Fractionation resulted in a loss of total repellence. As mosquito-net treating agents, the acetone and hexane extracts of C. anisata, both at 15 %, had average repellences of 46.89 ± 2.95 and 50.13 ± 2.02 %, respectively, 3 h after exposure. The C. anisata acetone extract and its hexane fraction caused mosquito knockdown and eventually death when nebulised into the testing chamber, with an EC50 of 78.9 mg/ml (7.89 %) and 71.6 mg/ml (7.16 %) in the first 15 min after spraying. C. anisata leaf extracts have potential to be included in protection products against mosquitoes due to the repellent and cidal compounds contained therein.


Assuntos
Aedes/efeitos dos fármacos , Clausena/química , Mordeduras e Picadas de Insetos/prevenção & controle , Repelentes de Insetos/farmacologia , Extratos Vegetais/farmacologia , Animais , Cobaias , Repelentes de Insetos/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , África do Sul
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