Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Ano de publicação
Tipo de documento
Intervalo de ano de publicação
1.
Ecol Evol ; 13(1): e9775, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36713481

RESUMO

At best, conservation decisions can only be made using the data available at the time. For plants and especially in the tropics, natural history collections remain the best available baseline information upon which to base conservation assessments, in spite of well-documented limitations in their taxonomic, geographic, and temporal coverage. We explore the extent to which changes to the plant biological record over 20 years have changed our conception of the conservation importance of 931 plant taxa, and 114 vegetation samples, recorded in forest reserves of the southwest Ghana biodiversity hotspot. 36% of species-level assessments changed as a result of new distribution data. 12% of species accepted in 2016 had no assessment in 1996: of those, 20% are new species publications, 60% are new records for SW Ghana, and 20% are taxonomic resolutions. Apparent species ranges have increased over time as new records are made, but new species publications are overwhelmingly of globally rare species, keeping the balance of perceived rarity in the flora constant over 20 years. Thus, in spite of considerable flux at the species record level, range size rarity scores calculated for 114 vegetation samples of the reserves in 1996 and 2016 are highly correlated with each other: r(112) = 0.84, p < .0005, and showed no difference in mean score over 20 years: paired t(113) = -0.482, p = .631. This consistency in results at the area level allows for worthwhile conservation priority setting over time, and we argue is the better course of action than taking no action at all.

2.
J Ethnopharmacol ; 266: 113427, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33022339

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria is caused by infection with some species of Plasmodium parasite which leads to adverse alterations in physical and hematological features of infected persons and ultimately results in death. Antrocaryon micraster is used to treat malaria in Ghanaian traditional medicine. However, there is no scientific validation of its anti-malaria properties. The plant does not also have any chemical fingerprint or standardization parameters. AIM OF THE STUDY: This study sought to evaluate the anti-malaria activity of standardized A. micraster stem bark extract (AMSBE) and its effect on mean survival time (MST) and body weight reduction of Plasmodiumberghei infested mice. And to study the effect of treatment of AMSBE on hematological indices of the P. berghei infested mice in order to partly elucidate its anti-malarial mechanism of action. MATERIALS AND METHODS: Malaria was induced in female ICR mice by infecting them with 0.2 mL of blood (i.p.) containing 1.0 × 107P. berghei-infested RBCs from a donor mouse and leaving them without treatment for 3 days. AMSBE or Lonart (standard control) was then orally administered at 50, 200 and 400 mg/kg or 10 mg/kg once daily for 4 consecutive days. The untreated control received sterile water. Malaria parasitemia reduction, anti-malarial activity, mean change in body weight and MST of the parasitized mice were evaluated. Furthermore, changes in white blood cells (WBCs), red blood cells (RBCs), platelets count, hemoglobin (HGB), hematocrit (HCT) and mean corpuscular volume (MCV) were also determined in the healthy animals before infection as baseline and on days 3, 5 and 8 after infection by employing complete blood count. Standardization of AMSBE was achieved by quantification of its constituents and chemical fingerprint analysis using UHPLC-MS. RESULTS: Administration of AMSBE, standardized to 41.51% saponins and 234.960 ± 0.026 mg/g of GAE phenolics, produced significant (P < 0.05) reduction of parasitemia development, maximum anti-malaria activity of 46.01% (comparable to 32.53% produced by Lonart) and significantly (P < 0.05) increased body weight and MST of P. berghei infected mice compared to the untreated control. Moreover, there were significant (P > 0.05) elevation in WBCs, RBCs, HGB, HCT and platelets in the parasitized-AMSBE (especially at 400 mg/kg p.o.) treated mice compared to their baseline values. Whereas, the non-treated parasitized control recorded significant reduction (P < 0.05) in all the above-mentioned parameters compared to its baseline values. The UHPLC-MS fingerprint of AMSBE revealed four compounds with their retention times, percentage composition in their chromatograms and m/z of the molecular ions and fragments in the spectra. CONCLUSIONS: These results show that A. micraster stem bark possessed significant anti-malaria effect and also has the ability to abolish body weight loss, leucopenia, anemia and thrombocytopenia in P. berghei infected mice leading to prolonged life span. The UHPLC-MS fingerprint developed for AMSBE can be used for rapid authentication and standardization of A. micraster specimens and herbal preparations produced from its hydroethanolic stem bark extract to ensure consistent biological activity. The results justify A. micraster's use as anti-malaria agent.


Assuntos
Anacardiaceae/química , Antimaláricos/farmacologia , Malária/tratamento farmacológico , Extratos Vegetais/farmacologia , Plasmodium berghei/efeitos dos fármacos , Animais , Antimaláricos/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Gana , Malária/parasitologia , Medicinas Tradicionais Africanas , Camundongos , Camundongos Endogâmicos ICR , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Casca de Planta , Extratos Vegetais/administração & dosagem
3.
J Ethnopharmacol ; 267: 113449, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33129949

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria is a global public health burden due to large number of annual infections and casualties caused by its hematological complications. The bark of Annickia polycarpa is an effective anti-malaria agent in African traditional medicine. However, there is no standardization parameters for A. polycarpa. The anti-malaria properties of its leaf are also not known. AIM OF THE STUDY: To standardize the ethanol leaf extract of A. polycarpa (APLE) and investigate its anti-malaria properties and the effect of its treatment on hematological indices in Plasmodium berghei infected mice in the Rane's test. MATERIALS AND METHODS: Malaria was induced by inoculating female ICR mice with 1.0 × 107P. berghei-infected RBCs in 0.2 mL (i.p.) of blood. Treatment was commenced 3 days later with APLE 50, 200, 400 mg/kg p.o., Quinine 30 mg/kg i.m. (Standard drug) or sterile water (Negative control) once daily per group for 4 successive days. Anti-malarial activity and gross malaria indices such as hyperparasitemia, mean change in body weight and mean survival time (MST) were determined for each group. Changes in white blood cells (WBCs), red blood cells (RBCs), platelets (PLT) counts, hemoglobin (HGB) concentration, hematocrit (HCT) and mean corpuscular volume (MCV) were also measured in the healthy mice before infection as baseline and on day 3 and 8 after inoculation using complete blood count. Standardization was achieved by UHPLC-MS chemical fingerprint analysis and quantitative phytochemical tests. RESULTS: APLE, standardized to its total alkaloids, phenolics and saponin contents, produced significant (P < 0.05) dose-dependent clearance of mean hyperparasitemia of 22.78 ± 0.93% with the minimum parasitemia level of 2.01 ± 0.25% achieved at 400 mg/kg p.o. on day 8. Quinine 30 mg/kg i.m. achieved a minimum parasitemia level of 6.15 ± 0.92%. Moreover, APLE (50-400 mg/kg p.o.) evoked very significant anti-malaria activity of 89.22-95.50%. Anti-malaria activity of Quinine 30 mg/kg i.m. was 86.22%. APLE also inverse dose-dependently promotes weight gain with the effect being significant (P < 0.05) at 50 mg/kg p.o. Moreover, APLE dose-dependently increased the MST of malaria infested mice with 100% survival at 400 mg/kg p.o. Quinine 30 mg/kg i.m. also produce 100% survival rate but did not promote (P > 0.05) weight gain. Hematological studies revealed the development of leukocytopenia, erythrocytosis, microcytic anemia and thrombocytopenia in the malaria infected mice which were reverted with the treatment of APLE 50-400 mg/kg p.o. or Quinine 30 mg/kg i.m. but persisted in the negative control. The UHPLC-MS fingerprint analysis of APLE led to identification of one oxoaporphine and two aporphine alkaloids (1-3). Alkaloids 1 and 3 are being reported in this plant for the first time. CONCLUSION: These results indicate that APLE possessed significant anti-malaria, immunomodulatory, erythropoietic and hematinic actions against malaria infection. APLE also has the ability to revoke deleterious physiological alteration produced by malaria and hence, promote clinical cure. These properties of APLE are due to its constituents especially, aporphine and oxoaporphine alkaloids.


Assuntos
Annonaceae , Antimaláricos/farmacologia , Malária/tratamento farmacológico , Extratos Vegetais/farmacologia , Folhas de Planta , Plasmodium berghei/efeitos dos fármacos , Anemia/sangue , Anemia/tratamento farmacológico , Anemia/parasitologia , Animais , Annonaceae/química , Antimaláricos/isolamento & purificação , Aporfinas/farmacologia , Modelos Animais de Doenças , Etanol/química , Feminino , Leucopenia/sangue , Leucopenia/tratamento farmacológico , Leucopenia/parasitologia , Malária/sangue , Malária/parasitologia , Camundongos Endogâmicos ICR , Carga Parasitária , Parasitemia/sangue , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Plasmodium berghei/crescimento & desenvolvimento , Policitemia/sangue , Policitemia/tratamento farmacológico , Policitemia/parasitologia , Solventes/química , Trombocitopenia/sangue , Trombocitopenia/tratamento farmacológico , Trombocitopenia/parasitologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA