Avaliação da toxicidade aguda pré-clínica do extrato metanólico das cascas do caule de Parahancornia amapa (Apocynaceae) / Preclinical acute toxicological evaluation of the methanolic stem bark extract of Parahancornia amapa (Apocynaceae)

Parahancornia amapa is an endemic plant species of Amapá in the Amazon region. This study aimed to evaluate the acute toxicity of methanol extract of the bark of P. amapa. Different concentrations of the extract were added to the brine shrimps (Artemia salina) and 50% lethality concentration (LC50) was assessed. The results of the brine-shrimp assay indicated that the extract was found to be non-toxic. Acute toxicity was studied in Wistar rats (males and females) after single dose (2000 mg kg-1) by oral gavage. Food and water intake, body weight, general behavioral changes and mortality of animals were noted. Blood samples were collected for haematological and serum biochemical parameters measurements. Subsequently, they were euthanized and their organs (heart, kidneys, liver and lungs) subjected to macroscopic and histopathological analysis. There was no mortality or any sign of behavioral change or toxicity observed after oral administration of the extract. Nevertheless, it was observed a significant increase (p<0.05) on water intake of female rats treated with the extract of P. amapa (127.64 mL) when compared to control group (101.93 mL). A significant increase (p<0.05) in platelet count was also observed in both male (288.00x103 mm3) and female (220.83x103 mm3) rats that received the extract when compared to their respective control groups (128.33x103 mm3; 109.50x103 mm3). Histopathological changes were not related to the treatment with extract in any of the analyzed organs. These results suggest that P. amapa extract has a non-toxic effect.

Parahancornia amapa é uma espécie endêmica do Estado do Amapá, na região Amazônica. Este estudo teve como objetivo avaliar a toxicidade aguda do extrato metanólico das cascas do caule de P. amapa. Diferentes concentrações do extrato foram adicionadas aos camarões de salmoura (Artemia salina) e a concentração letal média (CL50) foi avaliada. Os resultados desse ensaio indicaram que o extrato não era tóxico. A toxicidade aguda foi estudada em ratos Wistar (machos e fêmeas) após dose única (2000 mg kg-1) por gavagem. Ingestão de água e comida, peso corporal, alterações comportamentais e mortalidade foram anotados. Amostras de sangue foram coletadas para medições de parâmetros hematológicos e bioquímicos. Os animais foram eutanasiados e seus órgãos (coração, rins, fígado e pulmões) submetidos à análise macroscópica e histopatológica. Não houve mortalidade ou qualquer sinal de mudança de comportamento ou toxicidade observada após a administração oral do extrato. No entanto, observou-se um aumento significativo (p<0,05) sobre o consumo de água de ratas tratadas com o extrato de P. amapa (127,64 mL) quando comparadas ao grupo controle (101,93 mL). Um aumento significativo (p <0,05) na contagem das plaquetas também foi observado tanto em ratos machos (288,00x103 mm3) quanto em fêmeas (220,83x103 mm3, respectivamente) que receberam o extrato quando comparados com seus respectivos grupos controle (128,33x103 mm3; 109,50x103 mm3). Alterações histopatológicas não foram relacionadas ao tratamento com extrato em nenhum dos órgãos analisados. Estes resultados sugerem que o extrato de P. amapa tem um efeito geral não-tóxico.

Sub-acute toxicity studies of Catha edulis [Khat]

The aim of this study is to investigate the effect of [Catha edulis on some biochemical parameters on short and long-term basis. Fresh Khat in a dose of 20 grams/kilogram, was given to three groups of rabbits [nine each], for one, two, and three weeks, and a fourth group was left as a control, and in another trial fresh Khat was given in three doses 20, 30 and 40 gram/kilogram to three groups of rabbits [six each], for six months, and a fourth group was left as a control. The results were as follows: fasting blood sugar [FBS], triglyceride [TG], GOT, and GPT were increased in both trials. The CBC which was measured only in the second trial showed that Khat lowered hemoglobin, WBCs, and lymphocytes while it increased neutrophils. The Khat treated groups showed lowered body weights in the second [six months] trial. The heart weight relative to the body weight was increased in the first trial, while this result was not seen in the second trial