Avaliação da toxicidade pré-clínica aguda do estrato hidroalcoólico bruto das sementes de Vatairea guianensis (AUBLET)

Abstract

Vatairea guianensis (Fabaceae), popularly known as “faveira” and “fava-impigem”, is an original species of the Amazon region and widely used in folk medicine in the treatment of superficial dermatoses. For evaluating the safe use of this species and also in order to comply steps required for the registration of a possible herbal medicine, the aim of this study was to estimate the preclinical acute toxicity of the hydroalcoholic extract of the seeds of V. guianensis (EHVG). Therefore, a preliminary cytotoxicity test of the extract using Artemia salina Leach was conducted to obtain the median lethal concentration (LC50).Then it was evaluated the acute toxicity as established in the RE 90/2004 of the Agência Nacional de Vigilância Sanitária (ANVISA). For the acute toxicity study, it was used 24 Wistar rats (Rattus norvegicus albinus), which acutely received the EHVG (2000 mg/kg, po). General signs of toxicity, as well as weight gain, water intake, feed intake and disclosure of the lethal power of the extract were observed for 14 days after exposure. On the 15th day, blood samples of the animals were collected for the purpose of determination of hematological and biochemical parameters, and then they sacrificed for macroscopic analysis, calculation of the relative mass and histopathological examination of vital organs (heart, liver, lungs and kidneys). LC50 determined by bioassay using A. salina was 2692.39 μg/mL, suggesting that the EHVG has low toxicity. The extract of V. guianensis did not induce death in the animals, behavioral changes or significant changes in water intake and feed intake when compared with control groups. The weight gain proved to be different between males of the test and control groups, as well as the relative messes of the organs (heart **p < 0.01, liver *p < 0.05 and kidneys * p <0.05). The blood profile showed significant decrease in the differential counting of segmented cells of males (20.17 ± 1.51; 8.83 ± 1.70 – p = 0.0005***) and females (26.00 ± 2.39; 13.17 ± 1.25 – p = 0.0008***) and increase in lymphocytes of males (76.33 ± 1.20; 87.83 ± 2.09 – p = 0.0008***) and females (70.00 ± 2.45; 83.17 ± 1.62 – p = 0.0012**) in the test group. Biochemical parameters of the enzyme alanine aminotransferase (ALT) appeared reduced in both males (115.7 ± 18.9; 65.3 ± 6.5 – p = 0.0440*) and females (139.7 ± 20.7; 80.3 ± 10.2 – p = 0.0424*). Alkaline phosphatase (168.3 ± 32.9; 80 ± 10.3 – p = 0.0416*), total bilirubin (0.6 ± 0.04; 0.8 ± 0.03 – p = 0.0061**) and indirect bilirubin (0.33 ± 0.03; 0.55 ± 0.04 – p = 0.0025**) were changed only in females that received the EHVG. Changes in the macroscopic and histopathological examination were not evident. According to the overall results obtained in this experiment, it was noticed a differential sensitivity between the genders for the EHVG in various parameters, but we can infer that the extract has low acute toxicity when administered orally (2000 mg/kg). However, further sub-chronic and chronic toxicity studies are needed to elucidate the toxicological profile of the species