RESUMO

Due to its chemical composition and use in folk medicine, the dry standardized extract of Apeiba tibourbou Aubl. (Tiliaceae) leaves (DSEAT) was tested to assess its hepatoprotective activity against carbon tetrachloride (CCl4)-induced hepatotoxicity in mice. The animals were treated with DSEAT previously for 7 days, at doses of 25, 50, 100, 200, and 400 mg/kg and 18 mg/kg of rosmarinic acid; the liver damage was induced by administering CCl4 intraperitoneally (i.p.) at days 3 and 7, and 1 h before treating with DSEAT. The hepatoprotective activity was assessed using various biochemical assays such as alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), gammaglutamyltransferase (GGT), malondialdehyde (MDA) and histopatological studies. DSEAT doses of 400, 200, and 100 mg/kg were not capable of protecting the liver against CCl4. However, the dose of 50 mg/kg reduced AST by 31.50% the dose of 25 mg/kg reduced GGT by 57.18% compared to the CCl4 (p < 0.05). In the liver, DSEAT dose of 50 mg/kg and rosmarinic acid reduced MDA by 27.45% and 63.61%, respectively, whereas in plasma, MDA was reduced in all the groups treated with DSEAT and rosmarinic acid. In conclusion, DSEAT exhibits hepatoprotective effect only at low doses and antioxidant activity in vivo after peroral administration. The experimental protocol was approved by the Animal Research Ethics Committee of UFG (CEUA, no. 177/2011).

Assuntos

RESUMO

Due to its chemical composition and use in folk medicine, the dry standardized extract of Apeiba tibourbou Aubl. (Tiliaceae) leaves (DSEAT) was tested to assess its hepatoprotective activity against carbon tetrachloride (CCl4)-induced hepatotoxicity in mice. The animals were treated with DSEAT previously for 7 days, at doses of 25, 50, 100, 200, and 400 mg/kg and 18 mg/kg of rosmarinic acid; the liver damage was induced by administering CCl4 intraperitoneally (i.p.) at days 3 and 7, and 1 h before treating with DSEAT. The hepatoprotective activity was assessed using various biochemical assays such as alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), gammaglutamyltransferase (GGT), malondialdehyde (MDA) and histopatological studies. DSEAT doses of 400, 200, and 100 mg/kg were not capable of protecting the liver against CCl4. However, the dose of 50 mg/kg reduced AST by 31.50% the dose of 25 mg/kg reduced GGT by 57.18% compared to the CCl4 (p < 0.05). In the liver, DSEAT dose of 50 mg/kg and rosmarinic acid reduced MDA by 27.45% and 63.61%, respectively, whereas in plasma, MDA was reduced in all the groups treated with DSEAT and rosmarinic acid. In conclusion, DSEAT exhibits hepatoprotective effect only at low doses and antioxidant activity in vivo after peroral administration. The experimental protocol was approved by the Animal Research Ethics Committee of UFG (CEUA, no. 177/2011).(AU)

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RESUMO

O teste de toxicidade aguda estima a dose letal mediana (DL50 ) e classifica os toxicantes quanto à periculosidade, inclusive para extratos de plantas. A espécie Apeiba tibourbou Aubl (Tiliaceae), conhecida como pau-de-jangada ou pente-de-macaco, é empregada popularmente como antirreumática, antiespasmódica e expectorante, embora seja desconhecida quanto aos seus efeitos tóxicos. Assim, o objetivo desta pesquisa foi investigar o potencial de toxicidade aguda do extrato aquoso de A. tibourbou (EAT), administrado por gavagem, em camundongos fêmeas e ratos fêmeas, seguindo as diretrizes OECD Guideline 423/2001 e o screening hipocrático. Os camundongos fêmeas foram divididos em três grupos de três animais cada (C1 – controle, água filtrada, 0,25 mL; C2 –300 mg/kg de EAT; e C3 – 2000 mg/kg de EAT). Os ratos fêmeas foram divididos em dois grupos de três animais cada (R1 – controle, água filtrada, 0,5 mL; e R2 – 2000 mg/kg de EAT). O grupo C2 consumiu 28% de água a mais que o grupo C1 (p < 0,05); o grupo C3 produziu 31% de excretas a mais que o grupo C1 (p < 0,0001); o grupo R2 reduziu o consumo de ração e a produção de excretas em 20% e 28% em relação ao grupo R1 (p < 0,05), respectivamente. No screening hipocrático, nenhuma alteração motora e/ou sensorial foi observada. Não houve morte nem estado moribundo de nenhum animal. Conclui-se que o EAT possui DL50 estimada maior que 2000 mg/kg (Classe 5 de toxicidade, segundo o Globally Harmonized System – GHS, ONU), demonstrando reduzido potencial de toxicidade aguda.

The acute toxicity test estimates the median lethal dose (LD50) against a given test organism and classifies toxic substances, including plant extracts, according to their intrinsic toxicity. Apeiba tibourbou Aubl (Tiliaceae), a tree known in Brazil as “raft-wood” or “monkey’s comb”, is popularly used as an antirheumatic, antispasmodic and expectorant agent, although its toxic effects are unknown. The objective of this research was therefore to investigate the potential acute toxicity to female mice and rats of a water extract of A. tibourbou leaves (WET), administered by gavage, following OECD Guideline 423/2001 and hippocratic screening. The female mice were divided into three groups of three animals each (C1 – control, given 0.25 mL filtered water; C2 – treated with 300 mg/kg WET; C3 – with 2000 mg/kg WET). The female rats were divided into two groups of three animals each (R1 – control, given 0.5 mL filtered water; R2 – 2000 mg/kg WET). Group C2 consumed 28% more water than group C1 (p < 0.05); group C3 produced 31% more excreta than group C1 (p < 0.0001); group R2 reduced food consumption and excretion by 20% and 28%, relative to group R1 (p < 0.05), respectively. During the Hippocratic screening, no motor and/or sensorial alterations were observed. Neither death nor symptoms of impending death were observed in any animals. It can be concluded that WET has an estimated LD50greater than 2000 mg/kg (Class 5 toxicity, according to the UN Globally Harmonized System – GHS), demonstrating low acute toxicity potential.

Assuntos