The acute toxicity and lethality (LD50) of the methanol and the chloroform fractions were determined using mice according to slightly modified method of.5 The chemicals used for this study were of analytical grade and procured
from reputable scientific shops at Nsukka. They included the following: hyoscine butylbromide [standard anti-diarrhoeal drug (Sigma–Aldrich, Inc., St. Louis, USA)], methanol and chloroform (both supplied by BDH Chemicals Ltd., Poole, England), castor oil (laxative) ZD1839 in vitro and 3% (v/v) Tween 80 (vehicle for dissolving the extract). Castor oil-induced diarrhoea was evaluated using the methods of6 and 7 with a little modification. Castor oil-induced enteropooling was determined by the method of8. The data obtained from the laboratory results of Selleck Lumacaftor the tests were subjected to One Way Analysis of Variance (ANOVA). Significant differences were observed at p ≤ 0.05. The results were expressed as means of five replicates ± standard deviations (SD). This analysis was done using the computer software known as Statistical Package for Social Sciences (SPSS), version 16. The result of this investigation shows that there was no lethality or any sign of toxicity in the four groups of three mice each that received 10, 100, 1000 mg/kg body weight of each fraction of the chloroform–methanol extract of the seeds of P. americana and 5 ml/kg
body weight of 3% v/v Tween 80 respectively at the end of the first phase of the study. At the end of the second phase of the study, there was neither death nor obvious sign of toxicity in the groups of mice that received 1900 and 2600 mg/kg body weight of each fraction of the chloroform–methanol extract of the seeds of P. americana. However, there were death and obvious signs of toxicity (such as sluggishness, swollen face and eyes) in the groups of mice administered 5000 mg/kg body weight of the methanol and the chloroform fractions respectively within 24 h of administration. In the castor oil-induced diarrhoea experiment (wetness of faeces
test), the rats in the group that received neither castor oil nor any of the fractions of the chloroform–methanol extract of the seeds of Histone demethylase P. americana (group 1) had significantly (p < 0.05) decreased numbers of wet faeces (0.00 ± 0.00, 0.25 ± 0.50, 0.25 ± 0.50 and 0.00 ± 0.00) at the first, second, third and fourth hours of post-treatment respectively when compared to the values (1.50 ± 1.29, 2.00 ± 0.00, 2.00 ± 1.41 and 1.50 ± 0.58) obtained for rats in the castor oil-treated control group (group 2). The chloroform fraction of the extract at the dose of 200 mg/kg body weight, in a similar manner as the standard anti-diarrhoeal agent (hyoscine butylbromide), inhibited significantly (p < 0.05) the wetness of faeces of rats in group 7 as evidenced by the significant (p < 0.05) reduction in the number of wet faeces of rats in group 7 at the third and fourth hours of post-treatment (0.50 ± 0.82 and 0.50 ± 0.58 respectively) when compared to the values (2.