Toxicity Studies of the Extracts of Parkia biglobosa Stem Bark in Rats

Extracts of Parkia biglobosa stem bark is used in Nigerian traditional medicine (NTM) to treat malaria,
diarrhea and pains. To establish the toxicity profile of the medicine such parameters as the lethal dose
(LD50) as well as effects on body functions and organs were evaluated in albino Wistar rats. The
bioactive constituents of the water and methanol extracts were also evaluated as a link to toxicity. The
LD50 was greater than 5000mg/kg per oral (p.o) for both extracts. No significant (P< 0.05) changes
in body weights and vital organs of treated animals. However, at 5000mg/kg of water extract, a
significant increase in relative weight of the kidneys and hyper -cholesterolemic effects were
observed. The extract also elicited significant increase in blood glucose level. The kidneys and livers
of animals treated with P. biglobosa water extract for 14 days revealed histopathological evidence of
pathological lesions. The methanol extract did not show any changes in the levels of hepatic and
hematological parameters, histopathological evidence of pathological lesions, and serum level of
urea, uric acid, bilirubin, creatinine and total protein concentrations. Treatment elicited hypo -
cholesterolemic effects and significant reduction in blood glucose level occurred in all the groups. The
phytochemical screening revealed the presence of tannins, flavonoids, saponins, terpenes, cardiac
glycosides, phenols and reducing sugars in the methanol extract, the water extract showed the
presence of similar constituents with the absence of flavonoids and cardiac glycosides. This study has
shown the toxicity characteristics of the methanol and water extracts of the stem bark P. biglobosa in
short time treatment with the extracts. This study has shown the diversity in toxicity as well as the
chemical constituent of the stem barks of P. biglobosa in relation to the extraction solvent. However
this study provides the basis for further study on the detailed toxic and pharmacological effects of the
extracts of P. biglobosa stem bark and their active component(s).