Toxicological evaluation of the hydroethanol extract of Tabernaemontana crassa (Apocynaceae) stem bark.

AIM: Tabernaemontana crassa Benth. is a medicinal plant widely used in Cameroon folk medicine to treat a variety of affections. This study was aimed at evaluating its toxicological profile.

MATERIALS AND METHODS: The 70% (v/v) hydroethanol (HE) extract from the stem bark of this plant was given to albino Wistar rats by oral gavage to study the acute and sub-acute toxicities.

RESULTS: The results of histopathological studies revealed that there was a dose-related effect in liver, lungs and kidneys and that there was no difference in tissue profile of control group and those receiving 6 weeks daily treatment of 0.5 g/kg b.w. The result of the acute toxicity indicated the medium lethal dose (LD50) of 6.75 g/kg body weight (b.w.) after 48 h of treatment and the significant variation (P<0.05) of the relative body weight, serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), total bilirubin (TBil), direct bilirubin (DBil) and creatinine (SCr) at the dose of 6g/kg b.w. These results also indicated significant variation of the liver alkaline phosphatase, aspartate aminotransferase (AST), ALT, total proteins (TP), glutathione (GSH) and malondialdehyde (MDA) and renal creatinine (RCr) and urea (RU) at 6g/kg b.w. The result of the sub-acute toxicity showed significant changes in the body weight but no modification (P>0.05) of blood and liver indices for the animal taking 6 weeks daily doses of the HE compared to the control group.

CONCLUSIONS: The results showed that this extract was fairly non-toxic but that consumption of higher doses up to 6 g/kg b.w. could cause organ injuries. Moderated consumption of small doses up to 0.5 g/kg b.w. daily for 6 weeks appeared to be safe.