Acute oral toxicity study of ethanol extract of Oroxylum indicum leaf in mice

Abstract

The Oroxylum indicum plant is a herbal plant commonly eaten by the locals in Malaysia while the application of
herbal remedies from the plant has been inherited and passed down through generations. However, there is a lack of
toxicity profiling of the plant, hence this research aimed to investigate acute oral toxicity of ethanol extract of O. indicum
in C57BL/6 male mice at different concentrations, to determine the LD50 of the plant extract. A total of twenty-five mice
were randomly assigned into five experimental groups comprising the control (normal saline), vehicle (5% DMSO),
low dose (1000 mg/kg bw), medium dose (2000 mg/kg bw) and high dose (5000 mg/kg bw). The extracts were
administered in a single oral dose on day 1 and the mice were observed daily for mortality, physiological and
behavioural changes throughout the 14 day study period. At the end of the study, vital organs and blood samples were
collected to determine the effects of the extract on the relative organ weight, tissue changes and blood profile alterations.
No mortality nor behavioural changes were recorded for 2 weeks. Results of the body weight, relative organ weight,
haematological and serum biochemistry assessments showed no significant (p>0.05) changes. Nevertheless, there were
significant differences in the mean corpuscular volume (MCV), urea and alanine transaminase (ALT) values but the
levels were still within the normal range. Histopathological analysis of the liver and kidney tissues also revealed no
striking lesions. In summary, this study indicates that O. indicum leaf ethanolic extract up to 5000 mg/kg bw did not
cause any toxicological effects in the mice model and is safe to be used for therapeutic purposes.