ABSTRACT: The antibacterial activity, bioavailability and acute toxicity of the leaf extracts of Alchornea cordifolia were evaluated. The phytochemical screening was also done. Results of the in vitro antibacterial tests showed that all but the hexane extract exhibited antibacterial activities against P. aeruginosa (MIC = 2.5 mg mL<SUP>-1</SUP>), E. coli (MIC = 3.75 mg mL<SUP>-1</SUP>), S. aureus (MIC = 5 mg mL<SUP>-1</SUP>) and K. pneumoniae (MIC = 10 mg mL<SUP>-1</SUP>). Results of the serum antimicrobial activity test against P . aeruginosa showed that with animals administered the extract, serum antimicrobial activity was observed as from 3 h 45 min for the doses 2.84 and 5.68 g kg<SUP>-1</SUP>, independently of the sex of animals. The peaks of serum activity (maximum activity, A<SUB>max</SUB>) were obtained at 6 and 4 h (T<SUB>max</SUB>) with the doses 2.84 and 5.68 g kg<SUP>-1</SUP>, respectively. The area under the curve (AUC) was greater with the dose 2.84 g kg<SUP>-1</SUP> than with the dose 5.68 g kg<SUP>-1</SUP>. Flavonoids, triterpenes, saponins, anthocyanins, steroids, polyphenols and tannins were found in the leaves of this plant. Results of the acute toxicity study of the aqueous leaf extract of A. cordifolia with mice showed that the LD<SUB>50</SUB> was >32 g kg<SUP>-1</SUP>. The data obtained in this study suggest that the leaves of A. cordifolia contain antibacterial principle(s) which are biologically available and which may not be toxic. However, at doses ≥4 g kg<SUP>-1</SUP>, this extract may have a depressant or sedative effect on the central nervous system, may reduce the pain perception and may induce loss of body weight.
International Journal of Pharmacology. 01/2010;