RESUMO
The objective of the study was to evaluate scientifi cally the in-vitro antimicrobial activity of leaves of Kat-Se-Nae plant (Urena lobata Linn). Dried powder of the leaves of Kat-Se-Nae (Urena lobata Linn) was obtained by extracting with water, petroleum ether and ethyl acetate. Screening for antimicrobial activity of all the extracts were done by Agar Disc Diffusion Technique on seven control strains: Escherichia coli (0157) and American Type Culture Collections (ATCC): Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Candida albicans which are common causal agents for skin infections. Ciprofl oxacin and Norfl oxacin were used as control antibiotics. Petroleum ether extract showed small zone of inhibition on Escherichia coli (0157) (11 ± 1.000 mm) and Staphylococcus aureus (13 ± 1.732 mm) but no signifi cant activity on other tested organisms. Ethyl acetate extract showed signifi cant zone of inhibition (20 ± 2.000mm) against Staphylococcus aureus comparable to that of control drug (Ciprofl oxacin) (15 mm) but had no activity on other tested organisms. Watery extract had no antimicrobial activity on any of the tested organisms. Minimum Inhibitory Concentration (MIC) of the active extracts already shown to have antimicrobial activity on Staphylococcus aureus, and Escherichia coli (0157) was done by Tube Dilution Method. MIC of petroleum ether extract on Staphylococcus aureus and Escherichia coli was more than 5 mg/mL and that of ethyl acetate extract on Staphylococcus aureus was more than 1.25 mg/mL. Acute toxicity studies of the watery extracts were performed by using the albino mice. The results indicated that there was no lethality up to 8 g/kg body weight. The phytochemical analysis of watery extracts and dried leaves powder of Kat-Se-Nae (Urena lobata Linn) showed that they have alkaloid, steroid, saponin, tannin, carbohydrate, glycoside, reducing sugar, fl avonoid and amino acid, but lack of cyanogenic glycoside and polyphenol. Based on the above fi ndings, it can be concluded that ethyl acetate extract of the leaves of Kat-Se-Nae (Urena lobata Linn) may have useful antimicrobial activity in skin infections caused by Staphylococcus aureus.