Assessment of the anti-microbial and anti-viral properties of extracts from Nepeta septemcrenata
Nepeta septemcrenata is the only endemic species of the genus Nepeta in Egypt . A previous study reported the bactericidal properties of the hexane and EtOAc extracts of the mentioned species . Thereby, the methanol extract of the aerial part of N. septemcrenata was partitioned with hexane. The hexane extract was submitted to silica gel column chromatography using gradient of EtOAc/Hex solvent mixtures. The micro-titer dilution method was carried out to test the obtained five fractions (Fr. 1–5) against six types of bacteria and two types of fungi. The Minimum Inhibition Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC) were determined. Anti-viral activity against Herpes simplex virus type 1 (HSV1) was investigated with detection og inhibition of the cytopathogenic effect (CPE); produced on monolayers of VERO cells, and calculation of the reduction factor . The results revealed good bactericidal activity of Fr. 4 (40% hex fraction) against Bacillus cereus (MBC: 31µg/ml). Also, the same fraction showed an inhibitory activity against Staphylococcus aureus and Escherichia coli (MIC: 1000µg/ml). Activity of the other four fractions was obtained against B. cereus only. Concerning the antiviral results; Fr. 2 (80% hex fraction) showed the best activity at 100µg/ml (RF: 103) but caused certain pathogenic effect on the host cells whereas, the concentration 50µg/ml (RF: 102) was not affecting the host cells.
Acknowledgements: Department of Pharmaceutical Sciences, University of Antwerp (UIA), B-2610, Belgium.
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