Antimicrobial Activity of Medicinal Herbs against Salmonella gallinarum andStaphylococcus epidermidis

摘要

The present study was conducted to investigate the antimicrobial activities of extracts from approximately 40 different traditional Korean medicinal herbs against S. gallinarum and S. epidermidis. The extracts from Schizandra chinensis BailL Melia azedarach Linne, Caesalpinia sappan Linne. and Rhus javanica Linne. exhibited high antimicrobial activities against S. gallinarum, whereas the extracts from Melia azedarach Linne and Rhus javanica Linne. exhibited high antimicrobial growth for S. epidermidis. Minimum inhibitory concentrations (MIC) of Melia azedarach Linne, Caesalpinia sappan Linne. and Rhus javanica Linne. for S. gallinarum were 1.2 mg/mL, whereas MIC of exracts from Rhus javanica Linne. extract for S. epidermidis were 0.6 mg/mL. Heat treatment of the extracts from Schizandra chinensis Baill. and Rhus javanica Linne. caused a significant reduction in antimicrobial activities against S. gallinarum. but didn't affect antimicrobial activities against S. edidermidis. Alkaline treatment of the extracts from Schizandra chinensis Baill. caused a significant reduction in antimicrobial activities against S. gallinarum, while similar treatment of the extracts from Rhus javanica Linne. caused a significant increase in antimicrobial activities against S. edidermidis. Since extracts from Rhus javanica Linne. and Caesalpinia sappan Linne. exhibited the highest antimicrobial activities, these extracts at the concentrations of 100, 300 or 500 ppm were added and then bacterial growth-inhibiting activities for S. gallinarum and S. epidermidis by these two extracts were further examined. Optical density at 620 ran (OD_(620) after 24 hours incubation in the absence of Rhus javanica Linne. extract ranged from 0.30 to 0.45 compared with OD_(620) value ranging from 0.06 to 0.18 in the presence of 100, 300 or 500 ppm of the extract, indicating that growth of all bacteria was significantly inhibited within 24 hours by the addition of at least 100 ppm of Rhus javanica Linne extract. Value of OD_(620)after 24hours incubation in the absence of Caesalpinia sappan Linne. extract ranged from 0.30 to 0.55 compared with OD_(620)value ranging from 0.05 to 0.15 in the presence of 300 or 500 ppm of the extract, indicating that growth of all bacteria was also significantly inhibited within 24 hours by the addition of at least 300 ppm of Caesalpinia sappan Linne. extract. In conclusion, these findings suggest that extracts from Rhus javanica Linne. and Caesalpinia sappan Linne. may play important roles in antimicrobial activities against S. gallinarum and S. epidermidis.