Abstract
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 Linn$\acute{e}$, Caesalpinia sappan Linn$\acute{e}$. and Rhus javanica Linn$\acute{e}$. exhibited high antimicrobial activities against S. gallinarum, whereas the extracts from Melia azedarach Linn$\acute{e}$ and Rhus javanica Linn$\acute{e}$. exhibited high antimicrobial growth for S. epidermidis. Minimum inhibitory concentrations (MIC) of Melia azedarach Linn$\acute{e}$, Caesalpinia sappan Linn$\acute{e}$. and Rhus javanica Linn$\acute{e}$. for S. gallinarum were 1.2 mg/mL, whereas MIC of exracts from Rhus javanica Linn$\acute{e}$. extract for S. epidermidis were 0.6 mg/mL. Heat treatment of the extracts from Schizandra chinensis Baill. and Rhus javanica Linn$\acute{e}$. 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 Linn$\acute{e}$. caused a significant increase in antimicrobial activities against S. edidermidis. Since extracts from Rhus javanica Linn$\acute{e}$. and Caesalpinia sappan Linn$\acute{e}$. 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 nm ($OD_{620}$) after 24 hours incubation in the absence of Rhus javanica Linn$\acute{e}$. 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 Linn$\acute{e}$ extract. Value of $OD_{620}$ after 24 hours incubation in the absence of Caesalpinia sappan Linn$\acute{e}$. 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 Linn$\acute{e}$. extract. In conclusion, these findings suggest that extracts from Rhus javanica Linn$\acute{e}$. and Caesalpinia sappan Linn$\acute{e}$. may play important roles in antimicrobial activities against S. gallinarum and S. epidermidis.
40여종의 한약재 추출물을 제조하여 가금 질병에 관련이 있는 세균에 대한 한약재의 항균 활성을 조사하였다. S. gallinarum에서는 오미자, 천연자, 소목 및 오배자가 높은 항균성을 보였으며 S. epidermidis에서는 천연자와 오배자가 높은 항균성을 보였다. 최소 저해 농도는 S. gallinarum에서 천연자, 소목 및 오배자가 0.0012 g/mL, epidermidis에서 오배자가 0.0042 g/mL로 가장 낮은 농도에서 항균성을 보였다. 가열에 의한 항균성의 변화에서 S. gallinarum에서는 오미자와 오배자가 유의적 감소를 보였으며 S. epidermidis에서는 변화가 없었다. pH에 의한 항균성의 변화에서 S. gallinarum에서 오미자가, S. epidermidis에서는오배자가유의적으로증가하였다. 항균력이 가장 우수한 오배자와 소목 추출물의 미생물 증식 억제 효과를 조사하기 위해 증식 배지에 0, 100, 300 및 500ppm의 추출물을 첨가하여 균주의 증식을 조사하였다. 배양 후 24시간에 오배자 추출물 무첨가구의 $OD_{620}$값이 0.30~0.45인 반면 100 ppm 이상의 추출물 첨가 시 0.06~0.18정도로 균 증식을 현저히 억제하였고 소목추출물 무첨가구의 $OD_{620}$값이 0.3~0.55인 반면 300 ppm 이상의 추출물 첨가 시 0.05~0.15정도로 균 증식을 현저히 억제하였다.
