Antioxidative and Antimicrobial Activities of Persimmon Leaf Tea and Green Tea

감잎차와 녹차의 항산화 및 항균 활성 비교

In this study, the antioxidative and antimicrobial activities of persimmon leaf tea and green tea were assessed. The total polyphenol contents of green tea (0.5875 mg/mL) were slightly higher than those of persimmon leaf tea (0.3938 mg/mL). The electron-donating abilities (EDA) of persimmon leaf tea and green tea toward $\alpha$, $\alpha$-diphenyl-$\beta$-picyryl hydrazyl (DPPH) radical were $65.7{\pm}3.7%$ and $68.4{\pm}0.3%$, respectively, as compared to $68.6{\pm}1.1%$ for L-ascorbic acid (1%). The SOD-like activity of persimmon leaf tea ($29.7{\pm}0.9%$) was higher than that of green tea ($28.1{\pm}1.0%$). The nitrite scavenging ability was pH-dependent, highest at pH 1.2, and lowest at pH 6.0, in and persimmon leaf tea was found to exhibit more effective nitrite scavenging ability than green tea. The inhibitory effects of persimmon leaf tea and green tea against angiotensin I converting enzyme were $56.7{\pm}1.9%$ and $67.1{\pm}1.7%$, respectively. Persimmon leaf tea evidenced profound antimicrobial activities against Listeria monocytogenes, Staphylococcus aureus, Escherichia coil, and Salmonella typhimurium. These results clearly established the antioxidative and antimicrobial potency of persimmon leaf tea.

시중에서 쉽게 구할 수 있고 즐겨 마시는 차로 이용되고 있는 감잎을 시료로 택하여 실제 음용 조건으로 추출하여 일반 성분, 클로로필 및 총 페놀 함량을 분석하였고, 전자공여능에 의한 항산화 활성, ACE 저해도, SOD 유사 활성, 아질산염 소거능 및 항균 활성을 조사하였다. 그 결과 녹차와 비교하였을 때 비슷한 수준의 높은 항산화 활성을 나타내었으며, ACE 저해도 역시 50% 이상의 높은 값을 나타내었다. SOD유사 활성 및 아질산염 소거능의 경우 오히려 녹차보다 더 우수한 것을 확인하였다. 항균 활성의 경우 4가지 균주 모두에 대하여 항균 활성이 있는 것을 확인하였으며, 특히 Staphylococcus aureus를 제외한 3가지 균주(Listeria monocytogenes, Escherichia coil, Salmonella typhimudum)에 대해서는 녹차 보다 우수한 활성을 나타내었다.