탄닌계 색소를 함유한 식물의 열수추출물과 효소추출물의 항산화 및 항세균 활성

Abstract

The purpose of this study was to investigate the antioxidant and antibacterial activities of hot water and enzyme extracts obtained from plants containing tannin pigments. The antioxidant activities were confirmed by analysis of the total phenolic content, determination of the DPPH and ABTS+ radical scavenging activities and lipid peroxidation experiments. The antibacterial activities were verified using disc diffusion methods against Escherichia coli and Listeria grayi. The IC50 values representing the DPPH radical scavenging activities of the hot water extracts were determined to be 9.4 to 21.5 μg/mL, while the IC50 values of the enzyme extracts were 3.7 to 6.58 μg/mL. It was confirmed that both extracts exhibited a good antioxidant activity comparable to that of ascorbic acid (i.e., 10.5 μg/mL), which is commonly employed for comparison. In addition, the TPC and ABTS+ radical scavenging activities were also significant, and lipid peroxidation experiments demonstrated ≥50% suppression compared to the negative control. Furthermore, the enzyme extracts showed a higher level of activity than the hot water extracts, and the presence of greater quantities of tannin-containing polyphenols in enzyme extracts ensures a high activity even when low extraction temperatures are employed. These results clearly indicate that tannin-containing plant extracts may play an important role in suppressing the free radicals produced by oxidative stress in living organisms, and therefore could exhibit potential for application as new biological materials following additional in-depth research.