야생 왕고들빼기(Lactuca indica L.) 부위별 추출물의 생리활성에 관한 연구

Abstract

A study on physiological activity of extracts in different organs from Lactuca indica L.

Park, Jeong-Hun Advisor: Prof. Park, Hyeon-Yong,Ph.D. Department of life science, Graduate School of Chosun University

This study was focused on the physiological activity of Lactuca indica L. by parts (root, stem, leaf, flower), by using a methanol extract method from each part (root, stem, leaf, flower) of naturally-grown Lactuca indica L. in our region. For the specimen, extract from each part (root, stem, leaf, flower) of Lactuca indica L. was used, by using methanol as a solvent. This research found the following results. Total polyphenol contents were 13.50 mg/g extract D.W (Dry Weight) for root, 15.44 mg/g extract D.W for stem, 35.09 mg/g extract D.W for leaf, and 12.50 mg/g extract D.W for flower, and total flavonoid contents were 1.43 mg/g extract D.W for root, 5.34 mg/g extract D.W for stem, 26.90 mg/g extract D.W for leaf and 6.20 mg/g extract D.W for flower. DPPH radical scavenging activities were 10 ㎎/㎖, 32.65% for root, 64.23% for stem, 90.37% for leaf and 32.54% for flower, and the effects were good in the order of leaf, stem, flower, and then root. Especially DPPH radical scavenging activity of leaf section was 90.37%, which was almost the same level of activating ability as ascorbic acid and butylated hydroxyanisole of the control group. ABTS radical scavenging activities 20 ㎎/㎖ were 48.22% for root, 45.62% for stem, 99.84% for leaf and 65.32% for flower, and resultingly, the effects were good in the order of leaf, flower, root, and stem. Nitrite scavenging activities under the condition of pH 1.2 were 55.63% for root, 55.28% for stem, 21.49% for leaf and 21.25% for flower, and under the condition of pH 4.2, 49.85% for root, 42.35% for stem, 12.36% for leaf and 10.33% for flower. As a result, the scavenging ability was remarkably excellent under the condition of pH 1.2 and the effects were good in the order root, stem, leaf, and flower, and in particular, the scavenging ability was not shown under the condition of pH 6.0. For antioxidant enzyme activity, SOD (superoxide dismutase) activities were 85.05% for root, 89.43% for stem, 90.71% for leaf and 85.40% for flower - in other words, every parts showed high activity, all over 80%. And APX (ascorbate peroxidase) activities were shown as 660.27, 164.55, 88.25, 165.26 μM ascorbate oxidized/min/mg protein, each in the order of root, stem, leaf, and flower. Also catalase enzyme activities were 13.92, 2.77, 4.39, 3.72 μM H2O2 decomposed/min/mg protein, each in the order of root, stem, leaf and flower, and to sum those figures up, the root part showed the highest effect of antioxidative enzyme activity. POX (peroxidase) enzyme activities were 3.91, 7.04, 1.03, 5.73 μM tetraguaiacol formed/min/mg protein, each in the order of root, stem, leaf and flower. For the survival rate of cancer cell and human normal kidney cell (HEK293) by MTT assay, MCF-7 showed the highest anticancer activity as a result of the cell viability measurement by stages, by diluting each extract concentration as 50 ㎍/㎖, 100 ㎍/㎖, 200 ㎍/㎖, 400 ㎍/㎖ and 800 ㎍/㎖, and following that, HeLa and SNU-1066 were the second and third ones which showed a good anticancer activity. By contrast, HCT-116 showed inadequate anticancer activity. Human normal kidney cell (HEK293) showed over 80% of cell viability and it was possible to carry out a selective destruction between normal cell and cancer cell. Regarding six kinds of strain - Escherichia coli, Malassezia furfur, Staphy lococcus epidermidis, Candida albicans, Salmonella enterica subsp, Listeria monocytogenes – which went through an antibacterial activity test, most extracts from each part of Lactuca indica L. showed antibacterial activities, except Salmonella enterica subsp and Listeria monocytogenes. In contrast with other bacteria, Salmonella enterica subsp and Listeria monocytogenes showed almost no antibacterial activity. In case of tyrosinase inhibition activity, the concentrations of sample 5 ㎎/㎖ were 13.17% for root, 14.11% for stem, 19.67% for leaf and 21.01% for flower, and it was concentration dependent. It showed high tyrosinase inhibition activity and especially among all concentrations, an activity inhibition effect of tyrosinase of flower part showed the highest value. In conclusion, this study indicates that wild Lactuca indica L. could be a very important natural resource in the future for health functional food, cosmetic product as well as new medicine development, and it could be used in many ways.