목이버섯 3품종의 영양성분을 분석한 결과 유리당은 4종의 성분이 검출되었고, 그 중 trehalose는 11.56±0.59에서 27.17±0.27mg/g로 검출된 당 중에서 가장 많이 함유하고 있는 것으로 나타났으며 갈색목이가 가장 높은 것으로 나타났다. 유기산은 7종, 아미노산은 24종의 성분이 분석되었으며, 전체 함량에서 모두 흑목이가 가장 높게 나타났다. 그리고 유기산과 아미노산 성분 중에서 감칠맛을 내는 성분인 citric acid 및 glutamic acid, asparagine 등의 함량 또한 흑목이에서 가장 높은 것으로 나타나 천연 조미재료로서의 가능성을 제시하였다. 비타민D2함량은 1.66±0.1에서 5.43±0.08 ㎍/g으로 다른 버섯류에 비해 높게 나타났다. 식이섬유에는 3품종 모두 60% 정도의 함량을 나타냈으며, 품종 간 유의적인 차이는 없었다. ß-glucan 함량은 갈색목이가 25.21±0.37%로 털목이나 흑목이에 비해 높은 수준으로 나타났으며 항산화 성분인 총 폴리페놀 함량은 털목이, 갈색목이, 흑목이 순으로 높게 나타났다.

목이버섯(Auricularia)의 이름은 그리스어인 “Auricula"에서 왔으며 ”귀(ear)"라는 뜻이다. 따라서 보통 나무귀(tree ear), Jew's 귀 또는 귀버섯이라고 불린다. 즉 자실체의 형태가 귀 와 비슷하고, 촉감이 고무질과 젤라틴질에 의해 귀처럼 느껴지기 때문이다. Lowy에 의해 분류된 목이버섯 10여 종류 가운데 목이(A. auricula)와 털목이(A. polytricha)가 가장 인기있는 버섯으로 두종류 모두 사물기생균이다. 목이는 최초로 인공재배된 버섯으로 보고되었는데, A.D. 600년경부터 중국에서 재배되어왔으며, 최근 국내에서 수요가 증가하고있는 버섯이다. 시험에 사용한 배지재료로 사용한 참나무톱밥, 미강의 이화학적 특성을 조사한 결과, pH는 참나무톱밥 6.0, 미강 6.4 였으며, T-C는 참나무톱밥 46.6%, 미강 52.4%로 나타났고, T-N는 참나무톱밥이 0.28%, 미강 0.94%로 나타났다. CaO의 경우 참나무톱밥 0.92%으로 나타났으며, 미강 0.07%로 톱밥보다 미강이 낮았다. 목이버섯의 균사생장 최적온도를 구명하고자 15℃에서 35℃까지 5℃ 간격으로 처리하여 균사를 배양한 결과 Fig. 1에서와 같이 25～30℃가 배양적온으로 나타났다. 최적 pH는 전범위에서 비슷하게 생육하였으며, 최적배지는 MEA, 탄소원은 Mannose, 비타민은 Biotin, Pyridoxine, 최적 C/N비는 10:1~1:1로 나타났다. 자실체 발생시험에서 배양소요일수는 31일, 초발이소요일수 15일, 자실체 생육일수 18일로 나타났다. 수량의 경우 배지당 생체중이 295g, 건물중이 31g으로 나타났다. 목이버섯균의 cellulolytic activity 검정결과 congo red 염색에서 pH 7.0, 25℃에서 우수한 활성을 나타내었다. 목이버섯 자실체의 열수추출물에 대하여 SRB법과 MTT법으로 종양세포주(Sarcoma 180, P 388)를 이용하여 항암활성을 비교ㆍ평가하였다. 종양세포주는 7.5, 15, 30㎍/㎖ 그리고 Doxorubicin(DOX, 0.001-10mM)으로 처리하였다. 그 결과 DOX, 목이버섯추출물 종양세포 주에 대하여 농도 의존적으로 억제하는 결과를 보였다. 결론적으로, 이 연구에서 사용된 목이버섯추출물은 Sarcoma 180과 P 388에 항암활성을 보여주었다.

The aim of this study was to investigate the suppressive activity of 70% ethanol extract and its dichloromethane fraction from Auricularia auricula-judae against adipogenesis and lipogenesis in 3T3-L1 preadipocytes. The ethanol extract and its dichloromethane fraction suppressed the differentiation and decreased lipid droplets in vitro. The dose-dependent increasing concentration of glycerol and lower triglycerides accumulation were found significantly (P < 0.05) with the treatment of both fractions from 70% ethanolic Auricularia auricula-judae extract and the glycerol-3-3phosphate dehydrogenase (GPDH) activity was also inhibited by both extracts. Further, the expression of adipogenic mRNAs were investigated by RT-PCR amplification. The key transcriptional factors, PPARγ and C/EBPα were decreased significantly at dose-dependent manner by both extracts of Auricularia auricula-judae. The expressions of LPL and FAS were also decreased by presence of these extracts. The decreased expressions of C/EBPβ, C/EBPγ and ACC1 were observed only by ethanol extract at 300 μg/ml concentration, while the expression of SREBP-1c, GLUT4 and aP2 were not altered in the 3T3-L1 adipocytes. These changes were occurred without the cytotoxic effect of both extracts against 3T3-L1 adipocytes in vitro. A positive control, fenofibrate inhibited the differentiation, triglycerides accumulation through PPARγ signaling by 2/3 reduction of PPARγ expression. Thus, these findings suggest that both extracts of Auricularia auricula-judae might be used to inhibit the differentiation of 3T3-L1 preadipocytes and reduction of triglycerides accumulation.

The aim of this study was to investigate the antitumor activity of solvent fractions from Auricularia auricula-judae 70% ethanol extract and confirmed the active components of dichloromethane fraction showing a potent antitumor activity than other fractions in the broncheoalveolar and gastric cancer cells. The solvent fractions of Auricularia auricula-judae extract, inhibited the growth proliferation of tumor cells in dose-dependent manner. The principle components of dichloromethane fraction were 5,11,17,23-tetrakis (1,1-dimethyl)-28-methoxypentacyclo [19.3.1.1 (3,7).1 (… (65.85%) and diazane (6.17%). The antitumor active components, diazane and gibberellic acid (GA3) were identified in this fraction by GC-MS analysis and lower antitumor activities than dichloromethane fraction. The unknown components of dichloromethane fraction were responsible for its cytotoxic effects on tumor cells. Based on IC50 value, gibberellic acid was little cytotoxic itself. According to PCR amplification, the apoptosis of tumor cells were induced by the down-regulation of Bcl-2 and over-expression of P53 on the presence of solvent fractions, diazane and gibberellic acid. Thus, these findings suggest that the dichloromethane might be used as functional feed additive that suppress the tumor growth in the body than other solvent fractions of Auricularia auricula-judae extracts.

Auricularia auricula-judae has long been used as food and traditional remedies in Asian countries such as Korea and China. In this study, we evaluated the in vitro anti-tumor activity of various fractions from the ethanol extracts of Auricularia auricula-judae using various tumor cell lines. To do this, the mesh of Auricularia auricula-judae was mixed with 70% ethanol and heated at 1000C for 6 hrs and ethanol extract (ETOH) was collected. Ethanol extract was fractionated with dichloromethane (DCM), ethyl acetate, n-butanol and a water extract at room temperature as well as concentrated in a vacuum concentrator at a controlled temperature(<500C). The P388D1 macrophage and Sarcoma 180, human NSCLC NCI H358 (bronchioalveolar) and SNU1 cells (Gastric carcinoma) were cultured in RPMI. As the results, the cytotoxicity of the fractional extracts decreased significantly (P<0.05) in a dose-dependent manner. Dichloromethane extract (1 mg/ml) was the highest (P<0.05) in all experimental cell lines. There was also a significantly different sensitivity (P<0.05) among the P388D1, Sarcoma 180, NCI H358 and SNU1 cells for the fractional extracts. According to IC50 values, the most potent cytotoxic activity of dichloromethane fraction was found in Sarcoma 180 and NCI H358 cell lines. Butanol fraction appeared more cytotoxic to SNU1 cell line and water fraction had the highest cytotoxicity in P388D1 cell line. We did not find any significant difference between MTT and SRB assays in their ability to estimate cytotoxicity in all cell lines. Our findings suggest a potent antitumor activity of various fractions from the ethanol extracts of Auricularia auricula-judae depending on the solvent fractions and tumor cell lines. Further in vitro and in vivo studies will provide more information on the active compounds responsible for these activities and their potential as an anti-cancer remedy.

본 연구에서는 젖산발효를 통해서 얻어진 목이버섯과 녹각 추출액 혼합물의 항산화 및 생리활성평가를 수행하였다. 녹각 추출액의 GABA생성 최적조건에서 probiotics 및 기능성 강화를 위해 목이버섯을 2.5% 첨가하여 30℃에서 7일간 젖산발효를 하였다. 발효 7일 pH 5.06, 산도 0.77%로 나타났으며 1.3×108 CFU/mL로 높은 균수를 유지하였고 GABA를 1.4% 생성하는 것으로 나타났다. 목이버섯을 첨가했을 때 젖산균 발효물의 물성이 개선되며 단기간에 고농도의 GABA를 생성하는 것으로 나타났다. 녹각 추출액의 젖산발효물의 세포 생존율을 실험한 목이버섯 2.5% 조건에서 발효 전 6 mg/mL에서 독성이 나타났으나 발효 후 독성이 완화되는 것으로 나타났다. 발효 후 6 mg/mL 농도에서는 5.58 μM로 발효 후 NO 생성이 감소되는 것으로 나타났다. 결론적으로 녹각 추출액과 목이버섯 혼합물의 젖산균을 이용한 정치배양을 통해 단기간에 고농도의 GABA 생산이 가능하였으며, 젖산 발효물은 세포독성 완화 효과 및 NO 생성을 저해하는 것으로 나타났다. 따라서 발효물은 GABA, probiotic, 식이섬유 등을 함유하여 기능성 식품소재로 이용이 가능할 것으로 기대된다.

In order to produce the high quality of dried-ear mushroom, various drying methods such as hot-air drying at 40~80˚C, freeze drying and drying in vinyl house were carried out. Drying hours of hot-air drying, freeze drying and drying in vinyl house were 12.5~21.5, 36.0 and 72.0 hrs, respectively. Vitamin D2 content of sample was the highest as 6.77μg/g DW in drying in vinyl house and then followed by freeze drying as 5.90μg/g DW and hot-air drying as 1.89~5.01μg/g DW. After dry, external appearance and color of mushrooms applied hot-air drying and drying in vinyl house were better than freeze-dried one. After rehydration, water uptake of sample in drying in vinyl house and hot-air drying at 50~60˚C were 17.8 and 19.3~21.0 times, respectively. The methods of drying in vinyl house and hot-air drying at 50~60˚C also led to high hardness, good shape and resilience. As the results of production of dried-ear mushroom with high quality, we suggest that the best method for drying is the drying in vinyl house due to not only high vitamin D2 content, good external appearance and color after drying but also high hardness and good shape after rehydration.