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.