Muscle atrophy is characterized by a decrease in the mass of the muscle. With an increase in life expectancy and chronic illnesses, the incidence of muscle atrophy is increasing and the quality of life of patients is decreasing. Thus, reducing muscle atrophy is of high clinical and socio-economic importance. Mistletoe is a semi-parasitic plant that has been used as a traditional medicine in many countries to treat various human illnesses. It has been reported that Korean mistletoe extract (KME) has diverse biological functions including anti-tumor, anti-oxidant, anti-diabetic, anti-obesity properties, and extension of lifespan. Especially, we have recently reported that KME improves exercise endurance in mice, indicating its beneficial roles in enhancing the capacity of skeletal muscle. In this study, we investigated whether KME could activate the signaling pathway related to protein synthesis in a mouse model of muscle atrophy. Interestingly, KME efficiently activated the Akt/mTOR pathway, and Akt and mTOR are important signaling hub molecules for the acceleration of protein synthesis in muscle cells. In addition, KME also increased the activity of S6 kinase which is involved in the regulation of muscle cell size. Moreover, the ERK activity, required for transcription of ribosomal RNA for protein synthesis, was also enhanced in KME-treated mouse muscle. These data support the idea that KME increases muscle mass via increased protein synthesis. Our findings also suggest that Korean mistletoe might be a promising candidate for the development of functional foods that are beneficial for preventing muscle atrophy.

The study examined qualities including chlorophyll, total phenol, total flavonoid content and antioxidative activity in 7-year-old mistletoe that was artificially cultivated with Japanese apricots as the host. The chlorophyll a content of the artificially cultivated Japanese apricot mistletoe leaves was 7.67 mg/g (old leaves) and 3.17 mg/g (new leaves), while the chlorophyll b content was 0.80 ~ 3.53 mg/g and 1.31 ~ 3.56 mg/g. The carotenoid content of the Japanese apricot mistletoe leaves were in the range of 0.29 ~ 2.48 mg/g, and the old leaves (1.85 mg/g) had a carotenoid content 2.1 times higher than the new leaves (0.89 mg/g). The total polyphenol content of the leaves and nodes of the 7-year-old mistletoe was 60.22 mg/100 g TAE for the leaves and 35.50 mg/100 g TAE for the nodes. Among the host trees, polyphenol content was highest (81.44 mg/100 g TAE) in the old mistletoe leaves of the Quercus mongolica, while the total flavonoid content of the Japanese apricot mistletoe was higher in the new leaves (47.89 mg/100 g RUE) than the old leaves (42.19 mg/100 g RUE). The DPPH radical scavenging ability of the Japanese apricot mistletoe scored a low 22.4 ~ 28.5% in the leaves, but was relatively high in the nodes at 52.4 ~ 80.1%. In terms of 1mg/mL concentration, the new leaves (69.1%) and old leaves (82.3%) of the Quercus monglica mistletoe displayed the highest inhibition rate. Chestnut mistletoe displayed an inhibition rate of 21.9 ~ 31.9% for the leaves, and 35.0 ~ 63.8% for the nodes. These results indicate that Japanese apricot mistletoe would be substitute oak tree mistletoe as a source of bio-active property for functional food and medicine.

Traditionally, mistletoe is known as an effective anti-cancer medicinal plant, and lectin is recognized as a major component with cytotoxic and immuno-stimulant activity in mistletoe. A Korean mistletoe lectin (KML) has specificity to galactose and galactosamine and is distinguish from European mistletoe lectin (EML). When we examined the concentration of lectin in mistletoe originated from five different types of host trees, the result indicate that the lectin concentration is variable depending on the host tree. Noticeably, mistletoe from chestnut tree contains ten folds higher lectins than that of an oak tree. We also tested the concentration of KML and crude extract (KM-110) of Korean mistletoe that shows 90% cytotoxicity in L5178Y-ML25 lymphoma cell. In addition, the cells show 90% and 70% viability by the treatment of two neutralizing antibodies of KML, 9H7-D10 and 8B11-2C5 neutralization effect with two monoclonal antibodies of KML, 9H7-D10 and 8B11-2C5. Therefore, the result expected that the mistletoe contain some other cytotoxic components except lectin. Finally, the production of TNF-α and IL-6 by RAW 264.7 cells stimulated with lectin free-crude extract (LFKM-110) following neutralization by 9H7-D10 monoclonal antibody shows higher than that of lectin containing-crude extract (KM-110). These results suggest that the Korean mistletoe lectin ha a great potential to be developed as therapeutic agent of cancer.

본 연구에서는 겨우살이 열수 추출물인 미슬로 C의 안전성을 검토하고자 유전 독성 및 실험동물을 이용한 안전성 검사를 실시하였다. 미슬로 C의 미생물 돌연변이 실험을 S. typhimurium의 히스티딘 요구성 균주와 E. coli의 트립토판 요구성 균주를 이용하여 대사 활성계 적용 및 비적용 하에서 복귀돌연변이 시험을 실시한 바, 5,000 ㎍/plate의 처리 농도까지 복귀돌연변이 집락은 나타나지 않았다. ICR 마우스에게 500, 1,000 및 2,000 ㎎/㎏를 경구 투여하고, 골수세포를 수집하여 소핵을 측정한 결과, 정상마우스의 경우와 비교하여 유의한 소핵은 관찰되지 않았기에 미슬로 C는 유전독성을 유발하지 않는 것으로 판단되었다. 식품의약안전청의 의약품 등의 독성시험기준에 따라 암․수 SD 계열의 랫드에 시험물질을 0, 500, 1,000 및 2,000 ㎎/㎏/day의 용량으로 1회 경구 투여한 후, 14일간의 체중 변화 및 사망률을 조사한 결과, 대조군과 비교하여 유의한 체중 변화는 없었으며, LD50은 2,000 ㎎/㎏ 이상인 것으로 사료된다. 또한 0, 250, 500 및 1,000 ㎎/㎏/day의 용량으로 13주간 반복 투여하면서 실험동물의 일반증상, 체중변화, 혈액 및 혈액생화학적 변화, 부검소견, 조직학적인 변화를 관찰하였다. 시험기간 중 암․수 모든 군에서 시험물질 투여에 기인한 일반적인 증상 변화는 관찰되지 않았고, 시험물질의 반복 투여로 인한 사망 마우스 역시 관찰되지 않았다. 따라서 미슬로 C를 13주간의 랫드에 대한 13주 반복 경구투여 결과, 무독성량은 최소한 1,000 ㎎/㎏ 이하인 결과를 나타냈으며, 이 농도에서 독성을 유발하는 표적장기는 관찰되지 않았다.

Background : Mistletoe grown in eurasian continent range from England to northern Asia. It has abundant chlorophyll and phenolic compound in node and leaf which has anticancer activity. The purpose of the study is to improve nutritional quality and composition of the amino acids and mineral along with increasing seed set rates and productivity of Viscum album on Prunus mume. Methods and Results : This study was conducted to compare plant nutrients such as total nitrogen, Ca, Fe, K, Mg, Mn, Na, P and composition of amimo acids in leaves between Viscum album and its host tree, Prunus mume, which were artificially cultivated in field and green house with or without treatment of fertilizer. Total nirogen content in leaves of mistletoe and its host tree, Prunus mume was 3.90% and 2.09% in the fields fertilized and non-fertilized, respectively. In a greenhouse fertilized, mistletoe leaves contained higher nitrogen (3.78%) compared to the host tree (3.06%). NO3-N content in leaves was also higher in mistletoe (37.5 ppm & 20 ppm) than in host tree (22.5 ppm & 12 ppm) in a field fertilized and non-fertilized. Ca content (1.18%) were same in leaves of mistletoe and host tree in the field fertilized. Contents of Fe, K, and Mn in leaves of mistletoe were 61.37 ㎎/㎏, 3.33%, and 127.59 ㎎/㎏, which were 16%, 13%, and 48% lower than host tree, respectively. On the other hand, contents of Mg, N, and P were 0.22%, 127.95 ㎎/㎏, and 0.48%, which were 5%, 148%, and 92% higher than host tree, respectively. K contents were higher in host tree fertilized (3.33% in field & 2.55% in greenhouse) while higher K (4.07%) was contained in a field non-fertilized compare to host tree (3.96%). However, P content was higher in mistletoe grown in field (0.48%) and greenhouse (0.42%) fertilized. In non-fertilized field, mistletoe leaves contained higher P (0.65%) rather than in host tree (0.29%). Eighteen kinds of amino acids were investigated in leaves of host plant by 20 - 87%. Conclusion : This study indicates that nutrient management including fertilization is important to improve nutritional quality and productivity of mistletoe in the artificial cultivation on Prunus mume.

Background : Bioactive substances, viscumneoside III and homoflavoyadorinin B, were isolated from korean mistletoe. Before, the isolated compounds were performed to identify the effect on tyrosinase inhibition activity. It is generally known that the biological activity of aglycon is better than the glycone attached to sugars in natural products. Methods and Results : In this study, the glycone of mistletoe were converted into homoeriodictyol and velutin, which are aglycon, respectively, by microwave irradiation, and their tyrosinase inhibitory activity was investigated. Experimental results showed that microwave irradiation mistletoe extracts showed superior tyrosinase inhibitory activity than untreated extracts. Conclusion : These results revealed that the whitening acivity of microwave irradiation Korean mistletoe can be utilized for the skin cosmetics.

Various bioactive substances are found in mistletoe, including viscumneoside III (1) and homoflavoyadorinin B (2), both which inhibit tyrosinase. These two compounds are mainly found in the EtOAc fraction of the mistletoe extract and demonstrate higher rates of tyrosinase inhibition than ascorbic acid, which was used as a control. Our results suggest that mistletoe extracts can be utilized in skin whitening cosmetics.

Background : With the increasing demand of the mistletoe in larger quantities for cancer therapy, it has been depleted from its natural habitat in the Far East countries including Korea because of overharvesting for high-value products (e.g., lectins and viscotoxins). The rapid multiplication of mistletoe by tissue culture can help this problem and provide the benefits in the phamaceutical industry. Methods and Results : Mistletoe plants growing on oak trees were collected and their leaf and stem segments were inoculated on MS basal medium supplemented with various concentrations of growth regulators. Calli were induced only from stem explants on MS medium containing 2,4-D and transferred onto MS medium supplemented with various concentrations of 2,4-D, NAA and BAP, respectively, for their propagation. The best callus multiplication rate of more than 15 folds (759 mg) was obtained in treatment of 2,4-D (4 mg/L) that produced yellowish-green, white and friable callus on this medium. To compare biochemical characterization, lectins were partially purified from natural mistletoe plants (nML) and in vitro cultured mistletoe calli (cML), respectively. The former was purified by lactose-agarose affinity chromatography and the latter was done by ammonium sulfate precipitation followed Sephadex G-25 chromatography. Both nML and cML showed similar molecular weight on SDS-PAGE and Western blot analyses. In addition, they showed similar carbohydrate-binding specificities and hemagglutination activities. Conclusion : From the above results, we may suggest that nML and cML showed the similarity in biochemical characters.

Background : Lectins were individually isolated from natural Korean mistletoe (nML) and its in vitro cultured calli (cML). Both of the lectins showed the difference in bioactivities such as cytotoxicity and cytokine induction. Methods and Results : Target cells (1 x 104 cells/well) were seeded independently into each well of a 96-well culture plate and incubated with different concentrations of each lectin. Survivability of target cells was determined by CCK-8 kit (Sigma, USA) according to manufacturer’s directions. The nML showed 46, 34 and 5.5 times stronger than cML in cytotoxicity (IC50) to human melanoma cell line (SK-MEL-28), human carcinoma cell line (NCI-H1650) and murine macrophage (RAW 264.7), respectively. In addition, respective lectins directly stimulated macrophage RAW 264.7 but they showed the difference in enhanced productivity of some inflammatory cytokines. Compared with cML, the nML induced both TNF-α and IL-1β at its low concentration. Administration of two kinds of lectins (10-1000 μ g/kg body weight) to ICR mouse did not show any significant changes on the level of alanine transaminase (ALT), glutamate-oxaloacetic transaminase (GOT) and blood urea nitrogen (BUN) in sera. Conclusion : From the above results, we may suggest that nML and cML showed differences in cytotoxic effects and cytokine production due to the difference in amounts from sources.

Humankind has been searching for medicinal materials from various plant sources in an attempt to treat disease. Mistletoe is one indubitable plant source for these materials due to its effectiveness in treating various diseases, but it has almost disappeared from the mountainous areas of Korea due to excessive harvesting. In this study, in order to select host tree species for Korean mistletoe [Viscum album var. coloratum (Kom.) Ohwi] by seed inoculation and to clarify the effect of host specificity among various tree species were conducted for the purpose of gaining basic information for the artificial cultivation of Korean mistletoe. Almost all the seeds of Korean mistletoe germinated in vitro at the temperature of 15℃. Among host trees used in this study, Prunus mume showed the highest parasitic affinity with inoculated Korean mistletoe, compared with any other host plants. However, treatment of hormones could not increase the low survival rate of Korean mistletoe on the host trees.

This study was conducted to investigate the antimicrobial activities and antioxidant activities of the Korean mistletoe extract and its solvent fractions (e.g. n-hexane, ethyl ether, ethyl acetate, butanol). Ethyl ether fraction against Bacillus cereus showed stronger activities than benzoic acid (2.5 mg/mL). The MIC of korean mistletoe extract and slovent fractions were in the range of 6.25-25 mg/mL. The MIC (6.25 mg/mL) of ethyl acetate fraction onto Staphylocossus aureus was the lowest among them. Ethyl ether fraction which showed the strongest antioxidant activities by DPPH (1,1-diphenyl-2-picryl-hydrazyl) and FRAP (ferric ion reducing antioxidant power) methods had the highest total phenolic contents. It is suggested that Korean mistletoe could be utilized as natural preservative material through the study of the active compounds from ethyl ether fraction.

참나무 겨우살이의 생리활성을 알아보기 위해 전자공여 작용, SOD 유사활성, 총 폴리페놀 함량, Tyrosinase 저해효과 및 아질산염 소거작용을 측정하였다. 전자공여능은 추출용매의 비율에 따라 농도가 높아짐에 따라 전자공여능도 증가하였고, 특히 60% EtOH을 추출용매로 하여 25 mL/g의 비율로 추출한 실험구가 68.88%로 가장 높은 항산화력을 나타냈다(p50 mL/g>100 mL/g으로 농도가 높을수록 페놀함량도 유의적으로 높아졌고,

수요증가가 예상되는 겨우살이의 인공번식을 위한 기초자료로 활용하고자 겨우살이의 분포지역의 기주수종과 서식지 환경을 조사하여 분석하였다. 겨우살이의 자생지는 전국에 분포하고 있었으며, 기주식물로는 졸참나무와 같은 참나무류가 대부분이였고 밤나무, 벚나무, 오리나무, 돌배나무 등에서 볼 수 있었다. 군락지의 같이 자생하는 침엽수인 소나무, 잣나무와 활엽수인 느티나무, 감나무, 고로쇠나무, 단풍나무, 뽕나무, 은행나무에서는 관찰되지 않았다. 자생지의 고도는 해발 0~1200 m까지 잘 생육되고 방향과 지형을 가리지 않고 기주식물이 잘 생육 할 수 있는 곳이면 전국에서 재배가 가능할 것으로 판단되었으며, 종자 전파는 조류에 의함이 확인할 수 있었다. 겨우살이의 기생은 흡기 발생부터 기주식물의 표피 또는 조직성분에 따라 영향이 있을 것으로 생각되며 인공재배 연구의 좋은 성과를 위해 겨우살이가 잘 기생하는 기주식물의 기주 특이성에 대한 연구가 이루어져야 할 것으로 사료된다.

최근 천연의 의약품과 식품에 대한 관심이 높아지면서 약리성분이 우수하여 수요가 증가하고 있는 겨우살이 [Viscum album var. coloratum(Kom.) Ohwi] 와 겨우살이의 기주식물인 상수리나무(Quercus acutissima Carr.)가지의 조직특성을 조사하고 인공재배 기초 자료로 활용하기 위하여 수행한 결과는 다음과 같다. 겨우살이 종자가 기주목에 부착되면 종자로부터 성장한 흡기가 수피를 뚫고 들어가 형성층 부위에서 왕성한 세포분열을 통하여 여러 갈래로 분지를 형성하며, endophyte가 수피 속에서 성장하다가 일정한 시기가 되면 수피 외부조직으로 발달하여 줄기와 잎으로 성장하였다. 겨우살이 기주목인 상수리나무의 가지는 심재화가 진행되지 않았지만 타일로시스가 부분적으로 발달한 것은 겨우살이 endophyte의 침투영향으로 생각된다. 겨우살이 줄기의 구성세포는 도관상 가도관, 후벽세포, 방사유세포, 축방향유세포로 구성되어 있으며 활엽수로 분류되지만 도관이 분포하지 않았고 도관의 역할을하는 도관상 가도관이 있는 것으로부터 기주목 도관의 벽공과 겨우살이 가도관의 천공부가 결합하는 것으로 생각된다. 겨우살이 줄기의 구성세포 분포비율은 수령이 증가함에 따라 후벽세포의 분포비율이 높았다. 겨우살이 조직은 일반 목본식물에 비하여 유세포의 분포비율이 높고 세포내에 많은 내용물을 포함하고 있었다.

The protective effect of ethanol extract of Korean mistletoe (KM; Viscum album coloratum) on hydrogen peroxide (H2O2)-induced neurotoxicity was examined in primary cultured rat cortical neurons. H2O2 reduced viability of cortical neurons in a concentration-dependent manner. The addition of KM, over a concentration range of 10 to 100 μg/ml, concentration-dependently prevented the H2O2(100 μM)-induced neuronal cell death, as assessed by a 3-[4,5-dimethylthiazol-2-yl]-2,5-di-phenyl-tetrazolium bromide (MTT) assay and Hoechst 33342 staining. KM significantly inhibited H2O2-induced elevation of the cytosolic Ca2+ concentration ([Ca2+]c), which was measured by a fluorescent dye, fluo-4 AM. KM inhibited glutamate release into medium and generation of reactive oxygen species (ROS) induced by H2O2. These results suggest that KM may mitigate the H2O2-induced neurotoxiciy by interfering with the increase of [Ca2+]c, and inhibiting glutamate release and generation of ROS in cultured neurons.

한국산 겨우살이 (Viscum album L)는 면역조절작용이 있음이 밝혀졌다. 본 연구에서 한국산 겨우살이 열탕추출물 M11C (non-lectin components)가 비장세포를 활성화시켜 IL-1β를 생산 분비하게 하는지를 조사하였다. 비장세포를 M11C로 자극한 후, 배양액을 수집 혹은 세포 용해물을 수거해 IL-1β 분비와 전사량을 ELISA, immunoblotting, RT-PCR로 검사했었다. 비장세포로부터 IL-1β 분비와 전사 효과에 있어서 M11C는 농도 의존성과 자극시간 의존성을 보였다. 비장세포로부터 최대의 IL-1β 분비를 위한 M11C의 최대의 농도와 자극시간은 각각 200μg/ml와 8시간 이었다. 그리고 최대 IL-1β mRNA 전사를 위한 M11C의 최대의 농도와 자극시간은 각각 200μg/ml와 4시간 이었다. 최대의 전사시간은 최대의 분비시간보다 4시간 빨리 도달된 것으로 나타났다. 이러한 최대의 IL-1β 분비효과가 당분해효소인 Viscozyme L에 의해 완전히 저해되었다. 이는 M11C (non-lectin components)의 구성물질 들 중 다당체 혹은 올리고당들이 IL-1β 생산 분비를 유도하는 주된 물질임을 말해주고 있다.

한국산 겨우살이 (Viscum album)는 면역 활성효과와 항암효과가 있다는 것으로 잘 알려져 있다. 본 연구에서는 한국산 겨우살이 추출물 M11C (비렉틴 구성물질)가 사람의 말초혈액 단구를 활성화시켜 tumor necrosis factor-alpha (TNF-α)를 생산 분비하게 하는지를 규명하기 위해 실험에 이용되었다. 단구로부터 TNF-α의 생산에 있어 M11C의 효과를 알기 위해 단구를 여러 농도 (0-2000μg/ml)의 M11C로 0.5-24시간 동안 자극한 후 배양액 MCM을 수거했다. 수거한 배양액 MCM을 TNF-α에 민감한 L929 세포에 첨가한 후 L929 세포의 독성 정도를 MTT 기법으로 검사하였는데, 배양액 MCM이 L929 독성효과를 가졌으며, 이 MCM의 L929 세포 독성효과는 TNF-α 항체에 의해 거의 완전하게 억제되었다. 이러한 결과는 배양액 MCM에 TNF-α가 존재함을 지적했으며, 또한 M11C가 단구를 자극해 TNF-α를 생산하리라고 암시했었다. 이러한 암시를 확인하기 위해 immunoblotting 기법을 사용해 배양액 MCM에 존재하는 TNF-α을 검사를 수행했다. 검사결과 배양액 MCM에 많은 량의 TNF-α가 검출되었다. 이러한 TNF-α 검출량은 단구를 자극한 M11C의 농도와 자극시간에 비례해서 증가했다. 즉, 단구로부터 TNF-α의 생산 분비량은 M11C의 농도와 자극시간에 의존적이었다. 이러한 M11C의 농도와 자극시간의 의존적 효과는 단구로부터 TNF-α mRNA 발현에도 같은 경향을 보였다. 결론적으로 한국산 겨우살이로부터 열탕 추출한 M11C가 면역활성제로 작용할 수 있음을 시사함과 동시에 한방탕제로 사용되는 한국산 겨우살이가 면역학적 효능을 가지고 있음을 말해주고 있다.

기주목(상수리나무, 밤나무, 자작나무, 버드나무)별 겨우살이 ethanol 추출물의 5가지 분획물(hexane fr., chloroform fr., ethyl acetate fr., butanol fr., aqueous fr.)을 이용하여 in vitro에서 사람 면역세포주에 대한 생육활성, 사람 정상 세포주에 대한 세포독성, 사람의 각종 암 세포주에 대한 생육 저해능을 조사하였다. 4종의 한국산 겨우살이 분획물들의 정상세포에 대한 세포독성은 밤나무 겨우살이 chloroform fr.(28%)을 제외한 모든 겨우살이 분획물 0.5mg/ml이하의 농도로 투여시 정상세포에 대한 세포독성이 20%이하로 나타났다. 또한 암세포 생육 저해능의 경우, 폐암 세포주 A549와 위암세포주 AGS에 대하여 상수리나무, 밤나무, 버드나무 겨우살이 분획물에서 80%이상의 생육억제 효과를 보였다. Human B 세포주와 T 세포주에 대한 생육촉진 실험에서, B 세포주에 대하여 상수리나무 겨우살이 hexane fr. buthanol fr., 밤나무 겨우살이 hexane fr., 자작나무 겨우살이 ethyl acetate fr., 버드나무 겨우살이 hexane fr. chloroform fr. ethyl acetate fr.은 배양 3일에서 5일 사이 control에 비하여 약 1.5~3배의 세포 생육촉진을 보였다. T 세포주에 대하여 상수리나무 겨우살이 chloroform fr. ethyl acetate fr., 밤나무 겨우살이 chloroform fr. ethyl acetate fr., 자작나무 겨우살이 hexane fr. chloroform fr. ethyl acetate fr., 버드나무 겨우살이 hexane fr. chloroform fr. ethyl acetate fr.은 배양 3일에서 5일 사이 control에 비하여 약 1.5~2.3배의 세포 생육촉진을 보였다. 한국산 겨우살이 분획물들은 정상세포 대한 독성이 약하고, 면역세포의 생육을 촉진하며, 암세포 생육을 저해하는 효과가 있는 결과로부터 겨우살이는 신체질병에 대한 효과가 기대되며, 앞으로 보다 상세한 연구가 필요할 것으로 사료된다.