Research has found that the management of the host plant is essential to mistletoe cultivation. A Trunk injection test on the host plant that contained a mixture of indole-3-butryc acid (IBA) and liquid fertilizer was conducted with respect to the improvement of the one year survival rate of mistletoe. As a result, the trunk injection experiments showed the effect of the IBA and liquid fertilizer mixture in all treatments. This mixture was effective to increase the survival rate of mistletoe by 20% with the IBA at 100 ㎎/L and Hyponex at 100 ㎎/L. The examination proved that the host plant fertilizer effect was the most effective treatment for organic fertilizer with 60% added NPK (4-2-1). Its effects were higher compared to the control at the length and diameter of one-years-old branches in the host plant, even when the parasitic mistletoe improved its growth in length, diameter, and number of branches. Comparing the control and host plant fertilizer, the latter was the most effective way to process 20 ㎏ per a treatment effect in the experimental site and to process at any time after the inoculation. This treatment is effective to improve the growth of mistletoe by watering the host plant three times per week. Therefore, the management of the host plant is an essential element in the successful cultivation of mistletoe, not only to supply fertilizer and plant hormones to the host plant in the initial inoculation time but also to provide organic fertilizer and irrigation for the host plant.

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.

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.

겨우살이 기생위치는 숙주목(상수리나무 등)의 종류에 관계없이 대부분 지면에서 5-10m높이의 일사량이 많은 상단부에 기생하였다. 줄기의 분화는 주경에서 2개씩 연속분지를 형성하였고, 잎은 정단줄기의 상단부에 2매씩 대생하였으며, 종실은 연황색의 7-8mm 크기의 장과였다. 겨우살이 화아분화는 초기 둥근 돔형의 화아정단이 형성되고 엽원기가 1, 2매 차례로 분화한 다음 심장형으로 발달하며 악편이 발생하였는데, 중앙부에서 먼저 진행되었고 이어 양측 면에 2개를 형성하였다. 잎은 이면의 표피 2-3층 아래에 기공과 공변세포가 관찰되었고, 겨우살이는 기주목의 흡착부에서 기주조직의 코르크층을 통과하여 목질부에 뿌리를 내리고 여러 갈래로 분지하여 생장하는 것을 확인하였다.