Present anticancer drugs in the clinical side have not showed a conclusive effect of the chemotherapy for cancer patients. In order to find much more efficient antitumor agents fromnatural resources, various screening methods vivo and in vitro have been developed by manyresearchers. The intention of this paper is to provide an outline of some background on the tumorsystem in drug development of natural products, to review some screening programs for theevaluation of antitumor activity and to introduce the practical procedures of some antitumorscreening methods in vivo and in vitro. At the end of this paper, the current literatures related toantitumor natural products from higher plants at our laboratory are described.Key words'anticancer drugs, screening methods.

This experiment was Conducted ta screening for the anti-cancer efficacy from the wild plants which are naturally growing in the Korea. The results are as follows. The results were shown thatZea may L. nad significantly effects on mediculal efficacy anganist anti-tumor by usulg the totalpacked cell volume methods and also, severals plants, such as Sofonum nigrum, Patrinia hispidoBunge, Eragrostis, ferrugenia Beauv, Salaginela pouzolgiana Spring, Platrycarya strobilacea Bunge,Codonopsis lanceolata Benth. et Hook fil. which are collected from Giri and Mooju mountain in Koreaand Nagano in Japan were showed effects on auti-tumor. But the pharmaceologial activities ofPharbitis nil Choisy was believed to strong effec on anti - cancer tumors, while toxicity of its wasshown high that induced te kill all used mice. Extraction of Patrinia hispida Bunge, Pharbitis nilChoisy, Toilis japonica DC, Eragrostis erruginea Beauv. and Forsythia koreana Nakai showed effec-tively supressed on growth rate of cancer tumor by the below 50 percent of T/C ratio at 30mg /mlof extraction from plant. That Is strong activity while Reynouxria japonica Houtt. was observed onlymild activities. The above results many possibly suggest that Patrinia hispido Bunge and Eragrostisferrugina Beauv. inhibited the growth of cancer tumor by the both total packed cell volume methodand cytotoxicity method. Although basic research is still going on, we will find out an accurate moth-od for developing useful medicinal plant to improve pharmacological activites against anti-cancertumor, especialy, in Eragrostis ferruginea Beauv.

Many types of compounds have been isolated from higher plants till now, that is, alkaloids, terpenes, lignans, steroids and so on. One of them, named as RA series Cyclic hexapeptides isolated from Rubia akane and R. cordijofia also have strong antineoplastic activity against various types of tumors. Till now 10 kinds ofRA series compounds were isolated and named as RA - I, II, III, IV, V, VI, VII, VIII, IX and X. Moreover,monogl-ucoside of RA - V newly Isolated from same plant. Many kinds of derivatives including natural RAcompounds were tested for QSAR, and one of them, RA - VII was screened up as a most suitable substance asan antitumor agent. RA - VII(=RA-700) has strong cytotoxic activity against KB cells, P388 Iymphocyticleukemia and MM2 mammary carcinoma cells. RA - VII has been under investigation for Phase I clinical trials.

Now, many anticancer drugs are applying in the clinical side, but there is no conclusive effect of such a chemotherapy. Development ofnovel clinical useful anticancer drugs would be dependenton the screen-ing system and its test sample sources. So, it is necessary to outlinesome background on the tumor systems which have been used for screen-ing. This paper describes mainely on National Cancer Institute (NCI)program for anticancer screening systems, because the large number ofcompounds have been screened at NCI prograB and their relationship ofassesment between experimental animals and clinical Patients has beendiscussing and the uniform screefing protocols for various tumorsystens. At the end of this paper, some literatures of antitunor substances from various higher Plants at our laboratory are showed.

It was indicated that natural fiber crops Ln Korea have been major crops, such as cotton, flax, ramie and Kenaf. The major varieties andagronomic characterics are summarized as follows. Cotton variety, Mokpo 6 is long fiber length and, is high lint yield, flax variety, Wiera is hiTh amount of dry stem and grains weiTht. On the other hand, kenaf variety, Suweon 2 is high dry fiber weight and fiher ratio.