| In this dissertation, the author conducted a series of studies on tubeimoside (TBMS) and tubeimoside I (TBMS I ) which was isolated from a traditional Chinese medicine "Tu-Bei-Mu", Bolbostemma paniculatum (Maxim.) Franquet. TBMS and TBMS I have effects on inhibiting microtubule protein (MTP) polymerization and on cellular toxicity within low differentiated nasopharyngeal carcinoma (NPC) cell line (CNE-2Z cells). The following results were obtained:1. Firstly, we extracted TBMS and TBMS I from crude drugs quickly by using AKTATM explorer 100 system, it fitted to simplify the precedure of TBMS preparation。2. MTP was prepared from fresh pig brain by two cycles of warm assembly and cold disassembly. Inhibition of MTP polymerization induced by TBMS I was determined by a turbidity measurement and a sedimentation assay. TBMS I was effective at inhibition of MTP polymerization even its concentration was as low as 5 μmol/L.3. The interaction of TBMS or TBMS I with cellular microtubules was examined by immunofluorescence techniques in CNE-2Z cells. Untreated cells exhibited well-defined, cytoplasmic microtubule arrays radiating from the center to the cell periphery. Paclitaxel (PTX) , a positive control, increased microtubule polymerization by promoting nucleation and bundling microtubules. Colchicine (COL) was another positive control, it resulted in depolymerization of cellular microtubules, caused CNE-2Z cells to round up and the tubulin took on an amorphous appearance. The effects of TBMS and TBMS I on tubulin within CNE-2Z cells were similar to that of COL.4 . Electron micrographs demonstrated the effects of TBMS and TBMS I on ultrastructure of CNE-2Z cells. Untreated cells exhibited intact ultrastructure. After cells were treated with 25 μmol/L TBMS or 25 μmol/L TBMS I for 24 h, cellular microvilli disappered, endoplasmic reticulum was compressed, mitochondria swollen or crimpled. There were many autophagic vacuoles in cytoplasm.50μmol/L TBMS induced necrosis of considerable cells.
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