Effect of ß-elemene on the kinetics of intracellular transport of d-luciferin potassium salt (ABC substrate) in doxorubicin-resistant breast cancer cells and the associated molecular mechanism.

In order to explore the mechanism of the reversing multidrug resistance (MDR) phenotypes by ß-elemene (ß-ELE) in doxorubicin (DOX)-resistant breast cancer cells (MCF-7/DOX), both the functionality and quantity of the ABC transporters in MCF-7/DOX were studied. Bioluminescence imaging (BLI) was used to study the efflux of d-luciferin potassium salt, the substrate of ATP-binding cassette transporters (ABC transporters), in MCF-7/DOX cells treated by ß-ELE. At the same time three major ABC transport proteins and genes-related MDR, P-glycoprotein (P-gp, ABCB1) and multidrug resistance-associated protein 1 (MRP, ABCC1) as well as breast cancer resistance protein (BCRP, ABCG2) were analyzed by q-PCR and Western blot. To investigate the efflux functionality of ABC transporters, MCF-7/DOXFluc cell line with stably-overexpressed luciferase was established. BLI was then used to real-time monitor the efflux kinetics of d-luciferin potassium salt before and after MCF-7/DOXFluc cells being treated with ß-ELE or not. The results showed that the efflux of d-luciferin potassium salt from MCF-7/DOXFluc was lessened when pretreated with ß-ELE, which means that ß-ELE may dampen the functionality of ABC transporters, thus decrease the efflux of d-fluorescein potassium or other chemotherapies which also serve as the substrates of ABC transporters. As the effect of ß-ELE on the expression of ABC transporters, the results of q-PCR and Western blot showed that gene and protein expression of ABC transporters such as P-gp, MRP, and BCRP were down-regulated after the treatment of ß-ELE. To verify the efficacy of ß-ELE on reversing MDR, MCF-7/DOX cells were treated with the combination of DOX and ß-ELE. MTT assay showed that ß-ELE increased the inhibitory effect of DOX on the proliferation of MCF-7/DOX, and the IC50 of the combination group was much lower than that of the single DOX or ß-ELE treatment. In all, ß-ELE may reverse MDR through the substrates of ABC transporters by two ways, to lessen the ABC protein efflux by weakening their functionality, or to reduce the quantity of ABC gene and protein expression.

[Chemical Constituents from Rhizome of Valeriana jatamansi].

OBJECTIVE: To study the chemical constituents from the rhizome of Valeriana jatamansi. METHODS: The chemical constituents were separated and purified by silica gel, medium pressure column chromatography, and preparative HPLC. Their structures were determined by physicochemical properties and spectral data. RESULTS: Six compounds were isolated from the dibromochloromethane extract in the rhizome of Valeriana jatamansi, and identified as decursidin (1), decursitin B (2), decursitin A (3), 3'(S)-acetoxy-4'(R)-angeloyloxy-3',4'-dihydroxanthyletin (4), 8-acetoxyl-pathchouli alcohol (5) and dibutyl phthalate (6). CONCLUSION: Compounds 1-4 are coumarins which are isolated from this genus for the first time,and compound 6 is isolated from this genus for the first time.

[Optimization of ultrasonic extraction conditions of safflower yellow from Carthamus tinctorius by response surface methodology].

OBJECTIVE: To investigate the optimization of extraction conditions of safflower yellow from Cartbamus tirwtorius by response surface methodology. METHODS: Experimental factors and levels were selected by one-factor test, and then according to the central composite experimental design principle, response surface'-methodology with three factors and three levels was used to establish a mathematical model to obtain the optimal extraction conditions with hydroxysafflower yellow A being the target and its extraction yield as response value. RESULTS: The optimal extraction conditions of safflower yellow were as follows: extraction temperature was 55 t, ratio of water to raw material was 16:1 and extraction time was 39 mm for three times. CONCLUSION: Under these conditions, the extraction yield of safflower yellow is 1.798%, and the relative error between the predicted value with actual value is 2.758%. The optimized method can provide reference for the efficient extraction of safflower yellow from Carthomos tinctorius