A single drug chemotherapy fails to eliminate residual cancer cells due to the existence of the multidrug resistance （MDR）. In the present study, we aimed to develop a compound epirubicin plus quinine injection, to characterize the efficacy in treatment of the drug-resistant breast cancer, and to reveal the involved mechanisms. The HPLC-UV methods were developed for quantifications, and the evaluations were performed on the drug-resistant human breast cancer MCF-7/adr cells using a high content screening system. Results demonstrated that the compound epirubicin plus quinine injection was able to effectively block the drug efflux, exhibiting an evidently overall efficacy in treatment of the resistant breast cancer cells by direct killing effect and by apoptosis-inducing effect. In the formulation, quinine played multiple roles in blocking drug efflux and in inducing the apoptosis of the resistant breast cancer cells. The apoptosis signaling pathways were associated with a cascade of reactions by activating Caspase family and by inhibiting Bcl-2 family. In conclusion, the present study preliminarily revealed the efficacy and mechanism of the compound epirubicin plus quinine formulation in treatment of the drug-resistant breast cancer, and offered a potential strategy to overcome drug resistance in cancer treatments.
The intestinal permeability of two flavonoid compounds liquiritin （LQ） and isoliquiritin （ILQ） was investigated using the Caco-2 cell monolayer model. In order to evaluate the permeability and predict the absorption mechanism of the two compounds, the study on bidirectional permeability from the apical （AP） side to the basolateral （BL） side as well as from the BL side to the AP side was carried out. The determination was performed by HPLC-UV method. And the permeability parameters, especially the apparent permeability coefficients （Papp）, were then calculated. The Papp values of LQ and ILQ are （5.40±0.16）× 10^-7 and （8.69±0.15）× 10^-7 cm/s, respectively. The results of time- and concentration-dependent transport experiments indicate that both LQ and ILQ are poor absorbed mainly through passive diffusion.
Oxidative coupling of α-bromoarylacetonitriles and oxidative decyanation of diarylacetonitriles are efficiently realized by solid-liquid phase transfer catalysis using anhydrous K 3 PO 4 as base and TBAB as catalyst in acetone at room temperature. In this mild and convenient method, α,β-dicyanostilbenes and diarylketones were prepared in good to excellent yields.
Adhesion of leukocytes to endothelium plays an important role in inflammation-associated diseases.Our previous studies showed that multivalent lactosides were able to inhibit this process.Using 2-azide-l,3-propandiol and glutamic acid as spacers,we synthesized divalent lactoside An-2 and tetravalent lactoside Gu-4 by means of convergent method.These two compounds displayed high anti-adhesive activity and showed therapeutic effect in rats with severe burn shock.In addition, investigation of the anti-adhesion biological mechanism using labeled compounds YAn-2 and YGu-4 demonstrated that the target of multivalent lactosides was CD11b,theβ2 integrin subunit,on the surface of leukocytes.In this paper,the synthesis of these two new multivalent lactosides as well as their fluorescein-labeled and biotin-labeled compounds is reported.
The fragmentation patterns of a series of dispirocyclopiperazinium dibromides with strong analgesic activity during positive ion electrospray ionization mass spectrometry were analyzed. The [M-Br]^＋ 2 ions showed the characteristic isotopic peaks and were assigned as the molecular ions. The loss of a 44 Dalton unit from 2 produced ion 3 [M-Br-44]^＋ and the loss of HBr from 2 formed ion 4. Besides, the carbamates 1d-1e produced extra ions [M-2Br-33]^＋. The related fragmentation mechanisms were proposed.
A novel organoselenium compound,WB（1,2-[bis（1,2-benzisoselenazolone-3（2H）-ketone）]pentane） has indicated anti-tumor activity.Its pharmacokinetic data has never been determined.By using the H22 tumor bearing mouse model,the tissue distribution of WB after single and four consecutive doses（both were 120 mg/kg/d） was explored.The selenium content of the tissues was used as an indicator of WB absorption,distribution and metabolism.The selenium in the heart,liver, spleen,kidneys,lungs,stomach,pancreas,brain,colon,intestine,testes,plasma,and tumor were determined by generation atomic fluorescence spectrometry（AFS）.With single or multiple oral administration of WB,the selenium content significantly increased in the liver,stomach,colon,and intestine.The selenium content in the spleen,lungs,pancreas,testes,plasma and tumor also increased compared with the controls;but no significant changes were found in the brain and kidney.WB and its metabolites distributed predominantly in the colon,liver,stomach and intestine,which resulted in a significant increase in the selenium content in both groups.There was no observed significant accumulation of WB in the vital organs.
inducing resuscitation with herbal aromatics is important to modulate the brain intake of drugs in traditional Chinese medicine,but limited information has been available on the mechanism of action.The MDCK-MDRl monolayer is an excellent in vitro cell model to use as a tool to study blood brain barrier（BBB） screening.In this study,we established MDCK-MDR1 cell line by stable transfection and investigated the effects of several important herbal aromatics on BBB permeability.The characterization experiment demonstrated the MDCK-MDRl used in this study was valid.In a transport study,we found several herbal aromatics increased the permeability of fluorescein isothiocyanate-labeled dextran 4kDa（FD4） and inhibited efflux of Rhodaminel23（Rhol23）.These results demonstrated that herbal aromatics enhanced the BBB permeation of drugs by both inhibition of P-gp and opening of the BBB tight junction,thus providing new insights for understanding the mechanisms of aromatic compounds＇ BBB permeability.
RNA interference has been widely used for gene therapy of various infectious diseases and malignant tumors. However, its poor stability in serum has limited further clinic application. Here, we found that stability of siRNA in serum enhanced obviously when 3′-terminus of sense strand （siRNA-pS） was conjugated with peptide, while same conjugation at 3′-terminus of antisense strand brought no such effects. And it was also found that only the peptide residue in siRNA-pS could be cut off by RNase A. All these results indicated that nucleases in serum prefer to invade siRNA duplex through the 3′-end of sense strand.
