[Transport characteristics of Shuxiong prescription across Caco-2 cell monolayer model].

Shuxiong prescription (Notoginseng Radix et Rhizoma, Chuanxiong Rhizome and Carthami Flos) has the function of activating blood circulation to dissipate blood stasis, activating meridians to stop pain. This paper was mainly aimed to discuss the transport characteristics of Shuxiong prescription across Caco-2 cell monolayer. Safe concentration range of Shuxiong prescription against Caco-2 cell monolayer model was determined by MTT assay. The mechanism of Shuxiong prescription bidirectional transport was investigated by Caco-2 cell monolayer model. The apparent permeability coefficient Papp of digoxin was determined by high performance liquid chromatography (HPLC). The test results showed that the Papp of extract from Notoginseng Radix et Rhizoma, Chuanxiong Rhizome, Carthami Flos, Chuanxiong Rhizome+Carthami Flos and Shuxiong prescription transport from apical (AP) side to basolateral (BL) side was (3.12±0.73)×10⁻6, (2.58±0.41)×10⁻6, (4.97±0.64)×10⁻6, (4.63±0.57)×10⁻6, (5.79±0.68)×10⁻6 cm·s⁻¹, respectively, indicating that the transport of digoxin across Caco-2 cell monolayer model was active absorption, and the P-gp protein took part in the process. Chuanxiong Rhizome could significantly decrease the transport of digoxin from BL→AP(P<0.01) and increase its transport from AP→BL(P<0.05) significantiy. After the addition of Shuxiong prescription, the transport of digoxin from BL→AP was significantly inhibited(P<0.01). The results suggested that the extract of safflower had no effect on P-gp transport, nor on the independence diffusion of digoxin. The transport of digoxin could be degraded by the extract of Chuanxiong Rhizome and the extract of Shuxiong prescription from BL→AP(P<0.01), significantly; pseudo-ginseng had no effect on the independence diffusion of digoxin; the extract of safflower+Chuanxiong Rhizome had the same experimental result as Chuanxiong Rhizome extract.

Imaging of water soluble CdTe/CdS core-shell quantum dots in inhibiting multidrug resistance of cancer cells.

Two different colors of water-soluble core-shell quantum dots CdTe/CdS (green and orange red) have been synthesized and characterized in this paper. The formation of core-shell quantum dots not only improves the fluorescence quantum yield, but also reduces the biological toxicity of quantum dots, and improves the fluorescence lifetime. Two novel fluorescent bioprobes, CdTe/CdS (λem = 545 nm)-5-Fu and Bio-CdTe/CdS (λem = 600 nm)-TAM, have been synthesized via the interaction of these two core-shell quantum dots with anticancer drugs (5-Fu) and P-gp inhibitors (TAM), respectively. These two fluorescent probes have been simultaneously used in fluorescence imaging of human breast cancer cells MDA-MB-231/MDR. It can be observed that under the action of P-gp inhibitors distributed on the cell membrane, anticancer drugs can be retained in cancer cells. According to the color of quantum dots on the probe, the visualization results of the action of anticancer drugs and P-gp inhibitors can be obtained. This study shows that to prepare functional bioprobes using core-shell quantum dots CdTe/CdS has great potential in the field of biomedical research such as anticancer drugs.