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1. The expression and function of P-glycoprotein (P-gp) is associated with the phenotype of multidrug resistance (MDR). Saikosaponin A (SSA) is a triterpenoid saponin isolated fromRadix Bupleuri. This study was mainly designed to understand effects of SSA on MDR in MCF-7/ADR and HepG2/ADM cells. 2. MDR reversal was examined as the alteration of cytotoxic drugs IC50 in resistant cells in the presence of SSA by MTT assay, and was compared with the non-resistant cells. Apoptosis and uptake of P-gp substrates in the tumor cells were detected by flow cytometry. Western blot was performed to assay the expression of P-gp. 3. Our results demonstrate SSA could increase the chemosensitivity of P-gp overexpressing HepG2/ADM and MCF-7/ADR cells to doxorubicin (DOX), vincristine (VCR) and paclitaxel. SSA promoted apoptosis of MCF-7/ADR cells in the presence of DOX. Moreover, it could also increase the retention of P-gp substrates DOX and rhodamine 123 in MCF-7/ADR cells, and decrease digoxin efflux ratio in Caco-2 cell monolayer. Finally, a mechanistic study showed that SSA reduced P-gp expression without affecting hydrolytic activity of P-gp. 4. In conclusion, our findings suggest that SSA could be further developed for sensitizing resistant cancer cells and used as an adjuvant therapy together with anticancer drugs to improve their therapeutic efficacies. [ABSTRACT FROM AUTHOR]

Oscillating chemical fingerprint is a nonlinear dynamic fingerprint technology that reflects the overall redox activity of the entire system based on potential-time changes in multi-stage chemical reactions. This article summarizes the application of oscillating chemical fingerprint technology combined with mathematical analysis method in the qualitative and quantitative analysis of traditional Chinese medicine and food in recent years, including similarity analysis, principal component analysis, cluster analysis and other qua-litative analysis methods, as well as linear, logarithmic, exponential, polynomial, multivariate analysis and other quantitative analysis methods, so as to provide meaningful information for further quality control analysis of the oscillation chemical fingerprint technology in the field of traditional Chinese medicine and food.

A new method for qualitative and quantitative analysis of Rhodobryum giganteum by using the nonlinear oscillating chemical was established for improving the quality control standard of R. giganteum. Its potential(E)/time(t) curve was recorded by electrochemical workstation in the oscillation reaction system of BrO~-_3-Ce(SO_4)_2-H_2SO_4-malonic acid/tartaric acid. The nonlinear oscillating chemical fingerprints were investigated for repeatability, and it was found that the RSD values of the four characteristic parameters of R. giganteum were less than 4.1%, indicating a good repeatability and high precision of this experiment. After optimizing the experimental parameters such as particle size, rotation speed and temperature, a new method based on nonlinear oscillating chemical was used for qualitative and quantitative analysis of R. giganteum. The results showed that there was a good linear relationship between the induction time/the period of oscillation and the dosage of herbs(0.1-1.1 g), with the relative coefficients of 0.978 and 0.975, respectively. Besides, the highest potential showed a nonlinear relationship with the dosage of herbs, with the relative coefficient of 0.999. This method was also used to discriminate the R. giganteum and R. roseum. They were similar in appearance, but their fingerprints were quite different. Independent sample t test results showed that there were significant differences in the oscillation time, the maximum amplitude and the induction time, providing a basis for the identification of the basic sources of Herba Rhodobryi Rasei.