Protective effect of Pai-Nong-San against AOM/DSS-induced CAC in mice through inhibiting the Wnt signaling pathway.

Pai-Nong-San (PNS), a prescription of traditional Chinese medicine, has been used for years to treat abscessation-induced diseases including colitis and colorectal cancer. This study was aimed to investigate the preventive effects and possible protective mechanism of PNS on a colitis-associated colorectal cancer (CAC) mouse model induced by azoxymethane (AOM)/dextran sodium sulfate (DSS). The macroscopic and histopathologic examinations of colon injury and DAI score were observed. The inflammatory indicators of intestinal immunity were determined by immunohistochemistry and immunofluorescence. The high throughput 16S rRNA sequence of gut microbiota in the feces of mice was performed. Western blot was used to investigate the protein expression of the Wnt signaling pathway in colon tissues. PNS improved colon injury, as manifested by the alleviation of hematochezia, decreased DAI score, increased colon length, and reversal of pathological changes. PNS treatment protected against AOM/DSS-induced colon inflammation by regulating the expression of CD4+ and CD8+ T cells, inhibiting the production of HIF-α, IL-6, and TNF-α, and promoting the expression of IL-4 and IFN-γ in colon tissues. Meanwhile, PNS improved the components of gut microbiota, as measured by the adjusted levels of Firmicutes, Bacteroidetes, Proteobacteria, and Lactobacillus. PNS down-regulated the protein expression of p-GSK-3ß, ß-catenin, and c-Myc, while up-regulating the GSK-3ß and p-ß-catenin in colon tissues of CAC mice. In conclusion, our results suggested that PNS exhibits protective effect on AOM/DSS-induced colon injury and alleviates the development of CAC through suppressing inflammation, improving gut microbiota, and inhibiting the Wnt signaling pathway.

Rosmarinic acid, the active component of Salvia miltiorrhizae, improves gliquidone transport by regulating the expression and function of P-gp and BCRP in Caco-2 cells.

Salvia miltiorrhiza (Danshen) is typically used in the treatment of diabetic complications and is often co-prescribed with gliquidone in China. However, whether danshen affects the absorption of gliquidone has not been elucidated. In this study, the effects of an aqueous extract of danshen (danshen injection, DSI) and its primary compounds (danshensu, protocatechuic aldehyde, rosmarinic acid and salvianolic acid B) on gliquidone transport across Caco-2 monolayer cells was investigated. DSI enhanced the transport of gliquidone in Caco-2 cell monolayers from the apical (AP) to basolateral (BL) sides and from the BL to AP sides. Rosmarinic acid (RA) also significantly increased the Papp (AP-BL) value for gliquidone transport. Verapamil (a P-gp inhibitor) and Ko143 (a BCRP inhibitor) inhibited the BL-AP transport of gliquidone and promoted the AP-BL transport of gliquidone, whereas MK571 (an MRP1 inhibitor), probenecid (an MRP2 inhibitor), and benzbromarone (an MRP3 inhibitor) had no effect on gliquidone transport. RA also enhanced the intracellular accumulation of Rho123 and Hoechst 33342. The expression of P-gp and BCRP was significantly downregulated, and P-gp ATPase activity was promoted by RA in a dose-dependent manner. These results indicate that an aqueous extract of danshen can increase the transport of gliquidone in Caco-2 cell monolayers and that RA may be the primary compound associated with this activity, which is in agreement with RA simultaneously suppressing the function and expression of P-gp and BCRP.