Redefine the role of d-α-Tocopheryl polyethylene glycol 1000 succinate on P-glycoprotein, multidrug resistance protein 1, and breast cancer resistance protein mediated cancer multidrug resistance

Cancer drug resistance is an ever-changing problem that most patients need to face in their later stages of treatment, especially the multidrug resistant (MDR) type. The drug efflux transporters, including P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), and breast cancer resistance protein (BCRP), play the crucial roles in this sophisticated battle. In recent decades, researchers try to find potential inhibitors to impede the drug efflux function of above transporters. d-α-Tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS) is a prevalently used excipient in the formulation design. In the present study, the modulatory effects and mechanisms of vitamin E TPGS on the efflux transporters were investigated. And the cancer MDR reversing ability of vitamin E TPGS was evaluated as well. Stable-cloned transporter over-expressed cell lines were used for mechanisms study, while several types of MDR cancer cell lines were adopted as reversing evaluation models. The results exhibited that vitamin E TPGS significantly inhibited the efflux function of P-gp, MRP1, and BCRP under non-cytotoxic concentrations, but not influencing the protein expression levels. Through efflux assay and molecular docking, vitamin E TPGS was found to be an uncompetitive, non-competitive, and competitive inhibitor on chemotherapeutic drug doxorubicin efflux in P-gp, MRP1, and BCRP over-expressing cell lines, respectively. Furthermore, the basal ATPase activity of three transporters were significantly inhibited by vitamin E TPGS at 10 μM. And the cell membrane fluidity of P-gp over-expressing cell line was enhanced by 22.58% with 5 μM vitamin E TPGS treatment, compared to the parental Flp-In™-293 cell line (without P-gp). The resistance reversing ability of vitamin E TPGS was prominent in MCF-7/DOX MDR breast cancer cell line, which over-expressed P-gp, MRP1, and BCRP. These significant results suggested that vitamin E TPGS is a promising modulator on transporters mediated cancer MDR. Vitamin E TPGS is not an inert excipient, but possesses MDR-reversing pharmacological effects, and deserves a re-purposing application on the future combinatorial regimen design for MDR cancer treatment.

Facile production of chlorophyllides using recombinant CrCLH1 and their cytotoxicity towards multidrug resistant breast cancer cell lines

The purity of chlorophylls plays one of the key role for the production of chlorophyllides. We have designed a facile method for chlorophyll purification by twice solvent extraction. Twice extraction causes the loss of chlorophylls, but the purity of total chlorophylls can be enhanced 182%. Then, the purified chlorophylls can be converted to relatively pure chlorophyllides facilely. The results show that higher purity of chlorophyllides could be obtained when purified chlorophylls (ethanol-hexane extract) was used as starting materials than that of crude chlorophylls (ethanol-only extract). In biocompatibility test, the results showed that the prepared chlorophyllides can be applied as biomaterials. When the prepared chlorophyllides were applied to anticancer tests, they were active both in MCF7 and MDA-MB-231 (multidrug resistant breast cancer cells) cell lines. In addition, the results suggested that the prepared chlorophyllides could be a potential candidate of combination therapy with doxorubicin to breast cancers.

Trends in the Immunomodulatory Effects of Cordyceps militaris: Total Extracts, Polysaccharides and Cordycepin

Cordyceps militaris (C. militaris) is a fungus with a long history of widespread use in folk medicine, and its biological and medicinal functions are well studied. A crucial pharmacological effect of C. militaris is immunomodulation. In this review, we catalog the immunomodulatory effects of different extracts of C. militaris, namely total extracts, polysaccharides and cordycepin. Total extracts obtained using water or 50% ethyl alcohol and polysaccharides from C. militaris were discovered to tend to promote type 1 immunity, whereas total extracts obtained using 70-80% ethyl alcohol and cordycepin from C. militaris were more likely to promote type 2 immunity. This article is the first to classify the immunomodulatory effects of different extracts of C. militaris. In addition, we discovered a relationship between different segments or extracts and differing types of immunity. This review can provide the readers a comprehensive understanding on the immunomodulatory effects of the precious folk medicine and guidance on its use for both health people and those with an immunodeficiency.

LABA/LAMA fixed-dose combinations versus LAMA monotherapy in the prevention of COPD exacerbations: a systematic review and meta-analysis

Background:

Long-acting muscarinic antagonist (LAMA) monotherapy is recommended for chronic obstructive pulmonary disease (COPD) patients with high risk of exacerbations. It is unclear whether long-acting β2-agonist (LABA)/LAMA fixed-dose combinations (FDCs) are more effective than LAMAs alone in preventing exacerbations. The aim of this study was to systematically review the literature to investigate whether LABA/LAMA FDCs are more effective than LAMA monotherapy in preventing exacerbations.

Methods:

We searched several databases and manufacturers’ websites to identify relevant randomized clinical trials comparing LABA/LAMA FDC treatment with LAMAs alone ⩾24 weeks. Outcomes of interest were time to first exacerbation and rates of moderate to severe, severe and all exacerbations.

Results:

We included 10 trials in 9 articles from 2013 to 2018 with a total of 19,369 patients for analysis in this study. Compared with LAMA monotherapy, LABA/LAMA FDCs demonstrated similar efficacy in terms of time to first exacerbation [hazard ratio, 0.96; 95% confidence interval (CI) 0.79–1.18; p = 0.71], moderate to severe exacerbations [risk ratio (RR), 0.96; 95% CI 0.90–1.03; p = 0.28], severe exacerbations (RR, 0.92; 95% CI 0.81–1.03; p = 0.15), and a marginal superiority in terms of all exacerbations (RR, 0.92; 95% CI 0.86–1.00; p = 0.04). The incidence of all exacerbation events was lower in the LABA/LAMA FDC group for the COPD patients with a history of previous exacerbations and those with a longer treatment period (52–64 weeks).

Conclusion:

This study provides evidence that LABA/LAMA FDCs are marginally superior in the prevention of all exacerbations compared with LAMA monotherapy in patients with COPD.

The reviews of this paper are available via the supplemental material section.

Chrysin-induced ERK1/2 Phosphorylation Enhances the Sensitivity of Human Hepatocellular Carcinoma Cells to Sorafenib

BACKGROUND/AIM

Sorafenib is now standard treatment for advanced hepatocellular carcinoma (HCC). However, therapeutic efficacy is not as good as was predicted. Many efforts are being made to improve HCC sensitivity to sorafenib. Our previous study demonstrated that co-treatment with chrysin enhanced sorafenib sensitivity through inhibition of ATP-binding cassette super-family G member 2 (ABCG2). Whether there is another mechanism other than inhibition of ABCG2 underlying chrysin-mediated synergistic effect is still not completely elucidated.

MATERIALS AND METHODS

Phosphorylation of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) was examined by western blot. Cell viability was examined by crystal violet staining. The importance of ERK1/2 phosphorylation was assessed by overexpression and blockage of mitogen-activated protein kinase kinase 1 (MEK1).

RESULTS

Chrysin induced sustained ERK1/2 phosphorylation of HCC cells in both time- and dose-dependent manners. Overexpression of MEK1 enhanced, whereas blockage of MEK1 led to loss of chrysin-synergized sorafenib effect, through modulating ERK1/2 phosphorylation level.

CONCLUSION

These results identify another novel mechanism underlying chrysin-mediated synergistic effect on sorafenib activity in HCC cells.

c-Met inhibition is required for the celecoxib-attenuated stemness property of human colorectal cancer cells

Cyclooxygenase-2 (COX-2) is frequently overexpressed and enhances colorectal cancer (CRC) tumorigenesis, including cancer stem cell (CSC) regulation. Accordingly, nonsteroidal anti-inflammatory drugs (NSAIDs), inhibiting COX-1/2 activity, are viewed as potential drugs for CRC treatment. Accumulated evidence indicates that celecoxib has the most potency for antitumor growth among NSAIDs and the underlying mechanism is only partly dependent on COX-2 inhibition. However, the potency of these NSAIDs on CSC inhibition is still not known. In this study, we found that among these NSAIDs, celecoxib has the most potency for CSC inhibition of CRC cells, largely correlating to inhibition of c-Met, not COX-2. Further analysis reveals that c-Met activity was required for basal CSC property. Silence of c-Met blocked whereas overexpression of c-Met enhanced the celecoxib-inhibited CSC property. Collectively, these results not only first elucidate the mechanism underlying celecoxib-inhibited CSC but also indicate c-Met as a critical factor for the CSC property of CRC cells.