Abstract A chitosan-based edible coating was prepared by incorporating γ-polyglutamic acid and curcumin. The physical, mechanical and antimicrobial properties of the chitosan/γ-polyglutamic acid/curcumin edible coating were characterized. Furthermore, the effect of chitosan/γ-polyglutamic acid/curcumin edible coating on the shelf-life of fresh beef was investigated. The γ-polyglutamic acid and curcumin incorporation greatly improved the performance of chitosan coating, including coating formation and antimicrobial activity. After the application of coating, the chitosan/γ-polyglutamic acid/curcumin edible coating had a good protection effect on the color of beef and was conducive to prolonging the shelf life of beef with good quality compared to pure curcumin edible coating. These results revealed that application of chitosan/γ-polyglutamic acid/ curcumin edible coating will be a good way to preserve freshness of fresh beef.

Abstract Background Melanoma took top position among the lethal cancers and, despite there have been some great attempts made to increase the natural life of patients with metastatic disease, long-lasting and complete remissions are few. Piceatannol, owns the similar function as resveratrol, has been defined as an anti-cancer agent playing important role in inhibition of proliferation, migration and metastasis in various cancer. Thus, we aim to investigate the anti-cancer effect and mechanisms of piceatannol in melanoma cells. Methods Melanoma cell lines WM266-4 and A2058 were treated either with or without piceatannol. Cell viability and cell apoptosis were assessed by using MTT and Annexin V/PI assay, respectively. Cells were transfected with specific miRNA using Lipfectamine 2000. miRNA bingding ability to 3'-UTR region within specific gene was assed by firefly luciferase analysis. Gene and protein expression was eveluated by qRT-PCR and western blot analysis, respectively. Results Our study showed that piceatannol inhibited WM266-4 and A2058 cells growth and induced apoptosis. Totally, 16 differentially expressed miRNAs were screened out including 8 up-regulated and 8 down-regulated miRNAs. Expression level of miR-181a is significantly higher in piceatannol-treated cells than normal control and is lower in melanoma cancer tissues than its adjacent normal tissues. Bcl-2 is a target gene of miR-181a. Moreover, silencing of miR-181a reverses the decrease of cell viability induced by piceatannol in WM266-4 and A2058 cells. Taken together, present study uncovered the ability of piceatannol to repress melanoma cell growth and clarified the contribution of miR-181a in the anticancer role of piceatannol. Conclusion The present study proposes that piceatannol can be taken into account to be a hopeful anticancer agent for melanoma.