RESUMO
In fish processing, reducing the waste rate and increasing the economic value of products is an important issue for global environmental protection and resource sustainability. It has been discovered that cuttlefish bones can be an excellent resource for producing attractive amounts of chitin and chitosan. Therefore, this study optimized chitosan extraction conditions using response surface methodology (RSM) to establish application conditions suitable for industrial production and reducing environmental impact. In addition, Fourier-transform infrared spectroscopy (FTIR), 1H NMR and scanning electron microscope (SEM) characteristics of extracted chitosan were evaluated. The optimum extraction conditions for chitosan from cuttlebone chitin were 12.5M NaOH, 6 h and 80 °C, and the highest average yield was 56.47%. FTIR spectroscopy, 1H NMR, and SEM identification proved that the chitosan prepared from cuttlefish bone has a unique molecular structure, and the degree of deacetylation of chitosan was about 81.3%. In addition, it was also confirmed that chitosan has significant anti-oxidation and oil-absorbing abilities. This research has successfully transformed the by-products of cuttlefish processing into value-added products. The process not only achieved the recycling and utilization of by-products but also enhanced industrial competitiveness and resource sustainability.
RESUMO
Cancer is the most common disease worldwide, with death often occurring as a result of metastasis. Thus, interfering with metastasis has been regarded as a promising strategy to improve the current cancer treatments. However, exploration and development of novel anti-metastatic agents remains a major challenge. Recent evidence indicated that a polysaccharide isolated from Taxus yunnanensis suppressed tumor cells proliferation. With the objective of seeking bioactive extracts, we had previously isolated, purified and characterized a complex, water-soluble polysaccharides, PSY-1, from the leaves of Taxus chinensis var. mairei, and identified its anti-neoplastic effects. In this study, we focused on the effects of PSY-1 on cancer metastasis and its mechanism(s). The results illustrated that PSY-1 effectively suppressed the migration and invasion ability of the melanoma cancer cell line B16-F10, caused down-regulation of MMP-2 and MMP-9, and that the NF-kappaB pathway was involved in the anti-metastatic effects imposed by PSY-1.