Effect of protein-polysaccharide hybrid gelator system on the material properties and 3D extrusion printability of mashed potatoes.

Mashed potatoes (MP) are famous as ready-to-eat products due to their excellent taste and texture. Problems such as complex injection occur when MP is used as a 3D printing material. To improve the smoothness of MP loading into a 3D syringe barrel and its 3D extrusion printability, the effects of the protein-polysaccharide hybrid gelator developed with different gelatin-B (GB, 2%, 4%, 6%) and κ-carrageenan (KG, 1%) on the rheology and 3D extrusion printability of MP were studied. The rheological results showed that the MP developed a glass transition temperature by adding the hybrid gelator. Adding 1% KG+6% GB (w/w, dry base) to the hybrid gelator has good shear thinning and self-supporting properties and showed the best geometric accuracy. In the extrusion stage, the yield stress, the consistency index (K), and the flow behavior index (n) of MP were 470.69 Pa, 313.48 Pa·sn, and 0.159, respectively. In the recovery stage, the shear recovery time is 30 s. In the self-supporting stage, the storage modulus and loss modulus are significantly higher than those of other groups and have the strongest mechanical properties. Moreover, water distribution, Fourier transform infrared spectroscopy, X-ray diffraction analysis, and microstructure of printed MP with different hybrid gelators were observed. The addition of hybrid gelators reduced the content of free water in MP. Hybrid gelators did not produce new functional groups in the printed materials and did not change the structure of starch. These results provide new insights for applying protein and polysaccharide hybrid gelators in 3D printing.

Fatsioside A­induced apoptotic death of HepG2 cells requires activation of AMP­activated protein kinase.

Hepatocellular carcinoma (HCC) is one of the most malignant types of human primary tumor and has a poor prognosis, therefore, the development of novel therapeutic modalities is necessary. Fatsioside A is a novel baccharane­type triterpenoid glycoside, which is extracted from the fruits of Fatsia japonica. Previous data has revealed that fatsioside A can exert growth inhibition, cell cycle arrest and induce apoptosis in human glioma cells. However, no detailed investigations have been performed to determine its action on human hepatocellular cells, and the exact mechanisms underlying the induction of apoptosis remain to be elucidated. The aim of the present study was to investigate the anticancer effect of fatsioside A in the HepG2 human HCC cell line, and to investigate the underlying mechanisms by focusing on the AMP­activated protein kinase (AMPK) signaling cascade. The results of the present study demonstrated that fatsioside A induced apoptotic death of the human HepG2 HCC cells, which was associated with a marked activation of AMPK and increased expression of the downstream acetyl­CoA carboxylase carboxylase. Inhibition of AMPK by RNA interference or by its inhibitor, compound C, suppressed fatsioside A­induced caspase­3 cleavage and apoptosis in the HepG2 cells, while AICAR, the AMPK activator, elicited marked cytotoxic effects. Together, these results suggested that fatsioside A­induced apoptotic death requires AMPK activation in HepG2 cells.