Improved protease activity of Pixian broad bean paste with cocultivation of Aspergillus oryzae QM-6 and Aspergillus niger QH-3

BACKGROUND: The preparation of broad bean koji is a key process in the production of Pixian broad bean paste (PBP). Protease is essential for the degradation of proteins during PBP fermentation. To obtain broad bean koji with high protease activity using the cocultivated strains of Aspergillus oryzae QM-6 (A. oryzae QM-6) and Aspergillus niger QH-3 (A. niger QH-3), the optimization of acid and neutral protease activities was carried out using Box­Behnken design with response surface methodology (RSM). RESULTS: The optimum conditions were found to be as follows: inoculation proportion (X1), 3:1 (A. oryzae QM-6: A. niger QH-3, w/w); culture temperature (X2), 33°C; inoculum size (X3), 0.5% (w/w); incubation time (X4), 5 d. The acid and neutral protease activities were 605.2 ± 12.4 U/g and 1582.9 ± 23.7 U/g, respectively, which were in good agreement with the predicted values. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles revealed that the broad bean koji extracellular proteins in the case of cocultivation were richer compared to those in the case of A. oryzae QM-6 or A. niger QH-3 strain only. In addition, the free amino acids (FAAs) in the fermentation product were 55% higher in the cocultivation process than in that involving only A. oryzae QM-6, further confirming the diversity of proteases in the fermentation products. CONCLUSIONS: The optimal conditions of koji-making in PBP were obtained using RSM. The cocultivation of A. oryzae and A. niger increases the overall enzyme activities in the culture medium and the FAAs content, which would thus have potential application in the PBP industry.

Gramicidin inhibits human gastric cancer cell proliferation, cell cycle and induced apoptosis

BACKGROUND: Gastric cancer is a common malignant tumor with high morbidity and mortality worldwide, which seriously affects human health. Gramicidin is a short peptide antibiotic which could be used for treating infection induced by bacteria or fungi. However, the anti-cancer effect of gramicidin on gastric cancer cells and its underlying mechanism remains largely unknown. RESULTS: Gastric cancer cells SGC-7901, BGC-823 and normal gastric mucosal cells GES-1 were treated with different concentrations of gramicidin respectively. The results of CCK-8 experiment revealed cellular toxicity of gramicidin to cancer cells while cell colony formation assay showed that gramicidin significantly inhibited the proliferation of gastric cancer cells, but had little effect on normal gastric mucosal cells. In addition, the wound healing assay showed that gramicidin inhibited the migration of SGC-7901 cell. Meanwhile, apoptosis and cell cycle analysis revealed that gramicidin induced cell apoptosis with G2/M cell cycle inhibition. Furthermore, western blot analysis demonstrated that gramicidin down-regulated the expression of cyclinD1 and Bcl-2 as well as the FoxO1 phosphorylation. CONCLUSIONS: The current study illustrated the anti-tumor activity of gramicidin on gastric cancer cells, providing a possibility for gramicidin to be applied in clinical practice for the treatment of gastric cancer.

Apoptosis and antitumor effects between Beta-elemene and astragaloside and drug mechanism analysis

Beta-elemene is an effective anticancer drug extracted from Rhizoma curcumae. It is a non cytotoxic antineoplastic agent, which can obviously inhibit the proliferation of tumor cells. In this paper, we observed the proliferation inhibition and apoptosis of Beta-elemene and Astragaloside on human hepatoma cell HepG2 and mouse hepatoma H22 cells, and provide a reference for further proof that Beta-elemene and astragaloside can induce tumor cell apoptosis. The results showed that after 24 h, group astragaloside, Beta-elemene group and combined treatment group had inhibitory effect on the proliferation of HePG2 cells, in which the combined treatment group had the best effect and the inhibition rate reached 66.71%. The apoptosis rates of Hep G2 cells in the drug treatment group were 0.9%, 22.4% and 45.8%, respectively, and there was statistical significance in each drug group compared with the control group [P<0.05]. It can be seen that Astragalus membranaceus and â-elemene have obvious inhibitory effects on the growth of liver cancer cells and their combination has synergistic effect

Antibacterial effects and tensile bonding strength of orthodontic adhesive containing nanohydroxyapatite / 口腔疾病防治

Objective @# To evaluate the tensile bonding strength (TBS) and antibacterial properties when an orthodontic adhesive was added with nanohydroxyapatite (nHAp). @*Methods@#Light cure orthodontic adhesive (Grengloo) was blended with 2% TiO2 containing nHAp nanoparticles by 0%、10%、20%、30% (w/w), while the control was not blended with nHAp. Brackets were bonded to extracted premolars by these new adhesives. TBS of 5groups were determined, and the adhesive remnant index (ARI) scores were assessed. Composite discs specimen were prepared, incubated with bacterial suspension for 48 h, and tested for antibacterial properties. @*Results @#No significant difference was found in ARI. The colony unit counts and lactate productionof the groups containing 2%TiO2 were significantly reduced. The colony unit counts and lactate production were without relationship with nHAp. The tensile bonding strength drastically decreased when containing more than 10% nHAp. @* Conclusin@#nHAp might not enhance the antibacterial effects of Grengloo.