Gelatin/carboxymethylcellulose composite film combined with photodynamic antibacterial: New prospect for fruit preservation.

Plastic packaging causes environmental pollution, and the development of simple and effective biodegradable active packaging remains a challenge. In this study, gelatin (G) and sodium carboxymethylcellulose (CMC) were used as film materials, with the addition of curcumin (Cur), a photosensitive substance, to investigate the changes in the physical and chemical properties of the film and its application in fruit preservation. The results demonstrated that Cur was compatible with the film. With the addition of Cur, the thickness of the film increased up to 1.3 times, while the moisture content was reduced to 12.10 %. The tensile strength (TS) and elongation at break (EAB) of the film can reach 8.84 MPa and 19.33 %, respectively. The photodynamic antibacterial experiment revealed that the film containing 0.5 % Cur exhibited the highest antibacterial rate, reaching 99.99 % against Staphylococcus aureus (S. aureus) and 95 % against Escherichia coli (E. coli). During storage, the grapes remained unspoiled for up to 9 days after being phototreated with the film and the microbial content of the skin was much lower than that of the control group. In addition, Cur provided antioxidant activity for the film, with a scavenging activity of 39.54 % against the 2,2-diphenyl-1-picrind radical (DPPH). Bananas exposed to the film-forming solution for a short period of time remained fresh for up to 6 days. During preservation, the weight of the treated bananas decreased more slowly than that of the control group. In addition, the activity of SOD on the 7th day was approximately 20 U/g higher than that of the control group, which helped to reduce oxidative stress during banana preservation. In summary, G-CMC/Cur film is an optional fruit-cling film that can be used in food packaging.

Photodynamic antibacterial application of TiO2/curcumin/hydroxypropyl-cyclodextrin and its konjac glucomannan composite films.

Although photodynamic therapy (PDT) has great advantages for the treatment of bacterial infections, photosensitizers (PSs) often have many disadvantages that limit their application. Improving the shortcomings of PSs and developing efficient PDT antimicrobial materials remain serious challenges. In this study, a nanocomposite drug (TiO2/curcumin/hydroxypropyl-cyclodextrin, TiO2/Cur/HPCD) was constructed and combined with konjac glucomannan to form composite films (TiO2/Cur/HPCD films, KTCHD films). The stabilities of TiO2 and Cur were improved in the presence of HPCD. The particle size of TiO2/Cur/HPCD was approximately 33.9 nm, and the addition of TiO2/Cur/HPCD enhanced the mechanical properties of the films. Furthermore, TiO2/Cur/HPCD and KTCHD films exhibited good biocompatibility and PDT antibacterial effects. The antibacterial rate of TiO2/Cur/HPCD was 74.46 % against MRSA at 500 µg/mL and 99.998 % against E. coli at 400 µg/mL, while it was adsorbed on the surface of bacteria to improve the effectiveness of the treatment. In addition, studies in mice confirmed that TiO2/Cur/HPCD and KTCHD films can treat bacterial infections and promote wound healing, with a highest wound healing rate of 84.6 % in the KTCHD-10 films + Light group on day 12. Overall, TiO2/Cur/HPCD is a promising nano-antibacterial agent and KTCHD films have the potential to be employed as antibacterial and environment-friendly trauma dressings.

Total glucosides of peony attenuates experimental autoimmune encephalomyelitis in C57BL/6 mice.

Total glucosides of peony (TGP), an active compound extracted from the roots of Paeonia lactiflora Pall, has wide pharmacological effects on nervous system. Here we examined the effects of TGP on experimental autoimmune encephalomyelitis (EAE), an established model of multiple sclerosis (MS). The results showed that TGP can reduce the severity and progression of EAE in C57 BL/6 mice. In addition, TGP also down-regulated the Th1/Th17 inflammatory response and prevented the reduced expression of brain-derived neurotrophic factor and 2',3'-cyclic nucleotide 3'-phosphodiesterase of EAE. These findings suggest that TGP could be a potential therapeutic agent for MS.

Minocycline enhances hippocampal memory, neuroplasticity and synapse-associated proteins in aged C57 BL/6 mice.

Previous studies have suggested that minocycline can attenuate cognitive deficits in animal models of conditions such as Alzheimer's disease and cerebral ischemia through inhibiting microglia associated anti-inflammatory actions. However the pathway that minocycline targets to enhance cognitive performance is not fully defined. Here we examined the effects of minocycline on learning and memory in aged (22-month-old) C57 BL/6 mice. We treated one group of mice with minocycline (30 mg/kg/day), and another group of mice with donepezil (2 mg/kg/day) as a positive control. The Morris water maze and passive avoidance tests were used to evaluate the effects of minocycline on learning and memory deficits. We also used high-frequency stimulation-induced long-term potentiation and Golgi-Cox staining to assess the effect of minocycline on synaptic plasticity and synaptogenesis. The effects of minocycline on synapse-associated signaling proteins were determined by western blot. We found that minocycline ameliorates cognitive deficits, enhances neuroplasticity, activates brain-derived neurotrophic factor- extracellular signal-regulated kinases signaling and increases expression of Arc, EGR1 and PSD-95 in the CA1 and dentate gyrus regions of the hippocampus in aged mice. The effects of minocycline in aged mice were similar to those of donepezil. Our results suggest that minocycline could improve learning and memory through enhancing synaptic plasticity and synaptogenesis, modulating the expression of synapse-associated signaling proteins, which provide a rationale for exploring the viability of using minocycline treatment in cognitive deficits.