Antidepressant-like effect of endogenous SO2 on depression caused by chronic unpredictable mild stress.

Sulfur dioxide (SO2) is a toxic gas with harmful effects on various organs. However, recent studies have confirmed the protective effect of SO2 on ischemic heart disease, atherosclerosis, and lung infections. Therefore, the present study was designed to investigate the effect of endogenous SO2 on depression. The chronic unpredictable mild stress (CUMS) model was performed to cause depression. Depression-like behaviors in animals were determined using an open-field test, forced swimming test, and sucrose consumption. Animal spatial learning and memory were also assessed using the Morris water maze. Besides, the oxidative status of the hippocampus and serum corticosterone level were evaluated. A reduction in the tendency to consume sucrose, mobility, and curiosity, as well as learning and memory disorders were observed in CUMS animals. Depressed animals treated with SO2 revealed a significant improvement in behavioral and cognitive functions. SO2 also reduced neuronal damage and lipid peroxidation of the hippocampus and serum corticosterone level in the CUMS group. Various shreds of evidence support a mutual relationship between inflammation and depression; also, growing studies show the role of oxidative stress in the pathogenesis of mood-related disorders such as depression. This study indicated that increased hippocampal malondialdehyde (MDA) and serum corticosterone levels can be due to the existence of oxidative stress and possible activation of inflammatory processes. SO2 donors diminished MDA and corticosterone levels in depressed animals. According to the study results, SO2 may be able to reduce tissue damage and eventually behavioral disorders caused by depression by lowering oxidative stress and inflammation.

Use of gamma irradiation technology for modification of bacterial cellulose nanocrystals/chitosan nanocomposite film.

The objective of this work was to investigate the influence of different gamma ray dosages (5, 10, and 10 kGy) on the structural, mechanical, surface and barrier properties of chitosan (Ch) based nanocomposite film. The results showed gamma irradiation caused an increase in the surface hydrophobicity, water vapor permeability and sensitivity of films to water and also, yellowness and opacity of films increased, simultaneously. By increasing the irradiation doses up to 10 kGy, the mechanical properties of Ch/BCNC film was significantly enhanced. As observed by FTIR spectra, no change occurred in the chemical functional groups of the films during irradiation. XRD studies confirmed that crystallinity of films was increased after irradiation. The nanocomposite film irradiated by 10 kGy had the highest thermal stability. In conclusion, gamma radiation can be considered as a safe method for sterilization of foods and modification of Ch/BCNC film properties.

Preparation and characterization of cellulose nanocrystals from bacterial cellulose produced in sugar beet molasses and cheese whey media.

Bacterial cellulose (BC) is gaining considerable attention due to its unique physicochemical and mechanical properties. In this study, BC production by Gluconacetobacter xylinus PTCC 1734 in sugar beet molasses, cheese whey and standard Hestrin-Schramm (HS) media was evaluated. The synthesized BC was hydrolyzed by sulfuric acid to prepare bacterial cellulose nanocrystals (BCNC). The results showed that treated sugar beet molasses led to the highest BC concentration and productivity, followed by treated cheese whey. Structural analysis of BC and BCNC was carried out by Fourier Transform Infrared (FTIR) spectroscopy. The crystallinity index of the BCNC determined by X-ray diffraction (XRD) was higher than BC. The morphological analysis carried out by FE-SEM showed that microfibrils diameter decreases with acid treatment. TEM images confirmed the formation of rod like cellulose nanocrystals having an average diameter and length of 25 ±â€¯5 and 306 ±â€¯112 nm, respectively. In conclusion, food industrial byproducts can be used as cost-effective culture media to produce BC for large-scale industrial production and isolated cellulose nanocrystals are useful in the fabrication of bio-nanocomposite films for food packaging applications.