BACKGROUND: Numerous studies have investigated the positive effect of chitosan and nano-chitosan loaded clinoptilolite on growth performance, digestive enzyme activity, and intestinal histomorphology in different fish species. However, there are no data evaluating the potential effect of the composites on the fish stomach.OBJECTIVES: In the current study, the effects of chitosan and nano-chitosan loaded clinoptilolite on histological features and pepsin activity in the rainbow trout stomach were considered.METHODS: Chitosan and nano-chitosan loaded clinoptilolite were synthesized, and then two hundred and forty fish (~27.75 g) fish were distributed in eight groups each in three replicates. Ten days after adaptation, the fish were fed with eight diets, including control diet (CTR), clinpotilolite (T1), chitosan composites (T2, T3, T4), and nano-chitosan composites (T5, T6, T7) for 70 days. Afterward, all fish in each tank were anesthetized in clove extract (50 μl/l), and tissue samples were obtained for pepsin activity (n= 5) and histological assay (n = 5).RESULTS: The groups administrated with nanochitosan composites showed the highest pepsin activity (P˂0.05). Additionally, histological examinations exhibited a higher epithelial height, increased mucosal density, and oxynticopeptic cells hypertrophy in fish fed composites compared to the CTR group (P˂0.05). Meanwhile, nanochitosan composite administration could cause higher reaction of secreted granules to periodic acid–Schiff (PAS) staining.CONCLUSIONS: The findings demonstrated the potential application of chitosan and nano-chitosan loaded clinoptilolite composites for improvements in the histomorphology and pepsin activity of the rainbow trout stomach, resulting in higher growth performance.

Several new topical products have been applied to enhance wound healing and reduce scar formation. The present study aimed to evaluate the potential of the topically applied hyaluronic acid (HA) serum and chitosan (CH) gel for skin wound healing in dogs. Ten adult mongrel dogs were divided into two groups (n = 5 for each). Experimental skin wounds were created in all animals. Eight full-thickness round skin wounds of 2 cm diameter were made on both sides (four for each side) over the dog's dorsal area, where the left side wounds were kept as a control and treated with saline solution only. HA serum and CH gel were used to treat the right-side wounds in the first and second groups, respectively. Wound healing was evaluated clinically and histologically at the 7th, 14th, and 21st days post-treatment. In addition, the tensile strength was measured in both treated wound groups and compared with the control wounds and the normal skin. The results showed that HA-treated wounds exhibited higher wound contraction and better tensile strength compared with CH-treated group. In addition, the histological findings of HA-treated wounds showed marked improvement in histological repair scores compared with CH-treated ones. We concluded that topical HA in a serum formulation provided better skin wound healing compared to CH-treated group.

The main objective of the current study was to apply chitosan as a stabilizing material to improve the quality and extend the shelf life of camel meat emulsion. Chitosan may achieve these roles through the adsorption of the protective layer at oil-water interfaces and viscosity enhancement. The addition of chitosan at a concentration of 0.8% resulted in overcoming the detrimental impact of the heat-stable camel connective tissue and improve emulsion stability. The obtained results revealed that the addition of chitosan significantly decreased the total expressible fluid, released water, released fat and Thiobarbituric Acid Reactive Substances (TBARS) of raw camel meat batter with a significant increase in the batter's viscosity and water Holding Capacity (WHC) compared to the control. After cooking, the addition of chitosan led to significant reduction of TBARS value and extended the shelf life of camel sausage to 5 months at 5 °C when compared to the control that accepted only for 3 months. Moreover, the chitosan formulated sausage showed lower lightness (L*), yellowness (b*) and shear force values than the control throughout chilled storage at 5 °C for 5 months. Improvement of redness (a*), the sensory parameters and ultrastructure of camel luncheon sausage was also observed by the chitosan addition. Therefore, chitosan can be applied as a thickener and stabilizer for camel meat emulsion and produce more stable products through 5 months of refrigerated storage. Furthermore, the addition of chitosan may be safely used by meat processors as a novel technique for improving the quality and extending the shelf life of camel luncheon.