Veterinary Research Forum

Abstract Spinal cord injury (SCI) results in the demise of neural and glial cells, as well as extensive neuro- inflammation. Hydrogel formulation for prolonged release of melatonin (Mel) has demonstrated enhanced effectiveness and safety. In this study, SCI was induced in rats by contusion at the T₉ vertebrae. Chitosan (CH) /Mel hydrogel was fabricated and characterized using scanning electron microscopy (SEM) and Fourier transform infra-red to examine its specific effects on the apoptotic and histopathological markers of SCI. The scanning electron microscopy images revealed the presence of porosity in the CH/Mel hydrogel. Forty male Wistar rats were randomly divided into five groups (n = 8), including sham, control (SCI-induced treated locally with 100 µL CH hydrogel), and groups 3, 4, and 5 (treated locally immediately after SCI induction with 100 µL CH hydrogel containing 50.00, 100, and 200 mg kg^-1 Mel, respectively). The CH/Mel hydrogel at a dose of 25.00 mg mL^-1 significantly increased cell viability in the U87 cell line after 24 hr of exposure. However, at 48 and 72 hr after exposure, Bax and Bcl2 expressions were significantly increased and reduced in the SCI group, respectively, and CH/Mel hydrogel could alleviate their expressions, especially in higher doses. In addition, S100 protein expression was up-regulated in the SCI group. However, CH/Mel hydrogel down-regulated it in a dose-dependent manner. The histopathological findings demonstrated that CH/Mel hydrogel dramatically improved SCI outcomes, like vacuolar degeneration, necrosis, and severe cystic and axonal degenerations. In conclusion, CH/Mel hydrogel induced neuroprotection and it had the potential to be used as a therapeutic agent for the treatment of SCI.

Abstract Chitosan bears numerous properties, such as biocompatibility, biodegradability and non-toxicity making it suitable for use in different biomedical fields. Zinc (Zn) is required for fibroblasts proliferation and collagen synthesis as essential elements of wound healing. Its nanoparticles are well known for their capability to enhance wound healing by cell adhesion and migration improvement through growth factors-mediated mechanisms. Poor blood supply and unique histological characteristics of tendon make its regeneration always slow. Also, adhesion formation between tendon and its surrounding tissues is another problem for neotendon to return to its normal structure and functional activities. In this study, a novel tubular scaffold of zinc oxide (ZnO) nanoparticles loaded chitosan has been fabricated for tendon repair. Experimental complete tenotomy of deep digital flexor tendon in a rabbit model was done and scaffolds were placed in the transected area after two ends suturing. After four and eight weeks, adhesion formation around the tendons and tissue reaction to the scaffolds were evaluated macroscopically. Inflammation, angiogenesis and collagen fibers arrangement were also analyzed in histopathological evaluations. After eight weeks, the scaffolds were absorbed completely, adhesions around the tendon were decreased and there was no sign of significant tissue reaction and/or infection in histopathological analyses. The reduced adhesion formation, improved gliding function and better histopathological characteristics suggest this scaffold application as a potential therapy in treatment of tendon acute injuries.

Abstract Beef is susceptible to rapid spoilage due to its high amount of protein (18.00%) and moisture (72.00%). Food industries have recently found methods to extend beef shelf-life. The influence of beef dipping in hydro-alcoholic extract of sumac (SE) and chitosan (CH) coating incorporated with Zataria multiflora essential oil (ZEO) on microbial, chemical and sensory quality of beef was evaluated during refrigerated storage. Total viable counts (TVC), lactic acid bacteria, Pseudomonas spp., Enterobacteriaceae and yeasts-molds, total volatile nitrogen (TVN), thiobarbituric acid reactive substance values (TBARS) and peroxide value (PV) were founded to be significantly lower in all treatment groups compare to control groups during storage time.The highest level of antimicrobial effects induced by chitosan, SE 4.00% and ZEO. We found that in TVC (3.69 log CFU g^-1 reduction compared with control group (sterile distilled water), Enterobacteriaceae (3.61 log CFU g^-1 reduction) and lactic acid bacteria (2.67 log CFU g^-1 reduction), respectively. Sumac gave a pleasant effect on sensory attributes and chitosan coating enriched with ZEO significantly improved sensory scores except for flavor factor. The results revealed the bio preservative properties of chitosan, hydro-alcoholic extract of sumac and Z. multiflora Boiss essential oil during refrigeration in normal packaging of beef.

Abstract The aim of our study was to evaluate the effects of chitosan as immune stimulator on some hematological parameters and stress resistance in rainbow trout. Nine hundred rainbow trout (with initial body weight of 25 ± 0.1 g) were obtained from a local farm and acclimated to the laboratory conditions for one week. After that fish were randomly divided into four groups in three replicates. Each group received chitosan in diet at four concentrations as 0 (Control), 0.25, 0.5 and 1 percent chitosan, respectively. The trial was conducted for 8 weeks then feeding with chitosan stopped for 3 weeks later and during this time all fish were feed by control diet. The sampling was conducted to assay the hematological parameters of all groups every two weeks. In this study we assayed the resistance of fish against some environmental stresses immediately after changing the diet to the control. The results showed that using 0.25 percent chitosan in trout diets had a significant effect (P < 0.05) on hematological indices and stress resistance of rainbow trout in comparison the control group. Serum glucose level was higher in all treatment than control without any significance difference (P < 0.05). Based on the obtained results it concluded that the adding chitosan at 0.25 percent into the diet could enhance the hematological parameters and resistance against some environmental stresses in rainbow trout.