فصلنامه پاتوبیولوژی مقایسه ای
سال نوزدهم شماره 75 (بهار 1401)

Alzheimer's disease is the most important cause of dementia in human societies and the elderly population. One of the most important symptoms of this disease is amyloid plaques in the hippocampus. Inflammation and oxidative stress play an important role in the development of Alzheimer's disease. Nerolidol is one of the many metabolites of plants and has antioxidant and anti-inflammatory properties. Therefore, the aim of this study was to evaluate the effect of nerolidol on beta amyloid-induced model of Alzheimer's in rats. 48 male Wistar rats randomly divided into 8 groups including control, sham, streptozotocin induced model of Alzheimer's, Alzheimer's and drug solvent, Alzheimer's and treatment with donepezil, Alzheimer's and treatment with nrolidol dose 50, Alzheimer's and treatment with nrolidol dose 100 and protection groups (pre-treatment with nerolidol before Alzheimer's induction). Rats weight, catalase activity, and amount of amyloid plaque were measured. Histological studies were performed by fluorescent staining. Streptozotocin increased amyloid plaques, and decreased rat's weight and catalase activity. Donepezil and nerolidol, especially at doses of 100 and in the protective group, reduced the symptoms of Alzheimer's disease through weight gain, increased catalase activity, and decreased amyloid plaques. These findings show that nerolidol can be effective in improving Alzheimer's disease and its damage, and may possibly be effective in preventing Alzheimer's in people with a family history of Alzheimer's.

Many animals have a fear of novelty, which is known as neophobia. In the wild, avoiding new predators, meals, items, and places has an impact on life history and how animals adapt to new situations. However, because of the bird's anatomical structure, tolerance level, and physiology, this fear can occasionally cause irreparable harm and even death. The aim of this study was to evaluate the histopathological lesions leading to death in pink- collar parrots with neophobia. Necropsy was done and peripheral blood was obtained from the femoral vein and heart after a pink-collar parrot died suddenly. In addition, toxicological and biochemistry samples of bile, vitreous fluid, cerebral fluid, pericardial fluid, stomach contents, feathers, and samples of particular tissues (liver, kidney, and skeletal muscle) were taken. Pathological examinations of heart, lung, and brain tissues were also performed. It was clear that the right atrium had ruptured. The number of aortic cysts and the origin of the coronary artery had altered, indicating that cardiac arrest was more likely. Regurgitation, thickening or torsion of the cheeks' margins, rupture, perforation, calcification, fusion, or alterations in valve flushing were all visible problems in cardiac valves. The Papillary Muscles and the Corda Tendina had changed. Sudden death occurs at the end of a chain of events that leads to cardiac arrest; these events are commonly ventricular fibrillation (VF) or, less frequently, severe bradyarrhythmia.

Some yeasts, such as Z. bisporis and P. occidentalis, still need further study to determine their functional characteristics and how to use them in the food and pharmaceutical industries. The purpose of this study is the investigation of the functional and antioxidant properties of Z. bisporis and P.occidentalis isolated from Kombucha.

for this purpose, antioxidant capacity by 1,1-diphenyl-2-picrylhydrazyl radical method (DPPH) and functional properties (survival under simulated conditions of the gastrointestinal system, hydrophobicity, auto aggregation and antioxidant properties, antimicrobial activity against food-borne pathogenic bacteria such as Staphylococcus aureus, Yersinia enterocolitica, Bacillus cereus and Escherichia coli was investigated by spot method.

The results of this research showed that Z.bisporis and P.occidentalis have excellent antioxidant activity of about 67.67 and 69.18 percent, auto aggregation capacity of about 92.44 and 87.30 percent. After 24 hours and high hydrophobicity activity has provided about 87.51 and 86.127 percent. Also, the survival percentage of these isolates under the simulated conditions of the gastric juice was about 54.87 and 88.87%, under the simulated conditions of the duodenum, it was 97.09 and 94.40%. Z. bisporis studied in this test had antimicrobial activity against Yersinia enterocolitica, but did not show any activity against the tested microorganisms.

According to the obtained results, it is suggested to use more of these strains as a natural source of antioxidant and probiotic supplement in the production of food and pharmaceutical products after completing additional tests.

Mastitis, as a most costly disease of dairy cows, causes a lot of damage to the livestock industry in the world every year. One of the most important bacteria which causes clinical mastitis in cattle is S. aureus, which has become resistant to most common antibiotics in veterinary medicine. Therefore, researchers are looking for new methods in the treatment of such infections, in which the pigments of microorganisms fall into this category. The aim of this recent study was to optimize the production of carotenoid pigments by Rhododorula yeast and to investigate its antimicrobial effect on S. aureus isolates To isolate S. aureus, samples were taken from the milk of 100 cows with mastitis and the femA gene was identified for molecular confirmation among suspicious isolates of Staphylococcus by PCR method. Also, the isolate of R. glutinis obtained from one of the samples of mastitis was further examined and used as a sample of yeast producing pigment. The results showed that in addition to S. aureus as one of the causative agents of mastitis in dairy cattle, but also the yeast R. glutinis can be a causative agent of mastitis. The inhibitory effect on the growth of Staphylococcus using the pigment extracted from R. glutinis was also quite evident and more than 80% of S. aureus isolates were sensitive to the pigment at a concentration of 200 μg. R. glutenis inhibits excellent growth in S. aureus as one of the leading causes of mastitis in cows. The cause is the appearance of synthetic antibiotics and the reduction of microbial resistance.

Food intake is a set of physiological mechanisms affecting different central nervous system areas. The melanocortin system plays an important role in the central control of food intake in birds. Nesfatin-1 reduces food intake in birds. The present study was conducted to investigate the effect of the melanocortin system on food intake caused by nesfatin-1 in broiler chickens. 36 broilers were randomly divided into three experimental groups. Each experiment included a control group and 3 treatment groups (12 chickens in each group). In all experiments, after 3 hours of food deprivation (FD3), chicks received either control diluent or drug solution by intracerebroventricular (I.C.V.) injection. Then the birds had ad libitum access to the ‎food and fresh water, and then cumulative food intake (gr) was measured based on the ‎percentage of the body (%BW). In the first experiment, chickens in the first group were given the control solution, the second group nesfatin-1 (40 ng), the third group SHU9119 (0.5 nmol, antagonist of MC3/MC4 receptors), and the fourth group nesfatin-1 + SHU9119 intracerebroventricularly was injected. In the second experiment, chickens in the first group were injected with the control solution, the second group with nesfatin-1 (40 ng), the third group with MCL0020 (0.5 nmol, MC4 receptor antagonist), and the fourth group with nesfatin-1+ MCL0020. In the third experiment, chickens in the first group were injected with the control solution, the second group with nesfatin-1 (10 ng), the third group with MTII (2.45 pmol, an agonist of MC3/MC4 receptors), and the fourth group with nesfatin-1+ MTII. The results showed that the injection of nesfatin-1 with a dose of 40 ng decreased food intake (p<0.05). Co-injection of nesfatin-1 and SHU9119 and co-injection of nesfatin-1 and MCL0020 inhibited the hypophagia caused by nesfatin-1 (p < 0.05). Injection of Nesfatin-1 with a dose of 10 ng and MTII with a dose of 2.45 pmol did not affect food intake (p > 0.05). While the co-injection of nesfatin-1 with a dose of 10 ng and MTII with a dose of 2.45 pmol reduced food intake (p < 0.05). According to the results, food intake caused by nesfatin-1 in broilers is probably mediated by the melanocortin system.

The present study, evaluated the effect of PM2/5exposure on the cerebral tissue of neonatal rats. 24 female Wistar albino rats after mating and pregnancy, classified into three groups including "control", "Exposure1", and "Exposure2".  The Control group used air with a clean standard condition, and the other two groups were exposed to gaseous pollutants and gaseous pollutants plus PM2/5 respectively for 40 days. The cerebral tissues were removed. Gene expression analysis was conducted for S100 gene using quantitative Real-Time PCR and also methylation-sensitive high-resolution melting (MS-HRM) assay was performed for the control, Exposure1, and Exposure2 groups. The amount of malondialdehyde (MDA) involved in the oxidative stress (OS) process was assessed for all groups. The results showed the significant expression of S100 gene in Exposure1 and Exposure2 groups compared with the control group. MS-HRM assays detected only hypermethylation of Exposure 1 in comparison with control group. Based on the analysis of the involved enzymes in OS, malondialdehyde increased in the Exposure1 and Exposure2 groups. These findings may help provide insight to identifying therapeutic targets for reducing human cerebral disorders caused by exposure to PM2/5 or other air pollutants.