Mona K. Galal

The present study aimed to explain the mechanisms involved in cell-mediated immunotoxicity of atrazine (ATR) in rabbits and to evaluate the ameliorative role of glycyrrhizic acid (GA) against such toxic effects. Forty rabbits were assigned into 4 equal groups: control, ATR, GA, and ATR + GA groups. ATR (2475 ppm) and GA (60 μg of GA/ml of water) were administrated via food and drinking water, respectively, for 60 consecutive days. The cell-mediated immunotoxicity of ATR was clarified by the induced thymus immunotoxicity through downregulation of interleukin (IL)-9 gene and interferon-γ (IFN-γ) gene expression, upregulation in caspase-3, and significant decrease in the total leukocytic and lymphocyte counts. Histopathological investigations demonstrated severe depletion of lymphoid follicles in the medulla of the thymus gland. On the other hand, co-administration of GA for group 4 improved most of the undesirable impacts of ATR. In conclusion, the alteration in IL-9/IFN-γ expression may involve ATR-induced thymocyte apoptosis which may explain the mechanisms of ATR-induced cell-mediated immunotoxicity with a possible amelioration influence of GA administration.

The present study was led to investigate the defensive role of Terminalia laxiflora extract (TLE) on fipronil (FPN) induced hepatotoxicity and nephrotoxicity in male rats. Rats were administered with TLE (100 mg/kg) against the renal toxicity and hepatotoxicity induced by administration of FPN (10.5 mg/kg) for 30 days. At the end of the experimental period, the serum, liver, and kidneys were harvested and assessed for subsequent analysis. FPN administration to rats resulted in a significant elevation of serum transaminases, urea, and creatinine. Also, FPN-treated groups exhibited a marked reduction in total protein and albumin levels. Compared with the control group, the level of malondialdehyde (MDA) was elevated in groups treated with FPN, whereas superoxide dismutase (SOD), catalase (CAT) activities, and glutathione levels were distinctly reduced in this group. Significant increases in genomic DNA fragmentation and the expression level of the caspase-3 gene were also recorded. The biochemical result was supported by histopathological findings. Co-administration of TLE along with FPN significantly diminished the liver and kidney function tests decreased the level of lipid peroxidation, and enhanced all the antioxidant enzymes, while also diminishing the expression of caspase-3 and DNA laddering, indicating amelioration of DNA damage. These results indicate that TLE plays a vital role in diminishing FPN-induced hepatotoxicity and nephrotoxicity.

The present study was performed to evaluate the effect of vitamin C on the performance of Nile tilapia (Oreochromis niloticus) affected by the usage of engine oil. A total of 120 tilapia fish were randomly divided into four equal groups according to dietary treatments applied for 3 weeks: group I (control); group II was exposed to engine oil; group III was exposed to engine oil and supplemented with vitamin C: and group IV was fed only a diet supplemented with vitamin C. According to our results, the group exposed to engine oil (II) showed an induced elevation of kidney function parameters, an upregulation of CYP1A1 mRNA expression level, a reduction in antioxidant status (SOD, GSH) and severe abnormal histological and ultra-structural changes in the head kidney, trunk kidney and muscle tissue. Supplementation of group III with vitamin C ameliorated the toxic effect induced by engine oil through improvement of kidney function parameters, elevation of the antioxidant status of tissue and improvement of the histological images of renal and muscle tissues. In conclusion, vitamin C has the ability to ameliorate engine oil oxidative stress toxicity in Nile tilapia.

This study was carried out to detect polymorphisms in the melatonin receptor 1A (MTNR1A) and arylalkylamine N-acetyltransferase (AA-NAT) genes and their association with reproductive traits. Blood samples of 126 animals from three Egyptian sheep breeds were collected. DNA was extracted and subjected to PCR restriction fragment length polymorphism (RFLP) analysis using the RsaI and SmaI enzymes. Two alleles (C and T) and three genotypes (CC, CT and TT) for MTNR1A and for AA-NAT (A and G; GG, GA and AA) were detected. The alleles C and A and the genotypes CT and GA showed the highest frequencies for the MTNR1A and AA-NAT genes, respectively. Association analysis of the MTNR1A single nucleotide polymorphism (SNP) with ewe reproductive traits revealed significant associations in the Ossimi and Rahmani breeds with age at first lambing, and the C allele seemed to be the favorable allele. The results for the AA-NAT SNP demonstrated significant correlations in Ossimi with age at first lambing and litter size and in Rahmani with lambing interval; the G allele seemed to be the desirable allele. In the first conception season, ewes carrying CT exhibited a significantly lower age of first lambing in the unfavorable season. Additionally, GG ewes exhibited a significantly lower age of first lambing in the early favorable season, followed by the unfavorable season. To the best of our knowledge, this is the first study of these associations in Egyptian sheep breeds. In conclusion, the polymorphisms revealed in this study could be used as genetic markers to improve reproductive efficiency during the unfavorable season, and the obtained desirable genotypes could be considered in new genetic selection schemes.