Exposures to a wide variety of environmental substances are negatively associated with many biological cell systems both in humans and rodents. Trichloroethane (TCE), a ubiquitous environmental toxicant, is used in large quantities as a dissolvent, metal degreaser, chemical intermediate, and component of consumer products. This increases the likelihood of human exposure to these compounds through dermal, inhalation and oral routes. The present in vivo study was aimed to investigate the possible cellular and molecular etiology of liver abnormality induced by early exposure to TCE using a murine model. The results showed a significant increase in liver weight. Histopathological examination revealed a TCE-induced hepatotoxicity which appeared as heavily congested central vein and blood sinusoids as well as leukocytic infiltration. Mitotic figures and apoptotic changes such as chromatin condensation and nuclear fragments were also identified. Cell death analysis demonstrates hepatocellular apoptosis was evident in the treated mice compared to control. TCE was also found to induce oxidative stress as indicated by an increase in the levels of lipid peroxidation, an oxidative stress marker. There was also a significant decrease in the DNA content of the hepatocytes of the treated groups compared to control. Agarose gel electrophoresis also provided further biochemical evidence of apoptosis by showing internucleosomal DNA fragmentation in the liver cells, indicating oxidative stress as the cause of DNA damage. These results suggest the need for a complete risk assessment of any new chemical prior to its arrival into the consumer market.
Mohamed M. Al-Griw, Rabia O. Alghazeer, S. A. Al-Azreg, Emad M. Bennour(9-2016)

Bisphenol A (BPA), an endocrine and metabolic disruptor, is widely used to manufacture polycarbonate plastics and epoxy resins. Accumulating evidence suggests that paternal BPA exposure adversely affects male germlines and results in atypical reproductive phenotypes that might persist for generations to come. Our study investigated this exposure on testicular architecture and sperm quality in mouse offspring, and characterised underlying molecular mechanism(s). A total of 18 immature male Swiss albino mice (3.5 weeks old) were randomly divided into three groups and treated as follows: Group I, no treatment (sham control); Group II, sterile corn oil only (vehicle control); Group III, BPA (400 μg/kg) in sterile corn oil. At 9.5 weeks old, F0 males were mated with unexposed females. F0 offspring (F1 generation) were monitored for postnatal development for 10 weeks. At 11.5 weeks old, the animals were sacrificed to examine testicular architecture, sperm parameters, including DNA integrity, and oxidative stress biomarkers (malondialdehyde (MDA), protein carbonylation (PC), and nitric oxide (NO)). Results showed that BPA significantly induced changes in the body and testis weights of the F0 and F1 generation BPA lineages compared to F0 and F1 generation control lineages. A decrease in sperm count and motility with further, increased sperm abnormalities, no or few sperm DNA alterations and elevated levels of MDA, PC, and NO were recorded. Similar effects were found in BPA exposed F0 males, but were more pronounced in the F0 offspring. In addition, BPA caused alterations in the testicular architecture. These pathological changes extended transgenerationally to F1 generation males’ mice, but the pathological changes were more pronounced in the F1 generation. Our findings demonstrate that the biological and health BPA impacts do not end in paternal adults, but are passed on to offspring generations. Hence, the linkage of seen testis and sperm pathologies in the F1 generation to BPA exposure of their parental line was evident in this work. The findings also illustrate that oxidative stress appears to be a molecular component of the testis and sperm pathologies. arabic 18 English 101
Mohamed A. Al-Griw(11-2020)

Alterations in genes encoding the xenobiotic-metabolizing enzymes contribute to the variability in susceptibility to various cancers. In this study, we assessed the possible association between the CYP1A1 variants and lung cancer (LC) risk in a population of Libyan males. For this study, we selected 20 unrelated healthy controls and 32 patients with LC. DNA samples from the controls and patients were screened by DNA-PCR and direct DNA sequence analysis to search for genetic sequence variations in CYP1A1 gene (exon 7 and 3’ non-coding region). CYP1A1 mutations were identified in 11.5 % adult subjects and cases analyzed, and all were males. Overall, 11 CYP1A1 mutations were documented in this study implicating exon 7 and 3’ non-coding region. Nonsense, missense, and frame-shift mutations accounted for, respectively, 27.3 %, 63.6 % and 9.1 % of all CYP1A1 mutations. Three missense mutations namely CYP1A1*2B/m2 (rs1048943), CYP1A1*4/m4 (rs1799814), and CYP1A1*2A/m1 (rs4646903) have already been reported. The remaining mutations have not been described previously. We observed two apparently heterozygous carriers of mutation CYP1A1*2B/m2 (CYP1A1 4889A/G [642Ile/Val] genotype) in control group. We also observed two heterozygotic genotypes one containing mutation m4 (CYP1A1 4887C/A [461Thr/Asp]) and another containing mutation m1 (6235T/C) in cancer group. The mutations m2, m4, and m1 accounted for, respectively, 18.2 %, 9.1 % and 9.1 % of all CYP1A1 mutations. Comparing the clinical features showed that PLT and WBC counts were lower in CYP1A1 mutant than in CYP1A1 wild type, but they have not reached statistical significant (P > 0.05). The average age of CYP1A1 mutant was lower than in CYP1A1 wild type. Overall, these findings suggest that genetic alterations in the metabolic gene CYP1A1 are too rare to be of clinical relevance in this study, implying different pathways for the LC risk with respect to CYP1A1 polymorphisms as a risk factor for LC at least in this study.
Najah A. Fares, Othman A. El-Ansari, Mohamed A. Al-Griw(4-2017)