Crocin mitigates carbon tetrachloride-induced liver toxicity in rats

Carbon tetrachloride [CCl4] is one of the most dangerous hepatotoxic environmental pollutants thus this study aimed at investigating the potential preventive effect and mechanism of crocin against CCl4- induced hepatotoxicity. Forty Male rats were allocated for two weeks treatment with; corn oil, CCl4 in corn oil, crocin [100 mg/kg], or crocin plus CCl4. At time of euthanasia liver was removed, weighted and processed for histopathological evaluation and estimation of liver contents of active caspase3, lipid peroxidation [MDA] and reduced glutathione [GSH]. We also evaluated antioxidant enzymes activities [superoxide dismutase [SOD], glutathione peroxidase [GSH-Px] and catalase [CAT]], phase I metabolizing enzyme [cytochrome P450 sub family 2E1 [CYP2E1]] an Phase II metabolizing enzyme, [glutathione-S-transferase [GST]] in liver tissue. Blood samples were used for evaluation of liver function tests and inflammatory cytokines [interleukin 6 [IL-6] and tumor necrosis factor alpha [TNF-alpha]]. CCl4 induced significant [p < 0.001], increase in: relative liver weight to body weight, liver MDA content, liver active caspase-3 and plasma levels of IL-6 and TNF alpha. In addition, CCl4 disturbed liver histology, liver metabolizing enzymes [CYP2E1 and GST], and liver function tests [aspartate aminotransferase, alanine aminotransferase, total bilirubin and alkaline phosphatase]. CCl4 induced significant decrease in activities of SOD, CAT, GSH-Px and GSH content. Administration of crocin with CCl4 mitigated all CCl4-disturbed parameters and preserved liver histology close to normal. Crocin ameliorated CCl4-induced liver injury via inhibition of inflammatory cytokines, caspase3 and oxidative stress along with modulation of liver metabolizing enzymes favoring elimination of CCl4 toxic metabolite

Comparative studies on the corneal structural adaptation of two rodents inhabiting different environments

The corneas of Rattus rattus and Meriones shawi are composed of three main layers; an outer epithelium, a middle stroma [basement membrane, total stroma and Descemet's membrane] and an inner endothelium. The mean thickness of the epithelium, total stroma, Descemet's membrane, and endothelium was about 52 +/- 7.3 [micro]m, 275 +/- 18.7 [micro]m, 5.5 +/- 0.7 [micro]m, and 7.5 +/- 0.23 [micro]m in R. rattus, whereas it was 38 +/- 5.8 [micro]m, 124 +/- 4.7 [micro]m, 4 +/- 0.21 [micro]m, and 4.2 +/- 0.17 [micro]m in M. shawi. In R. rattus and M. shawi, the outermost cells of the corneal epithelium are mostly polygonal and hexagonal in shape with nearly regular borders and show a dense pattern of microplicae with different scatter electron that exhibits three and two polymorphic appearances, respectively. Type A: numerous light cells with dense microplicae; type B: many dark cells with a moderate density of microplicae, and type C: few dark cells with a less density of microplicae are found in R. rattus; whereas, types A and B are found in M. shawi. In both investigated species, the epithelial cells are characterized by some structural components, such as glycocalyx, fibrous components and tight junction between these cells, to resist the impact of the external stressed factors and to protect the underlying tissue, as well as to maintain an excellent transparency of the cornea. Among these structures, the cytokeratin filaments are the major components of the cytoplasm of the corneal epithelial cells [basal, polygonal, wing and squamous cells]. Actin filaments are also found in the corneal epithelial cells, but they are prominent within the apical epithelial cells. In R. rattus, the stroma is formed of an outer lamellar zone and an inner lamellar one; the latter is thicker and characterized by its interfibrillar spaces between the bundles of wavy dissociated collagen fibrils, which are arranged in an orthogonal manner. In M. shawi, however, the stroma is formed of one lamellar zone of flattened bundles of highly wavy and branched collagen fibrils, which are composed of perpendicular fibrillae alternating with longitudinal ones. In R. rattus, the SEM showed that the endothelial cell surfaces are slightly bulging with many blebs, whereas in M. shawi, it showed that the surfaces of the endothelial cells are flattened and nearly smooth. In conclusion, the transparency of the cornea, may be highly attributed to the increase in the thickness of the stroma, the presence of stromal interfibrillar spaces and the case of the stromal swelling. These aforementioned features are found in the corneal stroma of R. rattus, which live in different habitats of varying degrees of density such as water and dry or humid air, whereas these features are lacking in M. shawi, which live only in arid zones