Background: Lipoapoptosis has been identified as a key event in the progression of nonalcoholic fatty liver disease (NAFLD), and hence, antiapoptotic agents have been recommended as a possible effective treatment for nonalcoholic steatohepatitis (NASH). Silicon, included in meat as a functional ingredient, improves lipoprotein profiles and liver antioxidant defenses in aged rats fed a high–saturated fat, high-cholesterol diet (HSHCD). However, to our knowledge, the antiapoptotic effect of this potential functional meat on the liver has never been tested.
Objective: This study was designed to evaluate the effect of silicon on NASH development and the potential antiapoptotic properties of silicon in aged rats.
Methods: One-year-old male Wistar rats weighing ~500 g were fed 3 experimental diets containing restructured pork (RP) for 8 wk: 1) a high–saturated fat diet, as an NAFLD control, with 16.9% total fat, 0.14 g cholesterol/kg diet, and 46.8 mg SiO2/kg (control); 2) the HSHCD as a model of NASH, with 16.6% total fat, 16.3 g cholesterol/kg diet, and 46.8 mg SiO2/kg [high-cholesterol diet (Chol-C)]; and 3) the HSHCD with silicon-supplemented RP with amounts of fat and cholesterol identical to those in the Chol-C diet, but with 750 mg SiO2/kg (Chol-Si). Detailed histopathological assessments were performed, and the NAFLD activity score (NAS) was calculated. Liver apoptosis and damage markers were evaluated by Western blotting and immunohistochemical staining.
Results: Chol-C rats had a higher mean NAS (7.4) than did control rats (1.9; P < 0.001). The score in Chol-Si rats (5.4) was intermediate and different from that in both other groups (P < 0.05). Several liver apoptosis markers—including hepatocyte terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate (dUTP) nick end labeling, cytosolic cytochrome c, apoptosis-inducing factor, caspases 9 and 3, and the mitochondrial Bcl-2-associated X protein (BAX)-to-B-cell lymphoma 2 (BCL2) ratio—were 9–45% lower in Chol-Si than in Chol-C rats (P < 0.05) and did not differ from values in the control group.
Conclusions: Supplemental silicon substantially affects NASH development in aged male Wistar rats fed an HSHCD by partially blocking apoptosis. These results suggest that silicon-enriched RP could be used as an effective nutritional strategy in preventing NASH.
From: Garcimartin, A., Lopez-Oliva, M. E., Santos-Lopez, J. A., Garcia-Fernandez, R. A., Macho-Gonzalez, A., Bastida, S., Benedi, J., Sanchez-Muniz, F. J. http://jn.nutrition.org/cgi/content/short/147/6/1104?rss=1
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