Abstract
Colonic mucosa exhibits numerous functional alterations associated to type 2 diabetes mellitus (T2DM). Oxidative stress, a factor involved in T2DM pathogenesis and its complications, may contribute to some of the colonic alterations. Silicon (Si) is a trace element with antioxidant, anti-inflammatory and anti-diabetic effects. In this study, we examined if the intake of soluble G5 organic Si (2 mg/kg b.w./day), as a functional ingredient, might enhance the antioxidant status of the proximal colonic mucosal barrier in late-stage T2DM rats. A control-restructured meat matrix (RM) included in a high-saturated-fat hypercholesterolemic diet (HSFHCD-RM) and combined with low-dose streptozotocin plus nicotinamide was used to induce T2DM. Sixteen diabetic rats were divided into two groups and received different experimental diets for 8 weeks: LD group fed a HSFHCD-RM, and LD-Si group fed a Si-enriched RM (HSFHCD-Si-RM). We evaluated Si effects on the immunolocalizations and activities of antioxidant enzymes in proximal colonic mucosa. Compared to LD-group mucosa, LD-Si group showed stronger immunoreactivities in Cu, Zn-superoxide dismutase (SO1) (4.63 ± 0.02 vs. 1.5 ± 0.03; 626%, p = 0.00001), Mn-superoxide dismutase (SOD2) (3.63 ± 0.03 vs. 0.5 ± 0.05; 208.6%, p = 0.0001), catalase (CAT) (2.38 ± 0.03 vs. 0.75 ± 0.05, 131.51%, p = 0.0001), glutathione peroxidase (GPx) (3.25 ± 0.03 vs. 0.5 ± 0.05; 550.0%, p = 0.0001) and glutathione reductase (GR) (3.50 ± 0.05 vs. 2.56 ± 0.03; 36.75%, p = 0.001). Moreover, Si consumption led to higher total SOD (3.06 ± 0.42 vs. 2.53 ± 0.39; 20.94%, p = 0.001), CAT (34.10 ± 1.75 vs. 30.51 ± 1.81; 11.65%, p = 0.01) and GR (63.11 ± 13.22 vs. 51.46 ± 9.97; 22.60%, p = 0.001) activities, and lower GPx activity (191.82 ± 18.89 vs. 226.61 ± 20.07, 22.63%, p = 0.001). In summary, these results demonstrate the enhanced antioxidant status of the proximal colonic mucosa after Si intake in a late-stage T2DM model. Si effectively protected colonic mucosa against oxidative stress induced by T2DM. The incorporation of Si as a functional ingredient could be beneficial as a new nutritional tool to reverse colonic mucosa dysfunction associated to metabolic disorders, such as T2DM.
Supplementary Materials
The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/IECN2022-12403/s1.
Author Contributions
Conceptualization, M.E.L.-O., A.G., A.B., S.B., F.J.S.-M. and J.B.; methodology, M.H.-M., R.R.-C. and A.M.-G.; software, M.H.-M. and M.E.L.-O., validation, A.B., A.G., J.B. and M.E.L.-O.; formal analysis, M.H.-M. and M.E.L.-O.; investigation, M.H.-M., R.R.-C. and A.M.-G.; resources, M.J.G.-M.; data curation, M.H.-M. and M.E.L.-O.; writing—original draft preparation, M.H.-M., A.B. and M.E.L.-O.; writing—review and editing, M.H.-M., A.B., A.G. and M.E.L.-O.; visualization, M.H.-M., A.B., A.G., J.B., F.J.S.-M. and M.E.L.-O.; supervision, A.B., A.G., J.B., M.E.L.-O. and F.J.S.-M.; project administration, F.J.S.-M., S.B. and J.B.; funding acquisition, M.E.L.-O., A.G., S.B., F.J.S.-M. and J.B. All authors have read and agreed to the published version of the manuscript.
Funding
This study was supported by Spanish project PID2019-103872RB-I00; R.R-C. was supported by grant FPU20/02920 from the Spanish Ministry of Universities.
Data Availability Statement
The data used to support the findings of this study are included within the article.
Conflicts of Interest
The authors declare no conflict of interest.
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