| Autor: |
Bortolin RH; Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil., da Graça Azevedo Abreu BJ; Department of Morphology, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil., Abbott Galvão Ururahy M; Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil., Costa de Souza KS; Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil., Bezerra JF; Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil., Loureiro MB; Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil., da Silva FS; Department of Morphology, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil., Marques DE; Department of Morphology, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil., Batista AA; Department of Chemistry, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil., Oliveira G; Department of Chemistry, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil., Luchessi AD; Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil., Lima VM; Department of Pharmacy, State University of Paraiba, Campina Grande, Paraiba, Brazil., Miranda CE; Department of Pharmacy, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil., Lia Fook MV; Laboratory of Evaluation and Development of Biomaterials, Federal University of Campina Grande, Campina Grande, Paraiba, Brazil., Almeida Md; Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil., de Rezende LA; Department of Chemistry, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil., de Rezende AA; Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil. |
| Abstrakt: |
Several studies have established an association between diabetes and alterations in bone metabolism; however, the underlying mechanism is not well established. Although zinc is recognized as a potential preventive agent against diabetes-induced bone loss, there is no evidence demonstrating its effect in chronic diabetic conditions. This study evaluated the effects of zinc supplementation in a chronic (90 days) type 1 diabetes-induced bone-loss model. Male Wistar rats were distributed in three groups: control, type 1 diabetes mellitus (T1DM), and T1DM plus zinc supplementation (T1DMS). Serum biochemical analysis; tibia histomorphometric, biomechanical, and collagen-content analyses; and femur mRNA expression were evaluated. Relative to T1DM, the zinc-supplemented group showed increased histomorphometric parameters such as TbWi and BAr and decreased TbSp, increased biomechanical parameters (maximum load, stiffness, ultimate strain, and Young's modulus), and increased type I collagen content. Interestingly, similar values for these parameters were observed between the T1DMS and control groups. These results demonstrate the protective effect of zinc on the maintenance of bone strength and flexibility. In addition, downregulation of OPG, COL1A, and MMP-9 genes was observed in T1DMS, and the anabolic effects of zinc were evidenced by increased OC expression and serum ALP activity, both related to osteoblastogenesis, demonstrating a positive effect on bone formation. In contrast, T1DM showed excessive bone loss, observed through reduced histomorphometric and biomechanical parameters, characterizing diabetes-associated bone loss. The bone loss was also observed through upregulation of OPG, COL1A, and MMP-9 genes. In conclusion, zinc showed a positive effect on the maintenance of bone architecture and biomechanical parameters. Indeed, OC upregulation and control of expression of OPG, COL1A, and MMP-9 mRNAs, even in chronic hyperglycemia, support an anabolic and protective effect of zinc under chronic diabetic conditions. Furthermore, these results indicate that zinc supplementation could act as a complementary therapy in chronic T1DM. |
