Calcitriol attenuates inflammatory response in the lung of diabetes mellitus rat model.

Introduction: Inflammation caused by diabetes can damage multiple organs, including the lungs. Vitamin D (VD) has been shown to potentially reduce inflammation and boost the immune system. VD might play a role in diabetes' inflammatory response. This study aims to elucidate the evidence regarding the lung as the target organ for DM and the possible role of VD in preventing pulmonary damage progression in the diabetes rat model.

Material and methods: Thirty Sprague Dawley rats (3-monthold, 200 to 300 gm) were randomly divided into six groups, namely control (C), 4 weeks diabetes mellitus (DM1), 8 weeks DM (DM2) and three DM1 groups (VD1, VD2, and VD3) who received Vitamin D doses of 0.125, 0.25 and 0.50 μg/kg BW, respectively. After 4 weeks, daily VD was administered intraperitoneally for 30 days. Lung tissues were taken for IL- 6, MCP-1, NFKB and CD68 mRNA expression analysis and paraffin embedding. Immunohistochemical staining against CD68 and MCP-1 was conducted. Data were analysed using one-way ANOVA. p < 0.05 was considered statistically significant.

Results: DM2 group represented significantly higher IL6, MCP1, NFKB and CD68 mRNA expression than Control group (p < 0.05). Meanwhile, VD2 and VD3 groups revealed significantly lower mRNA expression of IL-6, MCP1, NFKB and CD68 than DM2 (p < 0.05). Immunostaining revealed the spreading of MCP1 protein expression in lung tissue along with macrophage infiltration in the DM2 group, which was reduced in the VD2 and the VD3 groups.

Conclusion: VD shows a protective effect on diabetesinduced lung damage by regulating inflammation factors.