# In Vitro Investigations on the Antioxidant Effects of Vitamin D in a Panel of Cancer Cell Lines

## TL;DR

This study shows that vitamin D reduces oxidative stress in various cancer cell lines, suggesting it may help prevent or treat certain cancers.

## Contribution

The study demonstrates vitamin D's antioxidant effects in multiple cancer types, highlighting its potential as a therapeutic agent.

## Key findings

- Vitamin D significantly reduced ROS levels in all cancer cell lines tested.
- Vitamin D increased SOD activity and protein expression across all cell lines.
- Antioxidant effects of vitamin D were dose-dependent and cell-type-specific.

## Abstract

Background: Oxidative stress plays a critical role in cancer initiation and progression. Although vitamin D exhibits multiple anti-tumorigenic properties, its antioxidant effects across different cancer types remain incompletely characterized. This study aimed to evaluate the antioxidant role of vitamin D in cancer. Methods: This in vitro study was conducted using breast (MCF-7, MDA-MB-231), colorectal (HCT-116, HT-29), and head and neck (Detroit-562, FaDu) cancer cell lines. Cells were treated with 1,25-dihydroxyvitamin D3 (1 nM, 10 nM, and 100 nM) for 48 h. Reactive oxygen species (ROS) were quantified using the ROS-Glo™ H2O2 assay. Oxidative stress biomarkers were assessed by measuring 8-hydroxy-2′-deoxyguanosine (8-OHdG) using enzyme-linked immunosorbent assay (ELISA), while thiobarbituric acid reactive substances (TBARS) and protein carbonyls (PC) were measured using colorimetric assays. Xanthine oxidase (XOD) protein levels were determined by ELISA, whereas superoxide dismutase (SOD) and catalase (CAT) activity and/or expression were evaluated using colorimetric assays. Results: Vitamin D significantly reduced ROS levels in all investigated cell lines in a dose-dependent manner compared with control cells (p < 0.05). Levels of 8-OHdG and TBARS were significantly decreased across all cell lines, whereas reductions in PC and XOD were cell-type-dependent. Vitamin D significantly increased SOD activity and protein expression in all cell lines, while CAT activity was elevated in most cell lines. Conclusions: This study provides proof-of-concept evidence that vitamin D exerts dose-dependent and cell-specific antioxidant effects in cancer. These findings suggest potential antioxidant roles for vitamin D in the prevention or treatment of breast, colorectal, and head and neck cancers.