Effects of Vitamin B6 and Folic Acid on Cardiometabolic Biomarkers and Cardiac Oxidative Stress in Homocysteine-Loaded Rats.

Background/Objectives: Elevated homocysteine (Hcy) levels are associated with endothelial dysfunction, oxidative stress, and inflammation, contributing to cardiovascular disease development. The aim of this study was to examine the effects of vitamin B6 and folic acid on cardiometabolic biomarkers, cardiac oxidative stress, metabolic enzyme activities and cardiovascular histomorphometric parameters in homocysteine-loaded rats. Methods: Male Wistar albino rats were divided into four groups (n = 10, per group): C-saline 0.2 mL/day s.c. + saline 0.5 mL i.p; H: Hcy 0.45 µmol/g b.w./day s.c. + saline 0.5 mL i.p; C-B6+FA-saline 0.2 mL/day s.c. + vitamin B6 (7 mg/kg b.w. i.p./day) and folic acid (FA) (5 mg/kg b.w. i.p./day); and H-B6+FA-Hcy (0.45 µmol/g b.w./day s.c.) + vitamin B6 (7 mg/kg b.w. i.p./day) and FA (5 mg/kg b.w. i.p./day). Substances were applied s.c. for 2 weeks and i.p for 4 weeks. Results: B6+FA supplementation significantly reduced serum Hcy and LDL concentrations and attenuated Hcy-associated increases in cardiac SOD activity and right ventricular wall thickness. However, B6+FA was associated with increased cardiac MDA levels. MDH activity increased mainly in non-Hcy-loaded supplemented rats, whereas LDH activity, the cardio-somatic index, and aortic histomorphometric parameters remained unchanged. Conclusions: Combined B6+FA supplementation may improve Hcy metabolism, the LDL profile, and selected cardiac structural/oxidative alterations, but its association with increased lipid peroxidation suggests complex redox effects requiring cautious interpretation.