Vitamin B₆ Compounds are Capable of Reducing the Superoxide Radical and Lipid Peroxide Levels Induced by H₂O₂ in Vascular Endothelial Cells in Culture

Abstract

Pyridoxamine, pyridoxine, and pyridoxal phosphate were tested to examine if they have antioxidant properties. Endothelial cells exposed to 0.5 mM H(2)O(2) for 2 hours increased the superoxide anion and lipid peroxide levels as biomarkers of oxidative stress. The increase of superoxide was mainly due to the activation of NADPH-oxidase by H(2)O(2). Preincubation of the endothelial cells with 0.1 or 1.0 mM of pyridoxamine or pyridoxal phosphate for one-half hour before H(2)O(2) exposure significantly reduced the superoxide and lipid peroxide compared to the cells exposed to H(2)O(2) only. Preincubation of the cells with 0.1 or 1.0 mM of pyridoxine also significantly reduced the lipid peroxide but did not significantly affect the superoxide level unless the preincubation time was extended to 24 hours. The prostacyclin release by endothelial cells was also significantly inhibited by H(2)O(2). However, the preincubation of endothelial cells with 1.0 mM of pyridoxamine, pyridoxine, or pyridoxal phosphate did not prevent that inhibition. These results indicate that pyridoxamine, pyridoxine, and pyridoxal phosphate acted as antioxidants and reduced the superoxide and lipid peroxides induced by H(2)O(2), but did not protect the cells from the effects directly related to H(2)O(2) itself.

Investigation of the effects of peppermint (Mentha piperita) on the biochemical and anthropometric profile of university students

“…The antioxidants also contribute to the reduction of oxidative stress in obese and diabetic persons (BEN SLAMA et al, 2009;MAHFOUZ et al, 2009;BENZIE;WACHTEL-GALOR, 2010). Flavonoids may act in distinct ways on various components of plasma lipid (DOYAMA et al, 2005), but the available literature still does not suffice to explain the exact mechanisms whereby phenolic acids, flavonoids and terpenoids exert these beneficial effects.…”

Plasma Homocysteine Is Associated with Increased Oxidative Stress and Antioxidant Enzyme Activity in Welders

“…Although the exact antioxidant mechanism has not been confirmed yet, PLP may directly scavenge radicals and inhibit lipid peroxidation [11, 16, 19–21] or may indirectly play an antioxidant role through serving as coenzymes in the glutathione antioxidant defense system. Plasma PLP serves as a coenzyme in the transsulfuration pathway of homocysteine to cysteine.…”

The influence of subchronic co-application of vitamins B6 and folic acid on cardiac oxidative stress and biochemical markers in monocrotaline-induced heart failure in male Wistar albino rats

“…Specifically, an adaptive increase in SOD activity that was observed after MCT treatment was abolished by vitamin B6 and FA administration, while GPX remained the same. Recent literature data suggest that vitamin B6 has the capacity to neutralize the superoxide anion, which might reverse adaptive upregulation of SOD, further potentiating profound oxidative modifications of key macromolecules (Mahfouz et al 2009). In view of the findings that after the onset of disease, vitamin B6 and FA have a disease-aggravating effect, these results are biologically plausible, although the mechanisms responsible remain unknown.…”