Interaction of peroxynitrite with carotenoids and tocopherols within low density lipoprotein

Abstract

Peroxynitrite is a powerful oxidising and nitrating agent generated in vivo by the combination of nitric oxide and superoxide. Previous studies have shown that on exposure to peroxynitrite, low density lipoprotein (LDL) is modified resulting in both a time-and concentration-dependent change to lipid and protein components. The present investigation highlights the reaction between carotenoids and tocopherols, present within the lipophilic phase of LDL, and peroxynitrite at varying concentrations. It was observed that the carotenoids were consumed by a significantly greater proportion than that of the tocopherols with lycopene (87.2 þ 11%) being more reactive than L L-carotene (68.2 þ 5.8%) when exposed to peroxynitrite (50 W WM) for 1 min. Among the tocopherols, K K-tocopherol (54.9 þ 20.2%) was more extensively depleted than Q Q-tocopherol (14.7 þ 1.09%) at peroxynitrite concentration of 500 W WM. It was also observed that peroxynitrite, unlike copper ions, does not lead to significant peroxidation of LDL as determined by the formation of conjugated dienes and thiobarbituric acid-reactive substances.z 1998 Federation of European Biochemical Societies.

Beta Carotene Modulates Nitric Oxide Production in the Renal Ischemia/Reperfusion Injury in Rat

“…This is in accordance with other reports that introduce beta carotene as an effective scavenger of toxic reactive nitrogen species like: nitrogen dioxide and peroxynitrous acid [27,28]. Then we conclude that beta carotene pretreatment in higher doses used in this study, despite more NO generation, could scavenge toxic NO metabolites effectively.…”

Effect of lycopene and β-carotene on peroxynitrite-mediated cellular modifications

“…This result shows that carotenoids incorporated into the cells are capable of scavenging peroxynitrite. As mentioned earlier, scavenging of peroxynitrite by lycopene or β-carotene in solution and in low density lipoproteins has been shown previously (Panasenko et al, 2000, Pannala et al, 1998). …”

“…Beta-carotene is a strong scavenger of RNS in solution, including nitrogen dioxide, and peroxynitrite (Kikugawa et al, 1997). Lycopene and β-carotene have also been shown to be consumed in the process of scavenging peroxynitrite in low density lipoproteins (Panasenko et al, 2000, Pannala et al, 1998.…”

Apolipoprotein A-I Promotes the Formation of Phosphatidylcholine Core Aldehydes That Are Hydrolyzed by Paraoxonase (PON-1) during High Density Lipoprotein Oxidation with a Peroxynitrite Donor

“…This acute phase HDL may be oxidatively modified by peroxynitrite. Peroxynitrite can directly oxidize polyunsaturated fatty acids (16), tocopherols (20 -22), carotenoids (20), proteins, carbohydrates, and DNA (16). As reviewed by Francis (7), a number of 1 The abbreviations used are: LDL, low density lipoproteins; apo, apolipoprotein; DMPC, dimyristoyl glycerophosphocholine; DTPA, Nbis(carboxymethylamino)-ethylglycinepentaacetic acid); HFBA, heptafluorobutyric acid; HDL, high density lipoproteins; LC/ESI/MS, liquid chromatography/electrospray ionization/mass spectrometry; PAF-AH, platelet-activating factor-acetylhydrolase; PLPC, palmitoyl-linoleoyl glycerophosphocholine; PON-1, paraoxonase-1; SIN-1, 3-morpholinosydnonimine; PAGE, polyacrylamide gel electrophoresis; PBS, phosphate-buffered saline; BHT, butylated hydroxytoluene; HPLC, high pressure liquid chromatography; C5 Ald PC, 1-palmitoyl-2-(5-oxo)-valeroyl-sn-glycero-3-phosphocholine; C5 Acid PC, 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphocholine; C9 Ald PC, 1-palmitoyl-2-(9-oxo)-nonanoyl-sn-glycero-3-phosphocholine; C9 Acid PC, 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine; PAPC, 1-palmitoyl-2-arachidonoyl glycero-3-phosphocholine.…”