Antioxidant Activity Of Carnosine Research Articles

Comparative Study of Antioxidant Activity between Carnosine and Its Amino Acid Constituents

A study was conducted to compare and analyze the antioxidant mechanism of carnosine to its constituent amino acids (β-alanine and L-histidine) and to imidazole. Concentrations ranging from 5 to 100 mM of carnosine, β-alanine, L-histidine and imidazole were prepared and antioxidant activity assays (TBARS inhibition, metal chelating activity, free radical scavenging activity) were conducted. The TBARS inhibition of carnosine was due to the imidazole ring present in the histidine and with no inhibition contributed to β-alanine. Metal chelating properties of carnosine was also due to the imidazole ring and not to histidine or β-alanine, while free radical scavenging activity of carnosine was attributed to histidine and not due to imidazole or β-alanine. Overall, results demonstrate that β-alanine and the peptide bond between L- histidine and β-alanine do not play a role in the antioxidant activity of carnosine. Furthermore, results show that  imidazole has antioxidant properties alone, and therefore, it could be used as an antioxidant in various foods and feed applications.

Effects of combined carnosine and ultra-high pressure on the inhibition of fishy off-odor of snakehead fillets and the possible mechanism

The effects of combined application of ultra-high pressure (300 Mpa, 900 s) and carnosine on the inhibition of fishy off-odor from snakehead meat were investigated. Results showed that the combination effectively inhibited the formation of fishy volatile organic compounds (VOCs) and trimethylamine (TMA-N). Further studies demonstrated that the reduction of VOCs was mainly due to the inhibition of lipids oxidation based on the antioxidant activity of carnosine and the inactivation of lipoxygenase by UHP. Moreover, the reduction of TMA-N was mainly attributed to the ability of UHP processing to reduce bacterial load, which also extended the shelf-life of snakehead fillets by ∼ 6 days and retarded the production of TVB-N. Additionally, the combined application allowed a better retention of pH, color, and textural quality of the fillets compared with the control. Therefore, the current combination is a promising technique in fishy off-odor removing and better preservation of snakehead meat.

Balenine, imidazole dipeptide, induces activation of superoxide dismutase in myotubes

Balenine is one of the endogenous imidazole dipeptides. It is composed of beta-alanine and 3-methyl-l-histidine, which exist mainly in the muscles and the brain. The exact biological properties of balenine are still not well known, although the antioxidant activity of carnosine, another imidazole dipeptide, is known. In this study we investigated whether balenine exhibits antioxidant activity. It was found to decrease the superoxide anion (O2−) and increased hydrogen peroxide (H2O2) generation. We found that SOD activity increased in balenine-treated C2C12 myotubes, although balenine did not increase expression of SOD mRNA. On the other hand, there were no changes in other antioxidant enzymes, CAT and GPX activity, and mRNA levels. In an in vitro assay, the direct activation of SOD treated by balenine was significantly higher than with carnosine treatment. Moreover, balenine constituent amino acids did not have the ability to activate SOD. Our results suggest that balenine contributes to antioxidant effects through activation of SOD.

Computational design of bio-inspired carnosine-based HOBr antioxidants.

During a respiratory burst the enzyme myeloperoxidase generates significant amounts of hypohalous acids (HOX, X = Cl and Br) in order to inflict oxidative damage upon invading pathogens. However, excessive production of these potent oxidants is associated with numerous inflammatory diseases. It has been suggested that the endogenous antioxidant carnosine is an effective HOCl scavenger. Recent computational and experimental studies suggested that an intramolecular Cl+ transfer from the imidazole ring to the terminal amine might play an important role in the antioxidant activity of carnosine. Based on high-level ab initio calculations, we propose a similar reaction mechanism for the intramolecular Br+ transfer in carnosine. These results suggest that carnosine may be an effective HOBr scavenger. On the basis of the proposed reaction mechanism, we proceed to design systems that share similar structural features to carnosine but with enhanced HOX scavenging capabilities for X = Cl and Br. We find that (i) elongating the β-alanyl-glycyl side chain by one carbon reduces the reaction barriers by up to 44%, and (ii) substituting the imidazole ring with strong electron-donating groups reduces the reaction barriers by similar amounts. We also show that the above structural and electronic effects are largely additive. In an antioxidant candidate that involves both of these effects the reaction barriers are reduced by 71%.

Inhibition of Lipid Oxidation in Chicken by Carnosine and Dietary α-Tocopherol Supplementation and its Determination by Derivative Spectrophotometry

The antioxidant activity of carnosine in chicken meat, and its relationship to dietary α-tocopherol supplementation, was examined. Broiler chickens were fed diets containing 30 (basal) or 200 (supplemental) mg α-tocopherol acetate kg −1 feed for 6 weeks. Raw and cooked thigh meat patties containing carnosine (0–1·5%) were prepared. Lipid oxidation, during refrigerated storage under fluorescent light, was assessed by monitoring malonaldehyde formation, using the TBA assay and single wavelength (conventional) or first derivative spectrophotometry. In raw patties, added carnosine improved oxidative stability for up to 10 days of refrigerated storage. In cooked patties, the 1·5% carnosine level provided the best antioxidant protection during 7 days of storage. Carnosine (1·5%) was at least as effective as supplemental α-tocopherol in improving the oxidative stability of raw and cooked patties. The presence of both antioxidants had an additive effect on oxidative stability. Overall, the use of derivative spectrophotometry improved the specificity of the TBA assay for monitoring MDA formation in refrigerated meats.

The antioxidant activity of carnosine and its consequences on the volatile profiles of liposomes during iron/ascorbate induced phospholipid oxidation

The natural dipeptide L-carnosine (β-Ala-His) exhibits antioxidative properties and can be used as an antioxidant in food products. Its antioxidant activity and its effect on the volatile compounds produced during lipid oxidation was studied in a meat-related model system (liposomes of muscle phospholipids). Oxygen uptake, conjugated dienes, trienes and ketodienes, thiobarbituric acid reactive substances (TBARS) and volatile compounds were measured after induction of oxidation by equimolar Fe(III)/ascorbate (45 μM). Inclusion of carnosine (2–10 mM) lead to a decrease in all indices of lipid oxidation, except for the initial rate of oxygen uptake, which increased, and the rates of oxygen uptake 5 or more min after catalyst injection, which remained constant. The decrease varied as a function of carnosine concentration, method of measurement and incubation time. When carnosine was added to previously oxidised liposomes, TBARS, t-2-undecenal, total 2-alkenals and hexanol amounts decreased significantly. Carnosine antioxidant activity is multifunctional: it has a buffering effect; it interferes in the initiation step of oxidation; it decreases the amount of preformed peroxides; it reacts with some secondary products.

Carnosine and related compounds inhibit chemiluminescence of human plasma lipoproteinsin vitro

The antioxidant activity of carnosine and related compounds (5 and 10 mM) is assessed from the chemiluminescence curve using a model of Fe-initiated lipid peroxidation of human serum apoB-lipoproteins. These agents lower to different degrees the amplitudes of “fast” and “slow” bursts, the reaction rate, and the chemiluminescence light sum; the latency is prolonged, which may occur upon reduction of lipid hydroperoxides and/or inactivation of free radicals.

Comparison of the antioxidant activity of carnosine in different chemical and biological models

Comparison of the antioxidant activity of carnosine in different chemical and biological models

Antioxidant activity of carnosine in cooked ground pork

Carnosine (0·5–1·5%) reduced ( P < 0·05) the formation of thiobarbituric acid reactive substances (TBARS) in cooked unsalted ground pork after 7 days of storage at 4°C. The antioxidant activity of carnosine was less in cooked salted ground pork, with only 1·5% carnosine inhibiting (P < 0·05) TBARS formation during refrigerated storage. The antioxidant activity of carnosine in cooked salted and unsalted ground pork was greater than those of the lipid-soluble free radical scavengers, butylated hydroxytoluene and α-tocopherol ( P < 0·05) but less than that of sodium tripolyphosphate ( P < 0·05). These data suggest that carnosine could be used to reduce the oxidative deterioration of cooked salted and unsalted ground pork.

Inhibition of lipid oxidation by carnosine

The antioxidant activity of carnosine, a β‐alanine‐histidine dipeptide found in skeletal muscle, was investigated. Carnosine (25 mM) inhibited the catalysis of lipid oxidation by iron, hemoglobin, lipoxidase and singlet oxygen from 35–96% suggesting that the antioxidant mechanism of carnosine is not solely due to metal chelation. Heating the carnosine at 100°C for 15 min had no effect on its ability to inhibit these lipid oxidation catalysts, and the activity of carnosine was not affected over the pH range of 5.1–7.1. Studies using tocopherol‐containing liposomes suggest that carnosine and tocopherol do not act synergistically to inhibit lipid oxidation. These data indicate that carnosine has excellent potential for use as a natural antioxidant in processed foods.

Antioxidant activity of carnosine, homocarnosine, and anserine present in muscle and brain.

Carnosine, homocarnosine, and anserine are present in high concentrations in the muscle and brain of many animals and humans. However, their exact function is not clear. The antioxidant activity of these compounds has been examined by testing their peroxyl radical-trapping ability at physiological concentrations. Carnosine, homocarnosine, anserine, and other histidine derivatives all showed antioxidant activity. All of these compounds showing peroxyl radical-trapping activity were also electrochemically active as reducing agents in cyclic voltammetric measurements. Furthermore, carnosine inhibited the oxidative hydroxylation of deoxyguanosine induced by ascorbic acid and copper ions. Other roles of carnosine, such as chelation of metal ions, quenching of singlet oxygen, and binding of hydroperoxides, are also discussed. The data suggest a role for these histidine-related compounds as endogenous antioxidants in brain and muscle.