Studies on the antioxidant activity of milk caseins

Abstract

The antioxidant properties of milk casein subunits (alpha-casein, beta-casein and kappa-casein) were evaluated in liposomal models. All the subunits of casein are able to inhibit Fe-induced peroxidation of arachidonic acid inserted into multilamellar liposomes of dipalmitoylphosphatidylcholine (0.2 mM and 0.8 mM, respectively). The peroxidation was monitored as thiobarbituric acid reactive substances, and the strongest inhibitory effect occurred when 500 micrograms of alpha-casein were added to 0.5 ml of liposomal suspension. At this concentration, peroxidation was completely inhibited in our experimental conditions (incubation for 2 h at room temperature, with a mixture of ferrous sulfate and ascorbate, 50 and 500 microM final concentration, respectively). The mechanisms of antioxidant action are complex, but the strongest effect is achieved by modifying the Fe2+/Fe3+ equilibrium; in fact, caseins seem to favour the autoxidation of iron, and thus inhibit lipid peroxidation.

Effect of nitrogen gas flushing treatments on total antioxidant capacity and ascorbic acid content in raw bovine milk during cold storage

“…Similar results were also reported by Cervato et al (1999) and Zulueta et al (2009), who found that casein fractions of milk were responsible for the majority of the antioxidant capacity. Free radical quenching activity of caseins is due to the oxi dation of aminoacid residues of caseins themselves (Zulueta et al, 2009).…”

Dietary solutions to dyslipidemia: Milk protein–polysaccharide conjugates as liver biochemical enhancers

“…Although the ratio between the single proteomic extract antioxidant ability seems to be close along the three antioxidant tests, the fact that in BTMP performing relatively higher in HS might be related to the Fe 2+ /Fe 3+ cycle interference provoked by casein as reported by Cervato, Cazzola, and Cestaro (1999), making this test less reliable.…”

“…NabM had higher contents of total phenolic content (TPC) and total flavonoid (TF) than PHM ( (Vavrusova et al, 2015) explain it partially; on the other hand, this hydrolysate is composed by single amino acids, modified amino acids (like phosphoserine), or small peptides which are more prone to reaction (exposed groups) than big proteins present in the BTMP mixtures (like casein) which antioxidant and radical-quenching groups are located in the inner motifs (nonexposed groups). Although, according to Cervato, Cazzola, and Cestaro (1999), casein has more antioxidant power than whey proteins like lactoferrin and lactalbumin; it was also proved that the summed antioxidant power of its subunits is higher than of casein as phosphoserine groups become exposed with the subunit's desegregation. Furthermore, Bassan et al (2015) demonstrated a 2.5-fold increase in the antioxidant capacity of whey proteins due to hydrolysis.…”

The Ayurvedic drug, Ksheerabala, ameliorates quinolinic acid-induced oxidative stress in rat brain

“…This action of Ksheerabala is also observed in the histopathological studies. The main ingredients of Ksheerabala : Sida cordifolia ,[2 3] milk,[4 5] and sesamum oil[6–14] have all been reported to possess antioxidant properties. The synergistic action of all the components might thus may have potentiated its neuroprotective effect.…”

“…[4] Studies conducted by Korpela et al . [5] have shown that cow's milk had both peroxyl radical-trapping capacity and superoxide radical-trapping capacity.…”