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Interactions between Carotenoids from Marine Bacteria and Other Micronutrients: Impact on Stability and Antioxidant Activity.

Sy C, Dangles O, Borel P, Caris-Veyrat C - Mar Drugs (2015)

Bottom Line: For comparison, β-carotene and lycopene in combination were shown to exhibit a slightly higher stability toward iron-induced autoxidation, as well as an additive antioxidant activity as compared to the carotenoids, individually.Synergism could arise from antioxidants interacting via electron transfer through the porphyrin nucleus of heme iron.Overall, combining antioxidants acting via complementary mechanisms could be the key for optimizing the activity of this bacterial carotenoid cocktail.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR408 SQPOV, F-84000 Avignon, France. sy_charlotte@hotmail.com.

ABSTRACT
Recently isolated spore-forming pigmented marine bacteria Bacillus indicus HU36 are sources of oxygenated carotenoids with original structures (about fifteen distinct yellow and orange pigments with acylated d-glucosyl groups). In this study, we evaluated the stability (sensitivity to iron-induced autoxidation) and antioxidant activity (inhibition of iron-induced lipid peroxidation) of combinations of bacterial HU36 carotenoids with the bacterial vitamin menaquinone MQ-7 and with phenolic antioxidants (vitamin E, chlorogenic acid, rutin). Unexpectedly, MQ-7 strongly improves the ability of HU36 carotenoids to inhibit Fe(II)-induced lipid peroxidation, although MQ-7 was not consumed in the medium. We propose that their interaction modifies the carotenoid antioxidant mechanism(s), possibly by allowing carotenoids to scavenge the initiating radicals. For comparison, β-carotene and lycopene in combination were shown to exhibit a slightly higher stability toward iron-induced autoxidation, as well as an additive antioxidant activity as compared to the carotenoids, individually. HU36 carotenoids and phenolic antioxidants displayed synergistic activities in the inhibition of linoleic acid peroxidation induced by heme iron, but not by free iron. Synergism could arise from antioxidants interacting via electron transfer through the porphyrin nucleus of heme iron. Overall, combining antioxidants acting via complementary mechanisms could be the key for optimizing the activity of this bacterial carotenoid cocktail.

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IC50 values for the inhibition of iron-induced linoleic acid peroxidation by α-tocopherol, chlorogenic acid, and rutin. Different letters indicate a significant difference between the IC50 values within the same experimental condition (ANOVA followed by the Tukey-Kramer post hoc test, p < 0.05). * indicates a significant difference between the IC50 value of the same antioxidant compared at pH 4 and 5.8 with MbFe as the initiator (Student’s t test, p < 0.05).
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marinedrugs-13-07020-f005: IC50 values for the inhibition of iron-induced linoleic acid peroxidation by α-tocopherol, chlorogenic acid, and rutin. Different letters indicate a significant difference between the IC50 values within the same experimental condition (ANOVA followed by the Tukey-Kramer post hoc test, p < 0.05). * indicates a significant difference between the IC50 value of the same antioxidant compared at pH 4 and 5.8 with MbFe as the initiator (Student’s t test, p < 0.05).

Mentions: Antioxidant capacities of phenolic antioxidants. The ability of α-tocopherol and two common dietary phenols, rutin and chlorogenic acid, to inhibit lipid peroxidation was first studied with individual antioxidants. Considering the curves of CD accumulation (data not shown), it is clear that α-tocopherol resulted in a longer induction period, which is consistent with the well-known activity of α-tocopherol as a chain-breaking antioxidant by reducing the propagating LOO• radicals [26]. In contrast, while rutin and chlorogenic acid did not prolong the induction period, they did continuously slow peroxidation. This phenomena is typical of antioxidants located in the aqueous phase and/or at the interface which act by reducing hypervalent heme iron or initiating radicals [12]. In all cases, the antioxidant hierarchy, based on the IC50 values, was: α-tocopherol > rutin ≥ chlorogenic acid (Figure 5). Moreover, all three antioxidants were more efficient against lipid peroxidation initiated by MbFeIII at pH 5.8 than at pH 4.


Interactions between Carotenoids from Marine Bacteria and Other Micronutrients: Impact on Stability and Antioxidant Activity.

Sy C, Dangles O, Borel P, Caris-Veyrat C - Mar Drugs (2015)

IC50 values for the inhibition of iron-induced linoleic acid peroxidation by α-tocopherol, chlorogenic acid, and rutin. Different letters indicate a significant difference between the IC50 values within the same experimental condition (ANOVA followed by the Tukey-Kramer post hoc test, p < 0.05). * indicates a significant difference between the IC50 value of the same antioxidant compared at pH 4 and 5.8 with MbFe as the initiator (Student’s t test, p < 0.05).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663564&req=5

marinedrugs-13-07020-f005: IC50 values for the inhibition of iron-induced linoleic acid peroxidation by α-tocopherol, chlorogenic acid, and rutin. Different letters indicate a significant difference between the IC50 values within the same experimental condition (ANOVA followed by the Tukey-Kramer post hoc test, p < 0.05). * indicates a significant difference between the IC50 value of the same antioxidant compared at pH 4 and 5.8 with MbFe as the initiator (Student’s t test, p < 0.05).
Mentions: Antioxidant capacities of phenolic antioxidants. The ability of α-tocopherol and two common dietary phenols, rutin and chlorogenic acid, to inhibit lipid peroxidation was first studied with individual antioxidants. Considering the curves of CD accumulation (data not shown), it is clear that α-tocopherol resulted in a longer induction period, which is consistent with the well-known activity of α-tocopherol as a chain-breaking antioxidant by reducing the propagating LOO• radicals [26]. In contrast, while rutin and chlorogenic acid did not prolong the induction period, they did continuously slow peroxidation. This phenomena is typical of antioxidants located in the aqueous phase and/or at the interface which act by reducing hypervalent heme iron or initiating radicals [12]. In all cases, the antioxidant hierarchy, based on the IC50 values, was: α-tocopherol > rutin ≥ chlorogenic acid (Figure 5). Moreover, all three antioxidants were more efficient against lipid peroxidation initiated by MbFeIII at pH 5.8 than at pH 4.

Bottom Line: For comparison, β-carotene and lycopene in combination were shown to exhibit a slightly higher stability toward iron-induced autoxidation, as well as an additive antioxidant activity as compared to the carotenoids, individually.Synergism could arise from antioxidants interacting via electron transfer through the porphyrin nucleus of heme iron.Overall, combining antioxidants acting via complementary mechanisms could be the key for optimizing the activity of this bacterial carotenoid cocktail.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR408 SQPOV, F-84000 Avignon, France. sy_charlotte@hotmail.com.

ABSTRACT
Recently isolated spore-forming pigmented marine bacteria Bacillus indicus HU36 are sources of oxygenated carotenoids with original structures (about fifteen distinct yellow and orange pigments with acylated d-glucosyl groups). In this study, we evaluated the stability (sensitivity to iron-induced autoxidation) and antioxidant activity (inhibition of iron-induced lipid peroxidation) of combinations of bacterial HU36 carotenoids with the bacterial vitamin menaquinone MQ-7 and with phenolic antioxidants (vitamin E, chlorogenic acid, rutin). Unexpectedly, MQ-7 strongly improves the ability of HU36 carotenoids to inhibit Fe(II)-induced lipid peroxidation, although MQ-7 was not consumed in the medium. We propose that their interaction modifies the carotenoid antioxidant mechanism(s), possibly by allowing carotenoids to scavenge the initiating radicals. For comparison, β-carotene and lycopene in combination were shown to exhibit a slightly higher stability toward iron-induced autoxidation, as well as an additive antioxidant activity as compared to the carotenoids, individually. HU36 carotenoids and phenolic antioxidants displayed synergistic activities in the inhibition of linoleic acid peroxidation induced by heme iron, but not by free iron. Synergism could arise from antioxidants interacting via electron transfer through the porphyrin nucleus of heme iron. Overall, combining antioxidants acting via complementary mechanisms could be the key for optimizing the activity of this bacterial carotenoid cocktail.

Show MeSH
Related in: MedlinePlus