ZeaLutein^â : A unique antioxidant composition

	ZeaLuteinâ contains a mixture of carotenoids which function as antioxidants
	The free radical scavenging ability of carotenoids becomes more pronounced with increasing polarity and number of conjugated double bonds1
	The mechanism of action is through one of the following:

Singlet oxygen quenching :

1O₂ + LUTEIN   -------------------> ³O₂  +   ³LUTEIN

3LUTEIN   ------------------->  LUTEIN + HEAT

 

Free radicals quenching:

R^· + LUTEIN(H) ------------------->  RH + LUTEIN^·

                          <--------------------
R^· + LUTEIN -------------------> R^- + LUTEIN^{· +}

R^· + O₂   ------------------->  RO_2·

LUTEIN + ROO·   ------------------->  [ROO-LUTEIN· ] or [ROO^- + LUTEIN· ]

LUTEIN + ROO·    -------------------> ROOH + LUTEIN· or ROO-LUTEIN·

ROO· + LUTEIN· or ROO-LUTEIN·  -------------------> inactive products

	Since xanthophylls, lutein and zeaxanthin, possess both hydrophilic and hydrophobic characteristics, they may span biomembranes with their polar end groups anchored at the polar sites of the membrane.
	Other carotenoids, such as b-carotene and lycopene, lack polar substituents and remain entirely within the inner part of the membrane (lipid layers).
	Thus, each carotenoid’s specific orientation within the biomembrane collectively shield it from free radicals and oxidants.2

References

1. Tsuchihashi, H. et al. (1995) Arch. Biochem. Biophys. 323:137-147.

2.  Stahl, W., et al. (1998) FEBS Letters, 427, 305-308.

 

	One study compared the efficacy of nineteen microbial and plant carotenoids as antioxidants1. The effects of the cayenne pepper carotenoids, capsanthin and capsorubin were found to be more pronounced than those of b-carotene and cryptoxanthin,
	The experiments measured the ability of the carotenoids to inhibit toluidene-blue sensitized photooxidation of linoleic acid.

Figure 1: Antioxidant activity of carotenoids: Oxygen consumption %

 

 

Figure 2: Antioxidant activity of carotenoids:conjugated diene formation (%)

1. Hirayama O, Nakamura K, Hamada S, Kobayasi Y  (1994)  Singlet oxygen quenching ability of naturally occurring carotenoids. Lipids 29(2):149-50.

 

 

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