Antioxidative properties of Lactobacillus GG

Antioxidative properties of Lactobacillus GG – Lactobacillus GG

M. Ahotupa

INTRODUCTION

Kaizu et al (1993) showed that intracellular cellfree extracts of 19 lactobacilli strains of the 570 studied strains had antioxidative properties when measured by using rat liver microsomes and thiobarbituric acid. In their second experiment 7 lactobacilli strains inhibited oxidation activity by 70%.

The aim of the present study was to examine if Lactobacillus rhamnosus GG (ATCC 53103) has any anti-or pre-oxidative properties.

METHODS

The cell pellet was first suspended in 0.15 M KC1. The cells were disrupted by ultrasonication, centrifuged, and the supernatant was taken for analyses. Before performing analyses on antioxidant potential, protein concentrations of the supernatants were determined and the samples were adjusted to similar protein concentrations.

Measured parameters:

*SSA (scavenging of superoxide anion): Ability of test substances to scavenge superoxide anion radicals. Superoxide anion is produced by xanthine-xanthine oxidase system and detected by chemiluminescence.

*TRAP (scavenging of peroxyl radical): Ability to test substances to scavenge peroxyl radicals. Peroxyl radicals are generated by thermal decomposition of ABAP and detected by chemi-luminescence.

*NADPH-LP (inhibition of lipid peroxidation induced by NADPH): Ability of test substances to inhibit “enzymatic” lipid peroxidation. Detection is based on the formation of TBA (thiobarbituric acid) reactants. Peroxidizing material is a microsomal preparation.

* PX-LP (inhibition of lipid peroxidation induced by tert-butylhydroperoxide) Ability of test substances to inhibit lipid peroxidation. Detection by chemiluminescence. Peroxidizing material rat liver microsomes.

RESULTS

Lactobacillus GG and Lactobacillus GG-fermented milk were potent scavengers of superoxide anion and inhibitors of lipid peroxidation reactions in vitro. The effects were comparable to those of the known antioxidants vitamin C and butylated hydroxytoluene (BHT). Lactobacillus GG bacteria did not show any peroxyl-radical-trapping capacity (Table 1).

[TABULAR DATA OMITTED]

Gradual addition of exogenous superoxide dismutase (SOD), as well as inhibition of SOD activity of Lactobacillus GG affected the ability of Lactobacillus GG to inhibit lipid peroxidation reactions. Exogenous catalase, on the contrary, had no effect (data not shown). Moreover, addition of either EDTA or Fe 2+ affected Lactobacillus GG’s ability to inhibit lipid peroxidation (data not shown). Thus, it is concluded that Lactobacillus GG-caused inhibition of lipid peroxidation reactions in vitro is, at least in part, due to (1) the superoxide anion scavenging and (2) iron-chelating properties of Lactobacillus GG.

In comparison to several other bacteria, the superoxide-anion-scavenging capacity of Lactobacillus GG was found to be exceptionally high (Table 2).

Table 2

In vitro superoxide anion scavenging by Lactobacillus GG in

comparison with that other selected bacteria

Superoxide anion scavenging

Lactabacillus rhamnosus GG 1.1

Lactobacillus rhamnosus Lc 705 0.0008

Lactobacillus acidophilus LA(a) 0.000006

Lactobacillus paracasei YEC 0.001

Bifidobactetium sp. BB12 0.02

Escherichia coli 0.001

The superoxide-anion-scavenging capacity of Lactobacillus GG was not dependent on availability of oxygen during growth; similar levels of scavenging activity were found in bacteria grown under aerobic or under anaerobic conditions (data not shown).

CONCLUSION

Lactobacillus GG is a potent scavenger of superoxide anion in vitro.

REFERENCE

Kaizu H, Sasaki M, Nakajima H, Suzuki T. Effect of antioxidative lactic acid bacteria on rats fed a diet deficient in vitamin E. J Dairy Sci 1993;76: 2493-2499.

COPYRIGHT 1996 Lippincott/Williams & Wilkins

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