Positive Health Online

Abstract

CALDEFIE-CHEZET and co-workers, Laboratoire de Botanique, Cryptogamie et Microbiologie, Faculte des Sciences, Clermont-Ferrand, France, florence.caldefie-chezet@u-clermont1.fr, have found anti-inflammatory effects of tea tree oil on white blood cells.

Background

The fungicidal and bactericidal actions of the essential oil of Melaleuca alternifolia (tea tree) seem well established, but their anti-inflammatory and anti-oxidative effects remain unclear. This study aimed to investigate in vitro the possible role of tea tree oil as a modulator of the oxidative response (i.e. reactive oxygen species production) of white blood cells (monocytes and polymorphonuclear neutrophils).

Methodology

White blood cells from 7 healthy human volunteers were incubated for 30 min with tea tree oil (0-0.1%) to determine their reactive oxygen species production by flow cytometry with or without stimulation of cells. The effects of 3 different stimulating agents acting differently on transductional pathways were compared.

Results

Tea tree oil at 0.1% directly stimulated reactive oxygen species production by polymorphonuclear neutrophils more than 8-fold and increased the intracellular reactive oxygen species produced by monocytes. When an oxidative response was stimulated, tea tree oil decreased the intracellular reactive oxygen species production by both types of white blood cells.

Conclusion

Tea tree oil may be both a direct activator of the bactericidal action of white blood cells and may also be efficient in protecting the organism from an excess of reactive oxygen species, through anti-oxidant and radical scavenging activity.

References

Caldefie-Chezet F, Guerry M, Chalchat JC, Fusillier C, Vasson MP, Guillot J. Anti-inflammatory effects of Melaleuca alternifolia essential oil on human polymorphonuclear neutrophils and monocytes. Free Radical Research 38 (8): 805-811, Aug 2004.