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Research: BURITS and colleagues,
Listed in Issue 69
Abstract
BURITS and colleagues, Institute of Pharmacognosy, Karl-Franzens-University of Graz, Universitaetsplatz 4/1, A-8010, Graz, Austria, examined the possible antioxidant (free radical scavenging) activities of three essential oils (Artemisia afra Jacq., Artemisia abyssinica Schultz-Bip. and Juniperus procera Hoechst ex Endl.).
Background
Methodology
First, a thin-layer chromatography (TLC) screening method was used to rapidly evaluate the possible antioxidant properties of the oils. The diphenylpicrylhydrazyl assay was used to check the oils' abilities to act as non-specific donors of hydrogen atoms or electrons . All three oils showed positive results and were examined further. The deoxyribose degradation assay assessed hydroxyl radical scavenging properties . The in vitro assay for non-enzymatic lipid peroxidation in liposomes further evaluated antioxidant potential.
Results
Oils of A. afra and J. procera were effective hydroxyl radical scavenging agents ; oils from A. abyssinica showed a paradoxical effect. Oils of A. afra and J. procera also showed antioxidant potential in liposomes ; it was not possible to measure the effect of A. abyssinica oil in this system, because certain compounds (eg. alk-2-enals) interfered with the assay. The compounds contributing to the radical scavenging activities of A. afra and J. procera were identified and then assessed for their effects in the various test systems. GC-MS (gas chromatography-mass spectrometry) was also used to study the qualitative and quantitative compositions of the essential oils.
Conclusion
References
Burits M et al. The antioxidant activity of the essential oils of Artemisia afra, Artemisia abyssinica and Juniperus procera. Phytotherapy Research 15 (2): 103-8. Mar 2001.