Arzneimittelforschung 2001; 51(10): 799-805
DOI: 10.1055/s-0031-1300118
Antioxidants
Editio Cantor Verlag Aulendorf (Germany)

Antioxidative Effects of Lemon Oil and its Components on Copper Induced Oxidation of Low Density Lipoprotein

Johanna Graßmann
a   Department of Plant Sciences, Institute of Pytopathology, Laboratory for Applied Biochemistry, Munich Technical University, Freising-Weihenstephan, Germany
,
Dagmar Schneider
a   Department of Plant Sciences, Institute of Pytopathology, Laboratory for Applied Biochemistry, Munich Technical University, Freising-Weihenstephan, Germany
,
Dieter Weiser
b   Oklahoma Medical Research Foundation - Lipid and Lipoprotein Laboratory, Oklahoma City, Oklahoma, USA
c   Steigerwald Arzneimittel GmbH, Darmstadt, Germany
,
Erich F. Elstner
a   Department of Plant Sciences, Institute of Pytopathology, Laboratory for Applied Biochemistry, Munich Technical University, Freising-Weihenstephan, Germany
› Author Affiliations
Further Information

Publication History

Publication Date:
26 December 2011 (online)

Summary

Oxidation of low density lipoprotein (LDL) has been implicated in atherogenesis since several years. Therefore many researchers are looking for potent antioxidants which are able to inhibit LDL-oxidation and thus lower the risk for atherosclerosis. In particular several flavonoids have been investigated for their anti-oxidant capacity and it was shown that many factors influence the ability of flavonoids to retard LDL-oxidation, among others their lipophilic character. Since essentail oils and some of their components which are highly lipophilic, have been shown to possess antioxidant properties, their effects on copper-induced LDL-oxidation were analysed. Plasma was incubated with different terpenoid substances and subsequently the LDL was isolated. It could be demonstrated that the terpenoids were enriched in LDL after incubation with plasma. To follow the kinetics of copper induced LDL-oxidation formation of conjugated dienes as well as loss of tryptophan fluorescence were measured. Furthermore the anti-oxidants α -tocopherol, β-carotene and lycopene were quantified in LDL. It could be shown that particularly lemon oil and one of its components, γ-terpinene, are efficiently slowing down the oxidation of LDL. This effect is independent of α-to-copherol stability in LDL, whereas the loss of carotenoids during oxidation is strongly retarded.

Zusammenfassung

Antioxidative Wirkung von Zitronenöl und seinen Komponeneten auf die Kup-fer-induzierte Oxidation von Low Density Lipoprotein

Die Oxidation von Low Density Lipo-protein (LDL) wird seit einigen Jahren mit der Atherogenese in Verbindung ge-bracht. Daher wird von vielen Arbeits-gruppen nach wirkungsvollen Antioxidantien gesucht, die in der Lage sind, die LDL-Oxidation zu verhindern und so das Atherosklerose-Risiko zu verringern. Be-sonderes Augenmerk gilt dabei verschiedenen Flavonoiden, deren antioxidative Kapazität von unterschiedlichen Fakto-ren abhängt, unter anderem von der Li-pophilic des jeweiligen Flavonoids. Etherische Öle, welche hochlipophil sind, besitzen antioxidative Eigenschaften und wurden daher hinsichtlich ihres Einflusses auf die kupferinduzierte LDL-Oxida-tion untersucht. Dazu wurde Plasma mit verschiedenen Terpenen inkubiert und anschließend LDL isoliert Diese Vorinkubation führt zur Anreicherung der Ter-pene im LDL. Während der kupferinduzierten LDL-Oxidation wurden die Bildung konjugierter Diene und die Ab-nahme der Tryptophanfluoreszenz bestimmt sowie die Antioxidation α-Tocopherol, β-Carotin und Lycopin im LDL quantifiziert. Die stärkste Verzögerung der LDL-Oxidation konnte mit Zitro-nenöl und einer seiner Komponenten,γ -Terpinen, erreicht werden. Dieser Effekt ist unabhängig vom α-Tocopherol-Ver-brauch, die Oxidation der Carotinoide wird hingegen in Anwesenheit von γ-Ter-pinen stark verzögert.