GC/FID-Quantification of oleanolic acid in mouse serum after treatment with mistletoe extract

Oleanolic acid belongs to the triterpene acids which can be found in different plant families like Lamiaceae, Sapindaceae and Santalaceae. These substances were already analyzed regarding to their impact on cell death and anti-cancer effects [1, 2]. Phytopreparations of Viscum album L. (Santalaceae) are already in use as an alternative treatment in cancer therapy [3]. Oleanolic acid is the main triterpene acid in lipophilic mistletoe extracts [4].

In this work, a GC-FID method was developed to quantify oleanolic acid in mouse serum after 30, 60 or 120 minutes of treatment with a lipophilic mistletoe extract and after treatment with a joint aqueous-lipophilic mistletoe extract, respectively. The lipophilic mistletoe extract was prepared by accelerated solvent extraction with n-Heptane [5] and the aqueous mistletoe extract was prepared by extraction with ascorbate phosphate buffer [6]. NSG mice were treated with 80 mg oleanolic acid i.v. per kg body weight (lipophilic extract) or 80 mg oleanolic acid and 6 g mistletoe lectin i.v. per kg body weight (joint aqueous-lipophilic extract). Oleanolic acid was extracted from the serum samples with chloroform and silylated for 30 minutes at 70 °C. Erythrodiol was added as internal standard and its recovery rate was 97,9 ± 0,1%. The GC-FID method uses a Zebron 35 column (30 m) and a temperature program with a maximum temperature of 330 °C.

A concentration of 460 ng/mL could be identified as limit of quantification. The limit of detection in this biological matrix is 300 ng/mL. After 120 incubation minutes, a middle oleanolic acid concentration of 2.27 µg/mL could be measured after treatment with the lipophilic extract, compared to 10.9 µg/mL after treatment with the joint aqueous-lipophilic mistletoe extract.

Keywords: GC/FID quantification, oleanolic acid, mistletoe extract, mouse study.

References:

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[6] Delebinski CI, Jaeger S, Kemnitz-Hassanin K et al. A new development of triterpene acid-containing extracts from Viscum album L. displays synergistic induction of apoptosis in acute lymphoblastic leukaemia. Cell Proliferation. 2012; 45(2):176 – 187

No conflict of interest has been declared by the author(s).