Abstract |
One of the major causes of multidrug resistance (MDR) in cancer cells is over-expression of P-glycoprotein (P-gp). We studied the effects of 20 triterpenes isolated from the floral spikes of Betula platyphylla var. japonica ( B. platyphylla) on P-gp function based on our previous finding that some of them showed MDR reversing effects. We evaluated accumulations and effluxes of rhodamine 123 as a P-gp substrate with P-gp over-expressing KB-C2 cells. Among the 20 triterpenes, compounds 3, 4, 8, 9, 13, 15, and 20 increased rhodamine 123 accumulations in KB-C2 cells, and three ( 8, 13, and 20) of them also inhibited efflux of rhodamine 123 out of cells. In addition, compounds 13 and 20 showed a weak inhibitory activity of P-gp ATPase. These results suggested that MDR reversing effects of compounds 13 and 20 are partly involved in inhibition of P-gp ATPase.
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Authors | Michiko Sekiya, Yoshiki Kashiwada, Tomohiro Nabekura, Shuji Kitagawa, Takashi Yamagishi, Takako Yokozawa, Takashi Ichiyanagi, Yasumasa Ikeshiro, Yoshihisa Takaishi |
Journal | Planta medica
(Planta Med)
Vol. 73
Issue 15
Pg. 1558-62
(Dec 2007)
ISSN: 0032-0943 [Print] Germany |
PMID | 18058609
(Publication Type: Journal Article)
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Chemical References |
- ATP Binding Cassette Transporter, Subfamily B, Member 1
- Antineoplastic Agents, Phytogenic
- Fluorescent Dyes
- Plant Extracts
- Triterpenes
- Rhodamine 123
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Topics |
- ATP Binding Cassette Transporter, Subfamily B, Member 1
(antagonists & inhibitors, metabolism)
- Antineoplastic Agents, Phytogenic
(administration & dosage, pharmacology, therapeutic use)
- Betula
- Cell Line, Tumor
(drug effects, metabolism)
- Drug Resistance, Neoplasm
(drug effects)
- Flowering Tops
- Fluorescent Dyes
- Humans
- Phytotherapy
- Plant Extracts
(administration & dosage, pharmacology, therapeutic use)
- Rhodamine 123
- Triterpenes
(administration & dosage, pharmacology, therapeutic use)
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