Abstract | BACKGROUND AND PURPOSE:
Cucurbitacin R, a natural anti-inflammatory product, has been shown to exhibit activity against both adjuvant-induced arthritis and delayed-type hypersensitivity reactions induced by various agents. Previous studies have demonstrated that the effects of cucurbitacin R stem from its inhibition of both cytokine production and lymphocyte proliferation. EXPERIMENTAL APPROACHES: Effects of cucurbitacin R were investigated on lipopolysaccharide-stimulated RAW 264.7 cells. Cell cycle evolution was analysed by flow cytometry, detection of apoptosis by DNA ladder, Bcl-2, p21, p53, Bax, cleaved caspase-1 (p10), caspase-9, and caspase-3, cleaved caspase (p17) and interleukin-1beta detection was followed by Western blot analysis and mRNA expression with quantitative real time reverse transcription-polymerase chain reaction (qRT-PCR). KEY RESULTS:
Cucurbitacin R was found to induce apoptosis in lipopolysaccharide-stimulated RAW 264.7 macrophages through the inhibition of Bcl-2 expression, which regulates pro-inflammatory caspase-1 activation and interleukin-1beta release. Also, cucurbitacin R arrested the cell cycle in the G(2)/M phase and increased the subG(0) population in lipopolysaccharide-stimulated RAW 264.7 macrophages. Moreover, it increased the expression of proteins p53 and p21, down-regulated the expression of Bcl-2, activated the activity of caspase-1 and augmented the production of interleukin-1beta. Finally, the transfection of RAW 264.7 macrophages with a Bcl-2 expression plasmid produced the inhibition of apoptosis and caspase-1 activation/ interleukin-1beta release induced by cucurbitacin R in RAW 264.7 cells. CONCLUSIONS AND IMPLICATIONS: Taken together, these results point to a new apoptotic process in which interleukin-1beta release is directly regulated by Bcl-2 status; this contributes to the evidence that apoptotic processes do not induce inflammation.
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Authors | J M Escandell, M C Recio, R M Giner, S Máñez, J L Ríos |
Journal | British journal of pharmacology
(Br J Pharmacol)
Vol. 160
Issue 7
Pg. 1844-56
(Aug 2010)
ISSN: 1476-5381 [Electronic] England |
PMID | 20649584
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Anti-Inflammatory Agents, Non-Steroidal
- Interleukin-1beta
- Lipopolysaccharides
- Proto-Oncogene Proteins c-bcl-2
- RNA, Small Interfering
- Triterpenes
- cucurbitacin R
- Caspase 3
- Caspase 1
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Topics |
- Animals
- Anti-Inflammatory Agents, Non-Steroidal
(pharmacology)
- Apoptosis
(drug effects, immunology)
- Blotting, Western
- Caspase 1
(genetics, metabolism)
- Caspase 3
(metabolism)
- Cell Cycle
(drug effects)
- Cell Line
- Flow Cytometry
- Interleukin-1beta
(metabolism)
- Lipopolysaccharides
(pharmacology)
- Macrophages
(drug effects, immunology, metabolism, pathology)
- Membrane Potential, Mitochondrial
(drug effects)
- Mice
- Proto-Oncogene Proteins c-bcl-2
(antagonists & inhibitors, biosynthesis, genetics)
- RNA, Small Interfering
(genetics)
- Reverse Transcriptase Polymerase Chain Reaction
- Transfection
- Triterpenes
(pharmacokinetics)
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