Archive for February 12th, 2008

XN and leukemia cells

Posted on February 12, 2008. Filed under: Research | Tags: , , , , , , , , , , , , |

Mol Nutr Food Res. 2005 Sep;49(9):844-50.

Xanthohumol kills B-chronic lymphocytic leukemia cells by an apoptotic mechanism.

Department of Hematology, Ghent University Hospital, Gent, Belgium.

B-chronic lymphocytic leukemia (B-CLL) is an indolent lymphoid malignancy with variable prognosis. Adverse prognostic factors comprise treatment resistance, cytogenetics (11q- and 17p-), the presence of unmutated Ig genes, and the more comprehensive activation marker Zap 70. In contrast to diminished sensitivity to chemotherapy, Zap 70+ B-CLL cells retain their responsiveness to manipulation of signal transduction and monoclonals. Xanthohumol (XA) has recently been documented to have an impact on breast cancer cell growth and invasiveness in vitro. Based on these observations, lymphocytes from patients with B-CLL were cultured in the presence of XA in vitro. XA induced a dose-dependent killing of B-CLL cells at an LD(50) ((24 h)) of 24.4 +/- 6.6 microM, independent of known adverse prognostic factors including functional loss of p53. Cell death was associated with poly (ADP)-ribose polymerase cleavage and annexin V positivity, suggestive of an apoptotic mechanism. Surprisingly, p 70(S 6 K) phosphorylation was stimulated upon XA treatment. In conclusion, XA has an antitumor activity on B-CLL cells in vitro. The molecular mechanisms behind this pro-apoptotic effect deserve further investigation.

PMID: 16144030 [PubMed – indexed for MEDLINE]

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XN and Prostate Cancer

Posted on February 12, 2008. Filed under: Research | Tags: , , , , , , , , , , |

Phytomedicine. 2006 Nov;13(9-10):732-4. Epub 2006 May 5.

Anti-proliferative properties of prenylated flavonoids from hops (Humulus lupulus L.) in human prostate cancer cell lines.

Ghent University-UGent, Faculty of Pharmaceutical Sciences, Laboratory of Pharmacognosy and Phytochemistry, and Ghent University Hospital, Department of Endocrinology, Belgium.

Chalcones xanthohumol (X) and desmethylxanthohumol (DMX), present in hops (Humulus lupulus L.), and the corresponding flavanones isoxanthohumol (IX, from X), 8-prenylnaringenin (8-PN, from DMX), and 6-prenylnaringenin (6-PN, from DMX), have been examined in vitro for their anti-proliferative activity on human prostate cancer cells PC-3 and DU145. X proved to be the most active compound in inhibiting the growth of the cell lines with IC50 values of 12.3+/-1.1 microM for DU145 and 13.2+/-1.1 microM for PC-3. 6-PN was the second most active growth inhibitor, particularly in PC-3 cells (IC50 of 18.4+/-1.2 microM). 8-PN, a highly potent phytoestrogen, exhibited pronounced anti-proliferative effects on PC-3 and DU145 (IC50 of 33.5+/-1.0 and 43.1+/-1.2 microM, respectively), and IX gave comparable activities (IC50 of 45.2+/-1.1 microM for PC-3 and 47.4+/-1.1 microM for DU145). DMX was the least active compound. It was evidenced for the first time that this family of prenylated flavonoids from hops effectively inhibits proliferation of prostate cancer cells in vitro.

PMID: 16678392 [PubMed – indexed for MEDLINE]

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