CONTINUATION OF CANCER ABSTRACTS

J Neurooncol. 2007 Mar;82(1):91-3. Epub 2006 Sep 26
A lipoxygenase inhibitor in breast cancer brain metastases.
Flavin DF.
Foundation for Collaborative Medicine and Research, Greenwich, CT 06831, USA.
Dana_FK@hotmail.com

The complication of multiple brain metastases in breast cancer patients is a life threatening condition with limited success following standard therapies. The arachidonate lipoxygenase pathway appears to play a role in brain tumor growth as well as inhibition of apoptosis in in-vitro studies. The down regulation of these arachidonate lipoxygenase growth stimulating products therefore appeared to be a worthwhile consideration for testing in brain metastases not responding to standard therapy. Boswellia serrata, a lipoxygenase inhibitor was applied for this inhibition. Multiple brain metastases were successfully reversed using this method in a breast cancer patient who had not shown improvement after standard therapy. The results suggest a potential new area of therapy for breast cancer patients with brain metastases that may be useful as an adjuvant to our standard therapy.

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J Immunol. 2006 Mar 1;176(5):3127-40
Acetyl-11-keto-beta-boswellic acid potentiates apoptosis, inhibits invasion, and abolishes osteoclastogenesis by suppressing NF-kappa B and NF-kappa B-regulated gene expression.
Takada Y, Ichikawa H, Badmaev V, Aggarwal BB.
Cytokine Research Section, Department of Experimental Therapeutics, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA.

Acetyl-11-keto-beta-boswellic acid (AKBA), a component of an Ayurvedic therapeutic plant Boswellia serrata, is a pentacyclic terpenoid active against a large number of inflammatory diseases, including cancer, arthritis, chronic colitis, ulcerative colitis, Crohn's disease, and bronchial asthma, but the mechanism is poorly understood. We found that AKBA potentiated the apoptosis induced by TNF and chemotherapeutic agents, suppressed TNF-induced invasion, and inhibited receptor activator of NF-kappaB ligand-induced osteoclastogenesis, all of which are known to require NF-kappaB activation. These observations corresponded with the down-regulation of the expression of NF-kappaB-regulated antiapoptotic, proliferative, and angiogenic gene products. As examined by DNA binding, AKBA suppressed both inducible and constitutive NF-kappaB activation in tumor cells. It also abrogated NF-kappaB activation induced by TNF, IL-1beta, okadaic acid, doxorubicin, LPS, H2O2, PMA, and cigarette smoke. AKBA did not directly affect the binding of NF-kappaB to the DNA but inhibited sequentially the TNF-induced activation of IkappaBalpha kinase (IKK), IkappaBalpha phosphorylation, IkappaBalpha ubiquitination, IkappaBalpha degradation, p65 phosphorylation, and p65 nuclear translocation. AKBA also did not directly modulate IKK activity but suppressed the activation of IKK through inhibition of Akt. Furthermore, AKBA inhibited the NF-kappaB-dependent reporter gene expression activated by TNFR type 1, TNFR-associated death domain protein, TNFR-associated factor 2, NF-kappaB-inducing kinase, and IKK, but not that activated by the p65 subunit of NF-kappaB. Overall, our results indicated that AKBA enhances apoptosis induced by cytokines and chemotherapeutic agents, inhibits invasion, and suppresses osteoclastogenesis through inhibition of NF-kappaB-regulated gene expression.

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Anticancer Res. 2002 Sep-Oct;22(5):2853-62
Cytostatic and apoptosis-inducing activity of boswellic acids toward malignant cell lines in vitro.
Hostanska K, Daum G, Saller R.
Departmment of Internal Medicine, University Hospital Z�rich, R�mistrasse 100, 8091 Z�rich, Switzerland. katarina.hostanska@access.unizh.ch

Boswellic acids from frankincense were indentified as the active compounds which inhibit leukotriene biosynthesis, 5-lipoxygenase and exert antiproliferative activity toward a variety of malignant cells. Because of the relevance for the clinical application, we tested the ethanolic extract of Boswellia serrata gum resin containing a defined amount of boswellic acids for its cytotoxic, cytostatic and apoptotic activity on five leukemia (HL-60, K 562, U937, MOLT-4, THP-1) and two brain tumor (LN-18, LN-229) cell lines by WST-1 assay and flow cytometry. The Boswellia serrata extract induced dose-dependent antiproliferative effects on all human malignant cells tested with GI50 values (extract concentration producing 50% cell growth inhibition) between 57.0 and 124.1 micrograms/ml. In three haematological cell lines (K562, U937, MOLT-4) the effect of total extract expressed in GI50 was 2.8-, 3.3- and 2.3-times more potent (p < 0.05) than pure 3-O-acetyl-11-keto-beta-boswellic acid (AKBA). Morphological changes after 24-27 hours and the detection of apoptotic cells by AnnexinV-binding and/or by the detection of propidium iodide-labelled DNA with flow cytometry, confirmed the apoptotic cell death. The results of this study suggest the effectiveness of Boswellia serrata extract with defined content of boswellic acids.

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CANCER --- CURCUMIN

Planta Med. 2007 Jul;73(8):725-30. Epub 2007 Jun 22
Curcumin decreases acid sphingomyelinase activity in colon cancer Caco-2 cells.
Cheng Y, Kozubek A, Ohlsson L, Sternby B, Duan RD.
Biomedical Centre, B11, Institution of Clinical Sciences, Lund University, Lund, Sweden.

Curcumin has been shown to inhibit cell growth and induce apoptosis in colon cancer cells. The metabolism of sphingomyelin has implications in the development of colon cancert. We examined whether curcumin affects the enzymes that hydrolyse sphingomyelin in Caco-2 cells. The cells were cultured in both monolayer and polarized conditions and stimulated with curcumin. The activities of sphingomyelinases were determined. Sphingomyelin and its hydrolytic products were analysed by thin layer chromatography. The changes of acid sphingomyelinase protein were examined by Western blotting. We found that curcumin reduced the hydrolytic capacity of the cells against choline-labelled sphingomyelin, associated with a mild increase of cellular sphingomyelin in the cells. Analysis of the hydrolytic products revealed that the activity was derived from acid sphingomyelinase not from phospholipase D. The curcumin-induced reduction of acid SMase required more than 8 h stimulation. Western blotting showed reduced acid sphingomyelinase protein after curcumin stimulation. The inhibitory effect was more potent in monolayer cells than in polarised cells. No changes of other sphingomyelinases were identified. In the concentrations inhibiting acid sphingomyelinase, curcumin inhibited DNA synthesis and induced cell death. In conclusion, curcumin inhibits acid sphingomyelinase and the effect might be involved in its antiproliferative property against colon cancer cells.

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Adv Exp Med Biol. 2007;595:471-80
Clinical studies with curcumin.
Hsu CH, Cheng AL.
Department of Oncology, National Taiwan University Hospital, Taipei. chih@ha.mc.ntu.edu.tw

Curcumin has long been expected to be a therapeutic or preventive agent for several major human diseases because of its antioxidative, anti-inflammatory, and anticancerous effects. In phase I clinical studies, curcumin with doses up to 3600-8000 mg daily for 4 months did not result in discernible toxicities except mild nausea and diarrhea. The pharmacokinetic studies of curcumin indicated in general a low bioavailability of curcumin following oral application. Nevertheless, the pharmacologically active concentration of curcumin could be achieved in colorectal tissue in patients taking curcumin orally and might also be achievable in tissues such as skin and oral mucosa, which are directly exposed to the drugs applied locally or topically. The effect of curcumin was studied in patients with rheumatoid arthritis, inflammatory eye diseases, inflammatory bowel disease, chronic pancreatitis, psoriasis, hyperlipidemia, and cancers. Although the preliminary results did support the efficacy of curcumin in these diseases, the data to date are all preliminary and not conclusive. It is imperative that well-designed clinical trials, supported by better formulations of curcumin or novel routes of administration, be conducted in the near future.

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