Effects of homeopathic preparations on human prostate cancer growth in cellular and animal models.

The use of dietary supplements for various ailments enjoys unprecedented popularity. As part of this trend, Sabal serrulata (saw palmetto) constitutes the complementary treatment of choice with regard to prostate health. In homeopathy, Sabal serrulata is commonly prescribed for prostate problems ranging from benign prostatic hyperplasia to prostate cancer. The authors' work assessed the antiproliferative effects of homeopathic preparations of Sabal serrulata, Thuja occidentalis, and Conium maculatum, in vivo, on nude mouse xenografts, and in vitro, on PC-3 and DU-145 human prostate cancer as well as MDA-MB-231 human breast cancer cell lines. Treatment with Sabal serrulata in vitro resulted in a 33% decrease of PC-3 cell proliferation at 72 hours and a 23% reduction of DU-145 cell proliferation at 24 hours (P<.01). The difference in reduction is likely due to the specific doubling time of each cell line. No effect was observed on MDA-MB-231 human breast cancer cells. Thuja occidentalis and Conium maculatum did not have any effect on human prostate cancer cell proliferation. In vivo, prostate tumor xenograft size was significantly reduced in Sabal serrulata-treated mice compared to untreated controls (P=.012). No effect was observed on breast tumor growth. Our study clearly demonstrates a biologic response to homeopathic treatment as manifested by cell proliferation and tumor growth. This biologic effect was (i)significantly stronger to Sabal serrulata than to controls and (ii)specific to human prostate cancer. Sabal serrulata should thus be further investigated as a specific homeopathic remedy for prostate pathology.

Cancer-related overexpression of the peripheral-type benzodiazepine receptor and cytostatic anticancer effects of Ginkgo biloba extract (EGb 761).

The peripheral-type benzodiazepine receptor (PBR) is an 18-kDa high affinity drug- and cholesterol-binding protein that is involved in various cell functions, including cell proliferation and apoptosis. PBR was shown to be overexpressed in certain types of malignant human tumors and cancer cell lines, correlating with enhanced tumorigenicity and cell proliferation rates. The present study was conducted in order to further define the role of PBR in cancer and to extend our recent findings regarding the possible anticancer effects of the standardized Ginkgo biloba extract EGb 761. Treatment with EGb 761 decreased PBR mRNA levels and inhibited the proliferation of breast, glioma and hepatocarcinoma cell lines, further corroborating our previous contention that its mechanism of action is through the modification of PBR expression. In vivo treatment with Ginkgo biloba extract led to dose-dependent decreases in xenograft growth of both MDA-MB-231 breast cancer and U-87 glioma cell lines in nude mice, although the effects were not maintained after 50 days of treatment in the latter. The results obtained in MDA-MB-231 xenografts indicated pronounced inhibition of tumor growth, verified by MRI imaging. These results were obtained using a modified experimental protocol where the animals were treated with the extract before cell inoculation. Although an exact role for PBR in relation to the initiation and progression of various types of cancer remains to be defined, our results indicate that PBR overexpression in certain cancer cells is related to an aggressive phenotype. Since EGb 761 treatment opposes this aggressive phenotype by decreasing PBR overexpression, it could be useful in preventing or treating cancer invasiveness and metastasis.

Common gene targets of Ginkgo biloba extract (EGb 761) in human tumor cells: relation to cell growth.

The standardized extract of Ginkgo biloba leaves (EGb 761) has been shown to inhibit aggressive human breast cancer cell proliferation both in vitro and in vivo. These results were extended to human glioma and hepatoma cells in vitro suggesting that EGb 761 may have a more widespread application for tumor growth control. To understand the mechanism by which EGb 761 acts to inhibit cell proliferation, we investigated the effects of EGb 761 on human breast cancer, glioma and hepatoma cell transcriptomes by means of various large-scale DNA array techniques. The data presented focus on genes regulated by EGb 761 that are common to the three tumor cell types and for which the data were verified by two different types of DNA microarray and/or RNA (Northern) blot analysis and real-time quantitative PCR. These results could therefore help elucidate the mechanism of cytostatic action of EGb 761 and identify genes important for tumor growth.