Herbal Science Research - probiotic

Apigenin suppresses cancer cell growth through ERbeta.

Site Editor — Wed, 31 Jan 2007 19:21:50 -0800

Apigenin suppresses cancer cell growth through ERbeta.: Neoplasia. 2006 Nov;8(11):896-904 Authors: Mak P, Leung YK, Tang WY, Harwood C, Ho SM

Two flavonoids, genistein and apigenin, have been implicated as chemopreventive agents against prostate and breast cancers. However, the mechanisms behind their respective cancer-protective effects may vary significantly. The goal of this study was to determine whether the antiproliferative action of these flavonoids on prostate (DU-145) and breast (MDA-MB-231) cancer cells expressing only estrogen receptor (ER) beta is mediated by this ER subtype. It was found that both genistein and apigenin, although not 17beta-estradiol, exhibited antiproliferative effects and proapoptotic activities through caspase-3 activation in these two cell lines. In yeast transcription assays, both flavonoids displayed high specificity toward ERbeta transactivation, particularly at lower concentrations. However, in mammalian assay, apigenin was found to be more ERbeta-selective than genistein, which has equal potency in inducing transactivation through ERalpha and ERbeta. Small interfering RNA-mediated downregulation of ERbeta abrogated the antiproliferative effect of apigenin in both cancer cells but did not reverse that of genistein. Our data unveil, for the first time, that the anticancer action of apigenin is mediated, in part, by ERbeta. The differential use of ERalpha and ERbeta signaling for transaction between genistein and apigenin demonstrates the complexity of phytoestrogen action in the context of their anticancer properties.

Fighting food allergy: current approaches.

Site Editor — Fri, 09 Jun 2006 03:58:16 -0700

Fighting food allergy: current approaches.: Ann N Y Acad Sci. 2005 Nov;1056:30-45 Authors: Nieuwenhuizen NE, Lopata AL

Food allergy is defined as an adverse immunologic reaction to allergens present in food and is associated with symptoms ranging from gastrointestinal discomfort to anaphylactic shock and death. The increase in prevalence and potential fatality of disease has led to increased efforts to find effective therapies and prophylaxis. While specific immunotherapy (SIT) is effective in desensitization against inhalant allergens, it is unadvised against food allergy because of the high risk of adverse side effects. A review of the recent literature shows that various approaches have been taken to develop safer and more effective SIT regimens. Here we discuss the use of recombinant allergens, peptides, DNA vaccines, immunostimulatory DNA sequences, and other bacterial products in SIT. In addition, we review nonspecific therapies such as anti-IgE administration and cytokine therapy as well as natural therapies such as probiotics and Chinese herbal medications. In conclusion, anti-IgE treatment and SIT using hypoallergenic recombinant allergens in combination with Th1-inducing adjuvants appear the most promising approaches. New initiatives to increase our understanding of the pathophysiology and immunologic mechanisms of food allergy along with the molecular characterization of food allergens should pave the way towards safer and more effective ways of combating this debilitating and potentially life-threatening disease.

Human Endogenous Microbial Ecosystems: The Next Frontier

Site Editor — Fri, 09 Jun 2006 03:24:40 -0700

Human Endogenous Microbial Ecosystems: The Next Frontier

Presented by: David A. Relman, M.D., Stanford University

Aired date: 10/27/2005 3:21:00 PM Eastern Time

Isoflavones and Functional Foods Alter the Dominant Intestinal Microbiota in Postmenopausal Women.

Site Editor — Fri, 09 Jun 2006 03:12:20 -0700

Isoflavones and Functional Foods Alter the Dominant Intestinal Microbiota in Postmenopausal Women. - J Nutr. 2005 Dec;135(12):2786-2792 Authors: Clavel T, Fallani M, Lepage P, Levenez F, Mathey J, Rochet V, Sérézat M, Sutren M, Henderson G, Bennetau-Pelissero C, Tondu F, Blaut M, Doré J, Coxam V

Dietary phytoestrogens, such as isoflavones, are used as food additives to prevent menopause-related disorders. In addition to other factors, their bioavailability strongly depends on the activity of intestinal bacteria but the underlying interactions remain poorly understood. A randomized, double-blind, placebo-controlled study was undertaken with 39 postmenopausal women to characterize changes in the dominant microbial communities of the intestinal tract after 2 mo of isoflavone supplementation with and without pro- or prebiotic. The diversity and composition of the dominant microbiota were analyzed by temporal temperature-gradient gel electrophoresis (TTGE) and fluorescent in situ hybridization. Isoflavones alone stimulated dominant microorganisms of the Clostridium coccoides-Eubacterium rectale cluster, Lactobacillus-Enterococcus group, Faecalibacterium prausnitzii subgroup, and Bifidobacterium genus. The stimulation of the Clostridium coccoides-Eubacterium rectale cluster depended on the women's equol excretion and was transient, with the exception of a prolonged bifidogenic effect. Lasting changes in the diversity of the dominant species were also observed. The probiotic strain supplied could be detected by TTGE during its passage through the intestinal tract, and ingestion of fructooligosaccharides triggered a marked and specific bifidogenic effect. In conclusion, this is the first human study that shows changes in the diversity and composition of dominant bacterial communities in response to dietary supplementation with hormone-related compounds combined with functional foods.