Because little is known about the actions of botanical estrogens (BEs), widely consumed by menopausal women, we investigated the mechanistic and cellular activities of some major BEs. We examined the interactions of genistein, daidzein, equol, and liquiritigenin with estrogen receptors ERα and ERβ, with key coregulators (SRC3 and RIP140) and chromatin binding sites, and the regulation of gene expression and proliferation in MCF-7 breast cancer cells containing ERα and/or ERβ. Unlike the endogenous estrogen, estradiol (E2), BEs preferentially bind to ERβ, but their ERβ-potency selectivity in gene stimulation (340- to 830-fold vs. E2) is enhanced at several levels (coregulator recruitment, chromatin binding); nevertheless, at high (0.1 or 1 μM) concentrations, BEs also fully activate ERα. Because ERα drives breast cancer cell proliferation and ERβ dampens this, the relative levels of these two ERs in target cells and the BE dose greatly affect gene expression and proliferative response and will be crucial determinants of the potential benefits vs. risks of BEs. Our findings reveal key and novel mechanistic differences in the estrogenic activities of BEs vs. E2, with BEs displaying patterns of activity distinctly different from those seen with E2 and provide valuable information to inform future studies.

The development of an automated, high-throughput fractionation procedure to prepare and analyze natural product libraries for drug discovery screening is described. Natural products obtained from plant materials worldwide were extracted and first prefractionated on polyamide solid-phase extraction cartridges to remove polyphenols, followed by high-throughput automated fractionation, drying, weighing, and reformatting for screening and storage. The analysis of fractions with UPLC coupled with MS, PDA and ELSD detectors provides information that facilitates characterization of compounds in active fractions. Screening of a portion of fractions yielded multiple assay-specific hits in several high-throughput cellular screening assays. This procedure modernizes the traditional natural product fractionation paradigm by seamlessly integrating automation, informatics, and multimodal analytical interrogation capabilities.Natural products are a vast resource of compounds with seemingly unlimited chemical and functional diversity, and have been a rich source for lead molecules in drug discovery programs. 1-4 Sixty percent of new drugs for cancer and 75% of those for infectious diseases have originated from natural sources. 5,6 Between 2001 and 2005, 23 natural product based drugs were launched in Europe, Japan, and the United States for treating various disorders such as cancer, diabetes, dyslipidemia, atopic dermatitis, Alzheimer's disease, bacterial and fungal infections, genetic diseases such as tyrosinemia, and Gaucher's disease. 7 However, during the last two decades, research efforts in the discovery of therapeutic natural products have waned because of the complications and significant time requirements inherent in compound isolation. Primary screening of crude plant extracts or microbial fermentations, followed by bioassay-guided fractionation, purification, and structure elucidation of novel bioactive compounds can take several months. 8 The required scale of isolation has been too large to be implemented effectively in an automated, high-throughput fashion. The combination of these and other factors has led to a lagging emphasis in natural product discovery. However, recent advances in high-throughput screening (HTS) technology have

Whether they are being taken as dietary supplements by the general public or being evaluated in a clinical study, the authenticity of botanical products is a matter of paramount concern. Botanical specimens and the dietary supplements derived from them can vary in quality and in chemical constituent profiles because of a number of factors. Subtle variations in botanical specimens are known to have profound effects on the quality, efficacy, and safety of botanical dietary supplements and can potentially alter the results of clinical studies that rely on these materials. A complete array of authentication and evaluation tools can be utilized to provide a well-rounded scientific approach to the authentication of botanical products. It is vital that the authenticity of botanical supplements be established using appropriate analysis tools regardless of whether the end products are being considered for evaluation in clinical studies or are being developed for the consumer market.