Evaluation of aqueous extracts of Taraxacum officinale on growth and invasion of breast and prostate cancer cells.

Ethnotraditional use of plant-derived natural products plays a significant role in the discovery and development of potential medicinal agents. Plants of the genus Taraxacum, commonly known as dandelions, have a history of use in Chinese, Arabian and Native American traditional medicine, to treat a variety of diseases including cancer. To date, however, very few studies have been reported on the anti-carcinogenic activity of Taraxacum officinale (TO). In the present study, three aqueous extracts were prepared from the mature leaves, flowers and roots, and investigated on tumor progression related processes such as proliferation and invasion. Our results show that the crude extract of dandelion leaf (DLE) decreased the growth of MCF-7/AZ breast cancer cells in an ERK-dependent manner, whereas the aqueous extracts of dandelion flower (DFE) and root (DRE) had no effect on the growth of either cell line. Furthermore, DRE was found to block invasion of MCF-7/AZ breast cancer cells while DLE blocked the invasion of LNCaP prostate cancer cells, into collagen type I. Inhibition of invasion was further evidenced by decreased phosphorylation levels of FAK and src as well as reduced activities of matrix metalloproteinases, MMP-2 and MMP-9. This study provides new scientific data on TO and suggests that TO extracts or individual components present in the extracts may be of value as novel anti-cancer agents.

Effects of crude aqueous medicinal plant extracts on growth and invasion of breast cancer cells.

Plants used in folklore medicine continue to be an important source of discovery and development of novel therapeutic agents. In the present study, we determined the effects of crude aqueous extracts of a panel of medicinal plants on the growth and invasion of cancer cells. Our results showed that extracts of L. tridentata (Creosote Bush) and J. communis L. (Juniper Berry) significantly decreased the growth of MCF-7/AZ breast cancer cells. The latter as well as A. californica (Yerba Mansa) inhibited invasion into the collagen type I gel layer. Furthermore, the phosphorylation levels of extracellular signal-regulated kinase 1 and 2 (ERK1/2) decreased when the cells were exposed to aqueous extracts of L. tridentata, J. communis L. and A. californica. This study provides original scientific data on the anticancer activity of selected aqueous medicinal plant extracts used in traditional medicine.

Effects of extracts from two Native American plants on proliferation of human breast and colon cancer cell lines in vitro.

Native American medicinal plants are traditionally used to prevent and treat a variety of diseases, including cancer. These herbal preparations are alleged to have many biological activities, such as stimulation or suppression of immune responses and antiproliferative effects on cancer cells. In the present study, we investigated the effects of aqueous and ethanol extracts from two Native American plants, Ligusticum porteri (Osha) and Anemopsis californica (Yerba Manza), on the growth of human MCF-7/AZ breast and HCT8/E11 colon cancer cells. The aqueous and ethanol extracts from A. californica potently inhibited growth of MCF-7/AZ in a concentration-dependent manner, whereas the growth of HCT8/E11 was unaltered. Extracts from L. porteri showed no activity on either cell line. In addition, we observed that the extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) activities were markedly decreased when exposed to both extracts from A. californica. These results suggest that the growth inhibitory effect of A. californica in breast cancer cells is ERK-mediated.

A comparison of surface water natural organic matter in raw filtered water samples, XAD, and reverse osmosis isolates.

This research compared raw filtered waters (RFWs), XAD resin isolates (XAD-8 and XAD-4), and reverse osmosis (RO) isolates of several surface water samples from McDonalds Branch, a small freshwater fen in the New Jersey Pine Barrens (USA). RO and XAD-8 are two of the most common techniques used to isolate natural organic matter (NOM) for studies of composition and reactivity; therefore, it is important to understand how the isolates differ from bulk (unisolated) samples and from one another. Although, any comparison between the isolation methods needs to consider that XAD-8 is specifically designed to isolate the humic fraction, whereas RO concentrates a broad range of organic matter and is not specific to humics. The comparison included for all samples: weight average molecular weight (Mw), number average molecular weight (Mn), polydispersity (rho), absorbance at 280 nm normalized to moles C (epsilon280) (RFW and isolates); and for isolates only: elemental analysis, % carbon distribution by 13C NMR, and aqueous FTIR spectra. As expected, RO isolation gave higher yield of NOM than XAD-8, but also higher ash content, especially Si and S. Mw decreased in the order: RO > XAD-8 > RFW > XAD-4. The Mw differences of isolates compared with RFW may be due to selective isolation (fractionation), or possibly in the case of RO to condensation or coagulation during isolation. 13C NMR results were roughly similar for the two methods, but the XAD-8 isolate was slightly higher in 'aromatic' C and the RO isolate was slightly higher in heteroaliphatic and carbonyl C. Infrared spectra indicated a higher carboxyl content for the XAD-8 isolates and a higher ester:carboxyl ratio for the RO isolates. The spectroscopic data thus are consistent with selective isolation of more hydrophobic compounds by XAD-8, and also with potential ester hydrolysis during that process, although further study is needed to determine whether ester hydrolysis does indeed occur. Researchers choosing between XAD and RO isolation methods for NOM need to consider first the purpose of the isolation; i.e., whether humic fractionation is desirable. Beyond that, they should consider the C yield and ash content, as well as the potential for alteration of NOM by ester hydrolysis (XAD) or condensation/coagulation (RO). Furthermore, the RO and XAD methods produce different fractions or isolates so that researchers should be careful when comparing the compositions and reactivities of NOM samples isolated by these two different techniques.