Antiestrogenic effect of 20S‐protopanaxadiol and its synergy with tamoxifen on breast cancer cells

Abstract

In this piece of work we focused our attention on the peroxidation step and alongside considered hydroperoxides as probes for the overall oxidative process. This technique of oxygen uptake actually monitors the amount of oxygen consumed during polymer degradation. Our present work aimed to investigate this technique to evaluate the oxygen uptake during in situ photoirradiation, under controlled atmosphere. Our experimental results clearly elucidate that the oxygen consumption data accounts for a very early stage of aging during the photo‐oxidation of polymers and provides us with an accurate and sensitive diagnosis about the formation of hydroperoxides. A straight‐line relationship was exhibited under our experimental conditions while observing a relation between oxygen pressure drop and hydroperoxide content in the polymer. This correlation was dependent upon the nature of polymer and of course on the aging conditions (temperature, irradiation, oxidative atmosphere). The impact of environmental atmosphere on aging was particularly kept in mind. To conclude, we emphasized that oxygen uptake is a promisingly powerful tool to identify the impact of the overall environmental parameters on the polymer photoaging. An important implication was on the understanding of atmospheric factors (including pollutants such as O3, NOx, etc.), which is usually given minor importance, on the degradation of polymer upon outdoor weathering. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006

Chinese Medicine and Biomodulation in Cancer Patients—Part Two

“…In addition, they may exert their estrogenic influence through either or both of receptor-dependent and receptor-independent mechanisms [33][34][35] . Other studies demonstrate inhibition of breast cancer cell models, particularly by ginseng and its extracts [36][37][38][39][40][41] . Piersen reviewed the conflicting data in detail 42 .…”

“…A study of 20(S)-protopanaxadiol, a major gastrointestinal metabolite of the ginsenosides, suggests that it inhibits estrogen-stimulated gene expression in MCF-7 estrogen receptor (ER)-positive breast cancer cells, inhibits xenograft growth, and enhances the cytotoxicity of tamoxifen in an ER-independent fashion 39 . The Rh2 ginsenoside extract hypersensitizes multidrug-resistant breast cancer cells to paclitaxel 37 .…”

“…At least five RCTs have shown that Chinese herbal treatment can decrease the degree of myelosuppression, reduce gastrointestinal side effects, and increase appetite 39,[68][69][70][71][73][74][75][76][77][78]80,216 . Importantly, such treatment can also increase the probability of completion of scheduled chemotherapy.…”

20(S)-Protopanaxadiol Induces Human Breast Cancer MCF-7 Apoptosis through a Caspase-Mediated Pathway

“…20 (S)-Protopanaxadiol (PPD) is an active ginseng metabolite, which is the final form of protopanaxadiol saponins metabolized by human intestinal microflora (Figure 1) (Xie et al, 2009). It was reported that 20 (S)-PPD showed anticancer effect in experimental animals and cultured cells though caspase-dependent and caspaseindependent pathway (Oh and Lee, 2004;Liu et al, 2007;Yu et al, 2007;Wang et al, 2008). At present, 20 (S)-PPD has been developed into a Chinese medicine, named "Yijinsheng Capsule", to assist radiotherapy and chemotherapy, currently in clinical stage Ⅲ.…”

Transformation Techniques for the Large Scale Production of Ginsenoside Rg3

“…예를 들면 여러 종류의 암세포에 대한 세포독성은 ginsenoside 의 당 분자 수가 감소함에 따라 증가한다. G-Rb1, -Rd, -Re, -Rg2와 -Rg3 중에서 G-Rg3가 가장 강한 활성을 보였고 (Wang et al, 2007a), 당잔기 2개를 가진 G-Rg3 보다 1개를 가진 G-Rh2가 항암활성이 강하고 당 잔기가 없는 PPD와 PPT가 더욱 강하다 (Yue et al, 2006;Yu et al, 2007a). 그러나 같은 수의 당 분자를 가지고 있지만 C-6 위치의 당분자의 존재는 입 체적 장해를 증가시켜 C-3와 C-20 위치의 당분자 결합에 비해 항암활성이 감소된다 Chen et al, 2009).…”