미성숙 암컷 흰쥐의 성 성숙에 미치는 genistein의 효과

이우철,이성호,안련섭,박미정 대한소아청소년과학회 2009 Clinical and Experimental Pediatrics (CEP) Vol.52 No.1

Puopose : Exposure to dietary phytoestrogens such as genistein during early childhood is a growing public health concern. We examined the effect of early exposure to genistein on sexual maturation in immature rats. Methods : Weaning (3wk-old) Sprague-Dawley female rats were assigned to three groups (n=6 for each): fed by high dose of genistein (100 mg/kg/d), low dose of genistein (10 mg/kg/d) and control group. First vaginal opening (VO) day was observed. Structural alterations in the ovary and uterus were assessed by histologically. Expression of genes of ERα, ERβ, and progesterone receptor (PR) in the ovary and uterus were investigated by RT-PCR. Results : High genistein group had earlier VO than control and low genistein group. Graafian follicles and corpora lutea were observed from the ovary of genistein-treated groups, while primary, secondary follicles and small atretic follicles were observed in the control group. Hypertrophy of luminal and glandular uterine epithelia were found in the genistein-treated groups while poor development of gland and fewer myometrial cell layers were evident in control group. In ovary, the transcriptional activities of ERα and ERβ were higher in high genistein group than in controls. In uterus, the transcriptional activities of ERα, ERβ and PR were higher in low genistein group than in controls. Conclusion : Acute exposure to genistein during the prepubertal period could activate the reproductive endocrine system resulting in the early onset of puberty in female rats. Further clinical investigation on the effect of genistein on the sexual maturation in children is warranted. 목 적 : 어린시기에 genistein과 같은 식물성 에스트로겐의 섭취가 사회적 관심사로 대두되고 있다. 본 연구에서는 어린 쥐에서 genistein에 노출이 사춘기 개시 및 생식기관에 미치는 영향을 알아 보았다. 방 법 : 이유기(3주령) 암컷 흰쥐를 저용량 genistein (10 mg/ kg/day), 고용량 genistein (100 mg/kg/day), 대조군의 세 그룹 (각 그룹 당 n=6)으로 나누고 첫 번째 질구 개방이 확인되는 날까지 농도별로 각각 경구 투여하였다. 질구 개방일을 확인하고 생식 기관의 무게를 측정하며 난소와 자궁에서 ERα, ERβ, PR 유전자들의 발현양상을 RT-PCR을 이용해 비교하였고, 난소와 자궁의 구조적 이상을 확인하기 위해 조직학적 분석을 실시하였다. 결 과 : 고용량 genistein 투여군은 저용량군 및 대조군에 비해 질구 개방일이 유의하게 촉진되었다. RT-PCR결과, ERα, ERβ, PR의 전사활성은 genistein에 노출된 쥐들의 난소와 자궁에서 유의하게 증가하였다. 그라프 난포와 황체는 genistein 투여군의 난소에서만 발견되었고, 대조군의 난소에서는 1차, 2차 난포들과 작은 미성숙 난포들만이 관찰되었다. Genistein 처리군의 자궁에서도 내막층 근막층 및 상피층이 과다성장상태였으나 대조군에서는 모든 세포층과 분비선이 미약하게 발달하였다. 결 론 : 결론적으로, 사춘기 이전 시기에 비교적 단기간의 genistein 노출이라도 미성숙 암컷 흰쥐에서 생식 내분비 활성을 일으켜 조기 사춘기와 성 스테로이드 호르몬 수용체의 발현 양상 변화를 초래할 수 있으며, genistein의 노출이 아동기 성성숙에 미치는 영향에 대한 더욱 많은 연구가 필요할 것으로 사료된다.

Pharmaceutical Evaluation of Genistein-loaded Pluronic Micelles for Oral Delivery

Kwon, Suk-Hyung,Kim, Sun-Young,Ha, Kyoung-Wook,Kang, Myung-Joo,Huh, Jin-Seo,Im, Tae-Jong,Kim, Yong-Min,Park, Young-Mi,Kang, Kyoung-Hoon,Lee, Sang-Kil,Chang, Jung-Yun,Choi, Young-Wook,Lee, Jae-Hwi 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.9

The purpose of the present study was to determine whether Pluronic F127 polymeric micelles could improve the oral bioavailability of a poor water-soluble drug, such as genistein. Genistein is a phytoestrogen that has estrogenic activity. F127 triblock copolymer consists of $PEO_{100}-PPO_{65}-PEO_{100}$. Genistein was incorporated in the Pluronic F127 polymeric micelles by a solid dispersion method. The genistein release of genistein-loaded polymeric micelles was studied in vitro (in pH 1.2 and pH 6.8). And the oral bioavailabilities of genistein powder and genisteinloaded micelles were estimated at a dose of 4.0 mg/kg as genistein in rats. Drug loading amount and drug loading efficiency were 11.18% and 97.41%, respectively. The average size of the genistein-loaded polymeric micelles was 27.76 nm. And genistein release of the genistein-loaded polymeric micelles in vitro was 58% (pH 1.2) and 82% (pH 6.8). The bioavailability of genistein-loaded polymeric micelles was better than genistein powder. Consequently, Pluronic F127 polymeric micelles are an effective delivery system for the oral administration of genistein.

Isoflavone 강화 기능성 계란 생산 : 난황내 Genistein 전이 효율 개선

황보종,이병석,이현정,정완태,조성백,홍의철,배해득,장종수,HwangBo, J.,Lee, B.S.,Lee, H.J.,Chung, W.T.,Cho, S.B.,Hong, E.C.,Bae, H.D.,Chang, J.S. 한국가금학회 2006 韓國家禽學會誌 Vol.33 No.3

Genistein의 전이율을 조사하기 위하여 순도 97% 이상의 genistein 250 mg을 펠렛으로 성형한 후 500 mg및 1 g의 용량으로 각각 2, 4개씩 산란계의 어깨 부위 피하에 이식하여 계란의 난황 내에서 검출되는 genistein의 함량을 HPLC 및 HPLC-MS를 이용하여 분석하였다. Genistein 500 mg 처리구에서, 12, 18, 30일에 각각 218, 395 ng/g, 500 ng/g의 genistein 이 전이되어 59일까지 계속적으로 유지되었다. 또한 genistein 1,000 mg 처리구에서는 12일 후에는 240 ng/g, 18일 후에는 406.5 ng/g, 30일 후에는 514 ng/g의 genistein이 전이되어 59일까지 계속적으로 유지되었다. 본 연구를 통하여, 500 ng/g 이상의 genistein이 함유된 계란을 59일 이상 지속적으로 생산할 수 있어 피하이식을 통한 비급이 방식은 기존의 급이 방식에 비해 20배 이상 효과적이었다. This study was carried out to determine whether genistein implants in laying hens could be transferred into their eggs. 250 mg genistein pellet was implanted two or four subcutaneously in the neck of laying hens. The contents of genistein in egg yolk transferred were analyzed with HPLC-MS. In 500 mg genistein pellets, it was detected as 395 ng/egg yolk on the day 18 after implanting and maintained as 546 ng/egg yolk after the day 59. In 1,000 mg, genistein was detected as 240 ng/egg yolk on the day 13, as 514 ng/egg yolk on the day 30 and maintained over 59 days. In conclusion, the direct genistein implants could be more twenty times efficiently transferred to egg yolks than dietary supplement.

인체 방광암 및 백혈병세포에서 genistein에 의한 세포주기 G2/M arrest 유발에 관한 연구

김의겸,명유호,송관성,이기홍,류충호,최영현,Kim, Eu-Kyum,Myong, You-Ho,Song, Kwan-Sung,Lee, Ki-Hong,Rhu, Chung-Ho,Choi, Yung-Hyun 한국생명과학회 2006 생명과학회지 Vol.16 No.4

본 연구에서는 T24 인체방광암 및 U937 백혈병 세포의 증식에 미치는 genistein의 영향을 조사 하였다. Genistein이 처리된 T24 및 U937 세포는 처리 농도 의존적으로 세포의 증식이 현저히 감소되었으며 심한 형태적 변형이 동반되었으나, U937 세포에서 보다 높은 감수성을 보였다. 이러한 T24 및 U937 세포의 증식억제 및 형태 변형은 G2/M기의 세포주기 억제 및 apoptosis 유발과 연관성이 있음을 flow cytometry를 이용한 세포주기의 분석을 통하여 확인하였다. T24 세포에서 genistein에 의한 G2/M arrest는 cyclin A, cyclin B1 및 Cdc25C 등의 단백질 발현 감소와 연관성이 있었으나, 종양억제 유전자 p53 및 Cdk inhibitor p21의 발현에는 큰 변화가 없었다. U937 세포에서 genistein에 의한 G2/M arrest는 cyclin B1 및 p53 비의존적인 p21의 발현 증가와 연관성이 있었다. 이상의 결과들은 현재까지 거의 연구가 진행된 바 없는 인체방광암 및 백혈병 세포에서 genistein의 항암작용을 이해하는데 중요한 자료가 될 것이고 나아가 genistein을 포함한 그와 유사한 항암제 후보물질들의 연구에 있어서 기초 자료로서 사용될 수 있을 것으로 생각된다. Genistein, a natural isoflavonoid phytoestrogen, is a strong inhibitor of protein tyrosine kinase and DNA topoisomerase activities. There are several studies documenting molecular alterations leading to cell cycle arrest and induction of apoptosis by genistein as a chemopreventive agent in a variety of cancer cell lines; however, its mechanism of action and its molecular targets on human bladder carcinoma and leukemic cells remain unclear. In the present study, we have addressed the mechanism of action by which genistein suppressed the proliferation of T24 bladder carcinoma and U937 leukemic cells. Genistein significantly inhibited the cell growth and induced morphological changes, and induced the G2/M arrest of the cell cycle in both T24 and U937 cells with a relatively stronger cytotoxicity in U937. The G2/M arrest in T24 cells was associated with the inhibition of cyclin A, cyclin B1 and Cdc25C protein expression without alteration of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1). However, the inhibitory effects of genistein on the cell growth of U937 cells were connected with a marked inhibition of cyclin B1 and an induction of Cdk inhibitor p21 proteins by p53-independent manner. These data suggest that genistein may exert a strong anticancer effect and additional studies will be needed to evaluate the different mechanisms between T24 and U937 cells.

Cell Survival, Apoptosis and AMPK-COX-2 Signaling Pathway of Mammary Tumor Cells after Genistein Treatment Combined with Estrogen

Lee, Yun-Kyoung,Hwang, Jin-Taek,Kim, Young-Min,Park, Ock-Jin The Korean Society of Food Science and Nutrition 2007 Preventive Nutrition and Food Science Vol.12 No.4

Genistein is an active component of legumes and other related food shown to be associated with prevention of degenerative diseases such as cancer through inducing signaling pathways. Treatment of genistein resulted in the induction of apoptosis in the cultured cancer cells. This induction of apoptosis was demonstrated by the Tunel assay in these cells. Unveiling the potential of genistein in cytotoxicity via apoptosis when it is treated with estrogen can predict the therapeutic capability of genistein in breast cancers in the presence of endogenous estrogen. We have found that apoptosis induced by genistein treatment in the presence of estrogen is agonistic or antagonistic depending on the concentrations and treatment periods applied in MCF-7 breast cancer cells. For the suppression of cell survival, 24 hr of treatment was required to induce a synergistic agonistic response between estrogen and genistein at low concentrations of genistein. After this period, the agonistic pattern of genistein to estrogen disappeared. The decrement of COX-2 expression in MCF-7 cells treated with genistein was accompanied with the activation of AMPK only at a high concentration of genistein. This association between AMPK activation and down-regulation of COX-2 by genistein was dampened in the presence of estrogen. It was also demonstrated that genistein and estrogen regulate cell survival and apoptosis by modulating p53 and caspase-3 in the opposite direction. These results suggest that genistein has the potential to control breast cancer development, and co-treatment with estrogen can cause agonistic or antagonistic action on breast cancer cell control.

Anti-invasive Activity of Human Breast Carcinoma Cells by Genistein through Modulation of Tight Junction Function

Sung Ok Kim(김성옥),Yong Kee Jeong(정영기),Yung Hyun Choi(최영현) 한국생명과학회 2009 생명과학회지 Vol.19 No.9

Tight junctions (TJs)은 인접된 세포 사이의 전해질 및 거대분자 확산 조절에 관여하는 paracellular permeability의 장벽 역할을 한다. 본 연구에서는 MCF-7 및 MDA-MB-231 인체유방암세포에서 대두의 대표적인 생리활성물인 genistein에 의한 암세포의 침윤 억제에서 TJs의 견고성 및 투과성과의 연관성을 조사하였다. 본 연구의 결과에 의하면 genistein에 의한 유방암세포의 증식 억제, 암세포 이동성의 저하 및 침윤성의 억제는 TJs의 증가된 견고성과 연관이 있었으며, 이를 transepithelial electrical resistance의 증가 및 paracellular permeability의 감소로 확인하였다. Genistein은 두 유방암세포에서 TJs의 주요 조절 단백질로서 paracellular transport 조절에 중요한 역할을 하는 claudin-3 및 claudin-4의 발현을 억제시켰다. 그리고 genistein은 암세포의 전이 조절 관련 유전자들인 like growth factor-1 receptor 및 snail의 발현을 억제하였으며, thrombospondin-1 및 E-cadherin의 발현은 증가시켰다. 또한 small interfering RNA를 이용하여 genistein의 유방암세포의 침윤 억제에서 claudin-3 단백질의 중요성을 확인하였다. 결론적으로 genistein이 TJs의 견고성 증가를 통하여 암세포의 침윤성을 억제할 수 있었으며, 이 과정에서 아마도 claudin 단백질의 발현 증가가 중요한 역할을 하고 있음을 알 수 있었다. 본 연구의 결과는 genistein이 종양 전이억제를 효과적으로 차단할 수 있음을 보여주는 것이다. Tight junctions (TJs) that act as paracellular permeability barriers play an essential role in regulating the diffusion of fluid, electrolytes and macromolecules through the paracellular pathway. In this study, we investigated the correlation between the tightening of TJs, permeability and the invasive activity of genistein - a bioactive isoflavone of soybeans - in human breast carcinoma MCF-7 and MDA-MB-231 cells. The inhibitory effects of genistein on cell proliferation, motility and invasiveness were found to be associated with the increased tightness of the TJs, which was demonstrated by an increase in transepithelial electrical resistance and a decrease in paracellular permeability. Additionally, the immunoblotting results indicated that genistein repressed the levels of the proteins that comprise the major components of TJ, claudin-3 and claudin-4, which play a key role in the control and selectivity of paracellular transport. Furthermore, genistein decreased the metastasis-related gene expressions of insulin like growth factor-1 receptor and snail, while concurrently increasing that of thrombospondin-1 and E-cadherin. In addition, we demonstrated that claudins play an important role in the anti-motility and invasiveness of genistein using claudin-3 small interfering RNA. Taken together, our results indicate a possible role for genistein as an inhibitor of cancer cell invasion through the tightening of TJs, which may counteract the up-regulation of claudins. In addition, our results indicate that this may be beneficial for the inhibition of tumor metastasis.

Genistein과 Daidzein 급여가 제2형 당뇨동물모델의 적혈구와 조직 중의 항산화방어계에 미치는 영향

박선애(Sun Ae Park),김명주(Myung-Joo Kim),장주연(Joo-Yeun Jang),최명숙(Myung-Sook Choi),여지영(Jiyoung Yeo),이미경(Mi-Kyung Lee) 한국식품영양과학회 2006 한국식품영양과학회지 Vol.35 No.9

제2형 당뇨 동물모델(C57BL/KsJ-db/db)을 대상으로 대두 이소플라본의 주성분인 genistein과 daidzein의 항산화효능을 검증하고자 5주령의 수컷 C57BL/KsJ-db/db 마우스와 그의 이형접합체인 C57BL/KsJ-db/+ 마우스를 2주간 환경에 적응시킨 후 비당뇨군(db/+), 당뇨대조군(db/db), genistein 급여군(db/db-genistein), daidzein 급여군(db/dbdaidzein)으로 나누어 6주간 사육하였다. 실험동물의 간, 부고환지방과 신주변지방의 조직무게는 당뇨군(db/db)이 비당뇨군(db/+)에 비해 유의적으로 높았으나, 심장무게는 유의적으로 낮았다. Genistein과 daidzein 급여는 장기무게 변화에 영향을 미치지 않았다. 적혈구의 SOD와 CAT활성은 혈당과 양의 상관성을 보였으나 GSH-Px활성은 음의 상관성을 나타내었다. 따라서 SOD와 CAT활성은 db/db군이 db/+군에 비해 유의적으로 높은 반면, GSH-Px 활성은 유의적으로 낮았다. Genistein과 daidzein 급여로 db/db군의 증가된 CAT활성은 감소되었으며 GSH-Px활성은 높게 나타났다. 적혈구의 GSH함량은 당뇨군들이 비당뇨군에 비해 유의적으로 높았으나 genistein과 daidzein에 의한 영향은 관찰되지 않았다. 간, 신장 및 심장조직 내 SOD활성은 유의적인 변화가 없었으나 간조직 중 CAT와 GSH-Px활성과 신장조직 중의 GSH-Px활성은 db/db군이 db/+군에 비하여 유의적으로 높게 나타난 반면 신장조직 중의 CAT활성과 심장조직 중의 CAT와 GSH-Px활성은 낮았다. 그러나 genistein과 daidzein 급여는 고혈당으로 인한 조직 내 CAT와 GSH- Px활성을 유의적으로 개선하였다. 적혈구를 비롯하여 모든 조직 내 지질과산화물 함량은 db/db군이 db/+군에 비하여 유의적으로 높았으나 genistein과 daidzein 급여로 간, 신장과 심장조직 중의 지질과산화물 생성이 유의적으로 억제되었다. 이와 같이 genistein과 daidzein은 제2형 당뇨동물에서 고혈당으로 야기되는 적혈구와 조직 내 항산화효소 변화를 완화하고 간, 신장 및 심장조직의 지질과산화물을 낮추는 것으로 관찰됨으로써 이들의 항산화작용을 통한 당뇨 합병증을 예방할 것으로 사료된다. Our preliminary study showed that genistein and daidzein improved blood glucose level in type 2 diabetic mice by enhancing the glucose and lipid metabolism. The objective of this study was to evaluate whether genistein and daidzein are associated with alterations in antioxidant defense mechanism of type 2 diabetic mice. Male C57BL/KsJ-db/db (db/db) mice and age-matched non-diabetic littermates (db/+) were used in this study. The db/db mice were divided into control, genistein (0.02%, w/w) and daidzein (0.02%, w/w) groups. The relative weights of liver, epididymal adipose tissue and perirenal adipose tissue were significantly higher in the db/db group than in the db/+ group, whereas heart weight was lower. The genistein and daidzein supplement did not affect the organ weights in db/db mice. The blood glucose level was positively correlated with superoxide dismutase (SOD, r=0.380, p<0.05) and catalase (CAT, r=0.345, p<0.05) activities and negatively correlated with glutathione peroxidase (GSH-Px, r=-0.404, p<0.05) activity in erythrocyte. Therefore, the erythrocyte SOD and CAT activities were significantly elevated in the db/db group compared to the db/+ group and the GSH-Px activity was lowered. However, the supplementation of genistein and daidzein reversed erythrocyte CAT and GSH-Px activities in type 2 diabetic mice. In this current study, the SOD activities in liver, kidney and heart were significantly not different between the groups. The CAT and GSH-Px activities in liver and GSH-Px activity in kidney were significantly higher in the db/db group than in the db/+ group, while the CAT activity in kidney, CAT and GSH-Px activities in heart were lowered. The supplementation of genistein and daidzein significantly attenuated the changes of CAT and/or GSH-Px activities in liver and heart. The supplementation of genistein and daidzein elevated GSH levels in kidney and heart compared to the db/db control group. The lipid peroxide levels in liver, kidney and heart were significantly lowered in the genistein and daidzein supplemented groups compared to the db/db control group. These results suggest that genistein and daidzein might be beneficial for the prevention of type 2 diabetic complication via suppressing changes of antioxidant enzymes activities with simultaneous reduction of lipid peroxidation.

이소플라본 genistein이 전지방세포 성장 및 지방세포형성과정에 미치는 영향

Seung-Hyun Lim(임승현),Hyo-Rim Kim(김효림),Min-Jeong Kim(김민정),Jong-Sik Kim(김종식) 한국생명과학회 2012 생명과학회지 Vol.22 No.1

이소플라본 genistein이 마우스 전지방 3T3-L1세포주의 성장과 지방세포형성과정에 미치는 영향을 연구하였다. 그 결과, 마우스 전지방 3T3-L1 세포주의 성장이 처리한 genistein 농도 의존적으로 저해되었다. 또한, Oil Red O 염색에 의하여 50 μM genistein 처리에 의해 지방세포형성과정이 억제됨을 확인하였다. 이러한 genistein에 의한 지방세포성장 억제효과의 분자생물학적 기전을 연구하기 위하여, oligo DNA 마이크로어레이 실험을 수행하였다. 발현이 증가된 유전자 중 항비만, 항염증 활성과 관련이 있는 것으로 알려져 있는 sirtuin-1 유전자를 선택하여 발현변화를 확인하였다. 처리한 네종류의 파이토케미칼(resveratrol, capsaicin, daidzein, genistein)에 의해 sirtuin-1의 발현이 증가됨을 확인하였고, 이 중 genistein에 의한 sirtuin-1 유전자의 발현이 가장 높았다. 또한, sirtuin-1-siRNA에 의한 sirtuin-1 유전자의 발현 감소에 의해 지방세포형성 억제과정이 복구됨을 확인하였다. 이러한 연구결과는, genistein에 의한 전지방세포의 성장 저해와 지방세포형성의 저해과정을 이해하는데 도움을 줄 것으로 기대된다. The effects of genistein on cell proliferation and adipogenesis were examined in mouse 3T3-L1 preadipocyte cells. Genistein decreased viability of 3T3-L1 pre-adipocytes in a dose-dependent manner. Oil Red O staining of these cells also indicated that adipogenesis was inhibited by 50 μM genistein treatment. We investigated the molecular mechanisms involved in the decrease in cell viability in genistein-treated 3T3-L1 cells by conducting an oligo DNA microarray analysis. We selected the sirtuin-1 gene, one of the upregulated genes, for further experimentation because sirtuin-1 belongs to the sirtuin family, which is associated with anti-obesity and anti-inflammation activities. We found that four phytochemicals (resveratrol, capsaicin, daidzein, and genistein) could increase sirtuin-1 expression. Genistein was the strongest inducer of sirtuin-1 among the tested phytochemicals. The inhibition of adipogenesis by genistein was recovered by surtuin-1 siRNA transfection. Overall, these results may further our understanding of the molecular mechanisms underlying the inhibition of proliferation and adipogenesis by genistein in mouse 3T3-L1 cells.

Pharmaceutical Evaluation of Genistein-loaded Pluronic Micelles for Oral Delivery

Suk Hyung Kwon,Sun Young Kim,Kyoung Wook Ha,강명주,Jin Seo Huh,Tae Jong Im,Yong Min Kim,Young Mi Park,Kyoung Hoon Kang,Sangkil Lee,Jung Yun Chang,이재휘,최영욱 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.9

The purpose of the present study was to determine whether Pluronic F127 polymeric micelles could improve the oral bioavailability of a poor water-soluble drug, such as genistein. Genistein is a phytoestrogen that has estrogenic activity. F127 triblock copolymer consists of PEO100- PPO65-PEO100. Genistein was incorporated in the Pluronic F127 polymeric micelles by a solid dispersion method. The genistein release of genistein-loaded polymeric micelles was studied in vitro (in pH 1.2 and pH 6.8). And the oral bioavailabilities of genistein powder and genisteinloaded micelles were estimated at a dose of 4.0 mg/kg as genistein in rats. Drug loading amount and drug loading efficiency were 11.18% and 97.41%, respectively. The average size of the genistein-loaded polymeric micelles was 27.76 nm. And genistein release of the genistein-loaded polymeric micelles in vitro was 58% (pH 1.2) and 82% (pH 6.8). The bioavailability of genistein-loaded polymeric micelles was better than genistein powder. Consequently, Pluronic F127 polymeric micelles are an effective delivery system for the oral administration of genistein.

Cell Survival, Apoptosis and AMPK-COX-2 Signaling Pathway of Mammary Tumor Cells after Genistein Treatment Combined with Estrogen

Yun-Kyoung Lee,Jin-Taek Hwang,Young Min Kim,Ock Jin Park 한국식품영양과학회 2007 Preventive Nutrition and Food Science Vol.12 No.4

Genistein is an active component of legumes and other related food shown to be associated with prevention of degenerative diseases such as cancer through inducing signaling pathways. Treatment of genistein resulted in the induction of apoptosis in the cultured cancer cells. This induction of apoptosis was demonstrated by the Tunel assay in these cells. Unveiling the potential of genistein in cytotoxicity via apoptosis when it is treated with estrogen can predict the therapeutic capability of genistein in breast cancers in the presence of endogenous estrogen. We have found that apoptosis induced by genistein treatment in the presence of estrogen is agonistic or antagonistic depending on the concentrations and treatment periods applied in MCF-7 breast cancer cells. For the suppression of cell survival, 24 hr of treatment was required to induce a synergistic agonistic response between estrogen and genistein at low concentrations of genistein. After this period, the agonistic pattern of genistein to estrogen disappeared. The decrement of COX-2 expression in MCF-7 cells treated with genistein was accompanied with the activation of AMPK only at a high concentration of genistein. This association between AMPK activation and down-regulation of COX-2 by genistein was dampened in the presence of estrogen. It was also demonstrated that genistein and estrogen regulate cell survival and apoptosis by modulating p53 and caspase-3 in the opposite direction. These results suggest that genistein has the potential to control breast cancer development, and co-treatment with estrogen can cause agonistic or antagonistic action on breast cancer cell control.