Subcutaneous body fat and Quetelet's Indices (QI) of 52, 18-29 year old normal female volunteers were determined. These body mass indices were then grouped according to the phase of each subject's menstrual cycle, early or late follicular and early or late luteal phase. The subcutaneous body fat is 27.07 +or- 1.0% in the early follicular but drops to 24.68 +or- 1.84% in the late follicular phase. The value then rises significantly higher than that in the late follicular phase to 30.14 +or- 1.15% (P0.02) in the early luteal drops to 27.17 +or- 0.55% towards the level of the early follicular phase (P0.05). Variations in the values of QI during each menstrual cycle exactly mirror those for subcutaneous body fat. The fall in the 2 body mass indices during the late follicular phase coincides somewhat with the established preovulatory LH and FSH surges as well as the high levels of estrogen of this period. On the other hand the significant rise in the 2 parameters during the early luteal phase coincides with the marked rise in the ratio of progesterone to estrogen. Clearly, increased levels of progesterone relative to estrogen appear to cause an increase in the body fat during each menstrual cycle. The implication of this finding for women on contraceptive pills which are predominantly progesterone and those whose normal menstrual cycle is "interrupted" at the early luteal phase by a successful fertilization raises very interesting questions with regards to prediction of ovulation.
The effects of castration with/ without testosterone replacement in male rats, and ovarectomy with oestrogen replacement in female rats, on serum lipids were studied. Simultaneous feeding with diets fortified with 20% weight/ weight (w/ w) soybean oil (Sb) or palm oil (P0) were done to determine the influence of these oils on serum lipids in castrated and sex hormone replaced rats. Two month old male and female Rattus norwegicus rats were given the above treatment for 4 months, and their sera assayed for lipid profile. Castration increased HDL-cholesterol (HDLchol) and total cholesterol (Tchol) concentrations. Testosterone or oestrogen replacement in male and female rats respectively increased HDLchol and decreased LDL-cholesterol (LDLchol) concentrations. Testosterone replacement also decreased Tchol concentration back to noncastrated levels, and reduced serum triglycerides (TG) to lower than non-castrated levels. Addition of Sb or P0 to the diet increased the LDLchol in the testosterone or oestrogen replaced male and female rats, but there was no difference between the two groups. P0 raised serum TG of the testosterone replaced group compared to control and Sb groups. In conclusion, testosterone and oestrogen were found to have favourable effects on serum lipids. Sb and P0 did not differ in their effects on lipoprotein cholesterol and Tchol, but P0 raised serum TG as compared to Sb.
Transforming growth factor-beta (TGF-beta) has been shown to inhibit the growth of mammary epithelial cells and may play a protective role in mammary carcinogenesis. In contrast, oestrogens promote the development of breast cancer. Oestrone sulphate (E1S) is a huge reservoir of active oestrogens in the breast being converted to the weak oestrogen, oestrone (E1), by oestrone sulphatase. E1 is reversibly converted by oestradiol-17beta hydroxysteroid dehydrogenase to the potent oestrogen, oestradiol (E2). The aim of this study was to assess the effect of the TGF-beta1 isoform on growth and oestrogen metabolism in the hormone-dependent MCF-7 and hormone-independent MDA-MB-231 human breast cancer cell lines. The results showed that TGF-beta1 significantly inhibited cell growth and stimulated the conversion of E1S to E1 and E1 to E2 in the MCF-7 cell line. In the MDA-MB-231 cell line TGF-beta1 significantly stimulated cell growth and inhibited the interconversions between E1 and E2. In conclusion, the growth inhibitory effect of TGF-beta1 on the MCF-7 cell line would appear to confer a protective effect in breast cancer. However, its ability to increase the amount of E2 would increase the risk of breast cancer. Which of these effects predominates in vivo remains to be explored. The growth stimulatory effect of TGF-beta1 on the MDA-MB-231 cell line probably acts through a mechanism independent of the effect of TGF-beta1 on oestrogen concentrations since this cell line is hormone unresponsive.
Reproductive dysfunction in the female diabetic rat is associated with impaired hypothalamic-hypophyseal system, anovulation, insufficiency of ovarian steroidogenesis and spontaneous failure of pregnancy. Formation of decidua, the highly modified endometrium of pregnancy and pseudopregnancy could only be achieved when the uterus was sensitized by a sequence of oestrogen and progesterone. In this study, we examined whether the impaired expression of endometrial decidualization in the pseudopregnant rat is linked with diabetes-associated hypersecretion of testosterone. Rats were made pseudopregnant by sterile mating. Diabetes was induced by streptozotocin on day 1 p.c. Deciduogenic stimulus was given on day 5 p.c. Treatment of cyproterone acetate (10 mg kg(-1)) was scheduled from day 5 through day 9 p.c. Animals were killed on day 10 p.c, and the degree of endometrial decidual growth, plasma levels of oestradiol, progesterone, ACTH and testosterone were determined. Results showed that compared to controls there was a concomitant drop in endometrial decidual growth concurrently with impaired levels of oestradiol and progesterone in diabetic pseudopregnant rats. ACTH and testosterone levels were, however, profoundly elevated. Cyproterone acetate treatment in the diabetic pseudopregnant rat resulted in a simultaneous elevation of oestradiol and progesterone, which eventually helped the endometrial differentiation to decidua in the diabetic pseudopregnant rat parallel to controls. Present experimental data suggest that diabetes-associated impaired endometrial decidualization in the pseudopregnant rat is possibly caused by testosterone-induced oestrogen deficiency.
Oestrogens play an important role in the development of breast cancer. Oestrone sulphate (E1S) acts as a huge reservoir of oestrogens in the breast and is converted to oestrone (E1) by oestrone sulphatase (E1STS). E1 is then reversibly converted to the potent oestrogen, oestradiol (E2) by oestradiol-17beta hydroxysteroid dehydrogenase (E2DH). The aim of this study was to assess the effects of transforming growth factor-beta1 (TGFbeta1), insulin-like growth factor-I (IGF-I) and insulin-like growth factor-II (IGF-II) on cell growth, E1STS and E2DH activities in the MCF-7 and MDA-MB-231 human breast cancer cell lines. TGFbeta1, IGF-I and IGF-II alone or in combination inhibited cell growth of both cell lines but no additive or synergistic effects were observed. The treatments significantly stimulated E1STS activity in the MCF-7 cell line, except for TGFbeta1 alone and TGFbeta1 and IGF-I in combination, where no effects were seen. Only TGFbeta1 and IGF-II acted synergistically to stimulate E1STS activity in the MCF-7 cells. There was no significant effect on E1STS activity in the MDA-MB-231 cells with any of the treatments. In the MCF-7 cells, TGFbeta1 and IGF-I, IGF-I and IGF-II, and TGFbeta1, IGF-I and IGF-II acted synergistically to stimulate the reductive E2DH activity, while only TGFbeta1, IGF-I and IGF-II synergistically stimulated the oxidative E2DH activity. There were no additive or synergistic effects on both oxidative and reductive E2DH activities in the MDA-MB-231 cells. In conclusion, TGFbeta1, IGF-I and IGF-II may have effects on oestrogen metabolism, especially in the MCF-7 cell line where they stimulated the conversion of E1S to E1 and E1 to E2 and, thus, may have roles to play in the development of breast cancer.
The effects of bisphenol A and nonylphenol on pubertal development in the intact juvenile/peripubertal male Sprague-Dawley rats was observed in this study from PND23-52/53. Two groups of rats were administered orally with either 100 mg/kg body weight of nonylphenol or bisphenol A. Another group of rats were administered orally with a mixture of 100 mg/kg body weight of nonylphenol and bisphenol A. Control group was administered with the vehicle of Tween-80 with corn oil (1:9 v/v). Observations made in this study included growth, age at preputial separation, thyroid, liver, testis and kidney weight and histology, epididymal and seminal vesicle plus coagulation gland weight. Nonylphenol and bisphenol A have been observed to cause delay in puberty onset as well as testicular damage in the treatment groups when compared to the control; spermatogenesis was affected in most treated rats. Bisphenol A also caused the enlargement of the kidney and hydronephrosis. Administration of nonylphenol and bisphenol A as a mixture has caused less than additive effects.
Bisphenol A is the monomer used in the manufacture of polycarbonate. Bisphenol A is also known to mimic the female hormone estrogen. In this study, the possibility of the leaching of bisphenol A from polycarbonate babies' bottles and feeding teats was investigated. Bisphenol A was extracted from water samples exposed to the bottles and teats using liquid-liquid extraction. Bisphenol A was analysed by gas chromatograph-mass spectrometer with quadrapole detector in selected ion monitoring mode. Mean leaching of bisphenol A from 100 used babies' bottles when filled with water at 25 degrees C and 80 degrees C were 0.71 +/- 1.65 ng/cm2 (mean +/- standard deviation) and 3.37 +/- 5.68 ng/cm2 respectively. Mean leaching of bisphenol A from 30 new babies' bottles when filled with water at 25 degrees C and 80 degrees C were 0.03 +/- 0.02 ng/cm2 and 0.18 degrees 0.30 ng/cm2 respectively. Bisphenol A was observed to have leached from babies' feeding teats into 37 degrees C water ranged from non-detectable to 22.86 ng/g. The technique employed in this study is fast, reliable and economical.
Vitamin E is important not only for its cellular antioxidant and lipid-lowering properties, but also as an antiproliferating agent. It has also been shown to contribute to immunoregulation, antibody production, and resistance to implanted tumors. It has recently been shown that tocotrienols are the components of vitamin E responsible for growth inhibition in human breast cancer cells in vitro as well as in vivo through estrogen-independent mechanisms. Although tocotrienols act on cell proliferation in a dose-dependent manner and can induce programmed cell death, no specific gene regulation has yet been identified. In order to investigate the molecular basis of the effect of a tocotrienol-rich fraction (TRF) from palm oil, we performed a cDNA array analysis of cancer-related gene expression in estrogen-dependent (MCF-7) and estrogen-independent (MDA-MB-231) human breast cancer cells. The human breast cancer cells were incubated with or without 8 mug/mL of tocotrienols for 72 h. RNA was subsequently extracted and subjected to reverse transcription before being hybridized onto cancer arrays. Tocotrienol supplementation modulated significantly 46 out of 1200 genes in MDA-MB-231 cells. In MCF-7 cells, tocotrienol administration was associated with a lower number of affected genes. Interestingly, only three were affected in a similar fashion in both cell lines: c-myc binding protein MM-1, 23-kDa highly basic protein, and interferon-inducible protein 9-27 (IFITM-1). These proteins are most likely involved in the cell cycle and can exert inhibitory effects on cell growth and differentiation of the tumor cell lines. These data suggest that tocotrienols are able to affect cell homeostasis, possibly independent of their antioxidant activity.
Articular cartilage extracellular matrix (ECM) plays a crucial role in regulating chondrocyte functions via cell-matrix interaction, cytoskeletal organization and integrin-mediated signaling. Factors such as interleukins, basic fibroblast growth factor (bFGF), bone morphogenic proteins (BMPs) and insulin-like growth factor (IGF) have been shown to modulate the synthesis of extracellular matrix in vitro. However, the effects of TGF-beta1 and beta-estradiol in ECM regulation require further investigation, although there have been suggestions that these factors do play a positive role. To establish the role of these factors on chondrocytes derived from articular joints, a study was conducted to investigate the effects of TGF-beta1 and beta-estradiol on glycosaminoglycan secretion and type II collagen distribution (two major component of cartilage ECM in vivo). Thus, chondrocyte cultures initiated from rabbit articular cartilage were treated with 10ng/ml of TGF-beta1, 10nM of beta-estradiol or with a combination of both factors. Sulphated glycosaminoglycan (GAG) and type II collagen levels were then measured in both these culture systems. The results revealed that the synthesis of GAG and type II collagen was shown to be enhanced in the TGF-beta1 treated cultures. This increase was also noted when TGF-beta1 and beta-estradiol were both used as culture supplements. However, beta-estradiol alone did not appear to affect GAG or type II collagen deposition. There was also no difference between the amount of collagen type II and GAG being expressed when chondrocyte cultures were treated with TGF-beta1 when compared with cultures treated with combined factors. From this, we conclude that although TGF-beta1 appears to stimulate chondrocyte ECM synthesis, beta-estradiol fails to produce similar effects. The findings of this study confirm that contrary to previous claims, beta-estradiol has little or no effect on chondrocyte ECM synthesis. Furthermore, the use of TGF-beta1 may be useful in future studies looking into biological mechanisms by which ECM synthesis in chondrocyte cultures can be augmented, particularly for clinical application.
Recent development had allowed non-invasive assessment of microvascular function in vivo; however, the method has not been fully optimized and standardized. In this study, we aimed to characterize the "effective" occlusion duration needed to elicit sufficient postocclusive hyperemia (PORH) responses in forearm skin using laser Doppler fluximetry (LDF), in subjects with differing age, gender and menstrual phases.
Hypercholesterolaemia, increase in lipid peroxidation and hyperhomocysteinaemia may contribute to the pathogenesis of atherosclerosis. This study was performed to examine the effects of repeatedly heated palm oil mixed with 2% cholesterol diet on atherosclerosis in oestrogen-deficient postmenopausal rats. Ovariectomy causes disruption of tunica intima layer of the rat aorta simulating a postmenopausal condition in females. Twenty-four ovariectomized female Sprague-Dawley rats were divided into four groups. The control group received 2% cholesterol diet without palm oil. A diet with 2% cholesterol content fortified with fresh, once-heated and five-times-heated palm oil was given to the other treatment groups. The rats were sacrificed at the end of 4 months of study and the aortic arch tissue was processed for histomorphometry and electron microscopy. On observation, there was disruption of the intimal layer of the ovariectomized rat aorta. There was no obvious ultrastructural change in the aorta of the rats fed with fresh palm oil. The ultrastructural changes were minimal with once-heated palm oil, in which there was a focal disruption of the endothelial layer. The focal disruption was more pronounced with five-times-heated palm oil. The results of this study show that the ingestion of fresh palm oil may have a protective effect on the aorta but such a protective action may be lost when the palm oil is repeatedly heated. The study may be clinically important for all postmenopausal women who are susceptible to atherosclerosis.
The effects of treatment processes on estrogenicity were evaluated by examining estradiol equivalent (EEQ) concentrations in influents and effluents of sewage treatment plants (STPs) located along Yeongsan and Seomjin rivers in Korea. The occurrence and distribution of estrogenic chemicals were also estimated for surface water in Korea and compared with seven other Asian countries including Laos, Cambodia, Vietnam, China, Indonesia, Thailand and Malaysia. Target compounds were nonylphenol (NP), octylphenol (OP), bisphenol A (BPA), estrone (E1), 17beta-estradiol (E2), 17alpha-ethynylestradiol (EE2) and genistein (Gen). Water samples were pretreated and analyzed by liquid-liquid extraction (LLE) and gas chromatography/mass spectrometry (GC/MS). The results showed that the treatment processes of Korean STPs were sufficient to reduce the estrogenic activity of municipal wastewater. The concentrations of phenolic xenoestrogens (i.e., NP, OP and BPA) in samples of Yeongsan and Seomjin rivers were smaller than those reported by previous studies in Korea. In most samples taken from the seven Asian countries, the presence of E2 and EE2 was a major contributor toward estrogenic activity. The EEQ concentrations in surface water samples of the seven Asian countries were at a higher level in comparison to that reported in European countries, America and Japan. However, further studies with more sampling frequencies and sampling areas should be carried out for better evaluation of the occurrence and distribution of estrogenic compounds in these Asian countries.
Benzeneboronate of catecholic carboxyl methyl esters, N-acetyldopamine, coumarin and catechol estrogens were prepared as crystalline derivatives in high yield. Related catechol compounds with extra polar functional group(s) (OH, NH2) do not form or only partially form unstable cyclic boronate derivatives.