The Action of Benzene, Resveratrol and Their Combination on Ovarian Cell Hormone Release.

The aim of our study was to examine the direct influence of plant polyphenol resveratrol and oil-related environmental contaminant benzene on ovarian hormone release, as well as the ability of resveratrol to prevent the effect of benzene. Porcine ovarian granulosa cells were cultured with and without resveratrol (0, 1,10 or 100 ug/ml) alone or in combination with 0.1% benzene. The release of progesterone, oxytocin and prostaglandin F was measured by enzyme immunoassay (EIA). Benzene promoted the release of progesterone, oxytocin and prostaglandin F. Resveratrol, when given alone, stimulated both progesterone and prostaglandin F, but not the oxytocin output. Moreover, resveratrol prevented and even inverted the stimulatory action of benzene on all analysed hormones. These observations demonstrate the direct influence of both benzene and resveratrol on porcine ovarian hormone release, as well as the ability of resveratrol to prevent the benzene action on the ovary.

Effect of turmeric on the viability, ovarian folliculogenesis, fecundity, ovarian hormones and response to luteinizing hormone of rabbits.

The present study investigated whether dietary turmeric (Curcuma longa L.) can improve rabbit reproduction, ovarian function, growth, or viability. Female New Zealand White rabbits were either fed a standard diet (n=15) or a diet enriched with 5 g (group E1) or 20 g (group E2) turmeric powder per 100 kg feed mixture (n=16 or 15, respectively). After 295 days, weight gain, conception and kindling rates, pup and mother viability, ovarian macro- and micro-morphometric indices, release of leptin in response to the addition LH, and the release of progesterone, testosterone and leptin by isolated ovarian fragments were analyzed. Dietary turmeric failed to affect ovarian length and weight but did increase the number of primary follicles (E2: 32.5% greater than control group), as well as the diameter of primary (E1: +19.4%, E2: +21.1%), secondary (E2: +41.4%), and tertiary (E1: +97.1%, E2: +205.1%) follicles. Turmeric also increased the number of liveborn (E1: +21.0%) and weaned (E1: +25.0%) pups and decreased the number of stillborn pups (E2: -87.5%) but did not affect weight gain, conception, or kindling rate. Furthermore, dietary turmeric decreased doe mortality during the first reproductive cycle (13.3% in control; 0% in E1; and 6.7% in E2) but not during the second cycle. In vitro, the ovaries of the turmeric-treated rabbits released more progesterone (E1: +85.7%, E2: +90.0%) and less testosterone (E2: -87.0%) and leptin (E2: -29.0%) than the ovaries of control rabbits. Moreover, LH decreased the leptin output of control rabbits but increased that of experimental rabbits. Therefore, it is likely that dietary turmeric improves pup viability and that it could promote rabbit fecundity by either (1) promoting the production of primary ovarian follicles or (2) stimulating the growth of follicles at all stages of folliculogenesis.

Direct effect of pholyphenol-rich plants, rooibos and ginkgo, on porcine ovarian cell functions.

The polyphenol-rich plants rooibos and ginkgo are widely used in folk medicine and in preparation of foods and drinks, but their effect on reproduction has not been properly studied yet. The aim of our in vitro experiments was to examine the possible direct effect of rooibos and ginkgo on the basic ovarian cell functions-proliferation, apoptosis and release of hormones progesterone (P4) and leptin (L). Porcine ovarian granulosa cells were cultured in the presence of rooibos or ginkgo extract (0, 1, 10 and 100 µg/ml of medium). The accumulation of markers of proliferation (PCNA and cyclin B1) and apoptosis (bax) and their mRNAs was analysed using immunocytochemistry and by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Release of P4 and L was evaluated by radioimmunoassay. It was observed that rooibos or ginkgo addition was able to inhibit proliferation (down-regulates PCNA, cyclin B1 and their mRNAs), to promote apoptosis (accumulation of bax) and to suppress both L and P4 release by ovarian cells. These data suggest a direct inhibitory (anti-proliferative, pro-apoptotic and hormone-suppressing) effect of polyphenol-containing plants rooibos and ginkgo on ovarian functions. The potential anti-reproductive effect of these medical plants is to be taken into account by their consumption.

The effect of HT-2 toxin on ovarian steroidogenesis and its response to IGF-I, leptin and ghrelin in rabbits.

T-2 toxin and its metabolite HT-2 toxin are one of the most toxic mycotoxins of type A-trichothecenes, which are produced mainly by Fusarium species. Therefore, study of Fusarium toxins T-2 toxin and HT-2 toxin is an essential issue because they could also play role in failures of reproductive functions as well as endocrine system of domestic animals. Assessment of the effect of A-trichothecene mycotoxin HT-2 toxin alone or combined with insulin-like growth factor (IGF-I), leptin and ghrelin on estradiol secretion by rabbit ovarian fragments in vitro was done. Rabbit ovarian fragments were incubated without (control group) or with HT-2 toxin, or its combinations with IGF-I, leptin and ghrelin at various concentrations for 24 h. Secretion of 17beta-estradiol was determined by ELISA. Firstly, HT-2 toxin at the doses 10 and 100 ng.ml(-1), but not at 1 ng.ml(-1) decreased 17beta-estradiol secretion by ovarian fragments. Secondly, 17beta-estradiol secretion was not affected by HT-2 toxin exposure combined with growth factor IGF-I, metabolic hormones leptin and ghrelin. In conclusion, HT-2 toxin has potent direct dose-dependent effects on ovarian steroidogenesis in rabbits. These direct effects of HT-2 mycotoxin on ovarian steroidogenesis could impact negatively on the reproductive performance of rabbits.

The isoflavone daidzein directly affects porcine ovarian cell functions and modifies the effect of follicle-stimulating hormone.

The key biological active molecule of soya is the isoflavone daidzein, which possesses phytoestrogenic activity. The direct effect of soya and daidzein on ovarian cell functions is not known. This study examined the effect of daidzein on basic porcine ovarian granulosa cell functions and the response to follicle-stimulating hormone (FSH). We studied the effects of daidzein (0, 1, 10 and 100 µm), FSH (0, 0.01, 0.1, 1 IU/ml) and combinations of FSH (0, 0.01, 0.1, 1 IU/ml) + daidzein (50 µm) on proliferation, apoptosis and hormone release from cultured porcine ovarian granulosa cells and ovarian follicles. The expression of a proliferation-related peptide (PCNA) and an apoptosis-related peptide (Bax) was analysed using immunocytochemistry. The release of progesterone (P4) and testosterone (T) was detected using EIA. Leptin output was analysed using RIA. Daidzein administration increased granulosa cell proliferation, apoptosis and T and leptin release but inhibited P4 output. Daidzein also increased T release and decreased P4 release from cultured ovarian follicles. Follicle-stimulating hormone stimulated granulosa cell proliferation, apoptosis and P4, T and leptin release. The addition of daidzein promoted FSH-stimulated apoptosis (but not proliferation) but suppressed FSH-stimulated P4, T and leptin release. Our observations of FSH action confirm previous data on the stimulatory effect of FSH on ovarian cell proliferation, apoptosis and steroidogenesis and demonstrate for the first time the involvement of FSH in the upregulation of ovarian leptin release. Our observations of daidzein effects demonstrated for the first time that this soya isoflavone affected basic ovarian cell functions (proliferation, apoptosis and hormones release) and modified the effects of FSH. Daidzein promoted FSH action on ovarian cell proliferation and apoptosis and suppressed, and even inverted, FSH action on hormone release. The direct action of daidzein on basic ovarian cell functions and the ability of these cells to respond to FSH indicate the potential influence of soya-containing diets on female reproductive processes via direct action on the ovary.

Ricinus communis L. stem bark extracts regulate ovarian cell functions and secretory activity and their response to Luteinising hormone.

Ricinus communis L. has ethnopharmacological contraceptive reputation but its stem bark has unexplored mechanisms of action in female reproductive system. In the present study, the effect of methanolic and aqueous extracts from the stem bark of the plant was examined on basic porcine ovarian granulosa cell functions and its response to Luteinising hormone (LH)-the upstream hormonal regulator. Systemic treatment of methanolic and aqueous extracts stimulated cell proliferation (proliferating cell nuclear antigen, PCNA) and also promoted cell apoptosis (caspase-3). Aqueous extract has inverted the stimulatory effect of LH on PCNA but not on caspase-3. Methanolic extract stimulated as well as inhibited progesterone release and stimulated testosterone secretion. Whereas aqueous extract inhibited both steroid releases and suppressed the stimulatory effect of LH on progesterone release and promoted the inhibitory effect of LH on testosterone release. In conclusion, the present study unveils the mechanism of action of R. communis stem bark in in vitro condition. These suggest its possible contraceptive efficacy by exerting its regulatory role over LH and on basic ovarian cell functions and secretion activity.