Effects of benzene, quercetin, and their combination on porcine ovarian cell proliferation, apoptosis, and hormone release.

We hypothesized that the environmental contaminant benzene and the plant antioxidant quercetin may affect ovarian cell functions and that quercetin could offer protection against the adverse effects of benzene. This study aimed to examine the action of benzene, quercetin, and their combination on porcine ovarian granulosa cell functions. We elucidated the effects of benzene (20  µ g mL - 1 ), quercetin (at the doses 0, 1, 10, 100  µ g mL - 1 ), and their combination on ovarian granulosa cell functions (proliferation, apoptosis, and hormone release) in vitro using immunocytochemistry and enzyme immunoassay respectively. Benzene alone stimulated proliferation, apoptosis, and oxytocin release and inhibited progesterone and prostaglandin F release. Quercetin alone inhibited proliferation, apoptosis, and stimulated oxytocin release but did not affect progesterone and prostaglandin F release. When used in combination with benzene, quercetin promoted the inhibitory effect of benzene on progesterone release. Overall, these data suggest that benzene and quercetin have direct stimulatory and inhibitory effects, respectively, on basic ovarian functions. Moreover, no protective action of quercetin against the effects of benzene was found. Rather, it was found to enhance the effect of benzene on progesterone release. Therefore, quercetin cannot be considered for preventing or mitigating the effects of benzene on reproductive processes.

Direct inhibitory effect of flaxseed on porcine ovarian granulosa cell functions.

Flaxseed is useful as a functional food and alternative medicine owing to its beneficial health effects. Its action on ovarian cell functions and interrelationships with the upstream hormonal regulators remain unknown. Our aim was to examine the direct influence of flaxseed extract on basal porcine ovarian functions (proliferation, apoptosis), leptin release, and response to insulin-like growth factor I (IGF-I). First, we examined the effect of flaxseed extract on the accumulation of proliferation (PCNA) and apoptosis (Bax) markers and on leptin release in cultured porcine ovarian granulosa cells. Next, granulosa cells were cultured with IGF-I with and without flaxseed extract and analyzed for PCNA and Bax accumulation by quantitative immunocytochemistry and for leptin release by radioimmunoassay. Flaxseed decreased the accumulation of PCNA and increased that of Bax at all doses and reduced leptin output at 100 µg/mL. In contrast, IGF-I promoted PCNA accumulation and suppressed Bax. Flaxseed did not modify IGF-I action on these parameters. Thus, we showed that flaxseed influences porcine reproductive processes, having a direct effect on the ovary and the ability to affect ovarian cell proliferation, apoptosis, and leptin release. Furthermore, we confirmed the pro-proliferative and antiapoptotic actions of IGF-I but showed that flaxseed action on ovarian cell proliferation and apoptosis is not due to changes in the cell response to IGF-I. The potential direct anti-reproductive action of flaxseed needs to be considered during its application in nutrition, medicine, and animal production.

Yucca schidigera extract can promote rabbit fecundity and ovarian progesterone release.

The aim of the present in vivo study was to determine the effects of yucca powder extract added to the rabbit females feed mixtures on kindling and conception rate. Rabbit does of the experimental groups were fed with the standard diet enriched with supplement of yucca dry extract at doses of 5 g/100 kg feed (E1 group) or 20 g/100 kg feed (E2 group) for 50 days. In our preliminary in vivo results, we shown that conception rate was significantly higher in both experimental E1 and E2 groups (82.4% and 100.0%, respectively) than in the control group (47.1%). The kindling rate was also significantly higher in the experimental groups (70.6% and 100.0%, respectively) than in the control group (41.2%). The differences between control and yucca-treated groups in the number of liveborn, stillborn, and weaned pups per doe were not statistically significant. To understand possible endocrine mechanisms of yucca action on fertility rate, we have examined the influence of yucca extract additions on the release of steroid hormones by isolated and cultured rabbit ovarian fragments. Yucca additions promoted release of progesterone (at dose of 1 µg/mL, but not at doses of 10 and 100 µg/mL). Yucca addition at these doses did not affect testosterone or estradiol release. Our observations show the stimulatory effect of yucca consumption on rabbit fecundity, which can be due to its direct stimulatory influence on ovarian progesterone but not on testosterone or estradiol output.