Publications (49) View all
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Article: The effects of Silymarin on ovarian activity and productivity of laying hens
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ABSTRACT: In a previous work we evaluated the effects of Silymarin, a natural antioxidant and hepatoprotective polyphenolic compound, on laying hens performances and health status. The aim of the present work was to further confirm the previous results and to investigate the effects of Silymarin on ovarian endocrine activity and productivity of laying hens as well as on egg traits. Eighteen laying hens were randomly allotted into 3 groups and observed for 20 weeks: control hens were fed control diet, while treated groups received supplementations of 200 (S200) and 400 (S400) ppm of Silymarin. S200 group showed improved eggs laying rate (+2.91%), feed conversion rate (-4.52%) and a significant (P<0.05) increase of dry matter content (+0.54%), total lipids (+0.72%) and total sterols (0.02%) of the eggs. Any significant difference was shown for Silymarin at the highest dose (400 mg/kg of feed). At the end of the trial the hens were sacrificed and hierarchical follicles were removed and cultured for 48h. Media were assayed for progesterone (P4) and estradiol-17 beta (E2). Average E2 production in- creased (P<0.05) from F5 (follicles with initial development) to F3 (follicles with intermediate develop- ment), then decreased (P<0.05) from F3 to F1 (pre-ovulatory follicles). Basal P4 production augmented (P<0.05) throughout all follicle growth. Both Silymarin treatment inhibited (P<0.05) steroidogenesis. Silymarin may act as an endocrine-modulating chemical affecting hen performances.Italian Journal of Animal Science. 01/2010; -
Article: The axonal guidance factor netrin-1 as a potential modulator of swine follicular function.
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ABSTRACT: This study was aimed to improve knowledge about swine ovarian follicular function, paying attention to angiogenesis, since new vessel growth is a fundamental event in ovarian function. In particular, we investigated a potential involvement of netrin-1, a protein known as a guidance axon factor. Firstly, we studied the expression and immunolocalization of netrin-1 in swine ovarian follicle and its effect on cultured swine granulosa cell viability and steroidogenesis. Furthermore, aortic endothelial cells were employed to verify a possible netrin-1 effect on angiogenesis. Our data demonstrate the expression and the presence of netrin-1 in swine follicular fluid; in addition, it was shown that netrin-1 inhibits granulosa cell viability and estradiol 17β levels while it stimulates progesterone production. Netrin-1 also inhibits aortic endothelial cell growth in the angiogenesis bioassay. This effect appears to be mediated by inhibiting vascular endothelial growth factor and stimulating nitric oxide. Therefore, we hypothesize that netrin-1 could be important for follicular function in the swine.Molecular and Cellular Endocrinology 01/2011; 331(1):41-8. · 4.19 Impact Factor -
Article: The impact of the phyto-oestrogen genistein on swine granulosa cell function.
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ABSTRACT: Soya and soybean products used in swine feeding contain genistein, a non-steroidal phyto-oestrogen which has been demonstrated to influence endocrine functions. This observation leads us to design this study to evaluate the effect of genistein on swine granulosa cell steroidogenesis and proliferation. In the attempt to unravel the genistein signal transduction mechanisms, we verified the effect of lavendustin, a Tyrosine Kinase (TK) inhibitor, and the potential involvement of NO/cGMP pathway. Finally, as angiogenesis is essential for follicle development, we tested the effect of the phyto-oestrogen on vascular endothelial growth factor production and on granulosa cell redox status, because free-radical species modulate neovascularization. Our data provide evidence that genistein interferes with granulosa cell steroidogenesis while it does not modulate cell growth: this effect could be at least partially produced by inhibiting TK-dependent signalling systems. On the contrary, NO/cGMP pathway or vascular endothelial growth factor production can be excluded as signalling mechanism involved in phyto-oestrogen effects. Remarkably, genistein stimulates hydrogen peroxide production thus potentially inhibiting follicular angiogenesis. Collectively, these results suggest that genistein consumption could potentially negatively impact swine reproductive function.J Anim Physiol a Anim Nutr 12/2010; 94(6):e374-82. · 0.86 Impact Factor -
Article: Netrin-1: just an axon-guidance factor?
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ABSTRACT: Netrin-1 was first identified as a guidance factor in axon outgrowth during central nervous system development and was later shown to be involved in the morphogenesis of other organs. This study, thus, aimed to verify netrin-1 gene expression in swine antral follicles and to detect netrin-1 protein expression in follicular fluid. In addition, since netrin-1 is also a potential guidance factor for endothelial cells during angiogenesis, an essential event for follicular development, we attempted to verify its effects on swine aortic endothelial cells. Our results show that netrin-1 is present in follicular fluid and is physiologically expressed in both the thecal and granulosa layers from swine antral follicles. Furthermore, by means of an angiogenesis bioassay, we documented the inhibition of vascular neoformation by netrin-1. In conclusion, our results demonstrate that netrin-1 can be synthesized by swine follicular cells and secreted in the follicular fluid where it appears to exert regulatory effects on both follicular function and vascular development.Veterinary Research Communications 06/2010; 34 Suppl 1:S1-4. · 0.82 Impact Factor -
Article: Expression and localization of stanniocalcin 1 in swine ovary.
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ABSTRACT: Stanniocalcin 1 (STC 1) is a glycoprotein involved in mineral homeostasis and was first identified in fish. Its mammalian homologue has been implicated in the regulation of various biological processes, including angiogenesis and steroidogenesis both of which are fundamental events in ovarian function. Interestingly, the highest level of STC 1 expression in mammals occurs in ovarian tissue but no information is available on swine species. Therefore, the present study was undertaken to investigate the expression and the immunolocalization of STC 1 in swine ovary. In addition, we evaluated whether swine granulosa cells synthesize STC 1 and its possible modulation by hypoxia, a physiological condition in ovarian follicle growth. Our data show STC 1 for the first time in swine ovary; moreover, we demonstrate STC 1 production by granulosa cells, both in basal condition and in response to oxygen deprivation. The latter is suggestive of a potential modulatory role for STC 1 in hypoxia-driven angiogenesis.General and Comparative Endocrinology 04/2010; 166(2):404-8. · 3.27 Impact Factor
