Briefly, 105 cells/200 < .001) inhibited E2 production by granulosa cells; on the contrary, 5 < .001) inhibited P4 production by granulosa cells having a dose-dependent effect (< .001) (Number 2). Open in a separate window Figure 1 Effect of the 48-hour treatment with quercetin (5 and 50 (E2) production by swine granulosa cell cultured in vitro. on ovarian physiology. Consequently, the possible reproductive effect of the flavonoid should be cautiously regarded as in animal nourishment. 1. Intro Quercetin (3,30,40,5,7-pentahydroxyflavone) is definitely a flavonoid belonging to a group of plant-derived GW1929 nonsteroidal compounds known as phytoestrogens . In vegetation, these compounds are involved in energy production and show strong antioxidant properties; in mammals, they have been shown to exert numerous biological and pharmacological effects [2, 3]. Several studies [4C6] have shown their significant health promoting activities, due to free radical scavenging and metallic chelating properties. On the other hand, quercetin can also show pro-oxidant effects . It has been shown [8C11] a relationship between quercetin free radical scavenging activity and its anticarcinogenic and anti-inflammatory properties. Most experimental data about the activity of flavonoids in different biological systems have been acquired by in vitro studies, and the knowledge of the pharmacokinetics and systemic availability of food-derived flavonoids in humans and animals is still incomplete: in particular, the bioavailability of quercetin appears low, but reported ideals range from 0% to 52% [12, 13]. Recent data acquired in vitro or in animal studies show that flavonoids may also improve cell function individually of their antioxidant power [14C16], influencing the overall process of carcinogenesis by different mechanisms. Since it is well known that neovascularization represents a key process in tumor growth, invasion, and metastasis, a lot of medical interest has developed in recent years about potential inhibitors of angiogenesis. Among natural health products, diet flavonoids have shown to possess antiangiogenic effects, inhibiting several important methods of fresh vessel growth: an impairment of VEGF manifestation by different flavonoids has been recorded [17, 18], as well as inhibitory effects on proliferation, migration, tube formation of endothelial cells in vitro [19C21]. In particular, many experimental evidences suggest a close link between quercetin antineoplastic effect and its antiangiogenic potential [22C25]. While both the antioxidant and antiangiogenic properties of quercetin are generally related to its protecting effects against oxidative stress and should also become relevant for its malignancy preventive effect [11, 26], the potential of the inhibition of vessel formation on female reproductive efficiency remains elusive; in fact, it is definitely well known the ovarian angiogenic process is definitely purely associated with follicular development . Furthermore, ROSs play a crucial part in the ovarian follicle as signalling molecules in both the angiogenic cascade  and the ovulatory process. Additionally, phytoestrogens are able to bind to estrogen receptors therefore activating several estrogen-responsive genes . In particular, quercetin has been found to exhibit both estrogenic and antiestrogenic actions in vitro therefore suggesting different potential effects on reproductive function. Consequently, the aim of this study was to evaluate GW1929 possible effects of quercetin within the function of granulosa cells, which play a complex and fundamental part in the development of the ovarian follicle. To this purpose, we analyzed the flavonoid action on granulosa cell proliferation, steroidogeneis, and redox status. Finally, since follicle growth requires fresh vessel formation, we also evaluated the effect of quercetin within the production of VEGF, the main proangiogenic element. 2. Materials and Methods All the reagents were from Sigma (St. Louis, Mo, USA) unless normally specified. 2.1. Granulosa Cell Tradition Swine ovaries were collected at a local slaughterhouse, placed into PLA2G5 chilly PBS (4C) supplemented with penicillin (500 IU/mL), streptomycin (500 = 0.92). Cell quantity/well was estimated from the producing linear regression equation. The assay detection limit was 103 cell/well, and the variance coefficient was less than 5%. The number of cells acquired GW1929 by this calculation was utilized for correcting hormones, VEGF production, and redox status data. 2.3. Steroid Production Briefly, 104 cells/well were seeded in 96-well plates in 200 estradiol (E2) dedication by validated RIAs . P4 assay level of sensitivity and ED50 were 0.24 and 1 nM/L, respectively; E2 assay level of sensitivity and ED50 were 0.05 and 0.2.