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.

Effect of quercetin on ovarian cells of pigs and cattle.

The bioflavonoid quercetin is a component of food with numerous biological effects, but its function in reproductive processes and mechanisms in various species remain unclear. The aim of this study was to examine the effect of quercetin on ovarian cells isolated from ovaries of two phytophagous mammalian species (i.e. pigs and cattle). There was analysis of the effect of quercetin (0, 1, 10, and 100 ng/mL) on cultured granulosa cells of pigs and cattle. Proliferation (PCNA) and apoptosis (bax) markers and release of progesterone (P4), testosterone (T), estradiol (E2), and IGF-I were quantified using quantitative immunocytochemistry, enzyme immunoassay, or radioimmunoassay. Treatments with quercetin reduced PCNA and bax accumulation and decreased P4 release from both granulosa cells of pigs and cattle. In cells of pigs, treatment with quercetin reduced T output, however, in cells of cattle quercetin increased T release. In cells of pigs, quercetin reduced IGF-I release. In cells of cattle, quercetin at smaller doses (1 or 10 ng/mL), promoted and at a large dose (100 ng/mL) reduced IGF-I secretions. There was no substantial E2 release from granulosa cells of pigs or cattle. These observations are the first to indicate there is a direct action of quercetin on basic ovarian cell functions (proliferation, apoptosis, and hormones release) which can be species-specific.

Can xylene and quercetin directly affect basic ovarian cell functions?

Exposure to xylene leads to dysfunction of mammalian female reproduction. Quercetin present in vegetables contribute significantly to their role as health-promoting foods. The effects of xylene and quercetin on ovarian cell function, their interrelationships, and mechanisms of action are insufficiently studied. In this in vitro study, we examined the effects of xylene, quercetin, and xylene/quercetin combination on basic bovine ovarian cell functions, such as proliferation, apoptosis, and hormone release. Furthermore, we examined the protective effect of quercetin against the potential negative effects of xylene. Proliferation and apoptosis were assessed via immunocytochemistry using PCNA and BAX markers. The release of progesterone, testosterone, and insulin-like growth factor (IGF-I) was analysed by EIA/RIA. Xylene stimulated proliferation and IGF-I release, but inhibited progesterone and testosterone release. Quercetin inhibited proliferation, apoptosis, and release of IGF-I, progesterone, and testosterone. When administered with xylene, quercetin prevented the action of xylene on proliferation and IGF-I release, induced the stimulatory action of xylene on apoptosis, and promoted the effect of xylene on release of progesterone but not testosterone. These results demonstrated the actions of both xylene and quercetin on basic ovarian cell functions. Furthermore, they show, that quercetin can either prevented or promote xylene effects on the ovarian cells, which indicates potential usefulness of quercetin for prevention of xylene action on female reproduction.