Effects of estrogen deficiency on liver function and uterine development: assessments of Medicago sativa's activities as estrogenic, anti-lipidemic, and antioxidant agents using an ovariectomized mouse model

Casein kinase 1α mediates estradiol secretion via CYP19A1 expression in mouse ovarian granulosa cells

BACKGROUND

Casein kinase 1α (CK1α), expressed in both ovarian germ and somatic cells, is involved in the initial meiosis and primordial follicle formation of mouse oocytes. Using in vitro and in vivo experiments in this study, we explored the function and mechanism of CK1α in estrogen synthesis in mice ovarian granulosa cells.

METHODS

A CK1α knockout (cKO) mouse model, targeted specifically to ovarian granulosa cells (GCs), was employed to establish the influence of CK1α on in vivo estrogen synthesis. The influence of CK1α deficiency on GCs was determined in vivo and in vitro by immunofluorescence analysis and Western blot assay. Transcriptome profiling, differentially expressed genes and gene functional enrichment analyses, and computation protein-protein docking, were further employed to assess the CK1α pathway. Furthermore, wild-type female mice were treated with the CK1α antagonist D4476 to elucidate the CK1α's role in estrogen regulation.

RESULTS

Ovarian GCs CK1α deficiency impaired fertility and superovulation of female mice; also, the average litter size and the estradiol (E2) level in the serum of cKO female mice were decreased by 57.3% and 87.4% vs. control mice, respectively. This deficiency disrupted the estrous cycle and enhanced the apoptosis in the GCs. We observed that CK1α mediated the secretion of estradiol in mouse ovarian GCs via the cytochrome P450 subfamily 19 member 1 (CYP19A1).

CONCLUSIONS

These findings improve the existing understanding of the regulation mechanism of female reproduction and estrogen synthesis.

TRIAL REGISTRATION

Not applicable.

Protective effect of phytoestrogens on nonalcoholic fatty liver disease in postmenopausal women

Non-alcoholic fatty liver disease (NAFLD) is a progressive metabolic disease characterized by hepatic steatosis, inflammation, and fibrosis that seriously endangers global public health. Epidemiological studies have shown that the incidence of non-alcoholic fatty liver disease in postmenopausal women has significantly increased. Studies have shown that estrogen deficiency is the main reason for this situation, and supplementing estrogen has become a new direction for preventing the occurrence of postmenopausal fatty liver. However, although classical estrogen replacement therapy can reduce the incidence of postmenopausal NAFLD, it has the risk of increasing stroke and cardiovascular diseases, so it is not suitable for the treatment of postmenopausal NAFLD. More and more recent studies have provided evidence that phytoestrogens are a promising method for the treatment of postmenopausal NAFLD. However, the mechanism of phytoestrogens in preventing and treating postmenopausal NAFLD is still unclear. This paper summarizes the clinical and basic research evidence of phytoestrogens and reviews the potential therapeutic effects of phytoestrogens in postmenopausal NAFLD from six angles: enhancing lipid metabolism in liver and adipose tissue, enhancing glucose metabolism, reducing oxidative stress, reducing the inflammatory response, regulating intestinal flora, and blocking liver fibrosis (Graphical Abstract).

Gestational cadmium exposure disrupts fetal liver development via repressing estrogen biosynthesis in placental trophoblasts

Cadmium (Cd), commonly found in diet and drinking water, is known to be harmful to the human liver. Nevertheless, the effects and mechanisms of gestational Cd exposure on fetal liver development remain unclear. Here, we reported that gestational Cd (150 mg/L) exposure obviously downregulated the expression of critical proteins including PCNA, Ki67 and VEGF-A in proliferation and angiogenesis in fetal livers, and lowered the estradiol concentration in fetal livers and placentae. Maternal estradiol supplement alleviated aforesaid impairments in fetal livers. Our data showed that the levels of pivotal estrogen synthases, such as CYP17A1 and 17β-HSD, was markedly decreased in Cd-stimulated placentae but not fetal livers. Ground on ovariectomy (OVX), we found that maternal ovarian-derived estradiol had no major effects on Cd-impaired development in fetal liver. In addition, Cd exposure activated placental PERK signaling, and inhibited PERK activity could up-regulated the expressions of CYP17A1 and 17β-HSD in placental trophoblasts. Collectively, gestational Cd exposure inhibited placenta-derived estrogen synthesis via activating PERK signaling, and therefore impaired fetal liver development. This study suggests a protective role for placenta-derived estradiol in fetal liver dysplasia shaped by toxicants, and provides a theoretical basis for toxicants to impede fetal liver development by disrupting the placenta-fetal-liver axis.

Effect of Medicago sativa compared To 17β-oestradiol on osteoporosis in ovariectomized mice

Phytoestrogens, with a wide range of beneficial effects, prevent bone loss caused by oestrogen deficiency.The purpose of this study was to evaluate the effect of Medicago sativa ethanol extract compared to 17β-oestradiol on osteoporosis in ovariectomized mice.The study was carried out on female mice, divided into five groups: control mice (GI), Medicago sativa treated mice (0.75 g/kg BW/day) (GII), ovariectomized mice (GIII) and ovariectomized mice treated either with Medicago sativa (GIV) or with 17β-oestradiol (50 µg/Kg BW/day) (GV).Our results showed that Medicago sativa or 17β-oestradiol treatments significantly attenuated perturbations of mineral levels, histological changes and oxidative stress in the femurs of ovariectomized mice.Medicago sativa prevented bone loss induced by oestrogen deficiency, which could be attributed to its richness in kaempferol, syringic acid, naringenin and myrictin. Its effects were more beneficial or similar compared to 17β-oestradiol.

Modulation of inflammatory markers by petroleum ether fraction of Trigonella foenum-graecum L. seed extract in ovariectomized rats

This study evaluates the modulation of inflammatory markers by petroleum ether fraction of Trigonella foenum-graecum L. (PE-TFG) seed extract in ovariectomized rats. The HPTLC method was used for standardization and to quantify the diosgenin in PE-TFG. For testing PE-TFG in rats, the total duration of treatment was 12-weeks, and the rats were sacrificed on week 12. The tissue samples such as blood, liver, heart, and aorta were isolated for testing inflammatory markers such as adiponectin, leptin, PPAR-γ, TNF-α, lipid profile, hepatic markers, antioxidants, and oxidative stress markers. The PE-TFG treatment decreased the elevation of total cholesterol, triglyceride, AST, and ALT. Upon PE-TFG treatment, there was a significant increase in adiponectin and PPAR-γ mRNA expression. Leptin and TNF-α were normal after treatment with PE-TFG seed extract. Further, micro-steatosis of hepatocytes marked glomerular hypertrophy in the kidney and increased thickness of tunica intima and media of common carotid artery was reversed after treatment with PE-TFG. PRACTICAL APPLICATIONS: Trigonella foenum-graecum L. is a curative plant used to treat inflammatory conditions like diabetes, obesity, dyslipidemia, arthritis, cancer, and digestive disorders. In our study, PE-TFG supplementation has a protective effect on OVX-induced inflammation, oxidative stress, mRNA expression of adiponectin and PPAR-γ, hepatic steatosis, and decreased thickness of tunica intima and media of common carotid artery.