A review on role of medicinal plants in polycystic ovarian syndrome: Pathophysiology, neuroendocrine signaling, therapeutic status and future prospects

Polycystic ovary syndrome (PCOS) is one of the most important gynecological disorders among reproductive-age women. In patients with PCOS, the secretion rate and metabolism of androgens and estrogens are disrupted. With regards to the increasing prevalence of PCOS and associated physical and mental problems as well as the effects of changes in sex hormones in development of this disease, our aim is to investigate the effects of different herbal extracts on changes in the serum levels of sex hormones and ovarian tissue. To conduct this review, an extensive literature search was conducted using, relevant publications published between 1990 and 2017, and indexed in Google Scholar, PubMed, Elsevier, Scientific Information Database, and Science Direct were studied. The search terms used to retrieve the publications were as follows: Herbal medical extract، Names of medicinal plants ، polycystic ovary syndrome, PCOS, the mechanism of hormone. According to the evidence, herbal extracts containing phytoestrogens cause decrease in hyperandrogenism, insulin resistance, and ovary weight as well as increase in ovulation. Therefore, these plants can be partly effective in this syndrome via affecting the serum levels of different hormones and ovarian weight and morphology, representing an opportunity to investigate and discovery new bioactive products. © 2018 Middle East Fertility Societ

Retinoic acid and fibroblast growth factor-2 play a key role on modulation of sex hormones and apoptosis in a mouse model of polycystic ovary syndrome induced by estradiol valerate

Objective: The main goal of the present study is to investigate the effects of retinoic acid and fibroblast growth factor-2 on serum levels of FSH and LH, histology, and apoptosis in the mouse model of Poly Cystic Ovary Syndrome (PCOS). Materials and methods: 80 female NMRI mice have been randomly divided into eight groups. Group 1 received normal saline as a control, and Group 2 received estradiol valerate (EV) at 4 mg/100 g of body weight. Moreover, Groups 3–4 were administered with RA (a dose of 0.05 μg/μl) and FGF2 (a dose of 0.01 μg/kg), respectively. Groups 5 and 6 respectively received the EV plus the RA (0.05 μg/μl) and FGF2 (0.01 μg/kg). Group 7 received the RA and FGF2 at doses corresponding to healthy mice, and Group 8 received the EV plus the RA + FGF2 (similar to previous doses). RA and FGF2 were injected three times per week for four weeks. Finally, histological and immunohistological parameters of the ovary were evaluated. Results: The study revealed that both single and combined injection of fibroblast growth factor-2 (FGF2) and retinoic acid (RA) in groups 5, 6, and 8 significantly reduced follicular diameters compared to group 2. Measurements confirmed that simultaneous injection of RA and FGF2 into polycystic mice significantly increased antral follicles, corpus luteum (CL), epithelial thickness, and oocyte diameter as well as decreased cystic follicles. Positive TUNEL cells that were considerably increased in the antral follicle of group 2 significantly decreased in the RA and FGF2 recipient groups, either alone or in combination. Besides, the injection of FGF2 increased preantral follicles and CL. Conclusion: The findings of the present investigation reveal that injection of RA and FGF2 has both protective and ameliorative effects that can promise new therapies for women with PCOS. © 202

Small-signal model analysis and control design of a double-ended forward converter in discontinuous-capacitor-voltage mode

A double-ended forward converter with an input inductor–capacitor filter has inherent power factor correction (PFC) properties and continuous input current when operating in discontinuous-capacitor-voltage mode (DCVM). In this study, the minimum separable switching configuration modelling is applied to the proposed converter operating in DCVM to obtain a small-signal model of the converter. The impact of the circuit parameters on the small-signal characteristic are discussed in details. The difference between the small-signal behaviour of the converter when operating as a DC/DC converter and a PFC converter is investigated. The modelling methodology is intended for the design of controllers in closed-loop operation. A 100 W prototype is implemented to demonstrate the feature of the small-signal behaviour