Metformin for the Treatment of Polycystic Ovary Syndrome:

Metformin improves epigenetic modification involved in oocyte growth and embryo development in polycystic ovary syndrome mice model

The possible relationship between dehydroepiandrosterone (DHEA)-induced polycystic ovary syndrome (PCOS) and epigenetic changes (ECs) leading to the impaired oocyte quality, has not been investigated yet. So, this study aimed to provide an insight into the relationship of the impaired oocyte quality with ECs in a mice DHEA-induced PCOS model and to further reveal the effect of metformin treatment. For this purpose, 80 female BALB/C mice were randomly divided into four equal groups, named as the control, sham, (DHEA) and DHEA + Metformin groups. The alterations in acetylation of H4K5 and H4K16, and in methylation of DNA (5MeC) and H3K9 were evaluated using immunocytochemical. Moreover, the expression of Hdac1, Hdac2, Dnmt1, and Dnmt3a genes involved in ECs were analyzed using reverse-transcription polymerase chain reaction. As well, the levels of mitochondrial membrane potential (MMP), oxidative stress (OS), embryo development, ovarian morphology, sexual hormone, ovulatory function, and AMPKα phosphorylation activity were compared in all the studied groups. Metformin attenuated the damages induced by DHEA as indicated by the normalized the estrous cycle, the improved ovarian morphology, the decreased sexual hormone and OS levels, and the increased MMP and AMPKα phosphorylation levels. In the metformin group, the Dnmt1, Dnmt3a, and Hdac2 genes have significantly upregulated compared to the DHEA group. However, metformin was found to have no effect on the expression level of Hdac1. In this regard, significant decrease and increase were observed in both the acetylated H4K16 and methylated H3K9 within MII oocytes in the DHEA + Metformin group compared with the DHEA group. Our results show that metformin could enhance the developmental competence of PCOS oocytes via reducing OS and ECs.

Treatment strategies for women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women, and it is the main cause of infertility in women of reproductive age due to anovulation. PCOS also increases the risk of diseases such as cardiovascular disease and type 2 diabetes in women with this disorder. The mechanism of pathogenesis is not clear, as it may be related to heredity, the environment and internal embryonic factors; thus, the treatment strategies remain unclear. This review summarizes current treatments for PCOS worldwide. Lifestyle modification (LSM) is considered the first-line treatment, regardless of fertility status, without the addition of metformin. Oral contraceptive (OC) pills should be used as a first-line treatment for long-term management for patients with no reproductive requirements. For patients with fertility requirements, ovulation therapy is an effective treatment. For refractory ovulation disorders, patients can choose from among the latest treatments, including ovarian hippocampal signal path block theory, the theory of leptin, inositol treatment, bilateral ovarian drilling to stimulate ovulation and assisted reproductive technology. Because current treatments cannot cure PCOS, lifelong administration is still the mainstream method of management; however, the optimal treatment plan needs further research and exploration.

Metformin administration was associated with a modification of LH, prolactin and insulin secretion dynamics in women with polycystic ovarian syndrome

AIM. To elucidate the dynamics of FSH, LH, prolactin (PRL), TSH and insulin secretion in women with polycystic ovarian syndrome (PCOS) treated with metformin (MET).

PATIENTS AND METHODS

In a prospective, controlled and randomised trial, 32 women with PCOS and 32 with normal cycle were recruited to receive MET (850 mg b.i.d.) or placebo (n: 16 for each subgroup) for an average of 40 days. Pituitary function and insulin secretion were assessed before and after intervention by GnRH-TRH tests and oral glucose tolerance test induced insulin response.

RESULTS

Basal and area under the response curve (AURC) LH values were higher in PCOS than in normal controls before MET and declined following treatment in the former group (P < 0.05). Ovulatory PCOS responders had lower basal LH, AURC(LH) and AURC(PRL) values during MET than anovulatory cases (P < 0.05 for all) and AURCins was lower in ovulatory than anovulatory PCOS before and on MET (P < 0.02-P < 0.05), with a rise of QUICKY index in the former group during MET treatment (P < 0.05). FSH and TSH were similar.

CONCLUSIONS

MET administration lowered LH activity in all PCOS women and in ovulatory responders and also compromised PRL stimulated secretion in the latter cases. These findings were indicative of an effect of MET on pituitary activity.