Background/Aims Polycystic ovary syndrome (PCOS) is an endocrine disorder characterized by abnormal hormone levels in peripheral blood and poor-quality oocytes. PCOS is a pathophysiological syndrome caused by chronic inflammation and oxidative stress. The aim of this study was to investigate the mechanism of melatonin regulation on androgen production and antioxidative damage in granulosa cells from PCOS patients with hypoestrogenia and hyperandrogenia. Methods Cumulus-oocyte complexes were collected from PCOS patients who had low levels of estrogen in follicular fluids. Results Melatonin triggered upregulation of cytochrome P450 family 19 subfamily A member 1 (CYP19A1) expression via the extracellular signal-regulated kinase pathway in luteinized granulosa cells. As a result, conversion of androgen to 17β-estradiol was accelerated. We also found that melatonin significantly reduced the levels of inducible nitric oxide (NO) synthetase and NO in luteinized granulosa cells. Levels of transcripts encoding NF-E2-related factor-2 and its downstream target heme oxygenase-1 were also increased, leading to anti-inflammatory and antioxidant effects. We also found that melatonin could improve oocyte development potential. Conclusion Our preliminary results showed that melatonin had a positive impact on oocyte quality in PCOS patients with hypoestrogenia and hyperandrogenia.

Insulin was administered to rats via nosedrops in the presence or absence of various alkylglycosides; systemic insulin absorption was measured as a fall in blood D-glucose concentration in animals made hyperglycemic by xylazine/ketamine anesthesia. Nosedrops (0.04 ml) containing alkylglycosides or regular porcine insulin alone were without effect. Nosedrops containing both a small amount of alkylglycoside (0.03-0.50%) and insulin (2 U regular porcine) caused a rapid decrease in blood D-glucose levels and a concomitant increase in serum immunoreactive insulin levels. The maximal hypoglycemic response was observed between 60 and 120 min after delivery of nosedrops. Decylmaltoside was less effective at enhancing systemic insulin absorption than dodecylmaltoside, tridecylmaltoside, or tetradecylmaltoside, whereas octylmaltoside was totally ineffective. Dodecylsucrose, a compound which differs from dodecylmaltoside only in one carbohydrate residue, had a similar effect on blood D-glucose values when it was included in the nosedrop formulation with insulin. Decylsucrose was considerably less potent than dodecylsucrose at enhancing systemic absorption of insulin. Nonylglucoside was effective at promoting insulin absorption from nosedrops only when used at higher doses (0.25-0.50%), whereas heptylglucoside and hexylglucoside were ineffective. These results indicated that nosedrops containing insulin plus an extremely low concentration (0.03%) of an absorption-enhancing agent such as tetradecylmaltoside can be used to lower blood D-glucose values.