Aims: Polycystic ovary syndrome (PCOS) is a widespread chronic reproductive disorder that is associated with metabolic disturbances. Traditionally, the marjoram plant is well-known to restore hormonal balance and regulate the menstrual cycle. We aimed to investigate the ameliorative effects of marjoram extract on hormonal profiles, body and ovaries weight, insulin sensitivity, inflammation, and oxidative stress in a rat model of PCOS.

Main methods: A 75 postpubertal (42 days old) female Wistar rats were randomly assigned into five groups (control, dehydroepiandrosterone (DHEA) induced-PCOS model, marjoram-treated PCOS rats, metformin-treated PCOS rats and the combination of marjoram+metfomin treated PCOS model). PCOS induction was performed by subcutaneous injection of DHEA 60 mg/kg daily for 24 days. Ovaries weight, adiponectin, hormonal levels, inflammatory, and oxidative stress biomarker levels were measured at the end of the treatment period using ELISA assay.

Key findings: The current study showed that marjoram significantly decreased ovaries' weight and the estradiol levels (P-value<0.05) compared to the DHEA group. Interestingly, marjoram improved insulin sensitivity as manifested by a significant increase in the adiponectin serum levels (P-value<0.05). Marjoram alone or in combination with metformin prominently decreased the IL-6 level and improved the levels of ovarian SOD and GPx enzymes (P-value<0.05). Additionally, the group treated with the combination of marjoram and metformin remarkably decreased the level of TBARS (P-value<0.05).

Significance: The present study established the beneficial effects of marjoram administration on DHEA-induced PCOS in female Wistar rats. The mechanistic effect includes improvement in the hormonal levels, ovaries weight, insulin sensitivity, antioxidants, and anti-inflammatory parameters.

Keywords: Dehydroepiandrosterone; Hormones; Inflammation; Marjoram; Oxidative stress; Polycystic ovary syndrome.