Protective effects of ethanol extracts of Artemisia asiatica Nakai ex Pamp. on ageing-induced deterioration in mouse oocyte quality

Summary Following ovulation, oocytes undergo a time-dependent deterioration in quality referred to as post-ovulatory ageing. Although various factors influence the post-ovulatory ageing of oocytes, oxidative stress is a key factor involved in deterioration of oocyte quality. Artemisia asiatica Nakai ex Pamp. has been widely used in East Asia as a food ingredient and traditional medicine for the treatment of inflammation, cancer, and microbial infections. Recent studies have shown that A . asiatica exhibits antioxidative effects. In this study, we investigated whether A . asiatica has the potential to attenuate deterioration in oocyte quality during post-ovulatory ageing. Freshly ovulated mouse oocytes were cultured with 0, 50, 100 or 200 μg/ml ethanol extracts of A . asiatica Nakai ex Pamp. After culture for up to 24 h, various ageing-induced oocyte abnormalities, including morphological changes, reactive oxygen species (ROS) accumulation, apoptosis, chromosome and spindle defects, and mitochondrial aggregation were determined. Treatment of oocytes with A . asiatica extracts reduced ageing-induced morphological changes. Moreover, A . asiatica extracts decreased ROS generation and the onset of apoptosis by preventing elevation of the Bax/Bcl-2 expression ratio during post-ovulatory ageing. Furthermore, A . asiatica extracts attenuated the ageing-induced abnormalities including spindle defects, chromosome misalignment and mitochondrial aggregation. Our results demonstrate that A . asiatica can relieve deterioration in oocyte quality and delay the onset of apoptosis during post-ovulatory ageing.