Pomegranate fruit (Punica granatum L.) is rich in antioxidants with a content of bioactive substances with high medicinal value. Punicalagin, a polyphenol from pomegranate fruit, has been studied for its antioxidant, anti-proliferative and anti-cancer activities. Ovarian cancer is one of the most common cancers in the female reproductive organs and with high rate of lethality. While it is confirmed that pomegranate has significant beneficial effects on several types of cancer, there are few detailed reports on epithelial ovarian cancer. In accordance with the potential health-promoting effects of pomegranate, the aim of our study was to examine the in vitro effect of punicalagin and pomegranate peel extract at the different concentrations (12.5, 25, 50, 100, and 200 µg/mL) for 24 h on the human ovarian granulosa cell line HGL5 and human ovarian carcinoma cell line OVCAR-3. For this experiment, the ethanol extract from lyophilized pomegranate peel was prepared. The metabolic activity was determined by AlamarBlueTM cell viability assay, the secretion of steroid hormones was assayed by the ELISA method. The results showed a significant (P≤0.001) decrease in the viability of HGL5 cells after the addition of the highest concentration of punicalagin (200 µg/mL). The number of viable OVCAR-3 cells was not significantly (P≥0.05) affected compared to the control. On the other hand, the concentrations 25, 50, 100, and 200 µg/mL of pomegranate peel extract led to a significant decrease in the viability of OVCAR-3 cells but did not cause any significant (P≥0.05) changes in the viability of HGL5. Although our studies revealed an increase in the release of 17β-estradiol levels by HGL5 cells after punicalagin treatment at the concentration 50 (P≤0.01) and 100 (P≤0.05) µg/mL, progesterone secretion was not significantly (P≥0.05) affected. Also, the release of 17ß-estradiol was significantly increased after the supplementation of pomegranate peel extract at the concentrations 50 (P≤0.01), 100, and 200 (P≤0.001) µg/mL. Furthermore, the levels of progesterone were significantly (P≤0.05) decreased at concentrations 12.5, 25, 50, and 100 µg/mL. In conclusion, pomegranate phytonutrients might be a promising modulator of secretion of steroid hormones and it might serve to be a potential chemoprotective agent, reducing viability of ovarian cancer cells.
punicalagin, pomegranate, ovarian cells, steroid hormones, cancer