Punica granatum L. Modulates Antioxidant Activity in Vitrified Bovine Ovarian Tissue

TL;DR

This study shows that an extract from pomegranate can help preserve bovine ovarian tissue during freezing and thawing by reducing oxidative stress and maintaining tissue structure.

Contribution

The novel finding is that pomegranate extract improves vitrification outcomes in bovine ovarian tissue by modulating antioxidant activity and preserving morphology.

Findings

EE-PG at 10 and 100 µg/mL preserved follicular morphology and mitigated vitrification-induced damage.

EE-PG increased SOD activity and reduced MDA levels, indicating improved redox balance.

Despite downregulation of antioxidant genes, EE-PG supported tissue metabolism and structure.

Abstract

This study aimed to evaluate the effects of an ethanolic extract from Punica granatum L. (EE-PG) on bovine ovarian tissue vitrification, focusing on follicular morphology, ultrastructure, stromal cell density, collagen distribution, redox status, and mRNA expression of antioxidant-related genes. Bovine ovarian cortex fragments were divided into a fresh control group for in vivo tissue evaluation or vitrified either with the base vitrification solution (αMEM) alone or supplemented with different concentrations of EE-PG (10, 50, and 100 µg/mL), and subsequently stored in liquid nitrogen for 5 days. After warming, fragments were allocated for morphological and oxidative stress analyses or incubated for 24 h to resumption of cellular metabolism. The concentrations of 10 and 100 µg/mL preserved follicular morphology immediately after warming, and were therefore selected for ultrastructural evaluation. Both concentrations mitigated vitrification-induced damage. Gene expression analysis showed decreased levels of catalase (cat), Glutathione Peroxidase 1 (gpx1), and Nuclear Factor Erythroid 2-Related Factor 2 (nrf2) compared with the fresh control, whereas Superoxide Dismutase (SOD) enzymatic activity increased after incubation with 10 µg/mL EE-PG compared with all experimental groups. Moreover, Malondialdehyde (MDA) levels in tissues treated with 10 or 100 µg/mL were comparable to fresh controls after incubation. Overall, EE-PG at 10 or 100 µg/mL in the vitrification solution supported the maintenance of tissue morphology, redox balance—despite the downregulation of essential antioxidant genes, which may be associated with a reduced demand for enzymatic antioxidant defense—and cellular metabolism, indicating potential for improving bovine ovarian tissue vitrification outcomes.

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