Use of protocatechuic acid as the sole antioxidant in the base medium for in vitro culture of ovine isolated secondary follicles.

Abstract

This study evaluated the effect of the protocatechuic acid (PCA) as the sole antioxidant in the base medium for in vitro culture of ovine secondary follicles. Secondary follicles (200-230μm) were isolated and cultured in α-minimal essential medium supplemented with BSA, insulin, glutamine and hypoxanthine (α-MEM: antioxidant-free medium) or α-MEM also added by transferrin, selenium and ascorbic acid (α-MEM+: with antioxidant) or α-MEM added by PCA (56.25; 112.5; 225; 450; or 900μg/ml). Moreover, after culture, oocytes were matured and the chromatin configuration and DNA fragmentation were evaluated. After 12days, the treatment containing 56.25μg/ml PCA showed higher percentage of normal follicles than control medium or the other treatments (p<.05), except for 900μg/ml PCA (p>.05). The antrum formation was significantly higher in treatments containing 56.25, 112.5 or 900μg/ml PCA, compared to the α-MEM and similar (p>.05) to the other treatments. The rates of fully grown oocytes (≥110μm) were similar (p>.05) among all treatments containing PCA and α-MEM+, and those were superior (p<.05) than α-MEM, except for 450μg/ml PCA (p>.05). GSH levels and mitochondrial activity were higher (p<.05) in α-MEM+ than in α-MEM and similar (p>.05) to all PCA treatments. The rates of meiotic resumption and DNA fragmentation were similar (p>.05) among α-MEM+ and 56.25μg/ml PCA. In conclusion, PCA at 56.25μg/ml as the sole antioxidant added to the medium for ovine isolated secondary follicle culture maintains follicular survival, GSH and active mitochondria levels, meiotic developmental competence and DNA integrity of cultured oocytes.