2-Hydroxy-4-Methylselenobutanoic Acid (HMSeBA) Promote Follicle Development By Antioxidant Pathway in Gilts

Background Dietary 2-hydroxy-4-methylselenobutanoic acid (HMSeBA) supplementation can exert antioxidant effects in poultry, pigs and weaned pigs. However, it is unknown whether HMSeBA could improve the development of follicle by anti-oxidize effects in gilt. This study was conducted to evaluate the effects of dietary HMSeBA supplementation on the follicle development in gilt. A total of 36 gilts were randomly fed the control diet (CON, negative control), Na2SeO3 diet containing 0.3 mg Se/kg (positive control) or the HMSeBA diet containing 0.3 mg Se/kg from weaning to the 19th day after the second estrus. In another study, the effect of HMSeBA on the cells viability, proliferation, release of 17βestradiol (E2 ) and antioxidant capacity were investigated in the mouse ovarian granulosa cells in vitro. Results Results showed that HMSeBA group increased the average daily body weight gain (ADG) and decreased the ratio of feed: gain during day 120 to 176 in gilts ( P < 0.05). The selenium (HMSeBA and Na 2 SeO 3 ) increased the weight of uterine at the third estrus. There was no effect of HMSeBA on the number of large follicles (diameter >5mm), but HMSeBA decreased the gene expression of growth differentiation factor-9 ( GDF-9 ) and bone morphogenetic protein-15 ( BMP-15 ) in cumulus-oocyte complexes (COCs). HMSeBA group increased the total selenium content in serum ( P < 0.05) and liver ( P < 0.01) and tended to increase the total selenium content in ovary ( P = 0.08). HMSeBA group decreased the malondialdehyde (MDA) concentration in the serum, liver and ovary ( P < 0.05), increased the total antioxidant capacity (T-AOC) in the liver, thioredoxin reductase (TrxR) in the ovary ( P < 0.05) and increased the activity of GPx in the serum, liver and ovary ( P < 0.05). Na 2 SeO 3 supplementation decreased MDA and increased the T-AOC in liver, increased the T-SOD and TrxR in the ovary compared with control. At the transcription level, HMSeBA group increased the glutathione peroxidase 2 ( GPx2 ) and TrxR1 ( P < 0.05) expression in the liver, and increased the GPx1 expression ( P < 0.05) in the ovary of gilts compared with Na2SeO3 treatment. Besides, HMSeBA group increased the expressions of superoxide dismutase 1 ( SOD1 ) and Thioredoxin l ( Trx1 ) in the liver. In vitro experiment, HMSeBA improved granulosa cells’ proliferation and E2 secretion ( P < 0.05). HMSeBA and Na 2 SeO 3 both increased the T-AOC and decreased MDA in granulosa cells in vitro. Meanwhile, HMSeBA increased T-SOD, GPx, glutathione reductase (GR) and TrxR activity in granulosa cells in vitro. In addition, HMSeBA up-regulated SOD2 and GPx1 gene expression in the granulosa cells in vitro.Conclusion These results demonstrate directly, HMSeBA was more conducive to absorption and storage of selenium in the liver and ovary in gilt, and beneficial to exert the effect of HMSeBA on the antioxidant function in the liver and ovary of gilt. Moreover, HMSeBA has stronger antioxidant capacity in granular cells in vitro , which is more conducive to promoting follicle development. Therefore, the new type of organic selenium, HMSeBA, could be potentially useful for the control of reproductive processes in gilt.