Oyster peptide prevents the occurrence of exercise-hypogonadal male condition by improving the function of pituitary gonadal axis in male rats.

This study evaluates the protective role of oyster peptide (OP) on the occurrence of Exercise-Hypogonadal Male Condition. Male rats were given heavy-load swimming training and / or OP was supplemented for 6 consecutive weeks. After heavy-load training, sperm count, sperm viability and sperm motility in epididymis, testosterone in serum and testis, glutathione peroxidase (GSH-px) and androgen receptor (AR) in testis and mating times were remarkably decreased, malondialdehyde (MDA), capture latency and mating latency were significantly increased, mRNA expression of steroidogenic acute regulatory (StAR) and P450 cholesterol side-chain cleavage enzyme (P450scc) were obviously down-regulated, but serum follicle-stimulating hormone (FSH) and luteinising hormone (LH) were not statistically changed. Conversely, when OP was supplemented at heavy-load training, sperm count, sperm viability and sperm motility in epididymis, serum FSH, LH, testosterone, GSH-px, superoxide dismutase (SOD), testosterone, AR in testis and mating times were dramatically increased, while testicular MDA, capture latency and mating latency were significantly decreased, and mRNA expression of StAR, StARD7, P450scc and 3ß-hydroxysteroid dehydrogenase (3ß-HSD) were significantly up-regulated. In conclusion, heavy-load training causes testicular spermatogenic and steroidogenic disorders by enhancing the generation of reactive oxygen species (ROS), which can be protected by the co-administration of OP by enhancing the function of pituitary gonad axis and lowering ROS generation.

Effects of Aerobic Exercise Combined with Oyster Peptide Supplement on the Formation of CTX-induced Late-Onset Hypogonadism in Male Rats.

The purpose of this study is to investigate the effect of aerobic exercise (AE) training and/or oyster peptide (OP) supplementation on the formation of late-onset hypogonadism (LOH). AE training and/or OP supplement was performed during Cytoxan (CTX)-induced LOH formation in male SD rats for 6 consecutive weeks. Low dose of CTX could decrease mating times, the levels of luteinizing hormone (LH), total testosterone (TT), free testosterone (FT) in serum and TT, androgen receptor (AR), androgen binding protein (ABP), and glutathione peroxidase (GSH-Px) in testicle, but increase capture latency, mating latency, and malondialdehyde, and downregulate the mRNA expression of steroidogenic acute regulatory (StAR), P450 cholesterol side chain cleavage enzyme (P450scc), and StAR-related lipid transfer domain 7 (StARD7) in testicle. Every change was altered by AE training combined with OP supplement significantly, except for serum LH. Moreover, the effect of AE training combined with OP supplement was better than that of AE training on serum TT, FSH, testicular TT, mating latency, capture times, and mating times. AE training combined with OP supplement during CTX-induced LOH formation can prevent the LOH development by enhancing pituitary-gonads axis's function and reducing testicular oxidative stress to promote testosterone synthesis and spermatogenesis.

Oyster oligopeptide improving cyclophosphamide-induced partial androgen deficiency of the aging male by promotion of testosterone synthesis.

AIM: The aim of this study was to investigate the effect of oyster oligopeptide (OOP) at different doses on testosterone secretion and its regulating mechanism in partial androgen deficiency syndrome of aging male. METHODS: The cyclophosphamide-induced partial androgen deficiency syndrome of the aging male rats were treated with a low, medium and high dose of OOP for 6 weeks. RESULTS: Cyclophosphamide could decrease levels of total testosterone and luteinizing hormone in serum, and testosterone and glutathione peroxidase in testis, and increase malondialdehyde, and downregulate the mRNA expression of steroidogenic acute regulatory protein, steroidogenic acute regulatory-related lipid transfer domain 7 and P450 cholesterol side chain cleavage enzyme in testis (P < 0.05). All these changes were reversed by OOP co-administration with different doses, although, OOP at a low dose did not increase serum testosterone, luteinizing hormone and testicular glutathione peroxidase levels. CONCLUSIONS: OOP treatment with different doses can effectively reduce oxidative stress in testicular tissue, promote the synthesis of testosterone and then prevent the formation of partial androgen deficiency syndrome of the aging male, with optimal effect at medium dose. Geriatr Gerontol Int 2021; 21: 268-275.