Abstract: Purpose: To study the ameliorative effect of Perilla seed peptide on cyclophosphamide-induced sexual function impairment in rats. Methods: Eighty specific pathogen-free (SPF) 6-week-old male Sprague Dawley (SD) rats were randomly divided into eight groups of ten rats each. All animals except those in the control group were injected with 20 mg/(kg mb · d) of cyclophosphamide, and then treated with perilla seed protein or peptide at various concentrations by gavage. Enzyme linked immunosorbent assay, real-time quantitative polymerase chain reaction (qPCR) and hematoxylin-eosin (HE) staining were used to evaluate the levels of cytokines, proteins and hormones in the serum of rats, gene expression in the testis, and pathological changes of testis and kidney tissues. Meanwhile, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in testis and kidney were determined, and testis, kidney and immune organ indexes were also measured. Results: Compared with the control group, the levels of serum testosterone, free testosterone, luteinizing hormone, follicle stimulating hormone, interleukin 2 (IL-2), interferon γ (IFN-γ) and immunoglobulin G (IgG) in rats in the model group were significantly decreased, the expression of relevant genes and SOD activity were significantly reduced, and MDA content was significantly increased (P < 0.05). Both Perilla seed peptide and protein could improve the above parameters at various degrees. Perilla seed peptide had more significant effects on testicular and renal oxidative stress and serum hormone levels (P < 0.05). Conclusion: Perilla seed peptide can effectively ameliorate cyclophosphamide-induced reproductive damage and consequently improve sexual function in rats and increase the serum levels of IL-2, IFN-γ and IgG as well as immune organ indices.

Key words: perilla seed peptide; testis; testosterone; sexual function; antioxidant