Scutellarein stimulates human sperm function by increasing the levels of intracellular calcium and tyrosine phosphorylation

As a kind of flavonoid, scutellarein is widely used to protect against various human diseases. Although the protective effects of scutellarein have been well studied, its influence on human reproduction remains unknown. In this research, we evaluated the effect of scutellarein on human sperm functions in vitro. Three different concentrations of scutellarein (1, 10, 100 μM) were applied to ejaculated human sperm. Fertilisation-essential functions, as well as the intracellular calcium concentration ([Ca²⁺ ]_i ) and protein-tyrosine phosphorylation, two factors which are vital for sperm function regulation, were evaluated. The results demonstrated that all concentrations of scutellarein utilised in this study could significantly increase sperm spontaneous capacitation and acrosome reaction through the enhancement of [Ca²⁺ ]_i . Besides, the level of tyrosine phosphorylation of sperm could also be increased by scutellarein. Meanwhile, the sperm motility could be improved by 10 and 100 μM scutellarein, which also make a significant enhancement in sperm penetration ability and hyperactivation. This is one of the limited studies showing the regulation of scutellarein on human spermatozoa functions and is helpful to enrich its application.