Study on the mechanism of different doses of lycium barbarum polysaccharides affecting sperm motility in Drosophila melanogaster

Lycium barbarum, a Solanaceae plant, yields bioactive polysaccharides (LBP) in its dried mature fruits. LBP has demonstrated protective effects on the reproductive system. This study took Drosophila melanogaster as the experimental subject to investigate the dose-dependence of LBP on male reproductive capacity. The flies were orally administered LBP (0–2000 mg/L) by the CAFE method. Twenty-four hours later, sperm motility, ovulation rate and testicular gene expression were evaluated. Key results: LBP modulates sperm motility and female ovulation rate in a dose-dependent manner. The dose-response curves of oamb, gish, zeste and cg9465 show an inverted U-shaped trend. LBP regulates spermatogenic genes through OAMB receptor. The PKA signal was positively correlated with histone methyltransferase (zeste), indicating that there are other regulatory pathways. Two-phase dose effects were observed: LBP enhanced motility at 0–150 mg/kg and 450–1000 mg/kg, while inhibited motility at 150–450 mg/kg and > 1000 mg/kg. In conclusion, the reproductive effects of LBP follow nonlinear dynamic laws. This complexity further highlights the necessity of conducting in-depth studies on each component of LBP in order to accurately assess its reproductive toxicity and optimize its therapeutic potential.