In recent years,the incidence of endometriosis (EMs) has increased significantly,bringing great harm to women's physical and mental health.Polysaccharide from Spirulina (PSP) is a class of natural biological macromolecules with multiple functions.They have various functions such as anti-inflammatory and anti-cell proliferation,and also have pharmacological potential to treat EMs.To investigate the effects and molecular mechanism,the PSP with purity of 89% was obtained by water extraction and analytical methods.SD rats were used as model animals.In the rat EMs model,an EMs rat model was successfully prepared by auto-transplantation surgery.Therapeutic effects of different doses of PSP on EMs were observed.The protein and transcription level expression of PI3K/Akt/mTOR in EMs tissue was detected by Western blot and qRT-PCR methods respectively.The results showed that compared with the control group,the EMs in the model group significantly increased the expression levels of TNF-α,VEGF and MMP-2 in the rat serum.Compared to model group,different doses of PSP alleviated the symptoms of EMs,which are specifically manifested as the reduction of EMs lesions and the decreased expression levels of TNF-α,VEGF and MMP-2 in serum.In the model group,the protein and transcription expression levels of PI3K,AKT and mTOR increased significantly,while the expression of PI3K,AKT,mTOR in the PSP treatment group decreased obviously.The research results indicated that PSP could improve the symptoms of EMs by inhibiting the PI3K/Akt/mTOR pathway and reducing TNF-α,VEGF,and MMP-2 contents in serum.