Effects Of Royal Jelly And Its Extracts On Endometrial Receptivity And MCF-7 Cell Growth In Rats With Thin Endometrium

Royal jelly has various biological functions such as antibacterial,antiinflammatory,antioxidant,and blood pressure lowering,and is widely used in the medical,cosmetic,and health product industries.Some studies suggest that royal jelly has estrogenic like effects and can regulate hormone secretion in the reproductive system of hormonal disorders.It is currently unclear which component of royal jelly dominates this effect.This study used the ethyl acetate method to separate and extract proteins and fatty acids from royal jelly.The hormonal regulatory effects of these two main components were analyzed through in vivo and in vitro experiments,providing a basis for the subsequent development of high value-added products.The main research content and results are as follows:(1)Evaluate the quality of experimental samples by evaluating the content of 10hydroxy-2-decene in royal jelly and its extracts using high-performance liquid chromatography.The results showed that the content of 10-hydroxy-2-decenoic acid in the lyophilized royal jelly powder was 4.61 ± 0.14;The content of 10-hydroxy-2decenoic acid in protein extracts was significantly reduced(1.28 ± 0.06),while the content of 10-hydroxy-2-decenoic acid in fatty acid extracts was significantly increased(8.10 ± 0.22).The experimental results indicate that the ethyl acetate extraction method can simultaneously separate and extract protein and fatty acid components from royal jelly.(2)Thin endometrium is mainly caused by insuficient estrogen secretion,and there is no research report on whether royal jelly can regulate and improve the symptoms of thin endometrium.The experiment was conducted by injecting 95%ethanol into the uterine cavity of rats to create a thin endometrium model.Royal jelly,protein extract,or fatty acid extract(500 mg/kg/d)were administered orally to explore the effects of royal jelly and its extract on rat behavior,uterine tissue,hormone secretion,and vascular growth related factors.The results showed that the thickness of endometrium,number of glands,and number of blood vessels in rats treated with 95%ethanol were significantly lower than those in the control group,indicating the successful establishment of the model rat;After oral administration of royal jelly and its extract,the expression of receptive related factors in thin endometrium rats was significantly increased,with the effect of fatty acid extract(P<0.05)being better than that of protein extract(P≥0.05).(3)The estrogen effect is that the ligand is produced by activating the estrogen receptor.breast cancer(MCF-7)cells are estrogen receptor positive expression cells and depend on estrogen to grow.Therefore,this study selected MCF-7 cells to investigate the effects of proteins and fatty acids in royal jelly on the growth and estrogen receptor expression of MCF-7 cells.Royal jelly and its extract were used to act on MCF-7 cells.Through cell proliferation experiments,0.9 mg/mL royal jelly,0.8 mg/mL protein extract,and 0.7 mg/mL fatty acid extract had the maximum proliferation effect on MCF-7 cells.After the dose was used to act on MCF-7 cells,each group increased the C1 phase phase of MCF-7 cells,reduced the number of cells in S phase and G2 phase,and increased the apoptosis rate of MCF-7 cells.Adding protein extract group and fatty acid extract group estrogen receptor(ER)α The expression level of ER in the royal jelly group significantly increased compared to the protein extract group and fatty acid extract group a The expression level of significantly decreased.It is worth noting that the royal jlly group and protein extract group ER β The expression level significantly increased compared to the control group,while significantly decreased compared to the fatty acid extract group,indicating that fatty acid extract may be the main substance exerting estrogenic effects.Royal jelly,its proteins,and fatty acid extracts exhibit estrogenic effects by regulating estrogen receptors.In summary,oral administration of royal jelly and its extracts can regulate the expression levels of endometrial receptivity related factors in rats with thin endometrium,accelerate the apoptosis of MCF-7 cells,and increase the expression of estrogen receptors in cells,indicating that royal jelly may have estrogenic like effects,and the fatty acid components may be the main substances that exert functions.