Characterization And Bioactivity Of Nanoparticles Synthesized From Paeonia Suffruticosa Andr. Seed Cake

Paeonia suffruticosa Andr.seed cake contains various active ingredients such as phenols,monoterpenes and oligomeric astragals as a by-product of oil extraction from P.suffruticosa Andr.seed.These ingredients have good biological activities such as antioxidant and antibacterial activities.However,P.suffruticosa Andr.seed cake is often directly discarded,resulting in environmental pollution and waste of resources.Nanoparticles are able to bind,adsorb and carry compounds,such as drugs,probes and proteins,due to their unique physical properties.The high toxicity of nanoparticles generated by chemical or physical processes,is harmful to their utilization.It has been reported that nanoparticles synthesized using plants are less toxic.The active ingredients in the plants have better biological activity and medicinal value.In this study,the active ingredients of P.suffruticosa Andr.seed cake was analyzed,and silver nanoparticles were synthesized using P.suffruticosa Andr.seed cake extracts and characterized for the biological activity.This study provides theoretical basis for the development and utilization of P.suffruticosa Andr.seed cake resources and the synthesis and application of new nanoparticles.Firstly,the results of the determination of total phenols,total flavonoids,total monoterpenes and the HPLC,LC-MS analysis of active ingredients in P.suffruticosa Andr.seed cake indicated that P.suffruticosa Andr.seed cake was rich in phenols,monoterpenes and oligomeric astragalus compounds.P.suffruticosa Andr.seed cake was rich in compounds such as paeoniflorin,oxypaeoniflorin,Albiflorin,resveratrol and dimer and trimer of resveratrol.Secondly,after the green synthesis of silver nanoparticles(PSCE-Ag NPs)with using P.suffruticosa Andr.seed cake extract(PSCE),the PSCE-Ag NPs were characterized by UVVis spectroscopy,X-ray diffraction(XRD)analysis,zeta potential particle size analysis,transmission electron microscope(TEM)and Fourier transform infrared spectroscopy(FTIR).The results showed that PSCE-Ag NPs showed a characteristic peak at 490 nm,demonstrating the formation of PSCE-Ag NPs.Spherical PSCE-Ag NPs could be observed in TEM analysis with the average particle size of 105.6±3.49 d.nm and the potential of-41.8±12.6 mV.The results of the bioactivity study of PSCE-Ag NPs indicated that PSCE-Ag NPs was strong DPPH radical and ABTS+radical scavenging activity.PSCE-Ag NPs inhibited the bacterial growth of B.cereus,S.aureus,E.coli and S.typhimurium.PSCE-Ag NPs had significant inhibitory effects on breast cancer cells(BT474)and lung cancer cells(A549),but not on HEK293 cells.PSCE-Ag NPs also showed low destructive power against erythrocytes and chick embryo chorioallantois membrane.Thirdly,paeoniflorin(Pae)was loaded onto mesoporous silica nanoparticles(SiO2 NPs)to investigate the characterization,cytotoxic and antibacterial activities of paeoniflorin-SiO2 NPs.FTIR analysis showed the presence of functional groups from Pae on the Pae-SiO2 NPs,demonstrating the successful loading of Pae onto SiO2 NPs.The crystallinity of Pae-SiO2NPs was determined by XRD analysis.TEM analysis revealed that both SiO2 NPs and Pae-SiO2 NPs were spherical and have porous on the surface.The loading of pae had no effect on the shape of SiO2 NPs.The biological activity of the Pae-SiO2 NPs was investigated.The result found that the Pae-SiO2 NPs showed strong bacterial inhibition activity against both S.aureus and B.cereus with MIC values of 800 μg/mL and 27μg/mL.The MBC value are 3.5 mg/mL and 54 μg/mL,respectively.To further evaluate the toxicity of the Pae-SiO2 NPs,the cytotoxicity and hemolysis of Pae-SiO2 NPs were measured.The results showed that the binding of Pae-SiO2 NPs reduced cytotoxicity and hemolysis and had less effect on cell membrane and ROS content.Overall,P.suffruticosa Andr.seed cake is rich in monoterpenes such as paeoniflorin,oxypaeoniflorin,albiflorin,suffruticosol isomer and other active ingredients such as phenols and flavonoids.These ingredients enabled the green synthesis of silver nanoparticles and influenced the physical properties of Ag NPs.Functional groups from P.suffruticosa Andr.seed cake was added to the surface of the nanoparticles and reduced the cytotoxicity of Ag NPs and enhanced antibacterial,anticancer and antioxidant activities.Paeoniflorin from P.suffruticosa Andr.seed cake was able to bind to SiO2 NPs,increased the antibacterial activity and reduced the cytotoxic and hemolysis.Silver nanoparticles synthesized using P.suffruticosa Andr.seed cake showed less cytotoxicity and strong biological activities such as antibacterial,anticancer and antioxidant activities.Paeoniflorin loaded on silica nanoparticles increased the antibacterial activity of silica nanoparticles against S.aureus and B.cereus and reduced cytotoxicity and hemolysis.