Preparation Of Gambogic Acid Nanoparticles And Evaluation Of Anti-inflammatory Activity

In the process of animal husbandry and breeding,the animal body is very easy to induce inflammation due to external stimuli.Excessive inflammation can cause irreversible damage to the body,which is easy to cause animal death and bring additional losses to farmers.In clinical practice,steroidal and non-steroidal anti-inflammatory drugs are usually used to suppress excessive inflammation,but long-term use of these two can cause serious toxic and side effects to the body.Therefore,it is necessary to develop new anti-inflammatory compounds with low toxicity and resistance to drug resistance.Gambogic acid is a cage-like xanthone compound extracted from the traditional Chinese medicine Garcinia Cambogia.It is one of the main active ingredients.Research in recent years has shown that it has a variety of biological activities such as inhibition of tumor cell proliferation,anti-inflammatory,anti-virus and neuroprotection.However,gambogic acid has extremely low water solubility,which severely limits its clinical application.Polylactic acid block copolymer?m PEG-PLA?has good biocompatibility,non-toxicity,biodegradability,long-term circulation in the body,etc.Therefore,this study tried to improve the solubility of gambogic acid by using polylactic acid block copolymer to prepare gambogic acid nanoparticles,thereby enhancing its anti-inflammatory effect.This experiment uses the emulsification solvent volatilization method to prepare,and uses ultracentrifugation to separate gambogic acid polyethylene glycol polylactic acid block copolymer nanoparticles?GA-m PEG-PLA-NPs?,and UV spectrophotometry detects GA-m PEG-PLA-GA content in NPs;use single factor to investigate the factors that can affect the encapsulation efficiency in the formulation,and adopt Box-Behnken response surface design to optimize its formulation method.The formulation was optimized,and its particle size,appearance,zeta,and in vitro release behavior were investigated.Through single factor investigation and response surface test,it is determined that the optimal preparation prescription of gambogic acid nanoparticles is 92 min,the mass ratio of drug to carrier is 1:35,the PVA concentration is 2.5%,and the ratio of organic phase to aqueous phase It is 1:2.At this time,the encapsulation rate of gambogic acid nanoparticles was 65.79±1.02%.The average diameter of the nanoparticles is about 338.9 nm;the Zeta potential is-10.2mv;round nanoparticles with uniform size and uniform dispersion can be observed under the transmission electron microscope.The release rate of the nanoparticles in 48h is 52.38%,which has a slow release effect.In order to evaluate the anti-inflammatory effects of GA-m PEG-PLA-NPs in vivo and in vitro,an LPS-induced RAW264.7 inflammation model and a mouse acute lung injury model were established.MTT method was used to detect the cytotoxicity of GA-m PEG-PLA-NPs to RAW264.7.The content of NO in the inflammation model in vivo and in vitro was detected by Griess method,and the content of TNF-?,IL-6,IL-1?,IL-10 and PGE₂was detected by enzyme-linked immunosorbent assay?ELISA?.The IC₅₀of GA-m PEG-PLA-NPs to RAW264.7 is 12.55?M,and 0-2?M GA-m PEG-PLA-NPs will not affect the cell viability of RAW264.7.GA-m PEG-PLA-NPs can also reduce the expression of inflammatory mediators NO and PGE₂in the inflammatory cell model,inhibit the production of pro-inflammatory factors TNF-?,IL-1,and IL-6,and promote the expression of IL-10.The anti-inflammatory activity of GA-m PEG-PLA-NPs was higher than that of GA under the same concentration of co-acting in vivo for 5 days.The prepared gambogic acid polyethylene glycol polylactic acid block end copolymer nanoparticles have low toxicity,sustained release effects,and good anti-inflammatory activity.