Preliminary Evaluation On The Impact Of In Situ Gel OALA To Biological Activity Of Chemotherapeutic Drugs

Objective:To observe and evaluate the impact of in situ gel OALA to biological activity of chemotherapeutic drugs,and provide the experimental basis for OALA to load chemotherapeutic drugs.Methods:①The test of acute toxicity:In the acute toxicity test,we use sequential method to determine the LD50 of in situ gel OALA(the same volume in different concentration and the same concentration in different volume).②The cytotoxicity of OALA in vitro:Using SRB method to evaluate the effects of OALA in different concentrations on the proliferation of tumor cells(A549 lung cancer cells,MCF-7 breast cancer cells,LOVO colon cells),then determine the non-toxic concentration of OALA to these cells in vitro.③The impact of OALA on the toxicity of chemotherapeutic drugs in vitro:Firstly pre-test to determine the IC50 of three commonly used chemotherapeutic drugs(E-ADM,DDP and 5-FU)acting on A549,MCF-7,LOVO and L929 cell lines respectively,then we use MTT method to evaluate the impact of OALA on cytotoxicity of chemotherapeutic drugs in vitro;④The impact of OALA on the toxicity of chemotherapeutic drugs in vivo:Firstly pre-test to determine the lethal dose of chemotherapeutic drugs(DNR,ADM,DDP,5-FU),then to intervene under different lethal dose injecting OALA intravenously,to compare mortality with the group of single chemotherapeutic drugs administrating intraperitoneally.⑤The impact of OALA to the bone marrow toxicity of chemotherapeutic drugs:KM mice were randomly divided into saline control group,OALA(5mg/mL)treated group,CTX(100mg/kg)treated group,Ara-c(250mg/kg)treated group,OALA combined with CTX group and OALA combined with Ara-c group,then collect blood for consecutive three days after administration,to detect the number of WBC using blood cell automatic analyzer.⑥The impact of OALA to the in vivo antitumor activity of chemotherapeutic drugs:Using the EAC tumor-bearing mice as the experimental model,to obsreve the impact of different doses of chemotherapeutic drugs(CTX,DDP,5-FU and ADM)and chemotherapeutic drugs combined with OALA to tumor growth in mice,then take tumor growth inhibition rate as its index.Results:①Acute toxicity test of OALA:The results showed that the LD50 of the same volume in different concentration is(7.53±0.576)mg/mL(0.4mL/20g,equivalent to 150.6mg/kg;the LD50 of the same concentration in different volume is(0.31 ±0.113)mL(7.53mg/mL,equivalent to 116.7mg/kg).②The results of cytotoxicity in vitro showed that the GALA-30μg/mL had no influence on the proliferation of A549,MCF-7 and LOVO cells.When the concentration was higher than 94μg/mL,OALA would inhibit cell growth,and interfere with the results(MTT);③OALA-30μg/mL was non-toxic or the inhibition was weak for A549,MCF-7,LOVO and L929 cell lines,OALA combined with three chemotherapeutic drugs would not increase or decrease the cytotoxicity of drugs itself.④OALA could increase the animal mortality in ADM(15mg/kg)low dose group,reduce the animal mortality in ADM(20mg/kg)median dose group,but had no impact on animal mortality in ADM(25mg/kg)high dose group;OALA could increase the animal mortality in DNR and DDP(respectively 5mg/kg,15mg/kg)low dose groups,but had no significant effect on the animal mortality of DNR and DDP high and median dose groups;OALA could decrease the animal mortality in 5-FU median and high dose groups,but had no significant effect on the animal mortality of its low dose group.⑤OALA could enhance the bone marrow toxicityof CTX itself.⑥ OALA could reduce the anti-tumor activity of 5-FU,could significantly enhance the antitumor activity of ADM,but had no effect on the anti-tumor activity of CTX and DDP.Conclusions:① The toxicity of in situ gel OALA were not only related to its concentration but also related with the volume of administration.② In vitro,OALA had no effect on the cytotoxicity of three chemotherapeutic drugs(E-ADM,DDP and 5-FU).③ In vivo,OALA could differently interfere with the toxicity and anti-tumor activity of chemotherapeutic drugs.④ Only using multi-methods,many aspects of pharmacology,could we be able to make objective and accurate evaluation to the"impact of OALA on the activity of antitumor drugs".