Anti-inflammatory And Anti-tumor Activities Of Curcumin Hydride

ObjectiveCurcumin(CUR)is extracted from rhizomes of Zingiberacease(ginger family)plants,such as turmeric,curcuma aromatic and zedoary.It has been researched and shown for anti-inflammatory,anti-oxidant,anti-tumor activities and so on.It has the potential clinical applications because of the well-tolerated and the Low biological toxicity.However,CUR has been proven to possess low stability in aqueous solution and poor systemic bioavailability,which would directly result in the difficulty in clinical applications.Therefore,it is important to find the active forms in CUR-induced biological effects.The aims of the study were to evaluate the anti-inflammatory and anti-tumor activities of tetrahydrocurcumin(THC)and octahydrocurcumin(OHC)compared with CUR and their mechanisms of action for providing the experimental evidences for clinical application of CUR.Methods1.Synthesis of OHC and preliminary study of acute toxicity of THC and OHCBased on the character of CUR molecule structure and the hydrogenation of sodium borohydride,the OHC was synthesized by controlling the reaction conditions.Its structure was confirmed by HPLC-MS,1H-NMR and 13C-NMR.In addition,the structure and purity of OHC was compared with the literatures that were already reported.The acute toxicity study was performed via combining median lethal(LD50)experiments and maximum tolerance dose(MTD)tests for a single dose toxicity study.2.The anti-inflammatory activities of curcumin hydrideKM mice were pretreatment with THC(10?20?40 mg/kg,p.o.),OHC(10?20?40 mg/kg?p.o.)and CUR(100 mg/kg)for 7days(q.d.).1 h after the last administration,the xylene-induced mouse ear edema model,the acetic acid-induced vascular permeability enhancement model and the carrageenan-induced mouse paw edema model were performed.After that the weight difference of ears,the OD difference of peritoneal lavage fluids and the volume difference of mouse paw were measured.Finally,all the inhibition rates were calculated.KM mice were pretreatment with THC(40 mg/kg,p.o.),OHC(40 mg/kg,p.o.)and CUR(100 mg/kg,p.o.)for 7days(q.d.).1 h after the last administration,the carrageenan-induced mouse paw edema model was performed.4 h after the carrageenan challenge,mice were sacrificed.The paw was collected for the analysis of COX-1,COX-2,NF-?B,TNF-?,IL-1? IL-6,PGE2,TAB1,TAK1 and p-TAK1.3.The anti-tumor activities of curcumin hydrideThe H22 ascites tumor-bearing model in KM mouse was duplicated,and they were pretreatment withTHC(5?10?20mg/kg,p.o.),OHC(5?10?20mg/kg,p.o.)and CUR(100 mg/kg)for 7days(q.d.).Their behaviors were observed every day,then statisticed the survival time and calculated the prolongation of life span.KM mice were pretreatment with THC(20 mg/kg,p.o.),OHC(20 mg/kg,p.o.)and CUR(100 mg/kg,p.o.)for 7days(q.d.).Then the body weights and abdomen circumferences were statisticed.1 h after the last administration,mice were sacrificed,the ascitic volume,cell viability and immune organ index were statisticed.Flow cytometry technique was used to assess H22 ascites tumor cell apoptosis;and the gene and protein levels of MDM2,p53,Bax,Bcl-2,cytochrome C,caspase-9 and caspase-3 were analyzed by PCR and western blot.Results.1.Synthesis of OHC and preliminary study of acute toxicity of THC and OHCAfter using the synthesis and purification strategy mention above and confirming by HPLC-MS,1H-NMR and 13C-NMR,it was proved that the synthesized compound was OHC,of which the purity of OHC was up to 98.06%.In addition,the data of preliminary acute toxicity indicated that the LD50 were both uncountable and the MTD were both more than 5 g/kg for a single dose toxicity study.2.The anti-inflammatory activities of curcumin hydrideThese models were duplicated successfully after comparing with the intact mice,and the results indicated that pretreatment with THC(10?20?40 mg/kg,p.o.),OHC(10?20?40 mg/kg,p.o.),CUR and Indo could significantly attenuated xylene-induced ear edema,decreased acetic acid-induced capillary permeability and reduced carrageenan-induced paw edema,in a dose--dependent manner,with THC(10?20?40 mg/kg,p.o.),OHC(10?20?40 mg/kg,p.o.)exerted dose-dependent inhibition on these three models.While compared with CUR,the THC(40 mg/kg,p.o.)and OHC(40 mg/kg,p.o.)group were more effective in inhibiting these three inflammation models.Preliminary mechanistic studies demonstrated that THC and OHC selectively suppressed the COX-2 protein expression,inhibited the NF-?B activation and increased the TAK1 levels,as well as attenuated the productions of TNF-?,IL-1?,IL-6,PGE2,TAB 1 and p-TAK1.Furthermore,the results also indicated that pretreatment with THC and OHC were more effective than CUR control.3.The anti-tumor activities of curcumin hydrideThe results indicated that oral administration of THC,OHC and CUR significantly prolonged the survival time,inhibited the body weights,abdomen circumferences,ascites volume and cell viability,while they had no apparent effects on immune organ index.Furthermore,THC and OHC were more effective than CUR in inducing H22 cells apoptosis via suppression of MDM2 and Bcl-2 activation and increase the p53,Bax,cytochrome C,caspase-9 and caspase-3 levels.ConclusionIn summary,this paper demonstrated that the synthesis strategy of OHC was safe and efficient with the high purity.Preliminary acute toxicity study showed that both THC and OHC had the lower toxicity with a relative high safety.Oral administration of THC and OHC possessed more considerable anti-inflammatory and anti-tumor effects than CUR.The anti-inflammatory mechanisms of THC and OHC may be related to the inhibiting the protein expression of TAK1/TAB1/NF-?B.And the anti-tumor mechanisms of THC and OHC may be related to induce the H22 cells apoptosis viaregulation of mitochondria apoptosis pathway.