ABSTRACT
As new BNCT reagents, we designed and synthesized dopamine analogues containing phenylboronic acid group, N-3,4-dihydroxyphenethyl-4-dihydroxyborylbenzamide (dopamine-PCBA) and N-[2-(3,4-dihydroxyphenetyl)ethyl]-3-(4-dihydroxyborylphenyl)promionamide (dopamine-CEBA). The efficacies of these compounds have not been investigated for biological samples. Therefore we have carried out experiments with cultured tumor cells and tumor-bearing mice, and evaluated possibility of these compounds as boron carriers. Dopamine-PCBA and dopamine-CEBA were synthesized by coupling between p-carboxyphenylboronic acid (PCBA) or 4-(2-carboxyethyl)benzeneboronic acid (CEBA) and 3,4-(dibenzyloxy)phenethylamine hydrochloride (DBPA-HCl) followed by catalytic hydrogenation using Pd catalyst. The effect of compounds on cell vitality was determined by MTT assay in various cells. In vivo biodistribution of compounds was determined in Balb/c and DDY mice in bearing implanted CT26 cells. These results have demonstrated that dopamine-CEBA was less toxic.
Subject(s)
Boron/chemistry , Boronic Acids/chemistry , Dopamine/analogs & derivatives , Animals , Boronic Acids/pharmacokinetics , Cell Line, Tumor , Dopamine/chemistry , HeLa Cells , Humans , Mice , Mice, Inbred BALB C , Tissue DistributionABSTRACT
High accumulation and selective delivery of boron into tumor tissues are the most important requirements to achieve efficient neutron capture therapy of cancers. We focused on liposomal boron delivery system in order to achieve a large amount of boron delivery to tumor. We synthesized the double-tailed boron cluster lipid 4c according to our reported procedure with modification. Size distribution of liposomes prepared from the boron cluster lipid 4c, DMPC, PEG-DSPE, and cholesterol was determined as 100 nm in diameter by an electrophoretic light scattering spectrophotometer. A high level of (10)B concentration (22 ppm) was observed in tumor tissue at 24 h after the administration of boron liposomes.
Subject(s)
Boron Compounds/administration & dosage , Boron Neutron Capture Therapy/methods , Nanocapsules/therapeutic use , Radiation-Sensitizing Agents/administration & dosage , Animals , Boron Compounds/chemical synthesis , Boron Compounds/chemistry , Boron Compounds/therapeutic use , Isotopes/administration & dosage , Isotopes/therapeutic use , Liposomes/chemistry , Male , Mice , Mice, Inbred BALB C , Nanocapsules/administration & dosage , Nanocapsules/chemistry , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/radiotherapy , Particle Size , Radiation-Sensitizing Agents/chemical synthesis , Radiation-Sensitizing Agents/chemistry , Radiation-Sensitizing Agents/therapeutic use , Tissue DistributionABSTRACT
The effects of 14 synthetic 2'-hydroxychalcone derivatives on prostaglandin E2 (PGE2) production in rat peritoneal macrophages stimulated by the protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA), were examined to clarify the structure-activity relationship. 2',4-Dihydroxy-4'-methoxychalcone (compound 3), 2',4-dihydroxy-6'-methoxychalcone (compound 8) and 2'-hydroxy-4'-methoxychalcone (compound 9) suppressed PGE2 production more potently than the other compounds. The IC50 (50% Inhibitory concentration) value for compounds 3, 8 and 9 was calculated to be 3 microM. The activity of cyclooxygenase (COX)-1 was inhibited slightly by compound 9, but that of COX-2 was not inhibited. At concentrations that inhibited the production of PGE2, compound 9 had no effect on the release of radioactivity from [3H]arachidonic acid-labelled macrophages stimulated by TPA. Western-blot analysis revealed that the induction of COX-2 protein by TPA was inhibited by compound 9 in parallel with the inhibition of PGE2 production. Compounds 3 and 8 had similar effects. These findings suggest that 4'-methoxyl and 6'-methoxyl groups are required for the expression of more potent inhibitory activity against PGE2 production, and that the inhibition of PGE2 production by these 2'-hydroxychalcone derivatives is due to the inhibition of TPA-induced COX-2 protein expression.
Subject(s)
Chalcone/analogs & derivatives , Chalcone/pharmacology , Dinoprostone/biosynthesis , Animals , Blotting, Western , Carcinogens/pharmacology , Chalcones , Cyclooxygenase 2 , Isoenzymes/biosynthesis , Macrophages, Peritoneal , Male , Prostaglandin-Endoperoxide Synthases/biosynthesis , Rats , Rats, Sprague-Dawley , Structure-Activity Relationship , Tetradecanoylphorbol Acetate/pharmacologyABSTRACT
Platycodin D, isolated from the root of Platycodon grandiflorum A. DC. (Campanulaceae) suppressed prostaglandin E2 production at 10 and 30 microM in rat peritoneal macrophages stimulated by the protein kinase C activator 12-O-tetradecanoylphorbol 13-acetate (TPA). Platycodin D3 and oleanolic acid showed no effect at these concentrations. Western blot analysis revealed that the induction of COX-2 protein by TPA was inhibited by platycodin D in parallel with the inhibition of prostaglandin E2 production. Platycodin D showed no direct effect on COX-1 and COX-2 activities. TPA-induced release of [3H]arachidonic acid from pre-labeled macrophages was also not inhibited by platycodin D.
