The Correlation between free radical-scavenging effects and anti-inflammatory effects of dental drugs

1996 Fiscal Year Final Research Report Summary

• Project/Area Number: 07672060
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 病態科学系歯学(含放射線系歯学)
• Research Institution: TOKYO DENTAL COLLEGE
• Principal Investigator: YAZAKI Kinya TOKYO DENTAL COLLEGE,DEP'T OF DENTISTRY,LECTURER., 歯学部, 講師 (70157973)
• Co-Investigator(Kenkyū-buntansha): KAWAGUCHI Mitsuru TOKYO DENTAL COLLEGE,DEP'T OF DENTISTRY,PROFESSOR, 歯学部, 教授 (20096473)
• Project Period (FY): 1995 – 1996
• Keywords: phenolic compounds / dental drugs / hydroxyl radical / Fenton reaction / active oxygen species / free radical scavenging / ascorbic acid / aldehydes

Research Abstract

Recently, several authors morphologically demonstrated the cell-activating effects of phenolic compounds and we previously reported that at doses lower than 10^<-8> M,guaiacol enhanced on the proliferation or ALP-activity or DNA-levels of the osteogenic cells. Phenolic compounds appeared to have an ability of the hydroxyl radical (OH・) -scavenging.
So, we performed to measure the (OH・) -scavenging ability of the 3 kinds of dental drugs ; guaiacol, phenol, or formaldehyde using deoxyribose-degradation method. Before these experiments, we made sure that ascorbate, which seemed to be a typical free radical-scavenger, did not playd as the free radical-scavenger but playd as the reducer of ferric-ion (Fe (III) ) to ferrous-ion (Fe (II) ) and as an enhancer of Fenton reaction. Then these experiments were performed. At doses lower than 10^<-5>M,dimethyl sulfoxide (DMSO), used as the solvents of dental drugs, showed no efficacy to scavenge OH・-radical. Guaiacol and phenol showed the scavenging effects in dose-dependent manner at doses more than 10^<-10>M or 10^<-6>M.And the value of ED_<50> was 10^<-6>M or 5*10^<-4>M,respectively. On the contrary, at doses more than 10^<-4>M of formaldehyde had some efficacy of OH・-scavenging and its ED_<50>-value was 0.05M.
Compared with 3 kinds of dental drugs ; such as guaiacol and phenol as phenolic compounds and formaldehyde ; guaiacol had the stronger scavenging effect than other 2 kinds of dental drugs : phenol had 5*10^2 times weaker than guaiacol and formaldehyde showed 5*10^4 times weaker than guaiacol and 10^2times weaker than phenol, respectively.
Scavenging effects of 3 kinds of dental drugs, in the order of intensity, was guaiacol>phenol>>formaldehyde, respectively. These results suggest that guaiacol and phenol seem to be able to scavenge active-oxygen species, especially, hydroxyl radical and perform anti-inflammatory effect. And phenolic compounds promote the activity or ability of the cells.