An Investigation of Inhibitory Agent against Acid Production of Oral Bacteria

Research Project

Project/Area Number	62570817
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Morphological basic dentistry
Research Institution	Nihon University School of Dentistry at Matsudo
Principal Investigator	IKEDA Tadashi Nihon university School of Dentistry at Matsudo, 松戸歯学部, 教授 (10050006)
Co-Investigator(Kenkyū-buntansha)	KURITA Tomoko Nihon university School of Dentistry at Matsudo, 松戸歯学部, 助手 (20130594) TAKADA Kazuko Nihon university School of Dentistry at Matsudo, 松戸歯学部, 助手 (20120496) OCHIAI Kuniyasu Nihon university School of Dentistry at Matsudo, 松戸歯学部, 講師 (50095444) HIRASAWA Masatomo Nihon university School of Dentistry at Matsudo, 松戸歯学部, 講師 (60095453) FUKUSHIMA Kazuo Nihon university School of Dentistry at Matsudo, 松戸歯学部, 助教授 (20009327)
Project Period (FY)	1987 – 1988
Project Status	Completed (Fiscal Year 1988)
Budget Amount *help	¥1,900,000 (Direct Cost: ¥1,900,000) Fiscal Year 1988: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 1987: ¥1,200,000 (Direct Cost: ¥1,200,000)
Keywords	Dental caries prevention / Inhibition of lactic acid / LDH阻害 / 乳酸発酵阻害物質 / 乳酸産生阻害 / S.mutans
Research Abstract	Inhibitory action of MLI(tentative name) against acid production of oral microoganisms was studied with bacteriocin C3603, iodoacetic acid and azalomycin as controls. MLI was partially purified from culture supernatant of Actinomyces sp. strain. MLI markedly suppressed lactic acid production from glucose by Streptococcus mutans group(serotype a-g) and Lactobacillus casei, and this effect was not due to its antibacterial action. On the other hand, C3603, iodoacetic acid and azalomycin also suppressed lactic acid production, but antibacterial actions were observed. MIL did not suppress productions of formic acid, acetic acid and the other metabolic substances tested by S.mutans group. MLI remarkably inhibited lactate dehydrogenase(LDH) activity depending upon MLI concentration, and nearly 95% inhibition of LDH activity was observed when 2.5 g/ml of MLI was added into the reaction mixture. However, C3603 and iodoacetic acid did not. MLI was analyzed by thin layer chromatography using preparative kiesel gel, and was separated into 4 spots of A,B,C,D showing different RF values, respectively. Only extract from D spot showed inhibition of lactic acid production without antibacerial activity. Then, fraction D was applied to high performans liquid chromatographic column, and 3 peaks were observed. Inhibitory actions of these 3 peaks are under the progress.