Koji Shibuya

Screening test for deodorizing substances from marine algae and identification of phlorotannins as the effective ingredients in Eisenia bicyclis

Aqueous extracts from 33 species of marine algae were assessed for their methyl mercaptan-trapping activity by gas chromatography to search for novel natural oral deodorants. Brown algae belonging to the Laminariales such as Eisenia bicyclis, Ecklonia cava and Ecklonia kurome were found to show remarkable deodorizing action against methyl mercaptan. The effective components in Eisenia bicyclis were identified as a phlorotannin, a group of molecules which are characteristic components of Laminariales. In addition phlorotannins extracted from E. bicyclis were more effective at reducing methyl mercaptan than conventional natural deodorants such as chlorophyll and sodium copper chlorophyllin.

Enhancement of oral moisture using tablets containing extract of Capparis masaikai Levl.

AIM OF THE STUDY This study was performed to examine the effects of tablets containing an extract of Capparis masaikai Levl. (M-tablets) on enhancing oral moisture. SUBJECTS AND METHODS The moistening effect of M-tablets was examined in 21 healthy subjects aged 25.1+/-2.4 (mean+/-S.D.) years in comparison with control tablets. After sucking tablets, the oral moisture was measured using a saliva wetness tester and a moisture checker. To evaluate the effects of the M-tablets on oral conditions, additional 50 subjects aged 30.6+/-7.5 years were examined. The subjects recorded changes in refreshment, oral moisture, ease in speaking, and taste of water using a visual analog scale (VAS). RESULTS The L-SALIVO value of the M-tablet increased significantly from 1.83+/-0.17 (mean+/-S.E.M.) at baseline to 3.02+/-0.21 at 15 min (P<0.01). The Mucus((R)) value of the M-tablet also increased from 37.50+/-0.22 at baseline to 38.30+/-0.26 at 15 min (P<0.01). The VAS value for oral moisture increased significantly from 47.4+/-2.0 to 69.6+/-2.2 after taking the M-tablet (P<0.01). The VAS value for taste of water also increased from 50.0+/-1.1 to 66.7+/-3.2 (P<0.01). CONCLUSION These results suggest that M-tablets are useful for enhancing oral moisture, which leads to improvement of oral conditions.

Deodorizing Substance in Black Cumin (Nigella sativa L.) Seed Oil

A deodorizing substance in black cumin (Nigella sativa L.), a spice for curry and vegetable foods in Southwest Asia, was examined. The essential oil prepared from the seeds of this plant exhibited strong deodorizing activity against methyl mercaptan, which is a main factor in oral malodor. After purification with silica gel column chromatography, the active substance in black cumin seed oil was identified as thymoquinone. This monoterpenic quinone functions as the main deodorizing substance in this oil against methyl mercaptan. Metabolite analysis suggested that the deodorizing activity may be generated by the addition of a reactive quinone molecule to methyl mercaptan. In the present study, the menthane-type quinone and phenol derivatives exhibited deodorizing activities via this mechanism.

A Study on Discoloration of Ag-Pd-Au Alloy Part 2. Relationship between the Composition of Ag-Pd-Au Alloys and Prevention of Discoloration

目的: 現在市販されている金銀パラジウム合金の組成と耐変色性との関係を明らかにすることを目的に, in vitroおよびin vivo両面から検討を加えた.方法: Fusobacterium nucleatumまたはStreptococcus mutansを加えたTHB (Todd Hewitt Broth) 培地に4種類の金銀パラジウム合金試料を入れ, 37℃ で嫌気培養を4週間行った.培養後, 輝度および色調の測定を行った. また使用義歯に6種類の金属試料 (金銀パラジウム合金, Ti, 14K金合金) を2カ月間埋入し, 撤去後に色差を算出した.結果: 金銀パラジウム合金は, メチルメルカプタンならびに硫化水素産生量の多いF.nucleatum培養環境下で, 大きな変色を示す傾向にあった. Cuを20.0mass%含む12%金銀パラジウム合金の変色は大きく, Tiや14K金合金の色差は小さかった. 組成の異なる4種類の金銀パラジウム合金 (Cu: 10.0-20.0mass%, Au: 12.0, 20.0mass%) は, in vitroおよびin vivoともに色差10以上の変色を認めた.結論: 市販の金銀パラジウム合金の耐変色性は合金組成の影響を受けるが, 口腔内の腐食性が高い患者では, いずれの組成の合金においても耐変色性が十分でなく, 著しい変色を示すことが確認された.