Basic research for applying human lactoferrin to periodontal treatments

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 12672039
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Periodontal dentistry
• Research Institution: Health Sciences University of Hokkaido
• Principal Investigator: NAKASHIMA Keisuke Health Sciences University of Hokkaido, Periodontology and Endodontology, Associate Professor, 歯学部, 助教授 (80227785)
• Project Period (FY): 2000 – 2002
• Keywords: Lactoferrin / Supragingival plaque / Subgingival plaque / Endotoxin

Research Abstract

1. Human lactoferrin (hLf) in gingival crevicular fluid (GCF) and saliva
We measured hLf levels in 15 GCF samples and 7 saliva samples, showing that hLf levels in GCF were significantly higher than in saliva (mean hLf levels; 226 μg/ml in GCF and 20μg/ml in saliva).
2. Distribution of hLf on periodontally-diseased dental root
The area displaying fluorescence was in agreement with the area with calculus after immunofluorescence staining with rabbit anti-hLf antibody. Powdery samples were prepared from extracted roots with a round bur-equipped electric motor-driven system. The samples were collected and partitioned into three groups on the basis of location: Layers I, II and III (from the root surface to the pulp cavity). Significantly higher hLf levels were detected in Layer I from the area with calculus in comparison to Layer I from the area without calculus. hLf and endotoxin levels decreased from Layer I to Layer III.
3. hLf levels in supra- and subgingival dental plaque
We measured hLf levels in supra- and subgingival dental plaque from 19 subjects, showing that hLf levels in supra- and subgingival dental plaque were not significantly different, while the levels were significantly correlated (0.609, p<0.01).
4. Effect of hLf on A. actinomycetemcomitans-infected THP-1 cells
LDH activity, DNA fragmentation and TNF-α production in the infected THP-1 cells were reduced upon addition of hLf. These findings suggested that hLf released by neutrophils is bound to LPS leading to inhibition of the immunobiological effects of LPS to host cells, which results in host protection.