specific egg yolk antibody (ovalgen dc) as a novel ... dc.pdf · •journal dental research 68,...
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Nguyen Van Sa, Ph.D
Immunology Research Institute in Gifu, Japan
Specific Egg Yolk Antibody (Ovalgen DC) as a Novel Supportive Immunotherapy for
Dental Caries
Scientific conference at Vietnam National Hospital of Odonto-
Stomatology 2013
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S. mutans and dental caries
In-vitro tests
Animal tests
Human volunteer trials
Content
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WHO, 2003
Worldwide Dental Caries Level
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•Journal of pediatric Dentistry 44(1): 8-17, 2006
•Journal Dental Research 68, 1989
Streptococcus mutans (S. mutans) as
the main causative agent of dental caries
•S. mutans had a strong relation with dental
caries index (p < 0.01).
•The adherence of S. mutans to teeth surface
leads to a suitable environment for other
bacteria to grow.
Reference
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Cell-associated glucosyltransferase (CA-Gtase)
is the main pathogenic factor of S. mutans.
CA-GTase enzyme plays a vital role in
the pathogenicity of S. mutans
There are 2 kinds of GTase:
1.CF-GTase: produces soluble glucan
2.CA-GTase: produces insoluble glucan
Insoluble glucan strongly binds to teeth surface
and helps S. mutans to form colonies (plaques).
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S. mutans binds to tooth surface
Formation of Glucan by Gtase
Acids produced by S. mutans cause dental decay
Mechanism of Dental Caries
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Contains specific IgY against
Gtase enzyme of S. mutans
Ovalgen DC
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Mechanism of Ovalgen DC
Sucrose Glucan
GTase
Sucrose
Mode of effect
1. Inhibits S. mutans from attachment to tooth surface
2. Inhibits glucan formation by the bacterium
Ovalgen DC
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Comparison of various IgY on glucan
synthesis inhibition
IgY (mg/ml) 0.5 1.0 0
100
200
Glu
can s
ynth
esis
(%)
●:CA- GTase IgY
▲:CF- GTase IgY
□:Anti-fimbriae IgY
■:Anti-whole cell IgY
○:Control IgY
Infect. Immun. 1991, vol. 59
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PBS Anti-Gtase IgY
5mg/ml
Control IgY
5mg/ml
PBS Anti-Gtase IgY
5mg/ml
Control IgY
5mg/ml
Vortexing
Ovalgen DC blocks S. mutans from binding to teeth surface
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10μm 10μm
Electronmicroscopic image of S. mutans
grown in a medium containing sucrose
Without IgY With Ovalgen DC
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Animal tests
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Comparison of various antigens Test 1
(Infect. Immun. 1991, vol. 59)
2 days 52 days
Treatment with various IgY samples
Test group : IgY against various antigens
(0.8% in feed diet)
Control group : IgY derived from non-immune egg
Diet 2000, containing 56% sucrose
Infection with S. mutans
S. mutans RT8148 (1×10 8 cfu/rat )
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01020304050607080
Con
trol
anti-
Who
le C
ell
anti-
CA-G
Tase
anti-
CF-
GTas
e
Sha
m-im
mun
ed
Cari
es S
core
P<0.01 P<0.001
P<0.05 P<0.001
Results
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2 days 17 days
Groups
Test group : Ovalgen® DC 10mg/ml
Fluoride 10ppm
Control group : IgY derived from non-immune egg
Diet 2000, containing 56% sucrose
Test 2 Effect of Ovalgen® DC on Caries Development
in Rats
Infection with S. mutans
S. mutans RT8148 (1×10 8 cfu/rat )
(Joined research project with Karolinska Institute, Sweden)
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Treatment Total Smooth
Caries score
Total Sulcal
Caries score
Ovalgen® DC 43.0 ± 13.4
a) 40.9 ± 6.8
b)
Fluoride 54.6 ± 5.6 46.6 ± 3.0
Control 59.6 ± 14.3 48.5 ± 2.2
Results
a) p<0.001 and p<0.01 v.s. Fluoride and Control groups, respectively
b) p<0.01 v.s. Fluoride and Control groups
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Infected rats
Control Ovalgen DC
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Clinical trial on volunteers
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Clinical test 1: mouth wash test
Study at IRIG in Japan
4 volunteers taking part in a 2-phase test: in phase 1, a
placebo mouth wash was used. After 2 weeks, a mouth
wash containing Ovalgen DC was used. Plaque scores
were compared between 2 phases.
The volunteers did not brush teeth during the test.
2 weeks of break Placebo IgY 3d
Remove
plaques
Plaque
scoring
Ovalgen DC 3d
Remove
plaques
Plaque
scoring
No brushing No brushing
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Results
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2.2
2.4
2.6
2.8
3
3.2
3.4
3.6
Placebo OVALGEN DC
Pla
qu
e S
core
s
Test 1
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Subjects: 99 student volunteers
- 2 test groups taking troches with OVALGEN DC
- 1 placebo group taking troches containing control
IgY
- 1 negative control untreated group
Test period: 5 days
– Volunteers used troches 5 times a day
– The test was carried out in a double blind manner.
Evaluation: S.mutans count score (by Mu-count kit)
Total anaerobic bacteria (by BHI medium)
Clinical test (Conducted at Hokkaido Medical College)
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Scoring by Mu-count kit
Score 0 Score 1 Score 2 Score 3 Score 4
Scoring method
CFU/kit Score
0 0
1-33 1
34-66 2
67-99 3
>100 4
Test 2
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0
0.5
1
1.5
2
2.5
3
Test 1 Test 2 Placebo Control
Before
After
Change in number of adherent S.mutans
Test 2
* *
*P < 0.001 by Wilcoxon
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Clinical trial results: Saliva S. mutans count
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Total anaerobic bacteria
Test 1 Test 2 Placebo Control
4.00
5.00
6.00
7.00
8.00
9.00
Lo
g1
0
CF
U/m
l
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Clinical Trial Result : Plaques
After
Before
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OVALGEN DC
Reduced number of S. mutans in saliva of human
volunteers
Did not affect normal flora in oral cavity
Is highly safe based on questionnaire result
Summary of human tests
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