Definition of Rare Sugars Monosaccharides and their derivatives that are rare in nature.
D-fructose D-mannose D-ribose D-galactose D-allose L-arabinose D-Psicose
Xylitol
D-glucose Abundantly existing sugars
D-xylose Rare sugars ( >50 kinds )
International Society of Rare Nature Sugars D L Kagawa’s L-Form Form D-Form
New Strategy L-Gulose D-Glucose
D-Glucitol L-Gulitol L-Sorbose D-Fructose L-Idose D-Mannose DTE
Polyol dehydrogenase L-Tagatose L-Galactose D-Allose D-Psicose
Aldose isomerase L-Talose D-Altrose
Aldose reductase L-Talitol Galactitol D-Altritol L-Altritol D-Talitol Allitol
D-Talose Aldoses(16) L-Altrose L-Psicose L-Allose D-Galactose D-Tagatose
Ketoses(8) L-Mannose L-Fructose D-Sorbose D-Idose D-Gulitol L-Glucitol
L-Mannitol Polyols(10) D-Iditol L-Glucose D-Gulose
Symmetric point 34 Hexoses D L D-Form How to make L-Form Form all mono- L-Gulose D-Glucose saccharides L-Iditol D-Mannitol D-Glucitol L-Gulitol L-Sorbose D-Fructose L-Idose D-Mannose DTE
Polyol dehydrogenase L-Tagatose L-Galactose D-Allose D-PsicosD-Psicosee
Aldose isomerase L-Talose D-Altrose
Aldose reductase L-Talitol Galactitol D-Altritol L-Altritol D-Talitol Allitol
D-Talose Aldose L-Altrose LL--PsiPsicosecose L-Allose D-Galactose D-Tagatose
Ketose L-Mannose L-Fructose D-Sorbose D-Idose D-Gulitol L-Glucitol
L-Mannitol Polyol D-Iditol L-Glucose D-Gulose D L Relationship L-Form Form D-Form between L-Gulose D-Glucose
rare sugars L-Iditol D-Mannitol
and D-Glucitol L-Gulitol L-Sorbose D-Fructose abundantly L-Idose D-Mannose existing sugars L-Tagatose L-Galactose D-Allose D-Psicose
L-Talose D-Altrose
L-Talitol Galactitol D-Altritol L-Altritol D-Talitol Rare sugars Allitol
D-Talose L-Altrose Abundantly existing L-Psicose L-Allose D-Galactose D-Tagatose sugars in nature
L-Mannose L-Fructose D-Sorbose D-Idose D-Gulitol L-Glucitol
L-Mannitol D-Iditol
L-Glucose D-Gulose 34 Hexoses DTE RHI
Enzymatic conversion allows to produce D-psicose from D-fructose by DTE (D-tagatose 3 epimerase), and D-allose from D-psicose by RHI (L-rhamnose isomerase). All hexoses comprise 6 carbons, 12 hydrogens and 6 oxygens with the identical molecular weight of 180. Rare sugar : D-psicose Effect of D-psicose and D-allose on ROS
Scavenging activity of various sugars (ESR) Scavenging activity of various sugars (NBT) 9 40 ) t
i 8 t) 35 n u 7 uni ( ( 30 y y t t
6 i v vi 25 i ti t c
c 5
a 20
a g g 4 n i 15 n i g 3 eng 10 v en 2 ca 5 S av c 1 S 0 0 0 5 10 25 50 0 5 10 25 50 Concentration (mM)
Concentration (mM) D-Psicose D-Allose D-Psicose D-Allose D-Fructose D-Glucose D-Fructose D-Glucose
Scavenging activity of oxygen-radicals was measured by the two different methods (ESR method and NBT reduction method). D-Allose and D- Psicose showed much higher activity than D-Fructose and D-Glucose. Supplementation of D-psicose prevents DEHP-induced atrophy of rat testis 2２ weeks週間投与系 administration mean±SEM 2.5
2 *** ***
) 1.5 (g
s *** e t s e 1 T ns 0.5 n=12 n=14 n=16 n=12 n=6
0 Control DEHP DEHP+1%Psicose DEHP+2%Psicose 2%Psicose
（*p<0.05, **p<0.01, ***p<0.001: vs DEHP group）
D-psicose effectively prevent DEHP-induced atrophy of rat testis. Normal testis DEHP
DEHP + 1% D-psicose DEHP + 2% D-psicose Effect of various monosaccharides on DEHP-induced atrophy of rat testis
110 100 90 80 70 60 50 l e Testis weight (% Control) se se s ol tro HP o se t n co co llo lli DE u ct si A A Co u P Gl Fr
D-psicose is the most potent monosaccharide inhibiting DEHP-induced atrophy of rat testis D-psicose reduced ROS production in the testis induced by DEHP administration ** *** ** 60 ns ue) s s i t
t 50 e w
l/g 40 o m n
A 30 D M ( n o i 20 n=6 n=12 n=7 n=7 n=6 uct d o r 10 p
S O
R 0
l P e e e tro H os os s n ll co DE ic A u Co s / l P P / H /G HP E DE D DEHP
（**p<0.01, ***p<0.001: vs DEHP group） Genes significantly altered by DEHP exposure in rat testis Gene Name Description Expression change
Oxidative Stress Txn Thioredoxin mRNA (NM_053800) ↑↑↑ Gpx1 Glutathione peroxidase 1 (Gpx1) mRNA ↑↑ Gpx2 Glutathione peroxidase 2 (Gpx2) mRNA ↑↑ Glrx1 Glutaredoxin 1 (thioltransferase) (Glrx1) mRNA ↓ Sod1 Superoxide dismutase 1 (Sod1), mRNA ↓↓
Detoxification Gsta2 Glutathione-S-transferase, alpha type2 (Gstα2) ↓↓
Steroidogenesis Cyp17a1 cytochrome P450, family17, subfamily a, polypeptide1 ↓↓↓ Hsd11β2 Hydroxysteroid 11-beta dehydrogenase 2 , mRNA ↓↓
Signal transduction S100a9 S100 calcium binding protein A9 (calgranulin B) ↑↑
Transcription factors Atf3 Activating transcription factor 3(Atf3), mRNA ↑↑ Changes in gene expression in rat testis after DEHP and Rare Sugar (D-psicose) treatment
300 DEHP DEHP+D-Psicose level) 250
200
150
100
50 ontrol (normal expession c % 0 thioredoxin gpx1 gsta2 glrx1 sod1 cyp17a1 Thioredoxin, Glutathione peroxidase 1 : DEHP ↑ D-psicose ↓ Glutathion S-transferase α2 : DEHP ↑ D-psicose ↓ Glutharedoxin, SOD : DEHP ↓ D-psicose → Cyp17a1 : DEHP ↓ D-psicose ↑ Summary of the study
1. Oral administration of DEHP, when converted to MEHP, causes an increase of ROS production in testis. 2. ROS are mainly superoxide radicals and H2O2. 3. ROS production mainly occurs in germ cells not in Sertoli cells. 4. Oxidative stress causes apoptosis of germ cells. 5. Vitamins C & E or D-psicose, one of rare sugars, can be used for the prevention of DEHP-toxicity. 6. Several molecular markers such as oxidative stress related genes are applicable to evaluate the toxicity. Future projects DEHPDEHP 1) Lower doses, longer exposure 2) Optimize the prevention method Vitamins C & E Rare sugars → other rare sugars 3) Mechanism What are the effective and responsible markers? Other possible mechanisms of the toxicity
OtherOther EDEDCCss 1) Oxidative stress could be more or less the common etiological factor for other EDCs. 2) Markers related to oxidative stress can be standardized. 3) Prevention has to be considered. Collaborators
Kagawa University 1) Faculty of Medicine 2) Rare Sugar Research Center Department of Cell Physiology K. Izumori F. Yamaguchi N. Hatano Y. Watanabe M. Muneto Osaka City University Department of Hygiene and Department of Biochemistry and Public Health Molecular Pathology F. Jitsunari M. Inoue S. Suna E. Kasahara Department of Urology F. Sato I. Takenaka M. Ishihara Department of Anatomy Y. Takeuchi M. Itoh Department of Pharmacology M. Kimura