Protective Effects of Oral Fructose-1, 6-diphosphate on Liver Injury in Animal Models

Aim To investigate the effects of FDP on different liver injury models to explore the possibility of FDP used as an oral liver protective agent. Methods Chronic liver injury model in rats was induced by carbon tetrachloride （ CCl4 ） ; Acute liver injury model in mice was induced by aminogalactose （GAIN） or lipopolysaccharide （LPS）. Results In CCl4-induced chronic liver injury model, FDP （1 , 4 g·kg^-1·d^-1, q.d., for 10 weeks） significantly lowered ALT, AST,γ-glutamyl transpeptidase （γ-GT）, alkaline phosphatase （ALP）, and total bilirubin （T-BIL） in serum compared with vehicle; simultaneously it evidently elevated abnormal total protein （TP）, albumin （ALB） and total cholesterol （ T-CHO ） levels in serum; it also dose-dependently reduced hydroxyproline contents in hepatic tissue. 4 g·kg^-1·d^-1 of FDP apparently decreased incidence of hepatic cirrhosis, and alleviated pathological changes of liver tissue. In GaiN-induced model, 1.0 - 4. 0 g·kg^-1·d^-1 of FDP （ bid, for 3 d ） significantly lowered alanine aminotransferase （ ALT ） and aspartate aminotransferase （ AST ） levels in serum ; it also decreased liver coefficient. 4. 0 g·kg^-1·d^-1 of FDP significantly alleviated pathological changes of cell ultra-structures. In LPS-induced model, only high dose of FDP （4. 0 g·kg^-1·d^-1, bid, for 12 d） significantly decreased ALT level in serum. Conclusion This study first demonstrated the protective effect of oral FDP on chronic liver injury caused by CCl4, and confirmed its effect on acute liver injury at the same time, suggesting that Long-term oral FDP is efficacious against liver injury induced by different factors and can be used as an oral liver protective agent in clinic.

Effects of fructose-1,6-diphosphate on concentration of calcium and activities of sarcoplosnic Ca^(2+)-ATPase in cardiomyocytes of Adriamycin-treated rats

Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin 1 (cTnl) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2+]) and activity of sarcoplosnic Ca2+-ATPase (SRCa2+-ATPase) in Adriamycin (ADR)-treated rats. Methods: Rats were intraperitoneally injected with ADR (2.5 mg/kg every other day for 6 times) and then with different dosages of FDP (every other day for twenty-one times). Bi-antibodies sandwich Enzyme linked immune absorption assay (ELISA) was performed to detect serum level of cTnl. CK-MB was detected by monoclonal antibody, Myo[Ca2+] was detected by fluorescent spectrophotometry and the activity of SRCa2+-ATPase was detected by inorganic phosphate method. Results: FDP (300, 600, 1200 mg/kg) significantly reduced the serum levels of cTnl and CK-MB, while at the same time decreased calcium concentration and increased SRCa2+-ATPase activity in cardiomyocytes of ADR-treated rats (P<0.01). Conclusions: FDP might alleviate the cardiotoxic effects induced by ADR through decreasing calcium level as well as increasing SRCa2+-ATPase activity in cardiomyocytes.

Clinical study of applying fructose-1,6-diphosphate and captopril to enhance the protective effects of cardioplegia solution on ischemic myocardium

In the present experiment,fructose-1,6-diphosphate（FDP）and captopril（Cap）wereadded to the cold potassium cardioplegia solution and the levels of malondialdehyde（MDA）,cre-atine phosphokinase MB（CPK-MB）,thromboxane B（TXB2）and 6-keto-PGF1α in plasma weremeasured during open-heart surgery.Quantitative study of myocardial ultrastructure and obser-vation of cardiac resuscitation were also undertaken.The findings suggested that FDP,especiallywhen combined with Cap could significantly strengthen the protective effects of cold potassiumcardioplegia solution on ischemic myocardium.

PRODUCTION OF FRUCTOSE-l,6-DIPHOSPHATE(FDP) BY PERMEABILIZED SACCHAROMYCES CEREVISIAE AND A KINETIC MODEL FOR FDP ACCUMULATION

Permeable yeast cells were used in the batch production of fructose-1,6-diphosphate(FDP).The optimum reaction conditions were reported to be:reaction temperature 30℃,tolueneconcentration 8%(V/V),and initial ratio of glucose to inorganic phosphorus(Pi)10:1.Addition ofAMP was found to be very beneficial to the FDP production.A multienzyme system model for FDPaccumulation was developed,in which FDP was regarded as a substrate of phosphor-fructokinase(PFK),to simulate the activation effect of FDP on PFK.The model simulations were in good agree-ment with the experimental data.

A New Method of Crystallization of Octahydro Trisodium Salt of Fructose- 1,6-diphosphate

In order to overcome the elementary heterogeneous nucleation whileoctahydro trisodium salt of fructose- 1, 6-diphosphate (FDPNa_3·8H_2O) is crystallized with ethanol precipitation at low temperature,a new crystallization method with alcohol precipitation combined withsalt precipitation has been presented. The ethanol-sodium ac- etatesystem for crystallization of salt of fructose-1, 6-diphosphate isbased on the mechanism of crystallization of FDPNA_3·8H_2O in theethanol-low temperature system. It is found that crystal size may becontrolled by regulating Temperature of pH value of solution in thecrystallization process, and the crystal yield increases to 95/100from 78/100 Which obtained in the ethanol-low temperature system.

Fructose-1,6-diphosphate-added total parenteral nutrition in septic animals and stressed patients

Objective To investigate the roles of fructose-1,6-diphosphate(FDP)-added total parenteral nutrition (TPN)in septic animals and stressed patients.Methods Thirteen adult dogs were randomly assigned to one of two study groups 6 hours after the induction of severe intra-abdominal infection.Group TPN(n =6)received 70 kcal· kg-1· d-1 of nonprotein calorie(NPC)and 0.56 g· kg-1· d-1 of nitrogen.1 g/kg of FDP was also infused to the animals in group TPN + FDP(n = 7)everyday.In the clinical study,the control group received routine TPN,while the study group(n = 16)was treated with TPN plus FDP(5 g,two times a day)for 7 days.Results In dogs with TPN support,plasma ATP levels were not changed significantly,while the value in the TPN + FDP group increased significantly from 0.18 μmol/L to 0.46 μmol/L at 24 h and 0.51 μmol/L at 48 h(P ＜ 0.01).Muscular ATP increased markedly in the TPN + FDP group.Muscular creatine phosphate alues were not significantly changed in the TPN group,but the values increased in the TPN + FDP group from 4.06 μmol/g·wt at the beginning to 4.93 μmol/g· wt at 24 h and 5.60 μmol/g·wt at 48 h(P ＜ 0.05),with a cytochrome oxidase increase in immunohistochemistry stain.In the clinical study,plasma ATP levels increased and urinary 3-methylhistidine production significantly decreased with an improved value for positive accumulative nitrogen balance in the FDP-infused group.Conclusion Our results suggest that total parenteral nutrition support with the supplement of fructose-1,6-diphosphate has a positive role in body energy production and protein metabolism in septic animals and stressed patients.

Cloning of a NaCl-induced fructose-1,6-diphosphate aldolase cDNA from Dunaliella salina and its expression in tobacco

Using Rapid Amplification of cDNA ends (RACE) technique, the full-length cDNA en-coding a NaCl-induced fructose-1, 6- diphosphate aldolase (DsALDP) was obtained. It was shown that the DsALDP had a relatively high homology (66%—73%) to chloroplast fructose-1, 6-diphos- phate aldolase (AldP) in many plants according to their amino acid sequences. The phylogenetic analysis further confirmed that AldP in alga is the nearest to DsALDP. As to its expression pattern, DsALDP was de novo synthesized by NaCl induction. Its expression level was significantly changed with inducing time. After the selected DsALDP cDNA subcloned into a binary vector pBI121, the new construct was introduced into tobacco by Agrobacterium tumefaciens. The results of Southern blot and RT-PCR analysis of four transgenic T1 plants indicated that DsALDP was integrated into genome of these transgenic plants and effectively expressed. Aldolase activities have been detected in T1-1, T1-2 and T1-3 plants by bioassay under 100—200 mmol/L NaCl. It was also observed that proline contents in them were differentially increased.