Yuping Li

Kyushu University, Fukuoka-shi, Fukuoka-ken, Japan

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Publications (9)9.74 Total impact

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    Cytotechnology 05/2012; 64(3):299. · 1.32 Impact Factor
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    ABSTRACT: Insulin-producing cells express limited activities of anti-oxidative enzymes. Therefore, reactive oxygen species (ROS) produced in these cells play a crucial role in cytotoxic effects. Furthermore, diabetes mellitus (DM) development is closely linked to higher ROS levels in insulin-producing cells. Hita Tenryosui Water(®) (Hita T. W., Hita, Japan) and Nordenau water (Nord. W., Nordenau, Germany), referred to as natural reduced waters (NRWs), scavenge ROS in cultured cells, and therefore, might be a possibility as an alternative to conventional pharmacological agents against DM. Therefore, this study aimed to investigate the role of NRWs in alloxan (ALX)-induced β-cell apoptosis as well as in ALX-induced diabetic mice. NRWs equally suppressed DNA fragmentation levels. Hita T. W. and Nord. W. ameliorated ALX-induced sub-G(1) phase production from approximately 40% of control levels to 8.5 and 11.8%, respectively. NRWs restored serum insulin levels (p < 0.01) and reduced blood glucose levels (p < 0.01) in ALX-induced mice. Hita T. W. restored tissue superoxide dismutase (SOD) (p < 0.05) activity but not tissue catalase activity. Hita T. W. did not elevate SOD or catalase activity in HIT-T15 cells. Nord. W. restored SOD (p < 0.05) and catalase (p < 0.05) activity in both cultured cells and pancreatic tissue to normal levels. Even though variable efficacies were observed between Hita T. W. and Nord. W., both waters suppressed ALX-induced DM development in CD-1 male mice by administering NRWs for 8 weeks. Our results suggest that Hita T. W. and Nord. W. protect against ALX-induced β-cell apoptosis, and prevent the development of ALX-induced DM in experimental animals by regulating ALX-derived ROS generation and elevating anti-oxidative enzymes. Therefore, the two NRWs tested here are promising candidates for the prevention of DM development.
    Cytotechnology 12/2011; 64(3):281-97. · 1.32 Impact Factor
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    ABSTRACT: It has been reported that a natural reduced water derived from a deep well in Japan (trademark, Hita Tenryousui water®; Nakanoshima, Hita city, Oita, Japan) scavenged intracellular reactive oxygen species (ROS) and protected a hamster pancreas β cell line HIT-T15 from oxidative damage by alloxan, a type 1 diabetes inducer. Here we demonstrated that the water also suppressed the fasted blood glucose levels of the alloxan-induced type 1-diabetes mice. Protein tyrosine phosphatase (PTP) is a redox-regulatable signal enzyme and activation of PTP in Type 2-diabetes patients is noted to be responsible to inactivation of insulin receptor. Hita Tenryousui water® suppressed the PTP activity, leading the activation of insulin receptor. This water stimulated glucose uptake into myotubes and showed a tendency to improve the impaired sugar tolerance of Type 2-diabetes model mice. An open clinical test of Hita Tenryousui water® against 65 patients with hyperglycemia and 50 patients with hyperlipemia for 2 months resulted in significant improvement of impaired blood sugar, plasma triglycerol and total cholesterol levels (P<0.05). These facts suggest that daily intake of natural reduced water will be beneficial to prevent and improve diabetes mellitus. KeywordsDiabetes-Hita tenryosui water-Natural reduced water-Reactive oxygen species-Protein tyrosine phosphatase
    06/2010: pages 307-313;
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    ABSTRACT: Vascular endothelial growth factor (VEGF) is a key mediator of tumor angiogenesis. Tumor cells are exposed to higher oxidative stress compared to normal cells. Numerous reports have demonstrated that the intracellular redox (oxidation/reduction) state is closely associated with the pattern of VEGF expression. Electrolyzed reduced water (ERW) produced near the cathode during the electrolysis of water scavenged intracellular H(2)O(2) and decreased the release of H(2)O(2) from a human lung adenocarcinoma cell line, A549, and down-regulated both VEGF transcription and protein secretion in a time-dependent manner. To investigate the signal transduction pathway involved in regulating VEGF expression, mitogen-activated kinase (MAPK) specific inhibitors, SB203580 (p38 MAPK inhibitor), PD98059 (ERK1/2 inhibitor) and JNKi (c-Jun N-terminal protein kinase inhibitor) were applied. The results showed that only PD98059 blocks VEGF expression, suggesting an important role for ERK1/2 in regulating VEGF expression in A549 cells. As well, ERW inhibited the activation of extracellular signal-regulated kinase (ERK) in a time-dependent manner. Co-culture experiments to analyze in vitro tubule formation assay revealed that A549 cell-derived conditioned medium significantly stimulated the formation of vascular tubules in all analyzed parameters; tubule total area, tubule junction, number of tubules, and total tubule length. ERW counteracted the effect of A549 cell-conditioned medium and decreased total tube length (p<0.01). The present study demonstrated that ERW down-regulated VEGF gene transcription and protein secretion through inactivation of ERK.
    Biological & Pharmaceutical Bulletin 01/2008; 31(1):19-26. · 1.85 Impact Factor
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    ABSTRACT: Catalyser-21(TM) is a mineral water derived from natural leaf soil containing various organic and inorganic substances. Previous reports suggested a possibility that Catalyser-21(TM) has antioxidative potential and could inhibit angiogenesis and cancer cell invasiveness. Angiogenesis is a prerequisite for cancer cells to spread to surrounding tissues. Vascular endothelial growth factor (VEGF) is a major angiogenic factor in the formation of blood capillaries by cancer cells to supply nutrients and oxygen for their sustained growth. Matrix metalloproteinase-2 (MMP-2) is another key enzyme for cancer cell metastasis. To assess the anti-angiogenic activity of Catalyser-21(TM), we first examined cell viability using a human cervical cancer cell line, HeLa, and a fibrosarcoma cell line, HT1080. The results showed that Catalyser-21(TM) decreased the viability of both cell types in a dose-dependent manner. Flow cytometric analysis proved that Catalyser-21(TM) scavenges intracellular H(2)O(2) in both cell types. RT-PCR demonstrated that both VEGF and MMP-2 gene transcription was suppressed after Catalyser-21(TM) treatment. Both Matrigel and tubule formation experiments showed an effect of Catalyser-21(TM). These results suggest that Catalyser-21(TM) has potential as an anti-tumor agent.
    Cytotechnology 01/2008; 55(2-3):61-70. · 1.32 Impact Factor
  • Z. Gadek, Yuping Li, S. Shirahata
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    ABSTRACT: The study examined changes in the relevant tests parameters of 320 diabetes patients (176 female, 144 male) drinking natural reduced water from the "Nordenau Spring" in Nordenau, Germany as well as the correlation of these changes with the fluctuation of the reactive oxygen species concentration in their blood. The average age of the test persons was 71.8 years old and the daily consumption of reduced water was as much as two liters. The average duration of stay in Nordenau lasted 6 days. The diagnostic parameters such as blood sugar, HbA1c, cholesterol, HDL, LDL, triglyceride and potassium were tested twice - at the beginning and at the end of the participants stay in Nordenau. Seventy-six of the test persons repeated the same procedure two or more times in the following months and years. Additionally a random sample of reactive oxygen species concentration in the blood of 50 patients had been taken in order to find out its possible causal connections to the diabetes relevant tests parameters. Blood sugar and HbA1c had been considered as the substantial tests parameters in order to break down the whole group into responder and non-responder. Two hundred and thirty six tested persons that is to say (73.8%) had been assigned to the responder group and 84 (26.2%) to non- responder. Similar ratio of 37 responders (74%) and 13 non-responders (26%) respectively had been obtained in the random sample group with an additional free oxygen radicals test (FORT). The survey pointed out the causal connections between the changes of blood sugar and HbA1c values and the fluctuation of reactive oxygen species concentration in the blood of the tested persons.
    12/2005: pages 377-385;
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    ABSTRACT: Fucoidan is a uniquely-structured sulfated polysaccharide found in the cell walls of several types of brown seaweed that has recently, especially as enzyme-digested fucoidan extract, attracted a lot attention due to its anti-tumor potential. In this study, we evaluated the effects of enzyme-digested fucoidan extracts prepared from seaweed Mozuku of Cladosiphon novae-caledoniae kylin on in vitro invasion and angiogenesis abilities of human tumor cells. First, we evaluated the effect of the fucoidan extracts on oxidative stress of tumor cells, and demonstrated that intracellular H(2)O(2) level and released H(2)O(2) from tumor cells were both greatly repressed upon the treatment with the fucoidan extracts, suggesting that fucoidan extracts ameliorate oxidative stress of tumor cells. Next, we tested for the effects of fucoidan extracts on invasion ability of human fibrosarcoma HT1080 cells, showing that fucoidan extracts significantly inhibit their invasion, possibly via suppressing matrix metalloproteinases (MMPs) MMP-2/9 activities. Further, we investigated the effects of the fucoidan extracts on angiogenesis of human uterine carcinoma HeLa cells, and found that fucoidan extracts suppressed expression and secretion of an angiogenesis factor vascular endothelial growth factor (VEGF), resulting in suppressed vascular tubules formation of tumor cells. The results taken together clarified that enzyme-digested fucoidan extracts from Cladosiphon novae-caledoniae kylin possess inhibitory effects on invasion and angiogenesis of tumor cells. These effects might, at least partially, be elicited by the antioxidative potential of enzyme digested fucoidan extracts.
    Cytotechnology 02/2005; 47(1-3):117-26. · 1.32 Impact Factor
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    ABSTRACT: In the two-stage cell transformation theory, cancer cells first receive initiation, which is mainly caused by DNA damage, and then promotion, which enhances transformation. Murine Balb/c 3T3 cells are widely used for transformation experiments because they lose contact inhibition ability when transformed. Electrolyzed reduced water (ERW), which is produced near a cathode during electrolysis of water, is an alkaline drinking water that is beneficial to health. ERW contains a high concentration of dissolved hydrogen and scavenge reactive oxygen species (ROS), along with a small amount of platinum (Pt) nanoparticles (Pt nps) derived from Pt-coated titanium electrodes. Pt nps stably disperse in aqueous solution for a long time, and convert hydrogen molecules to active hydrogen (atomic hydrogen) that can scavenge ROS. Therefore, ERW supplemented with synthesized Pt nps is a model strong reduced water. This is the first report that ERW supplemented with synthesized Pt nps strongly prevents transformation of Balb/c 3T3 cells. ERW was prepared by electrolysis of 0.002 M NaOH solution using a batch-type electrolysis device. Balb/c 3T3 cells were treated with 3-methyl cholanthrene (MCA) as an initiation substance, followed by treatment with phorbol-12-myristate-13-acetate (PMA) as a promotion substance. MCA/PMA-induced formation of a transformation focus was strongly suppressed by ERW supplemented with Pt nps but not by ERW or Pt nps individually. ERW supplemented with Pt nps suppressed transformation at the promoter stage, not at initiation, suggesting that ERW supplemented with Pt nps suppressed the PMA-induced augmentation of intracellular ROS. ERW supplemented with Pt nps is a potential new antioxidant against carcinogenesis.
    Cytotechnology 02/2005; 47(1-3):97-105. · 1.32 Impact Factor
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    ABSTRACT: Reactive oxygen species (ROS) cause irreversible damage to biological macromolecules, resulting in many diseases. Reduced water (RW) such as hydrogen-rich electrolyzed reduced water and natural reduced waters like Hita Tenryosui water in Japan and Nordenau water in Germany that are known to improve various diseases, could protect a hamster pancreatic beta cell line, HIT-T15 from alloxan-induced cell damage. Alloxan, a diabetogenic compound, is used to induce type 1 diabetes mellitus in animals. Its diabetogenic effect is exerted via the production of ROS. Alloxan-treated HIT-T15 cells exhibited lowered viability, increased intracellular ROS levels, elevated cytosolic free Ca(2+) concentration, DNA fragmentation, decreased intracellular ATP levels and lowering of glucose-stimulated release of insulin. RW completely prevented the generation of alloxan-induced ROS, increase of cytosolic Ca(2+) concentration, decrease of intracellular ATP level, and lowering of glucose-stimulated insulin release, and strongly blocked DNA fragmentation, partially suppressing the lowering of viability of alloxan-treated cells. Intracellular ATP levels and glucose-stimulated insulin secretion were increased by RW to 2-3.5 times and 2-4 times, respectively, suggesting that RW enhances the glucose-sensitivity and glucose response of beta-cells. The protective activity of RW was stable at 4 degrees C for over a month, but was lost by autoclaving. These results suggest that RW protects pancreatic beta-cells from alloxan-induced cell damage by preventing alloxan-derived ROS generation. RW may be useful in preventing alloxan-induced type 1-diabetes mellitus.
    Cytotechnology 12/2002; 40(1-3):139-49. · 1.32 Impact Factor

Publication Stats

94 Citations
9.74 Total Impact Points

Institutions

  • 2002–2012
    • Kyushu University
      • • Faculty of Agriculture
      • • Graduate School of Systems Life Sciences
      Fukuoka-shi, Fukuoka-ken, Japan
  • 2008
    • Jiangxi University of Science and Technology
      Kan-chou-chieh, Jiangxi Sheng, China