Protective mechanism of reduced water against alloxan-induced pancreatic β-cell damage: Scavenging effect against reactive oxygen species

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 β 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 Ca²⁺ 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 Ca²⁺ 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 β-cells. The protective activity of RW was stable at 4 °C for over a month, but was lost by autoclaving. These results suggest that RW protects pancreatic β-cells from alloxan-induced cell damage by preventing alloxan-derived ROS generation. RW may be useful in preventing alloxan-induced type 1-diabetes mellitus. This revised version was published online in August 2006 with corrections to the Cover Date.     

Therapeutic activity of plant-derived alkaloid conophylline on metabolic syndrome and neurodegenerative disease models

Increasing metabolic syndromes including type-2 diabetes mellitus, obesity, and steatohepatitis are serious problems in most countries in the world. Neurodegenerative diseases such as Alzheimer, Parkinson’s, and Huntington’s diseases are increasing in many countries. However, therapy for these diseases is not sufficient yet. Thus, effective chemotherapy for these diseases is being expected. Conophylline is an alkaloid isolated from the leaves of Ervatamia microphylla and related plants. It was found to induce beta-cell differentiation in the precursor pancreatic cells. Oral administration of this compound ameliorated type-2 diabetes mellitus model in mice and rats. Later, fibrosis of the pancreatic islets was found to be greatly reduced by conophylline in the pancreatic islets. It also inhibited chemically induced liver cirrhosis. Further study indicated that conophylline inhibited non-alcoholic steatohepatitis in the model mice. On the one hand, loss of autophagy often causes protein aggregation to give neural cell death. Conophylline was found to activate autophagy in cultured neural cells. Activation of autophagy ameliorated cellular models of Parkinson’s and Huntington’s diseases. Thus, conophylline is likely to be useful for the development of chemotherapy for metabolic and neurodegenerative diseases.     

Synthesis of novel benzbromarone derivatives designed to avoid metabolic activation

We synthesized six novel BBR derivatives that were designed to avoid metabolic activation via ipso-substitution and evaluated for their degree of toxicity and hURAT1 inhibition. It was found that all of the derivatives demonstrate lower cytotoxicity in mouse hepatocytes and lower levels of metabolic activation than BBR, while maintaining their inhibitory activity toward the uric acid transporter. We propose that these derivatives could serve as effective uricosuric agents that have much better safety profiles than BBR.     

Age-related changes in blood pressure in the senescence-accelerated mouse (SAM): aged SAMP1 mice manifest hypertensive vascular disease

Age-related changes in systolic blood pressure were assessed, using the senescence-accelerated mouse (SAM) model for aging research with strains SAMR1, SAMP1, and SAMP8. Each of the strains manifested a characteristic change in blood pressure with age. The SAMR1 strain, with normal aging, did not have chronologic changes from 2 to 27 months of age. The SAMP1 strain, with accelerated senescence, had a significant increase in blood pressure with age, and some (8 of 39) mice manifested hypertensive vascular disease characterized by high blood pressure, cardiac hypertrophy, and arteriolar fibrinoid necrosis at 11 to 14 months of age. The gradual increase in blood pressure after 8 to 10 months was considered to be preceded by progressive renal changes, from glomerulonephritis to contraction of the kidney, suggesting that the high blood pressure in the SAMP1 strain was of renal origin. Blood pressure in the SAMP8 strain, with age-related deficits in learning and memory, gradually decreased after 5 to 7 months of age, and was suggested to be due to the astrogliotic changes in response to spongiform degeneration in the medulla oblongata at 11 to 14 and 15 to 18 months of age.     

Factors Affecting Infection of Protoplasts with Deoxyribonucleic Acid of Actinophage PK-66

To establish a method for transmission of genetic materials in the genus Streptomyces, the conditions of infection of protoplasts of S. kanamyceticus by actinophage PK-66 deoxyribonucleic acid (DNA) were studied. The protoplasts of Streptomyces were prepared by treatments with lysozyme and trypsin. The infectivity of the phage DNA was enhanced by the presence of NaCl in the medium. The optimal concentration of the protoplasts for infection with DNA was 7 x 10(7) to 4 x 10(8)/ml. A proportional relationship was found between the infectivity and the DNA concentration within a certain range. The maximal production of mature phage was achieved after 19 hr of incubation. The number of phage propagated in the infection mixture reached 10(4) plaque-forming units per ml under the appropriate conditions. The phage DNA infected not only protoplasts prepared from S. kanamyceticus but also those prepared from S. violaceoniger and S. acidomyceticus, which were resistant to intact phage PK-66.