Garland chrysanthemum consumption ameliorates age-related hearing loss in C57BL/6 mouse; model system to explore hearing loss prevention foods in a short period.

Garland chrysanthemum (Glebionis coronaria L.) is an antioxidant-rich leafy vegetable. We found that garland chrysanthemum consumption ameliorated age-related hearing loss (AHL) in C57BL/6J mice, an early onset model. We also found that AHL progression was significantly ameliorated by three of ten products. Metabolome analysis of the 10 products using nuclear magnetic resonance (NMR) spectroscopy indicated that phytosterols may be involved in the amelioration of AHL. However, the direct inhibitory effect of phytosterol mixture on mouse AHL progression was not identified. These results suggest that garland chrysanthemum consumption delays AHL development in mice and its efficiency varies depending on the source of the product. Our findings also suggest that phytosterol content in garland chrysanthemum functions as an evaluation marker for the efficiency. Furthermore, to accelerate the search for foods that prevent AHL, we have used these data to develop an automatic threshold determination method for auditory brainstem response using machine learning.

Leisure-time physical activity and incidence of objectively assessed hearing loss: The Niigata Wellness Study.

Previous cohort study reported that high physical activity was associated with a low risk of self-reported hearing loss in women. However, no studies have examined the association between physical activity and the development of hearing loss as measured using an objective assessment of hearing loss in men and women. Here, we used cohort data to examine the association between leisure-time physical activity and incidence of objectively assessed hearing loss in men and women. Participants included 27 537 Japanese adults aged 20-80 years without hearing loss, who completed a self-administered physical activity questionnaire between April 2001 and March 2002. The participants were followed up for the development of hearing loss as measured by audiometry between April 2002 and March 2008. During follow-up, 3691 participants developed hearing loss. Compared with the none physical activity group, multivariable adjusted hazard ratios (HRs) for developing hearing loss were 0.93 (95% confidence interval (CI), 0.86-1.01) and 0.87 (0.81-0.95) for the medium (<525 MET-min/week) and high (≥525 MET-min/week) physical activity groups, respectively (p for trend = 0.001). The magnitude of risk reduction was slightly greater in vigorous-intensity activity than in moderate-intensity activity (p for interaction = 0.01). Analysis by sound frequency showed that the amount of physical activity was inversely associated with high frequency hearing loss development (p for trend <0.001), but not with low frequency hearing loss development (p for trend = 0.19). Higher level of leisure-time physical activity was associated with lower incidence of hearing loss, particularly for vigorous-intensity activities and high sound frequencies.

Chronically skipping breakfast impairs hippocampal memory-related gene expression and memory function accompanied by reduced wakefulness and body temperature in mice.

Acute or chronic effects of consuming or skipping breakfast on cognitive performance in humans are controversial. To evaluate the effects of chronically skipping breakfast (SB) on hippocampus-dependent long-term memory formation, we examined hippocampal gene expression and applied the novel object recognition test (NORT) after two weeks of repeated fasting for six hours from lights off to mimic SB in mice. We also examined the effects of SB on circadian rhythms of locomotor activity, food intake, core body temperature (CBT) and sleep-wake cycles. Skipping breakfast slightly but significantly decreased total daily food intake without affecting body weight gain. Locomotor activity and CBT significantly decreased during the fasting period under SB. The degree of fasting-dependent CBT reduction gradually increased and then became stabilized after four days of SB. Electroencephalographic data revealed that repeated SB significantly decreased the duration of wakefulness and increased that of rapid eye movement (REM) and of non-REM (NREM) sleep during the period of SB. Furthermore, total daily amounts of wakefulness and NREM sleep were significantly decreased and increased, respectively, under SB, suggesting that SB disrupts sleep homeostasis. Skipping breakfast significantly suppressed mRNA expression of the memory-related genes, Camk2a, Fkbp5, Gadd45b, Gria1, Sirt1 and Tet1 in the hippocampus. Recognition memory assessed by NORT was impaired by SB in accordance with the gene expression profiles. These findings suggested that chronic SB causes dysregulated CBT, sleep-wake cycles and hippocampal gene expression, which results in impaired long-term memory formation.

Cacao polyphenols regulate the circadian clock gene expression and through glucagon-like peptide-1 secretion.

Energy metabolism and circadian rhythms are closely related together, i.e., the timing of nutrient intake affects metabolism under the regulation of circadian rhythms. Previously, we have reported that cacao liquor procyanidin (CLPr) promotes energy metabolism, resulting in preventing obesity and hyperglycemia. However, it is not unclear whether CLPr regulates clock gene expression. In this study, we investigated whether the administration timing of CLPr affected clock gene expression and found that CLPr regulated the circadian clock gene expression through the glucagon-like peptide-1 (GLP-1) signaling pathway. CLPr administration at Zeitgeber time 3 increased the expression level of Per family and Dbp in the liver. At the same administration timing, CLPr increased GLP-1 and insulin concentration in the plasma and phosphorylation of AMPK in the liver. It was noteworthy that an antagonist for GLP-1 receptor Exendin (9-39) canceled CLPr-increased expression of Per family and Dbp and phosphorylation of AMPK in the liver, in addition to insulin secretion. These results strongly suggest that CLPr-induced GLP-1 regulates the changes in clock gene expression in the liver through increased insulin. Thus, CLPr is a possible functional food material for prevention and/or amelioration of metabolic disorders through preventing circadian disruption through GLP-1 and AMPK pathways.

Modulation of circadian clocks by nutrients and food factors.

Daily activity rhythms that are dominated by internal clocks are called circadian rhythms. A central clock is located in the suprachiasmatic nucleus of the hypothalamus, and peripheral clocks are located in most mammalian peripheral cells. The central clock is entrained by light/dark cycles, whereas peripheral clocks are entrained by feeding cycles. The effects of nutrients on the central and peripheral clocks have been investigated during the past decade and much interaction between them has come to light. For example, a high-fat diet prolongs the period of circadian behavior, a ketogenic diet advances the onset of locomotor activity rhythms, and a high-salt diet advances the phase of peripheral molecular clocks. Moreover, some food factors such as caffeine, nobiletin, and resveratrol, alter molecular and/or behavioral circadian rhythms. Here, we review nutrients and food factors that modulate mammalian circadian clocks from the cellular to the behavioral level.

Time-fixed feeding prevents obesity induced by chronic advances of light/dark cycles in mouse models of jet-lag/shift work.

Recent findings have uncovered intimate relationships between circadian clocks and energy metabolism. Epidemiological studies have shown that the frequency of obesity and metabolic disorders increases among shift-workers. Here we found that a chronic shift in light/dark (LD) cycles comprising an advance of six hours twice weekly, induced obesity in mice. Under such conditions that imitate jet lag/shift work, body weight and glucose intolerance increased, more fat accumulated in white adipose tissues and the expression profiles of metabolic genes changed in the liver compared with normal LD conditions. Mice fed at a fixed 12 h under the LD shift notably did not develop symptoms of obesity despite isocaloric intake. These results suggest that jet lag/shift work induces obesity as a result of fluctuating feeding times and it can be prevented by fixing meal times. This rodent model of obesity might serve as a useful tool for understanding why shift work induces metabolic disorders.

Harmine lengthens circadian period of the mammalian molecular clock in the suprachiasmatic nucleus.

The circadian clock is a cell-autonomous endogenous system that generates circadian rhythms in the behavior and physiology of most organisms. We previously reported that the harmala alkaloid, harmine, lengthens the circadian period of Bmal1 transcription in NIH 3T3 fibroblasts. Clock protein dynamics were examined using real-time reporter assays of PER2::LUC to determine the effects of harmine on the central clock in the suprachiasmatic nucleus (SCN). Harmine significantly lengthened the period of PER2::LUC expression in embryonic fibroblasts, in neuronal cells differentiated from neuronal progenitor cells and in SCN slices obtained from PER2::LUC mice. Although harmine did not induce the transient mRNA expression of clock genes such as Per1, Per2 and Bmal1 in embryonic fibroblasts, it significantly extended the half-life of PER2::LUC protein in neuronal cells and SCN slices. Harmine might lengthen the circadian period of the molecular clock by increasing PER2 protein stability in the SCN.

{2,7-Dieth-oxy-8-[(naphthalen-2-yl)carbon-yl]naphthalen-1-yl}(naphthalen-2-yl)methanone.

In the title compound, C36H28O4, the two 2-naphthoyl groups at the 1- and 8-positions of the central 2,7-dieth-oxy-naphthalene ring system are aligned almost anti-parallel and make a dihedral angle of 48.35 (5)°. The dihedral angles between the central 2,7-dieth-oxy-naphthalene ring system and the terminal naphthalene ring systems are 77.64 (4) and 73.73 (4)°. In the crystal, mol-ecules are linked into chains along the a-axis direction by dual C-H⋯O inter-actions between naphthoyl groups.

[8-(4-Chloro-benzo-yl)-2,7-dimeth-oxy-naphthalen-1-yl](2,4,6-trimethyl-phen-yl)methanone.

In the title compound, C(29)H(25)ClO(4), the dihedral angle between the benzene rings of the 2,4,6-trimethyl-benzoyl group and the 4-chloro-benzoyl group is 65.19 (9)°. The dihedral angles between the naphthalene ring system and the benzene rings of the 2,4,6-trimethyl-benzoyl group and the 4-chloro-benzoyl group are 85.66 (8) and 69.48 (8)°, respectively. In the crystal, two types of inter-molecular C-H⋯O inter-actions and an intra-molecular C-H⋯O inter-action are observed. Moreover, there is a short intra-molecular C=O⋯C=O contact of 2.614 (2) Šbetween the benzoyl substituents.

[2,7-Dimeth-oxy-8-(2,4,6-trimethyl-benzo-yl)naphthalen-1-yl](2,4,6-trimethyl-phen-yl)methanone.

In the title compound, C(32)H(32)O(4), the dihedral angle between the two benzene rings of the 2,4,6-trimethyl-benzoyl groups is 71.43 (7)°. The dihedral angles between the two benzene rings and the naphthalene ring system are 81.58 (5) and 84.92 (6)°. An intra-molecular C-H⋯O inter-action is observed.

(3,5-Dimethyl-phen-yl)[8-(3,5-dimethyl-benzo-yl)-2,7-dimeth-oxy-naphthalen-1-yl]methanone.

In the title mol-ecule, C(30)H(28)O(4), the inter-planar angle between the two benzene rings of the 3,5-dimethyl-benzoyl groups is 50.35 (7)°. The dihedral angles between the two benzene rings and the naphthalene ring system are 81.87 (6) and 83.55 (6)°. In addition, the conformations of the pairs of methyl groups and their counterparts differ from each other though their environment is very similar. In the crystal, weak C-H⋯O inter-actions occur.

Effect of regular and irregular stimulation cycles of dexamethasone on circadian clock in NIH3T3 cells.

Animal studies have shown that irregular light-dark cycles cause circadian desynchronization, while few studies have addressed the effect of regular/irregular stimulation cycles of signaling hormones on the cellular clock in vitro. Here, we examined how cellular clocks respond to regular and irregular stimulation cycles of dexamethasone, using NIH3T3 cells transfected with the Bmal1 promoter-driven luciferase (Bmal1-Luc) reporter gene. Cyclic stimulation with dexamethasone at different time intervals (18-28 h, 3 times regularly) revealed that Bmal1-Luc bioluminescence rhythms can be entrained to 22 and 24 h cycles during the stimulation period, but not to other cycles. The rhythm entrained for 24 h cycles persisted for at least one day after the last stimulation. Irregular dexamethasone treatment (16, 24, and 16 h, sequentially; short-term jet lag protocol) resulted in an overall upregulation and phase shifts of the temporal expression of several clock genes and cell cycle genes, including c-Myc and p53. Regular dexamethasone stimulation three times with 24 h cycles also caused upregulation of Per1 and Per2 expression, but not c-Myc and p53 expression. In conclusion, our study identified the entrainable range of the circadian clock in NIH3T3 cells to the dexamethasone stimulation cycle and demonstrated that irregular dexamethasone treatment could disturb the expression of cell cycle genes.

Caffeine lengthens circadian rhythms in mice.

Although caffeine alters sleep in many animals, whether or not it affects mammalian circadian clocks remains unknown. Here, we found that incubating cultured mammalian cell lines, human osteosarcoma U2OS cells and mouse fibroblast NIH3T3 cells, with caffeine lengthened the period of circadian rhythms. Adding caffeine to ex vivo cultures also lengthened the circadian period in mouse liver explants from Per2::Luciferase reporter gene knockin mice, and caused a phase delay in brain slices containing the suprachiasmatic nucleus (SCN), where the central circadian clock in mammals is located. Furthermore, chronic caffeine consumption ad libitum for a week delayed the phase of the mouse liver clock in vivo under 12 h light-dark conditions and lengthened the period of circadian locomotor rhythms in mice under constant darkness. Our results showed that caffeine alters circadian clocks in mammalian cells in vitro and in the mouse ex vivo and in vivo.

High-speed carbon nanotube actuators based on an oxidation/reduction reaction.

Actuators with a high-speed response under a high-frequency (more than 100 Hz) applied square-wave voltage of ±2 V have been developed with an electrode composed of millimeter-long single-walled carbon nanotubes synthesized by the "supergrowth method" (SG-SWNTs) and ionic liquids (ILs). Detailed studies concerning induced electric current and transferred charge in the electrode as well as cyclic voltammetric studies of the electrode revealed that the high-speed response originates from the electric current generated by an oxidation/reduction (redox) reaction in addition to electric double-layer charging. The contribution of the redox reactions of SG-SWNTs to the actuation is sensitive to the presence of supporting polymers, the thickness of the electrolyte, and the amplitude of the applied voltage.

7-Meth-oxy-1-(4-nitro-benzo-yl)naph-thalen-2-yl 4-nitro-benzoate.

In the title compound, C(25)H(16)N(2)O(8), the dihedral angle between the naphthalene ring system and the benzene ring of the nitro-phenyl ketone unit is 82.64 (7)°. The bridging ester O-C(=O)-C plane makes dihedral angles of 42.12 (8) and 11.47 (9)°, respectively, with the naphthalene ring system and the benzene ring of the nitro-phenyl ester unit. In the crystal, two types of weak inter-molecular C-H⋯O inter-actions are observed.

[2,7-Dimeth-oxy-8-(2-naphtho-yl)naphthalen-1-yl](naphthalen-2-yl)methanone.

The mol-ecule of the title compound, C(34)H(24)O(4), possesses crystallographically imposed twofold C(2) symmetry. The two 2-naphthoyl groups at the 1- and 8-positions of the central naphthalene ring are aligned almost anti-parallel [5.21 (5)°]. The dihedral angle between the central 2,7-dimeth-oxy-naphthalene unit and the terminal naphthyl groups is 75.13 (4)°. In the crystal, weak C-H⋯O hydrogen bonds and π-π stacking inter-actions [centroid-centroid and inter-planar distances are 3.6486 (8) and 3.3734 (5) Å, respectively] are observed.

{8-[4-(Bromo-meth-yl)benzo-yl]-2,7-dimeth-oxy-naphthalen-1-yl}[4-(bromo-meth-yl)phen-yl]methanone.

In the title compound, C(28)H(22)Br(2)O(4), the two 4-bromo-methyl-benzoyl groups at the 1- and 8-positions of the naphthalene ring system are aligned almost anti-parallel, the benzene rings forming a dihedral angle of 2.94 (16)°. The dihedral angles between the benzene rings and the naphthalene ring systems are 70.98 (13) and 72.89 (13)°. In the crystal, centrosymmetric-ally-related mol-ecules are linked into dimeric units by inter-molecular C-H⋯O inter-actions.

(2,7-Dimeth-oxy-naphthalen-1-yl)(2,4,6-trimethyl-phen-yl)methanone.

In the title compound, C(22)H(22)O(3), the dihedral angle between the naphthalene ring system and the benzene ring is 82.93 (5)°. The bridging carbonyl C-C(=O)-C plane makes dihedral angles of 50.11 (6) and 46.87 (7)°, respectively, with the naphthalene ring system and the benzene ring. In the crystal, three types of weak inter-molecular C-H⋯O inter-actions are observed.

1,2-Bis(benz-yloxy)-1,2-bis-(4-chloro-phen-yl)-3,8-dimeth-oxy-acenaphthene.

In the title compound, C(40)H(32)Cl(2)O(4), the two chloro-benzene rings are in syn orientations with respect to the naphthalene ring system and make dihedral angles of 57.12 (6) and 85.74 (6)° with it. The benzene rings of the benz-yloxy group make dihedral angles of 75.34 (6) and 83.95 (7)°, with the naphthalene ring system. In the crystal, the mol-ecules are linked by inter-molecular C-H⋯Cl inter-actions between the methyl-ene H atoms of the benz-yloxy group and the Cl atoms in adjacent mol-ecules. Furthermore, centrosymmetrically related mol-ecules are linked into dimeric units by pairs of C-H⋯π inter-actions.

[8-(4-But-oxy-benzo-yl)-2,7-dimeth-oxy-naphthalen-1-yl](4-but-oxy-phen-yl)methanone.

The mol-ecule of the title compound, C(34)H(36)O(6), is located on a twofold rotation axis. The two 4-but-oxy-benzoyl groups at the 1- and 8-positions of the naphthalene ring system are aligned almost anti-parallel. The dihedral angles between the benzene rings and the naphthalene ring system are 71.70 (4)°. In the crystal, the mol-ecules are connected via C-H⋯π inter-actions into a layer parallel to (010).