Theobromine (TB) is a primary methylxanthine found in cacao beans. cAMP-response element-binding protein (CREB) is a transcription factor, which is involved in different brain processes that bring about cellular changes in response to discrete sets of instructions, including the induction of brain-derived neurotropic factor (BDNF). Ca2+/calmodulin-dependent protein kinase II (CaMKII) has been strongly implicated in the memory formation of different species as a key regulator of gene expression. Here we investigated whether TB acts on the CaMKII/CREB/BDNF pathway in a way that might improve the cognitive and learning function in rats. Male Wistar rats (5 weeks old) were divided into two groups. For 73 days, the control rats (CN rats) were fed a normal diet, while the TB-fed rats (TB rats) received the same food, but with a 0.05% TB supplement. To assess the effects of TB on cognitive and learning ability in rats: The radial arm maze task, novel object recognition test, and Y-maze test were used. Then, the brain was removed and the medial prefrontal cortex (mPFC) was isolated for Western Blot, real-time PCR and enzyme-linked immunosorbent assay. Phosphorylated CaMKII (p-CaMKII), phosphorylated CREB (p-CREB), and BDNF level in the mPFC were measured. In all the behavior tests, working memory seemed to be improved by TB ingestion. In addition, p-CaMKII and p-CREB levels were significantly elevated in the mPFC of TB rats in comparison to those of CN rats. We also found that cortical BDNF protein and mRNA levels in TB rats were significantly greater than those in CN rats. These results suggest that orally supplemented TB upregulates the CaMKII/CREB/BDNF pathway in the mPFC, which may then improve working memory in rats.

In Japan, the incidence of heat illness in older people has rapidly increased during midsummer in the last decade, and we suggested that whey-protein+carbohydrate supplementation during aerobic training would increased plasma volume (PV) to enhance thermoregulatory adaptation in older men ( J Appl Physiol 107: 725-733, 2009); however, >60% of people age 65 and older suffer from hypertension, and the symptoms may be worsened by hypervolemia. To examine this, we randomly divided 21 older men (∼69 yr) with ∼160 mmHg for systolic and ∼90 mmHg for diastolic blood pressure at rest into two groups: Glc ( n = 11) consuming glucose alone (25 g) and Pro-Glc ( n = 10) consuming whey protein (10 g) + glucose (15 g), immediately after cycling exercise at 60–75% of peak aerobic capacity (V̇o2 peak) for 60 min/day, 3 days/wk, for 8 wk. Before and after training, we measured PV (dye dilution), baroreflex sensitivity (BRS) of heart rate (Valsalva maneuver), and carotid arterial compliance (CAC) from carotid arterial diameter (ultrasound imaging) responses to pulsatile arterial pressure change (photoplethysmography) at rest. Additionally, we measured esophageal temperature (Tes) and forearm skin blood flow (plethysmography) during exercise at 60% pretraining V̇o2 peak for 20 min in a warm environment. We found that the forearm skin vascular conductance response to increased Tes was enhanced in Pro-Glc with increased PV, but this was not found in Glc; however, despite the increased PV, arterial blood pressures rather decreased with increased CAC and BRS in Pro-Glc. Thus, the prescription was applicable to older men with hypertension to prevent heat illness during exercise.

Previous research has shown that habitual chocolate intake is related to cognitive performance and that frequent chocolate consumption is significantly associated with improved memory. However, little is known about the effects of the subchronic consumption of dark chocolate (DC) on cognitive function and neurotrophins. Eighteen healthy young subjects (both sexes; 20–31 years old) were randomly divided into two groups: a DC intake group (n = 10) and a cacao-free white chocolate (WC) intake group (n = 8). The subjects then consumed chocolate daily for 30 days. Blood samples were taken to measure plasma levels of theobromine (a methylxanthine most often present in DC), nerve growth factor (NGF), and brain-derived neurotrophic factor, and to analyze hemodynamic parameters. Cognitive function was assessed using a modified Stroop color word test and digital cancellation test. Prefrontal cerebral blood flow was measured during the tests. DC consumption increased the NGF and theobromine levels in plasma, enhancing cognitive function performance in both tests. Interestingly, the DC-mediated enhancement of cognitive function was observed three weeks after the end of chocolate intake. WC consumption did not affect NGF and theobromine levels or cognitive performance. These results suggest that DC consumption has beneficial effects on human health by enhancing cognitive function.

A reduction in exercise efficiency with aging limits daily living activities. We examined whether 5-aminolevulinic acid (ALA) with sodium ferrous citrate (SFC) increased exercise efficiency and voluntary achievement of interval walking training (IWT) in older women. Ten women [65 ± 3(SD) yr] who had performed IWT for >12 mo and were currently performing IWT participated in this study. The study was conducted in a placebo-controlled, double-blind crossover design. All subjects underwent two trials for 7 days each in which they performed IWT with ALA+SFC (100 and 115 mg/day, respectively) or placebo supplement intake (CNT), intermittently with a 2-wk washout period. Before and after each trial, subjects underwent a graded cycling test at 27.0°C atmospheric temperature and 50% relative humidity, and oxygen consumption rate, carbon dioxide production rate, and lactate concentration in plasma were measured. Furthermore, for the first 6 days of each trial, exercise intensity for IWT was measured by accelerometry. We found that, in the ALA+SFC trial, oxygen consumption rate and carbon dioxide production rate during graded cycling decreased by 12% (P < 0.001) and 11% (P = 0.001) at every workload, respectively, accompanied by a 16% reduction in lactate concentration in plasma (P < 0.001), although all remained unchanged in the CNT trial (P > 0.2). All of the reductions were significantly greater in the ALA+SFC than the CNT trial (P < 0.05). Furthermore, the training days, impulse, and time at fast walking were 42% (P = 0.028), 102% (P = 0.027), and 69% (P = 0.039) higher during the ALA+SFC than the CNT intake period, respectively. Thus ALA+SFC supplementation augmented exercise efficiency and thereby improved IWT achievement in older women.

No long-term exercise training regimen with high adherence and effectiveness in middle-aged and older people is broadly available in the field. We assessed the adherence to, and effects of, our long-term training program comprising an interval walking training (IWT) and an information technology network system and the factors affecting adherence. Middle-aged and older men and women [n = 696, aged 65 ± 7(SD) yr] underwent IWT. The subjects were instructed to repeat five or more sets of fast and slow walking for 3 min each at ≥70 and 40% peak aerobic capacity for walking (V̇O2peak), respectively, per day ≥4 days/wk for 22 mo. Adherence was assessed as training days accomplished relative to the target of 4 days/wk over 22 mo. The effects on the V̇O2peak and lifestyle-related disease score were evaluated every 6 mo. The independent factors affecting adherence were assessed by multiple-regression analysis after adjustment for baseline physical characteristics and other possible covariates, including vasopressin V1a receptor polymorphisms. The adherence over 22 mo averaged 70% and was highly correlated with a 13% reduction in the lifestyle-related disease score (R(2) = 0.94, P = 0.006) and with a 12% increase in V̇O2peak (R(2) = 0.94, P = 0.006). The major determinant of higher adherence was lower baseline body mass index (BMI) (P < 0.0001) and male sex (P < 0.0001). For men, in addition to BMI, nonsmokers (P = 0.031) and V1a receptor polymorphisms (P = 0.033) were independent determinants of higher adherence. Thus the long-term IWT program is an effective regimen. Moreover, baseline BMI and sex for all subjects, and smoking and V1a receptor polymorphisms for men, were associated with adherence.

Key points• Arterial blood pressure rises at the onset of voluntary locomotion, which is probably advantageous for increasing blood flow to contracting muscles without delay.• We previously reported in free-moving mice that the feedback control of arterial blood pressure through peripheral baroreceptors, which was dominant at rest, was suppressed during activation of the cerebral cortex; however, no neurotransmitter for the mechanisms has been identified.• Central suppression of the feedback control of arterial blood pressure at the onset of voluntary locomotion was abolished in vasopressin V1a receptor-deficient mice and by local infusion of a V1a receptor antagonist into the brainstem area, termed the nucleus tractus solitarii, of control mice.• Thus, central vasopressin might play an important role as a neurotransmitter in the pressor response at the onset of voluntary locomotion.Abstract We previously reported that cerebral activation suppressed baroreflex control of heart rate (HR) at the onset of voluntary locomotion. In the present study, we examined whether vasopressin V1a receptors in the brain were involved in these responses by using free-moving V1a receptor knockout (KO, n = 8), wild-type mice locally infused with a V1a receptor antagonist into the nucleus tractus solitarii (BLK, n = 8) and control mice (CNT, n = 8). Baroreflex sensitivity ( HR/ MAP) was determined from HR response ( HR) to a spontaneous change in mean arterial pressure ( MAP) every 4 s during the total resting period, which was ∼8.7 h, of the 12 h measuring period in the three groups. HR/ MAP was determined during the periods when the cross-correlation function (R(t)) between HR and MAP was significant (P < 0.05). Cerebral activity was determined from the power density ratio of θ to δ wave band (θ/δ) on the electroencephalogram every 4 s. Spontaneous changes in θ/δ were significantly correlated with R(t) during 62 ± 3% of the total resting period in CNT (P < 0.05), but only 38 ± 4% in KO and 47 ± 2% in BLK (vs. CNT, both P < 0.001). When R(t) and HR/ MAP were divided into six bins according to the level of θ/δ, both were positively correlated with θ/δ in CNT (both P < 0.001), while neither was correlated in KO or BLK (all P > 0.05). Moreover, the probability that mice started to move after an increase in θ/δ was 24 ± 4% in KO and 24 ± 6% in BLK, markedly lower than 61 ± 5% in CNT (both P < 0.001), with no suppression of the baroreflex control of HR. Abbreviations AVP, arginine vasopressin; CBF, cerebral blood flow; CNT, control; EEG, electroencephalogram; HR, heart rate; MAP, mean arterial pressure; NTS, nucleus tractus solitarii; REM, rapid eye movement; R(t), cross-correlation function between spontaneous changes in HR and MAP; V1a BLK, V1a receptor blockade; V1a KO, V1a receptor knockout; WT, wild-type; Z R (t) , transformed R(t); HR/ MAP, HR response to the spontaneous change in MAP; θ/δ, the power density ratio of θ to δ wave band in EEG.

Theobromine is a caffeine derivative and the primary methylxanthine in Theobroma cacao. We have shown previously that theobromine inhibits the Akt-mammalian target of rapamycin (mTOR) signal in vitro. In this study, we investigated whether orally administered theobromine could inhibit mTOR activity in rats. mTOR is phosphorylated by Akt. Thus, the level of phosphorylated mTOR was used as an index of mTOR activity. Male Wistar rats were divided into two groups. The control group (CN) was fed a normal diet, while the theobromine group (TB) was fed a diet supplemented with 0.05% theobromine for 40 days.We measured body-weights and tissue weights, food and water intake, blood count, concentrations of theobromine in the plasma, liver and brain, and the levels of phosphorylated mTOR in the liver and brain. Orally administered theobromine did not affect the body-weights and tissue weights, food and water intake, and blood count as determined by comparison with levels in rats that were fed standard chow. Theobromine was detected in the plasma, liver and brain obtained from TB rats, but was not detected in tissues obtained from CN rats. The phosphorylated mTOR levels in the liver and brain were significantly lower in TB rats than in CN rats. The results suggest that oral theobromine inhibits mTOR signalling in vivo. K E Y W O R D S4E-BP1, Akt, cerebral cortex, liver, mTOR, theobromine

Anredera cordifolia extract increased learning and memory by enhancing levels of hippocampal BDNF, PSD95, NR2A, and p-CREB in SAMP8 mice.