Laughter and humor as complementary and alternative medicines for dementia patients.

BACKGROUND: The number of dementia patients has increased worldwide, with an estimated 13.7 million dementia patients in the Asia Pacific region alone. This number is expected to increase to 64.6 million by the year 2050. DISCUSSION: As a result of advances in research, there several pharmacological therapies available for the treatment of dementia patients. However, current treatments do not suppress the disease process and cannot prevent dementia, and it will be some time before these goals are realized. In the meantime, complementary and alternative medicine (CAM) is an important aspect in the treatment of dementia patients to improve their quality of life throughout the long course of the disease. Considering the individuality of dementia patients, applicability of laughter and humor therapy is discussed. Even though there are many things that need to be elucidated regarding the mechanisms underlying the beneficial effects of laughter and humor, both may be good CAM for dementia patients if they are applied carefully and properly. SUMMARY: In this debate article, the physiological basis and actual application of laughter and humor in the treatment of dementia patients are presented for discussion on the applicability to dementia patients.

Impaired prepulse inhibition and habituation of acoustic startle response in Japanese patients with schizophrenia.

Prepulse inhibition (PPI) and habituation of the acoustic startle reflex (ASR) are considered to be candidate endophenotypes of schizophrenia. However, to our knowledge, only one group has investigated these startle measures in Asian patients with schizophrenia. In the present study, we evaluated these startle measures in 51 Japanese patients with schizophrenia and compared them with those of 55 healthy age- and sex-matched Japanese controls. A human startle response monitoring system was used to deliver acoustic startle stimuli, and record and score the electromyographic activity of the orbicularis oculi muscle. The startle measures examined were mean magnitude of ASR to pulse alone trials in initial block (SR), habituation of ASR during the session (HAB), and PPI at prepulse intensities of 82 dB (PPI82), 86 dB (PPI86), and 90 dB (PPI90) sound pressure level. SR was not significantly different between the patients and controls. Patients displayed significantly reduced HAB and PPI for all prepulse intensities compared to controls. The greatest statistical difference in PPI between patients and controls was found with PPI86. This did not correlate with any clinical variable in each group. Our results indicate that PPI and habituation of ASR are impaired in Asian patients with schizophrenia.

Curcumin structure-function, bioavailability, and efficacy in models of neuroinflammation and Alzheimer's disease.

Curcumin can reduce inflammation and neurodegeneration, but its chemical instability and metabolism raise concerns, including whether the more stable metabolite tetrahydrocurcumin (TC) may mediate efficacy. We examined the antioxidant, anti-inflammatory, or anti-amyloidogenic effects of dietary curcumin and TC, either administered chronically to aged Tg2576 APPsw mice or acutely to lipopolysaccharide (LPS)-injected wild-type mice. Despite dramatically higher drug plasma levels after TC compared with curcumin gavage, resulting brain levels of parent compounds were similar, correlating with reduction in LPS-stimulated inducible nitric-oxide synthase, nitrotyrosine, F2 isoprostanes, and carbonyls. In both the acute (LPS) and chronic inflammation (Tg2576), TC and curcumin similarly reduced interleukin-1beta. Despite these similarities, only curcumin was effective in reducing amyloid plaque burden, insoluble beta-amyloid peptide (Abeta), and carbonyls. TC had no impact on plaques or insoluble Abeta, but both reduced Tris-buffered saline-soluble Abeta and phospho-c-Jun NH(2)-terminal kinase (JNK). Curcumin but not TC prevented Abeta aggregation. The TC metabolite was detected in brain and plasma from mice chronically fed the parent compound. These data indicate that the dienone bridge present in curcumin, but not in TC, is necessary to reduce plaque deposition and protein oxidation in an Alzheimer's model. Nevertheless, TC did reduce neuroinflammation and soluble Abeta, effects that may be attributable to limiting JNK-mediated transcription. Because of its favorable safety profile and the involvement of misfolded proteins, oxidative damage, and inflammation in multiple chronic degenerative diseases, these data relating curcumin dosing to the blood and tissue levels required for efficacy should help translation efforts from multiple successful preclinical models.

Dietary n-3 polyunsaturated fatty acid depletion activates caspases and decreases NMDA receptors in the brain of a transgenic mouse model of Alzheimer's disease.

Epidemiological data indicate that low n-3 polyunsaturated fatty acids (PFA) intake is a readily manipulated dietary risk factor for Alzheimer's disease (AD). Studies in animals confirm the deleterious effect of n-3 PFA depletion on cognition and on dendritic scaffold proteins. Here, we show that in transgenic mice overexpressing the human AD gene APPswe (Tg2576), safflower oil-induced n-3 PFA deficiency caused a decrease in N-methyl-D-aspartate (NMDA) receptor subunits, NR2A and NR2B, in the cortex and hippocampus with no loss of the presynaptic markers, synaptophysin and synaptosomal-associated protein 25 (SNAP-25). n-3 PFA depletion also decreased the NR1 subunit in the hippocampus and Ca2+/calmodulin-dependent protein kinase (CaMKII) in the cortex of Tg2576 mice. These effects of dietary n-3 PFA deficiency were greatly amplified in Tg2576 mice compared to nontransgenic mice. Loss of the NR2B receptor subunit was not explained by changes in mRNA expression, but correlated with p85alpha phosphatidylinositol 3-kinase levels. Most interestingly, n-3 PFA deficiency dramatically increased levels of protein fragments, corresponding to caspase/calpain-cleaved fodrin and gelsolin in Tg2576 mice. This effect was minimal in nontransgenic mice suggesting that n-3 PFA depletion potentiated caspase activation in the Tg2576 mouse model of AD. Dietary supplementation with docosahexaenoic acid (DHA; 22 : 6n-3) partly protected from NMDA receptor subunit loss and accumulation of fodrin and gelsolin fragments but fully prevented CaMKII decrease. The marked effect of dietary n-3 PFA on NMDA receptors and caspase/calpain activation in the cortex of an animal model of AD provide new insights into how dietary essential fatty acids may influence cognition and AD risk.

A diet enriched with the omega-3 fatty acid docosahexaenoic acid reduces amyloid burden in an aged Alzheimer mouse model.

Epidemiological studies suggest that increased intake of the omega-3 (n-3) polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) is associated with reduced risk of Alzheimer's disease (AD). DHA levels are lower in serum and brains of AD patients, which could result from low dietary intake and/or PUFA oxidation. Because effects of DHA on Alzheimer pathogenesis, particularly on amyloidosis, are unknown, we used the APPsw (Tg2576) transgenic mouse model to evaluate the impact of dietary DHA on amyloid precursor protein (APP) processing and amyloid burden. Aged animals (17-19 months old) were placed in one of three groups until 22.5 months of age: control (0.09% DHA), low-DHA (0%), or high-DHA (0.6%) chow. beta-Amyloid (Abeta) ELISA of the detergent-insoluble extract of cortical homogenates showed that DHA-enriched diets significantly reduced total Abeta by >70% when compared with low-DHA or control chow diets. Dietary DHA also decreased Abeta42 levels below those seen with control chow. Image analysis of brain sections with an antibody against Abeta (amino acids 1-13) revealed that overall plaque burden was significantly reduced by 40.3%, with the largest reductions (40-50%) in the hippocampus and parietal cortex. DHA modulated APP processing by decreasing both alpha- and beta-APP C-terminal fragment products and full-length APP. BACE1 (beta-secretase activity of the beta-site APP-cleaving enzyme), ApoE (apolipoprotein E), and transthyretin gene expression were unchanged with the high-DHA diet. Together, these results suggest that dietary DHA could be protective against beta-amyloid production, accumulation, and potential downstream toxicity.

Insulin-degrading enzyme as a downstream target of insulin receptor signaling cascade: implications for Alzheimer's disease intervention.

Insulin-degrading enzyme (IDE) is one of the proteins that has been demonstrated to play a key role in degrading beta-amyloid (Abeta) monomer in vitro and in vivo, raising the possibility of upregulating IDE as an approach to reduce Abeta. Little is known, however, about the cellular and molecular regulation of IDE protein. Because one of the main functions of IDE is to degrade insulin, we hypothesized that there is a negative feedback mechanism whereby stimulation of insulin receptor-mediated signaling upregulates IDE to prevent chronic activation of the pathway. We show that treatment of primary hippocampal neurons with insulin increased IDE protein levels by approximately 25%. Insulin treatment also led to phosphatidylinositol-3 (PI3) kinase activation evidenced by Akt phosphorylation, which was blocked by PI3 kinase inhibitors, wortmannin and LY 294002. Inhibition of PI3 kinase abolished the IDE upregulation by insulin, indicating a cause-effect relationship between insulin signaling and IDE upregulation. Further support for this link was provided by the findings that deficient insulin signaling (decreased PI3 kinase subunit P85) was correlated with reduced IDE in Alzheimer's disease (AD) brains and in Tg2576 Swedish amyloid precursor protein transgenic mice fed a safflower oil-enriched ("Bad") diet used to accelerate pathogenesis. Consistent with IDE function in the degradation of Abeta monomer, the IDE decrease in the Bad diet-fed Tg2576 mice was associated with increased Abeta monomer levels. These in vitro and in vivo analyses validate the use of enhanced CNS insulin signaling as a potential strategy for AD intervention to correct the IDE defects occurring in AD.

NSAID and antioxidant prevention of Alzheimer's disease: lessons from in vitro and animal models.

Both oxidative damage and inflammation are elevated in brains of Alzheimer's disease (AD) patients, but their pathogenic significance remains unclear. The reduced AD risk associated with high intake of both nonsteroidal anti-inflammatory drugs (NSAIDs) and antioxidants suggests causal roles, but clinical trials in AD patients have yielded only limited or negative results. To test the potential efficacy and mechanisms of candidate approaches, we have explored conventional and unconventional NSAIDs, antioxidants, and combined NSAID/antioxidants in cell culture and animal models for AD (including aging APPsw transgenic mice and soluble Abeta rodent infusion models). The conventional NSAID ibuprofen has the strongest epidemiological support. At sustainable doses designed to mimic protective consumption in the epidemiology, ibuprofen reduces amyloid accumulation but suppresses a surprisingly limited subset of inflammatory markers in APPsw transgenic mice. Both Ab production (APP, beta- and gamma-secretases) and post-production pathways (those affecting Abeta aggregation or clearance: e.g., IL-1 or alpha1ACT) are potentially involved in ibuprofen and other NSAID anti-AD activities. The post-production pathways are predictably shared with other seemingly protective NSAIDs, including naproxen that do not lower Abeta42 in vitro. Using clinically feasible dosing, brain levels of NSAIDs appear too low to implicate a number of pharmacological dose targets that have been demonstrated in vitro. Ibuprofen did not suppress microglial markers related to phagocytosis. The putative anti-inflammatory omega-3 fatty acid DHA had a profound impact on pathogenesis but did not lower inflammation, while vitamin E was surprisingly ineffective in reducing oxidative damage or amyloid in the aged APPsw mouse. In contrast, the unconventional NSAID/antioxidant curcumin was effective, lowering oxidative damage, cognitive deficits, synaptic marker loss, and amyloid deposition. Curcumin proved to be immunomodulatory, simultaneously inhibiting cytokine and microglial activation indices related to neurotoxicity, but increasing an index of phagocytosis. Curcumin directly targeted Abeta and was also effective in other models, warranting further preclinical and clinical exploration.