Enzyme-assisted Solvent Extraction of High-yield Paeonia suffruticosa Andr. Seed Oil and Fatty Acid Composition and Anti-Alzheimer's Disease Activity.

Enzyme-assisted solvent extraction (EASE) of Paeonia suffruticosa Andr. seed oil (PSO) was optimized by response surface methodology (RSM). The fatty acid composition and anti-Alzheimer's disease (AD) activity of PSO were analyzed. An enzyme mixture composed of cellulase and hemicellulase (1:1, w/w) was most effective in determining the extraction yield of PSO. The ideal extraction conditions were a pH value of 5.1, an enzymolysis time of 68 min, and a temperature of 50℃. The average extraction yield of PSO was 38.2 mL/100 g, 37.4% higher than that of untreated peony seed (27.8 mL/100 g). The fatty acid composition of PSO under optimal conditions for EASE was analyzed by gas chromatography-mass spectrometry (GC-MS). The predominant unsaturated fatty acids of PSO were determined to be more than 90.00%, including n-3 α-linolenic acid (43.33%), n-6 linoleic acid (23.40%) and oleic acid (23.59%). In this experiment, the anti-AD effect of PSO was also analyzed by performing learning and memory ability tests with Drosophila. PSO retarded the decrease in climbing ability in AD Drosophila. The 1% and 5% PSO groups were significantly different from the model group (b p < 0.05). The smell short-term memory ability test revealed the number of Drosophila in barrier and barrier-free centrifuge tubes in each group. PSO feeding improved learning and memory in AD Drosophila, with the highest number entering the barrierfree centrifuge tube. The performance index (PI) measured by the Pavlov olfactory avoidance conditioning test also demonstrated the effect of PSO on the learning and memory abilities of Drosophila. The PI of the PSO group was significantly increased compared to that of the model group. HE-stained brain tissue sections of AD Drosophila showed higher neurodegenerative changes, while PSO significantly reduced neurodegenerative damage. These results indicated that PSO can significantly improve the cognitive function of AD Drosophila and may help to prevent AD.

A new screening method for identifying chemosensory receptors responding to agonist.

Humans sense taste and smell of various chemical substances through approximately 430 chemosensory receptors. The overall picture of ligand-chemosensory receptor interactions has been partially clarified because of numerous interactions. This study presents a new method that enables a rapid and simple screening of chemosensory receptors. It would be useful for identifying chemosensory receptors activated by taste and odor substances.

Examination of the influence of cedar fragrance on cognitive function and behavioral and psychological symptoms of dementia in Alzheimer type dementia.

We examined whether symptoms of dementia are improved by olfactory nerve stimulation in Alzheimer type dementia patients. First, a stick-type olfactory identification ability test was performed in patients with Alzheimer type dementia, to select patients without olfactory dysfunctions. Then, these patients were randomly assigned into the intervention (n = 19) and the control groups (n = 17). To evaluate the effects of olfactory nerve stimulation, we exposed the intervention group to a disinfecting ethanol with added aroma extracts from ceder and the control group to the ethanol without the added aroma extracts. Each group underwent the intervention for 8 weeks, cognitive and behavioral functions were evaluated before and after treatments using the Neuropsychiatric Inventory (NPI), the Japanese version of Zarit Caregiver Burden interview (J-ZBI), and the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog). A significant improvement was observed in the NPI score and J-ZBI in the intervention group compared to the control group at 4 and 8 weeks. On the other hand, there was no significant difference in the score of ADAS-cog. Exposure to cedar fragrance improved behavioral and psychological symptoms of dementia (BPSD) in Alzheimer type dementia and may reduce the burden of nursing care. In addition to its effectiveness, the procedure is simple and minimally invasive and would be a valuable non-pharmaceutical treatment.

Individual differences in the perception of orthonasal irritation induced by food.

Oral responsiveness to the burning/spicy sensation affects food behaviors and diet; therefore, it is reasonable to hypothesize that the variation in nasal responsiveness to irritant foods may play a role in modulating food behaviors. This study explored the variation among individuals in orthonasal irritation induced by smelling food ingredients containing irritant compounds: mustard oil (2.0, 10.0, and 100.0% v/v mustard oil in corn oil; irritant compound: allyl isothiocyanate); vinegar (3.5, 42.3, and 98.6% v/v vinegar in water; irritant compound: acetic acid); and wasabi (0.1, 0.2, and 0.4% w/w wasabi powder in water; irritant compound: allyl isothiocyanate). Sixty-eight subjects (40% males; 19-87 years) smelled the nine samples and rated their perceived intensity of odor, irritation and liking. Wide individual variation in the perception of irritation and odor intensity was found, especially at the highest concentrations. Young individuals were the most sensitive to all stimuli. No significant differences were found between males and females. Fifty-seven percent of subjects were "HYPO" and 43 percent "HYPER" responsive to irritation, respectively. Perceived irritation was positively correlated with odor intensity and tended to be negatively correlated with liking, especially in familiar stimuli. The results suggest that the variation in nasal responsiveness to irritant foods may contribute to influencing food acceptance and therefore, to modulating food behaviors.

Changes in responsiveness to allatostatin treatment accompany shifts in stress reactivity in young worker honey bees.

Exposing honey bees to isopentylacetate (IPA) can cause stress-related changes in learning performance. In bees of foraging age, IPA's effects on learning are mimicked by C-type allatostatins (AstCC, AstCCC) injected into the brain. Here we ask whether allatostatins induce a similar response in young (6-day-old) bees and if so, whether their effects on learning performance are modulated by queen mandibular pheromone (QMP). We found that young bees exposed to IPA responded less to the conditioned stimulus during training than controls (Type 1-like stress response). AstCC treatment induced a similar response, but only in bees maintained without QMP. Bees exposed to QMP responded to AstCC with increased odour responsiveness and odour generalisation in the 1-h memory test (Type 2-like response). Type 2-like responses could be induced also by the A-type allatostatin, AstA. However, in bees exposed to QMP, AstA-induced odour generalisation was absent. Effects of AstCCC treatment in young bees were weak, indicating that responsiveness to this peptide changes with age. Our findings are consistent with the hypothesis that honey bee allatostatins play a role in stress reactivity, but suggest in addition that allatostatin signalling is age dependent and susceptible to modulation by pheromone released by the queen bee.

Acute exposure to selenium disrupts associative conditioning and long-term memory recall in honey bees (Apis mellifera).

A plethora of toxic compounds - including pesticides, heavy metals, and metalloids - have been detected in honey bees (Apis mellifera) and their colonies. One such compound is selenium, which bees are exposed to by consuming nectar and pollen from flowers grown in contaminated areas. Though selenium is lethal at high concentrations, sublethal exposure may also impair honey bees' ability to function normally. Examining the effect of selenium exposure on learning and memory provides a sensitive assay with which to identify sublethal effects on honey bee health and behavior. To determine whether sublethal selenium exposure causes learning and memory deficits, we used proboscis extension reflex conditioning coupled with recall tests 30min and 24h post-conditioning. We exposed forager honey bees to a single sublethal dose of selenium, and 3h later we used an olfactory conditioning assay to train the bees to discriminate between one odor associated with sucrose-reinforcement and a second unreinforced odor. Following conditioning we tested short- and long-term recall of the task. Acute exposure to as little as 1.8ng of an inorganic form of selenium (sodium selenate) before conditioning caused a reduction in behavioral performance during conditioning. And, exposure to 18ng of either an inorganic form (sodium selenate) or an organic form (methylseleno-l-cysteine) of selenium caused a reduction in the bees' performance during the long-term recall test. These concentrations of selenium are lower than those found in the nectar of plants grown in selenium-contaminated soil, indicating that even low-grade selenium toxicity produces significant learning and memory impairments. This may reduce foragers' ability to effectively gather resources for the colony or nurse bees' ability to care for and maintain a healthy colony.

Neuroprotective effect of Valeriana wallichii rhizome extract against the neurotoxin MPTP in C57BL/6 mice.

Oxidative stress and inflammation are some of the contributing factors for dopaminergic neurodegeneration in Parkinson's disease (PD). Though Valeriana wallichii D.C. is known for its nervine activities its effect against PD is yet to be studied. This is the first report on the antioxidant and anti-inflammatory effect of V. wallichii rhizome extract (VWE) in MPTP induced PD mice. GC-MS analysis of VWE indicated the presence of phytoconstituents like isovaleric acid and acacetin. PD induced mice were treated orally with three different doses (50, 100 and 200mg/kg body weight (BW)) of VWE for 14 days and their behavioural changes were studied on days 0, 8, 13 and 21. The levels of striatal dopamine, mid brain tyrosine hydroxylase positive (TH(+)) cell count, TH protein expression, reactive oxygen species (ROS), lipid peroxidation (LPO), antioxidants and inflammatory cytokines were analysed. Mid brain glial fibrillary acidic protein (GFAP) expression was assessed by immunohistochemistry and western blotting. Also mid brain histopathological analysis was performed. VWE treatment significantly recuperated the altered behavioural test scores, striatal dopamine levels, mid brain TH(+) cell count and TH protein levels, increased GFAP expression and the histopathological changes observed in PD mice. Similarly, diminished levels of antioxidants, elevated levels of ROS, LPO and inflammatory cytokines were also significantly ameliorated following VWE treatment. The effective dose of VWE was found to be 200mg/kg BW. Conclusively, V. wallichii rhizome extract has the potential to mitigate oxidative stress and inflammatory damage in PD.

Paradoxical mineralocorticoid receptor-mediated effect in fear memory encoding and expression of rats submitted to an olfactory fear conditioning task.

There is general agreement that the substantial modification in memory and motivational states exerted by corticosteroids after a traumatic experience is mediated in complementary manner by the mineralocorticoid (MR) and glucocorticoid (GR) receptors. Here we tested the hypothesis that pharmacological manipulation of MR activity would affect behavioral strategy and information storage in an olfactory fear conditioning (OFC) task. Male Wistar rats were submitted to the OFC with different training intensities. We observed that following high intensity OFC acquisition, a set of defensive coping strategies, which includes avoidance and risk assessment behaviors, was elicited when subjects were exposed to the conditioned stimulus (CS) 48 h later. In addition, following either OFC acquisition or retrieval (CS-I test) a profound corticosterone secretion was also detected. Systemic administration of the MR antagonist spironolactone altered the behavioral coping style irrespective the antagonist was administered 60 min prior to the acquisition or before the retrieval session. Surprisingly, the MR agonist fludrocortisone given 60 min prior to acquisition or retrieval of OFC had similar effects as the antagonist. In addition, post-training administration of fludrocortisone, following a weak training procedure, facilitated the consolidation of OFC. Fludrocortisone rather than spironolactone reduced serum corticosterone levels, suggesting that, at least in part, the effects of the MR agonist may derive from additional GR-mediated HPA-axis suppression. In conclusion, the present study suggests the involvement of the MR in the fine-tuning of behavioral adaptation necessary for optimal information storage and expression, as revealed by the marked alterations in the risk assessment behavior.

Decalepis hamiltonii root extract attenuates the age-related decline in the cognitive function in Drosophila melanogaster.

Age-associated accumulation of oxidative damage linked to decline of antioxidant defense mechanism, leads to impairment of cognitive function in many organisms. These damages can pass through generations and affect the cognitive quality of progenies. In Drosophila, classical olfactory conditioning results in the formation of different types of memory. Age-related memory impairment (AMI) causes reduction in middle term memory (MTM) and parental senescence causes decline in short-term memory (STM) of the offspring. We have further examined the neuromodulatory effect of Decalepis hamiltonii (Dh) root extract, which is a cocktail of novel antioxidant molecules, on the biochemical oxidative defenses in relation to cognitive ability of the aged flies and their offspring. There is a strong correlation between the age-related decline in the activity of the antioxidant enzymes and the lower cognitive ability of the aged flies and their offspring. Feeding of aged flies in the diet containing 0.1% Dh, markedly enhances the cognitive ability of both aged flies and their offspring which is associated with enhanced antioxidant defenses as evident for the activity of superoxide dismutase (SOD) and catalase. Our findings, for the first time, show that the antioxidant-rich Dh root extract attenuates the age-related decline in cognitive ability of Drosophila, and also shows ameliorative effect on the memory of the offspring.

Role of nitric oxide in pheromone-mediated intraspecific communication in mice.

Nitric oxide is known to take part in the control of sexual and agonistic behaviours. This is usually attributed to its role in neural transmission in the hypothalamus and other structures of the limbic system. However, socio-sexual behaviours in rodents are mainly directed by chemical signals detected by the vomeronasal system, and nitric oxide is abundant in key structures along the vomeronasal pathway. Thus, here we check whether pharmacological treatments interfering with nitrergic transmission could affect socio-sexual behaviour by impairing the processing of chemical signals. Treatment with an inhibitor of nitric oxide synthesis (Nomega-Nitro-l-arginine methyl ester hydrochloride, L-NAME, 100mg/kg) blocks the innate preference displayed by female mice for sexual pheromones contained in male-soiled bedding, with a lower dose of the drug (50mg/kg) having no effect. Animals treated with the high dose of L-NAME show no reduction of olfactory discrimination of male urine in a habituation-dishabituation test, thus suggesting that the effect of the drug on the preference for male pheromones is not due to an inability to detect male urine. Alternatively, it may result from an alteration in processing the reinforcing value of pheromones as sexual signals. These results add a new piece of evidence to our understanding of the neurochemistry of intraspecific chemical communication in rodents, and suggest that the role of nitric oxide in socio-sexual behaviours should be re-evaluated taking into account the involvement of this neuromodulator in the processing of chemical signals.

Estradiol prevents ozone-induced increases in brain lipid peroxidation and impaired social recognition memory in female rats.

There is increasing concern about the neurodegenerative and behavioral consequences of ozone pollution in industrialized urban centers throughout the world and that women may be more susceptible to brain neurodegenerative disorders. In the present study we have investigated the effects of chronic (30 or 60 days) exposure to ozone on olfactory perception and memory and on levels of lipid peroxidation, alpha and beta estrogen receptors and dopamine beta-hydroxylase in the olfactory bulb in ovariectomized female rats. The ability of 17beta-estradiol to prevent these effects was then assessed. Results showed that ozone exposure for 30 or 60 days impaired formation/retention of a selective olfactory recognition memory 120 min after exposure to a juvenile stimulus animal with the effect at 60 days being significantly greater than at 30 days. They also showed impaired speed in locating a buried chocolate reward after 60 days of ozone exposure indicating some loss of olfactory perception. These functional impairments could all be prevented by coincident estradiol treatment. In the olfactory bulb, levels of lipid peroxidation were increased at both 30- and 60-day time-points and numbers of cells with immunohistochemical staining for alpha and beta estrogen receptors, and dopamine beta-hydroxylase were reduced as were alpha and beta estrogen receptor protein levels. These effects were prevented by estradiol treatment. Oxidative stress damage caused by chronic exposure to ozone does therefore impair olfactory perception and social recognition memory and may do so by reducing noradrenergic and estrogen receptor activity in the olfactory bulb. That these effects can be prevented by estradiol treatment suggests increased susceptibility to neurodegenerative disorders in aging women may be contributed to by reduced estrogen levels post-menopause.