Arachidonic acid-enriched triacylglycerol improves cognitive function in elderly with low serum levels of arachidonic acid.

Arachidonic acid (ARA) is an n-6 PUFA and is thought to have an important role in various physiological and psychological functions. Recently, supplementation with ARA-enriched TAG was shown to improve age-related decreases in cognitive function in healthy elderly men. To investigate the influence of baseline serum ARA status on cognitive function and its improvement, we analyzed cognitive function stratified by serum ARA level. The stratified analysis was also conducted for the effects of ARA-enriched TAG supplementation on cognitive improvement. Cognitive function was evaluated by measuring event-related potentials (ERPs), including P300 latency and amplitude. When participants were stratified by baseline serum ARA level, P300 latency was significantly longer and P300 amplitude was generally lower in the low-ARA group than in the high-ARA group. No significant difference in P300 components was observed when participants were stratified by serum levels of any other fatty acid. ARA-enriched TAG supplementation significantly shortened P300 latency and increased P300 amplitude in the low-ARA group, although no significant differences were observed in the high-ARA group. These findings suggest that lower serum ARA levels were associated with cognitive function in elderly men and that ARA-enriched TAG supplementation is more effective in improving cognitive function in healthy elderly men with low serum ARA levels than in those with high serum ARA levels.

Arachidonic acid supplementation decreases P300 latency and increases P300 amplitude of event-related potentials in healthy elderly men.

In the present study, we examined the effects of arachidonic acid (ARA) on age-related event-related potential (ERP) changes in 25 healthy elderly men. This study was performed using a double-blind crossover design. The subjects were administered 600 mg/day of ARA-enriched triglyceride (SUNTGA40S; containing 240 mg ARA) in capsules or the same amount of olive oil in capsules as an inactive placebo for 1 month. ERPs were measured before capsule administration and after 1 month of administration, and P300 latency and amplitude were also measured. In subjects administered 240 mg/day ARA, P300 latency was significantly shorter, and P300 amplitude was significantly higher than in those administered olive oil capsules, and they exhibited a significant increase in ARA content in serum phospholipids. These findings suggest that supplementation of ARA can improve cognitive function in healthy elderly men.

Effects of arachidonate-enriched triacylglycerol supplementation on serum fatty acids and platelet aggregation in healthy male subjects with a fish diet.

The changes in fatty acid composition of serum and in platelet aggregation induced by supplementation of arachidonate-enriched TAG were investigated in twenty-four healthy Japanese men in a double-blind, placebo-controlled study. The arachidonate-enriched TAG ingested was an edible oil, extracted and purified from a biomass of submerged fermented Mortierella alpina. Mean daily intake of fish and shellfish by subjects was 87.2 (se5.3) g/d, while dietary intakes of arachidonic acid (ARA) by the ARA group and placebo group were 175 (se12) and 179 (se13) mg/d, respectively. In the ARA group, after 2-week supplementation of 838 mg ARA/d, ARA concentration in serum phospholipids was increased from 9.6 (se0.4) to 13.7 (se0.4) g/100 g total fatty acids, and was significantly different from that in the placebo group (P < 0.001). This level was maintained for 4 weeks but returned to baseline level after a 4-week washout period. Linoleic acid concentration in serum phospholipids decreased from 19.2 (se0.8) to 16.3 (se0.6) g/100 g total fatty acids in the ARA group. Similarly, ARA content of serum TAG increased after ARA supplementation. Neither the EPA nor DHA content of serum phospholipids or TAG was altered by ARA supplementation. The platelet aggregation induced in platelet-rich plasma by adding adenosine diphosphate, collagen and ARA, physical characteristics of subjects, and biochemical parameters were unchanged throughout the test period. These findings suggest that ARA concentration in serum phospholipids and TAG can be safely increased by supplementation of arachidonate-enriched TAG oil.

Antihypertensive effect of angiotensin I-converting enzyme inhibitory peptides from a sesame protein hydrolysate in spontaneously hypertensive rats.

Sesame peptide powder (SPP) exhibited angiotensin I-converting enzyme (ACE) inhibitory activity, and significantly and temporarily decreased the systolic blood pressure (SBP) in spontaneously hypertensive rats (SHRs) by a single administration (1 and 10 mg/kg). Six peptide ACE inhibitors were isolated and identified from SPP. The representative peptides, Leu-Val-Tyr, Leu-Gln-Pro and Leu-Lys-Tyr, could competitively inhibit ACE activity at respective Ki values of 0.92 microM, 0.50 microM, and 0.48 microM. A reconstituted sesame peptide mixture of Leu-Ser-Ala, Leu-Gln-Pro, Leu-Lys-Tyr, Ile-Val-Tyr, Val-Ile-Tyr, Leu-Val-Tyr, and Met-Leu-Pro-Ala-Tyr according to their content ratio in SPP showed a strong antihypertensive effect on SHR at doses of 3.63 and 36.3 microg/kg, which accounted for more than 70% of the corresponding dosage for the SPP-induced hypotensive effect. Repeated oral administration of SPP also lowered both SBP and the aortic ACE activity in SHR. These results demonstrate that SPP would be a beneficial ingredient for preventing and providing therapy against hypertension and its related diseases.

Itaconate reduces visceral fat by inhibiting fructose 2,6-bisphosphate synthesis in rat liver.

OBJECTIVE: Itaconate is an analog of phosphoenolpyruvate, which is an inhibitor of fructose-6-phosphate 2-kinase (F6P2Kinase), an enzyme that synthesizes fructose 2,6-bisphosphate (F26BP). Carbohydrates ingested are preferentially used for glycogen synthesis in the liver and muscles, and excess carbohydrates are metabolized by glycolysis in the liver and used for fatty acid synthesis. We hypothesized that itaconate is incorporated into liver cells and suppresses fat synthesis by inhibiting liver glycolysis at the step of phosphofructokinase, which is activated by F26BP. METHODS: Rats were allowed to eat ad libitum for 3 wk or, in separate experiments, to limit food intake by pair feeding. One group was given drinking water (control group) and the other group was given a 10 g/L itaconate solution (itaconate group). We measured body weight gain, visceral fat accumulation, and F6P2Kinase activity. RESULTS: Body weight gain in the itaconate group was lower than that in the control group (P < 0.05). In the dietary-controlled rats, there was no difference in body weight increase between groups, but visceral fat content (P < 0.01), plasma free fatty acid, and triacylglycerol levels (P < 0.05) were lower in the itaconate group than in the control group. Further, itaconate decreased the F26BP level (P < 0.05) in vivo and partly inhibited rat liver-type F6P2Kinase in vitro. CONCLUSIONS: These results indicate that itaconate, which is a decarboxylate and resembles phosphoenolpyruvate, is incorporated into liver cells and suppresses glycolysis by decreasing the level of F26BP, resulting in decreased visceral fat.

Hypoglycemic action of Cyclocarya paliurus (Batal.) Iljinskaja in normal and diabetic mice.

This study examined the hypoglycaemic activity of Cyclocarya paliurus (Batal.) Iljinskaja (C. paliurus) in ICR mice by oral glucose tolerance testing. The blood glucose level was significantly lower in the C. paliurus extract treatment group than in the control group after animals were given sucrose. This difference was not observed following the administration of glucose. We demonstrated that the chronological change in the level of blood glucose in genetically hyperglycemic obese KK-Ay mice is significantly lower when C. paliurus extract is administered daily for three weeks. An in vitro study showed that C. paliurus inhibits alpha-glucosidase, a disaccharide-degrading enzyme in the small intestinal mucosa, leading to a decrease in the absorption of glucose into the blood and a subsequent lowering of the blood glucose level.

Occurrence of periodontal bacteria in healthy children: a 2-year longitudinal study.

OBJECTIVES: To examine the occurrence of specific periodontal bacteria in children and adolescents. METHODS: Ten putative periodontal bacteria were longitudinally examined in plaque and saliva samples from 119 periodontally healthy children (2-15 years old) using a polymerase chain reaction method. RESULTS: Capnocytophaga ochracea, C. sputigena, and Actinobacillus actinomycetemcomitans were frequently found in saliva, and tended to persist in saliva for the remainder of the study, whereas Porphyromonas gingivalis, Treponema denticola, and Prevotella intermedia were rarely detected. P. nigrescens was more frequently detected in plaque and its prevalence increased with age. Eikenella corrodens and Campylobacter rectus were sometimes detected in both plaque and saliva, while Tannerella forsythensis was occasionally detected in saliva. CONCLUSION: A. actinomycetemcomitans, C. ochracea, C. sputigena, P. nigrescens, C. rectus, and E. corrodens are common members of the oral microbial flora of healthy children, whereas P. gingivalis, P. intermedia, and T. denticola appear to be transient organisms.

Influence of moderate drinking on purine and carbohydrate metabolism.

BACKGROUND: We examined the influences of a moderate intake level of three types of alcoholic beverages--beer, whisky, and Shochu (Japanese distilled liquor)--on purine and carbohydrate metabolism and excretion in healthy male volunteers, concerning (1) the extent of contribution of purine bodies contained in beer to uric acid metabolism and (2) a comparison between two types of distilled spirits with (whisky) and without (Shochu) aging in oak wood barrel storage. METHODS: Three sets of studies were conducted in which 10 to 13 healthy adult men were instructed to drink three types of alcoholic beverages at a slightly higher level (0.8 ml of ethanol equivalent/kg body weight) than moderate drinking (approximately 30.4 ml or less for men). A low purine beer was test-manufactured by treating nucleosides that were contained in wort and remained in beer with purine nucleoside phosphorylase derived from Ochrobacterium anthropi, thereby converting them into corresponding purine bases that were easily assimilated by beer yeast. RESULTS: Although beer intake enhanced the level of serum uric acid by 13.6%, blood glucose by 26.7%, and insulin level by 5.1-fold, drinking a moderate level of distilled liquor (whisky, Shochu) did not increase the serum uric acid level or the other two parameters. The serum uric acid level observed after drinking beer with a purine body concentration reduced by 28% (68% in nucleosides and purine bases) was almost identical to the level observed after drinking regular beer. Whisky has been found to have a property that decreases the serum uric acid level. Excretion of uric acid from blood is increased by 27% after drinking whisky. CONCLUSIONS: Moderate drinking of distilled liquors did not enhance serum uric acid level, blood glucose, or insulin level in healthy male subjects. Increased serum uric acid after beer intake could not be explained mostly with their purine body congeners. Whisky showed the eliminative property in serum uric acid through excretion of it from blood to urine. At a moderate drinking level, beer and whisky have different effects on purine metabolism or excretion.