Oral sodium hyaluronate relieves knee discomfort: A 12­week double­blinded, placebo­controlled study.

Sodium hyaluronate (SH) is a high molecular-weight polysaccharide composed of repeating polymeric disaccharides of D-glucuronic acid and N-acetyl-D-glucosamine. SH is present in every connective tissue and organ, with synovial fluid having the highest concentration of SH in the body. The effectiveness of oral SH on gonarthrosis is known; although, its influence on the knees of healthy individuals is not. However, as severe diseases may require surgery, it is better to take care of healthy knees before the onset of gonarthrosis. Therefore, the present study investigated the functionality of SH on the knee of healthy individuals. The present study was a randomized double-blind, placebo-controlled trial in which healthy adults (mean age: Placebo group, 61.50±1.59; SH group, 58.50±1.81), rated as grade ≤1 based on the Kellgren-Lawrence classification, were administered 111 mg/day SH for 12 weeks. The evaluation of visual analog scales were performed to assess the discomfort in the knees of the participants and were conducted at baseline, and then 6 and 12 weeks after the start of SH ingestion. Additionally, a locomotive syndrome risk test quantifying the mobility of the participants, a one-leg standing time with eyes open test evaluating the strength of the leg muscle as well as the ability to balance by measuring the time to stand on one leg and a blood test (interleukin-10, aspartate aminotransferase, alanine transaminase, γ-glutamyl transferase, lactate dehydrogenase, creatine kinase and C-reactive protein) were performed at baseline and then 12 weeks after the start of SH ingestion. A significant suppression of knee symptoms were demonstrated in the SH group compared with the placebo group in terms of the total visual analog scale scores for pain, stiffness and discomfort for the 31 healthy adult subjects. Significant suppression of symptoms was also demonstrated in the placebo group in terms of discomfort in the knees when descending stairs and pain in the knees after walking for a longer distance or duration than normal. No significant differences between the two groups were demonstrated in the locomotive syndrome risk test, one-leg standing time with eyes open test and the blood test. The results of the present study suggest the possibility that oral SH may help to maintain a healthy condition of the knees. The study protocol was registered with the University Hospital Medical Information Network Clinical Trial Registry in advance (registration no. UMIN000045980, November 4, 2021).

Effects of egg yolk choline intake on cognitive functions and plasma choline levels in healthy middle-aged and older Japanese: a randomized double-blinded placebo-controlled parallel-group study.

BACKGROUND: Choline, as a neurotransmitter acetylcholine precursor, is reportedly associated with cognitive function. Although there are several cohort and animal studies on choline-containing foods and cognitive function, only a few interventional studies were reported. Egg yolk is a rich source of different choline-containing chemical forms, such as phosphatidylcholine (PC), lysophosphatidylcholine (LPC), and α-glycerophosphocholine (α-GPC). This study aimed to investigate the effect of consuming 300 mg of egg yolk choline per day on cognitive function of Japanese adults. METHODS: A 12-week, randomized, double-blind, placebo-controlled, parallel-group study was conducted in 41 middle-aged and elderly males and females (43.9% female) aged ≥ 60 years and ≤ 80 years without dementia. Participants were randomly assigned to placebo and choline groups. The choline group received a supplement containing egg yolk choline (300 mg/day), and the placebo group received an egg yolk supplement free from choline for 12 weeks. Assessments of Cognitrax, Trail Making Tests (TMT) part A and B, the MOS 36-Item Short-Form Health Survey (SF-36), the Simplified Japanese Version of the WHO-Five Well-Being Index (WHO-5), and plasma choline levels were performed before and 6 and 12 weeks after supplement intake. In the present study, 19 subjects (9 in the placebo group and 10 in the choline group) were excluded due to the violation of the discontinuation criteria or participant compliance, and 41 subjects were analyzed. RESULTS: The change amount of verbal memory scores and verbal memory test-correct hit (delay) was significantly higher in the choline group than in the placebo group at baseline-6 and baseline-12 weeks. The plasma free choline level was significantly higher in the choline group compared with the placebo group at 6 weeks. Conversely, the choline group showed significantly lower Cognitrax processing speed scores, symbol digit coding testing correct responses, and SF-36 physical quality of life summary scores compared to the placebo group at 6 weeks. CONCLUSIONS: The results suggested that continued 300 mg/day intake of egg yolk choline improved verbal memory, which is a part of cognitive functions. To confirm the observed effects of egg yolk choline, more well-designed and large-scale studies are warranted. TRIAL REGISTRATION: Study protocols were pre-registered in the Clinical Trials Registration System (UMIN-CTR) (UMIN 000045050).

Isolation and identification of hyaluronan-degrading bacteria from Japanese fecal microbiota.

Hyaluronan (HA) is a high-molecular-weight glycosaminoglycan and widely distributed in all connective tissues and organs with diverse biological functions. HA has been increasingly used as dietary supplements targeted to joint and skin health for humans. We here first report isolation of bacteria from human feces that are capable of degrading HA to lower molecular weight HA oligosaccharides (oligo-HAs). The bacteria were successfully isolated via a selective enrichment method, in which the serially diluted feces of healthy Japanese donors were individually incubated in an enrichment medium containing HA, followed by the isolation of candidate strains from streaked HA-containing agar plates and selection of HA-degrading strains by measuring HA using an ELISA. Subsequent genomic and biochemical assays identified the strains as Bacteroides finegoldii, B. caccae, B. thetaiotaomicron, and Fusobacterium mortiferum. Furthermore, our HPLC analysis revealed that the strains degraded HA to oligo-HAs of various lengths. Subsequent quantitative PCR assay targeting the HA degrading bacteria showed that their distribution in the Japanese donors varied. The evidence suggests that dietary HA is degraded by the human gut microbiota with individual variation to oligo-HAs components, which are more absorbable than HA, thereby exerting its beneficial effects.

Heated egg white has no effect, but lactic fermented and unheated egg white reduces abdominal fat in rats.

BACKGROUND: We previously reported the abdominal fat-reducing effect of unheated egg white proteins (EWP); however, unheated egg white is actually rarely consumed. We thus investigated the effect of heated egg white on abdominal fat in rats. METHODS: Male SD rats were divided into two groups that were allowed to consume different dietary preparations containing casein or heated egg white for 4 weeks (Trial 1). We studied whether a heated form and a lactic fermented form of egg white (FLE) are as effective as unheated egg white for reducing abdominal fat. For this, we divided male SD rats into four groups that were allowed to consume different dietary preparations containing casein, unheated egg white, heated egg white, or lactic fermented egg white for 4 weeks (Trial 2). RESULTS: Animals in the heated egg white group showed no significant difference in abdominal fat weight compared with those in the casein group (Trial 1). Animals in the unheated egg white group and the FLE group had significantly lower levels of abdominal fat weight than those in the casein group (Trial 2). Ovalbumin in heated egg white was degraded by pepsin, whereas ovalbumin in unheated egg white and lactic acid fermented egg white was not degraded appreciably by pepsin. It was reported that EWP inhibit triglyceride absorption in rat. In the present study, EWP pepsin hydrolysate inhibited the micellar solubility of fatty acids in vitro. In particular, ovalbumin inhibited the micellar solubility of fatty acids. CONCLUSIONS: These results indicate that lactic fermented egg white reduces visceral fat in rats and suggest that different levels of susceptibility of ovalbumin to pepsin digestion underlie the varying effectiveness among the egg white preparations.

Egg white hydrolysate improves fatigue due to short-term swimming load test in mice.

We studied the effect of egg white hydrolysate (EWH) on swimming endurance in mice. 7-week-old male ddY mice (28-30 g) were divided into three groups and fed an AIN-93G diet supplemented with casein (n = 8), EWH (n = 7), or egg white protein (EWP, n = 8) for 14 days. From day 11, the mice underwent a swimming test daily with a weight load equivalent to 10% of their body weight, and the lengths of time they swam were recorded. Blood was sampled for testing on the last day of the study. We observed that increases in the swimming duration through day 14 were significantly greater in the EWH group than in the casein group (p = 0.049). As a factor underlying this, the hexanoyl-lysine level in blood was confirmed to be decreased in the former group (p = 0.013). These findings indicate that consumption of EWH extended the swimming duration and suggest the mechanistic involvement of an antifatigue effect mediated by its antioxidant activity.

Heating Has No Effect on the Net Protein Utilisation from Egg Whites in Rats.

Egg whites (EW) are a good source of protein; however, they are typically heated prior to consumption. Therefore, we investigated the effects of different heating conditions on the protein utilisation rate of EW. Male Sprague-Dawley rats (n = 36, 198 ± 1 g) were divided into six groups and fed American Institute of Nutrition-76 chow containing unheated EW, soft-boiled EW, boiled EW, milk whey protein, soybean protein, or no protein over a 10-day period using pair-feeding. Urine and faeces were sampled daily beginning on day 5 to measure nitrogen content and the net protein utilisation (NPU) rate. The soybean protein group had a significantly lower level of food intake and was thus excluded from subsequent analyses. The NPU value was similar among the unheated, soft-boiled, and boiled EW groups (97.5 ± 0.4, 96.5 ± 0.1, and 96.5 ± 0.7, resp.). The EW group values were significantly higher than the whey group values (90.5 ± 1.0). These results show that EW serve as a good source of protein, irrespective of heating.

Absorption of Orally Administered Hyaluronan.

Hyaluronan (HA) has been utilized as a supplement. However, the absorption of orally administrated HA remains controversial. The degradation and absorption of HA in the intestine were investigated in this study. HA excretion into the feces, degradation in the intestinal tract, absorption through the large intestine, and translocation to the blood and skin were examined. HA administered orally was not detected in rat feces. HA was degraded by cecal content, but not by artificial gastric juice and intestinal juice. Oligosaccharide HA passed through excised large intestine sacs. Furthermore, disaccharides, tetrasaccharides, and polysaccharides HA were distributed to the skin of rats following oral administration of high molecular weight HA (300 kDa). The results of the study suggest that orally administered HA is degraded to oligosaccharides by intestinal bacteria, and oligosaccharide HA is absorbed in the large intestine and is subsequently distributed throughout the tissues, including the skin.

Orally administered hyaluronan affects skin dryness and epidermal thickening in photoaged hairless mice.

The oral administration of hyaluronans (HAs) (molecular weight, 300k and less than 10k) to photoaged hairless mice increased the moisture content of the stratum corneum and decreased the epidermal thickness, respectively. Furthermore, orally administered HAs suppressed the low-molecular weight of HA content of the skin. This study indicates oral administered HAs may ameliorate the skin condition resulting from photoaging.

Oral administration of hyaluronan prevents skin dryness and epidermal thickening in ultraviolet irradiated hairless mice.

Hyaluronan is a component of the extracellular matrix that plays a role in water retention in tissues. In this study, we orally administered hyaluronans of varying molecular weights (300k and less than 10k) repeatedly to hairless mice exposed to ultraviolet (UV) irradiation and examined their effects on the skin of these mice. UV irradiation induces a marked increase in the epidermal thickness of the dorsal skin and a marked decrease in the skin moisture content; however, orally administered hyaluronan, particularly that with a molecular weight of less than 10k, markedly reversed the increase and decrease in the epidermal thickness and skin moisture content, respectively. Furthermore, on analyzing the mice skin, orally administered hyaluronan with a molecular weight of less than 10k increased the levels of the HAS2 gene expression in the skin. Based on these findings, it is assumed that orally administered hyaluronans, with molecular weight of 300k and less than 10k, reversed UV irradiation-induced skin disturbance. In particular, it was considered that the increase in the skin moisture content by orally administered hyaluronan, with a molecular weight of less than 10k, was related to the effect on skin cells.

Mayonnaise contributes to increasing postprandial serum ß-carotene concentration through the emulsifying property of egg yolk in rats and humans.

We performed in vitro, animal, and human studies to clarify the effect of mayonnaise on ß-carotene intake and its mechanism. In an artificial gastric juice model, we examined the transfer of ß-carotene from grated carrot to mayonnaise or vegetable oil. Mayonnaise was more easily dispersed in artificial gastric juice than vegetable oil. The ß-carotene concentration was greater in mayonnaise than vegetable oil. In rats, the postprandial serum ß-carotene concentration in the mayonnaise group (ß-carotene with mayonnaise) was higher than that in the control (ß-carotene only) and vegetable oil (ß-carotene with vegetable oil) groups. Continuous feeding of dietary ß-carotene (14 d), employing mayonnaise or egg yolk, resulted in an increased accumulation of ß-carotene in the liver. In a human study, diets were provided in the form of (1) carrot as a control (CON), (2) carrot juice (JU), (3) carrot with oil (OIL) and (4) carrot with mayonnaise (MS). Following collection of fasting blood samples, nine adult males consumed one of the four diets in random order. Fasting and postprandial changes in serum ß-carotene were assessed at 2, 3, 4, 6 and 8 h following ingestion of each diet. The incremental areas under the curves of serum ß-carotene concentration were higher following MS than following both CON and JU. In conclusion, we suggest that mayonnaise contributes to raising the serum ß-carotene concentration when consumed with carrots rich in ß-carotene, and that its mechanism is related to the emulsifying property of the egg yolk contained in mayonnaise.

Mechanism for the cholesterol-lowering action of egg white protein in rats.

Eggs are a popular source of dietary cholesterol, but their consumption does not necessarily result in an increased serum cholesterol concentration. We investigated the cholesterol-lowering activity of egg white protein (EWP) and its potential mechanism in rats. The consumption of EWP resulted in a decreased concentration of cholesterol in the serum, liver and intestinal mucosa. The excretion of fecal neutral sterols and bile acids was greater by rats fed with EWP than by those fed with casein. The ratio of cholesterol and bile acids in the micellar phase to those in the solid phase was lower in the intestinal contents from rats fed with EWP than from those fed with casein. These results suggest that the cholesterol-lowering activity of EWP can be attributed to lowering the cholesterol absorption by intervening in the micellar formation in the intestines.

Cholesterol-lowering activity of plant sterol-egg yolk lipoprotein complex in rats.

Free plant sterols cannot be dissolved in oil or water. Using free plant sterols and egg yolks, we developed a plant sterol-egg yolk lipoprotein complex (PSY) that can be dispersed in water and considered suitable for use in processed foods. The cholesterol-lowering activity of PSY was equal to that of free plant sterols and plant sterol esters. Consumption of a freeze-dried PSY-containing omelet reduced serum and hepatic cholesterol concentrations. The results suggest that PSY has cholesterol-lowering activity equivalent to that of free plant sterols and plant sterol esters. Moreover, the cholesterol-lowering activity of PSY was maintained in processed foods.

[Allergenic activity of non-calcinated egg shell calcium].

BACKGROUND: There is few data to prove the safety of egg shell calcium as allergen. Especially, non-calcinated egg shell calcium is not allowed to use without the description of origin of egg on food labels in Japan. METHOD: We evaluated the possibly contaminated egg allergens in commercial non-calcinated egg shell calcium made from egg by in vitro methodologies (SDS-PAGE, western blotting, inhibition ELISA and sandwich ELISA) and by single-blind oral non-calcinated egg shell calcium challenge on 6 egg hypersensitivity patients. RESULTS: The allergenic activity of non-calcinated egg shell calcium was almost negligible compared to egg white by all in vitro methods. Furthermore, six patients with egg hypersensitivity were unresponsive to oral non-calcinated egg shell calcium challenge test. CONCLUSION: These results indicate that there is little contamination of egg white in non-calcinated egg shell calcium, and that the allergenic activity of non-calcinated egg shell calcium is equivalent to that of calcinated egg shell calcium.