Safety and efficacy of dietary freshwater clam (Corbicula fluminea) extract in clinical research

Background: The freshwater clam (Corbicula spp.) is a popular edible bivalve mollusk that is commonly eaten in East Asia. Freshwater clam extract (FCE) is known to have various effects. For example, it has anti-inflammatory effects and improves cholesterol metabolism. Often used as a folk remedy, FCE might be effective against liver disease and at ameliorating liver damage. These results indicate that FCE has preventative or ameliorating effects against steatosis and mild chronic liver damage. Additionally, FCE has a documented neuroprotective effect, potentially improving sleep quality. However, no clinical research into these topic areas have been carried out. Objective: No clinical research has been carried out concerning the action of FCE on liver function. In this study, we conducted a clinical trial involving healthy volunteers with relatively high liver test values to determine the influence of FCE on hepatic function. Moreover, no previous studies have described the effects of FCE on sleep. Thus, we also assessed sleep quality after FCE intake using the Oguri-Shirakawa-Azumi (OSA) sleep inventory middle-aged and aged (MA) version and a Likert scale in a randomized controlled clinical trial. Methods: We performed a prospective randomized controlled trial to assess safety and the effects of freshwater clam extract. Thirty four volunteers were analyzed. The subjects ingested 2 placebo softgels, 2 FCE-containing softgels, or 10 FCE-containing softgels. We tried to clarify 2 issues, safety in the liver and quality of sleep. An assessment of the safety of long-term and excessive FCE intake, especially its actions on hepatic function, was performed by administering 10 FCE-containing softgels (5 times the normal dose) to the subjects in the high FCE dose group for 18 weeks. A sleep evaluation comparing the placebo and normal FCE dose groups was also conducted. We conducted a double-blind parallel clinical trial to evaluate the effects of FCE on sleep quality over 12 weeks. The subjects were assigned to 3 groups (the placebo group, the normal FCE dose group, and the high FCE dose group). Results: Significant reductions in the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyl transpeptidase (γ-GTP) were observed at 12 and 18 weeks after the consumption of a high dose of FCE capsules. The subjects’ ferritin levels were significantly reduced after 18 weeks’ high-dose FCE intake. Moreover, the consumption of two FCE softgels (normal dose) for 12 weeks resulted in significant better quality in terms of both sleep onset and maintenance compared with that seen after the placebo treatment. FCE intake also resulted in a longer sleep duration than the placebo treatment. The same dose of FCE tended to reduce subjective fatigue. These results suggest that FCE is a safe supplemental food and increases sleep quality.Conclusions: These results suggest that FCE is a safe supplemental food and increases sleep quality.Keywords:  freshwater clam, hepatotoxicity, randomized study, sleep

Delayed Meal Timing, a Breakfast Skipping Model, Increased Hepatic Lipid Accumulation and Adipose Tissue Weight by Disintegrating Circadian Oscillation in Rats Fed a High-Cholesterol Diet

Background: To investigate whether shifted timing of eating, breakfast skipping, induces alterations in the circadian clock and abnormal lipid metabolism, we have established a delayed meal timing (DMT) protocol for rats, which started eating food 4 h delay. In the present study, control and DMT rats were fed a high-cholesterol diet during zeitgeber time (ZT) 12-24 and ZT 16-4, respectively. The DMT protocol increased the hepatic lipids and epididymal adipose tissue weight without changes in food intake and body weight. The surge in body temperature was delayed by 4 h in the DMT group, suggesting that energy expenditure was decreased in response to DMT. The peaks of the diurnal rhythm of serum non-esterified fatty acids and insulin were delayed by 2 and 4 h due to DMT, respectively. The oscillation peaks of hepatic de novo fatty acid synthesis gene expression was delayed by 4 h in response to DMT, whereas the peak of hepatic clock genes were 2 h delayed or not by DMT. Although metabolic oscillation is considered to be controlled by clock genes, the disintegration rhythms between the clock genes and lipid metabolism-related genes were not observed in rats fed a high-fat diet in our previous study. These data suggest that the circadian rhythm of de novo fatty acid metabolism is regulated by timing of eating, but is not directly controlled by clock genes. The present study suggests that breakfast skipping would complicate fatty liver and body fat accumulation.

High sucrose diet-induced dysbiosis of gut microbiota promotes fatty liver and hyperlipidemia in rats

Excess sucrose intake has been found to be a major factor in the development of metabolic syndrome, especially in promoting nonalcoholic fatty liver disease. The excess fructose is believed to targets the liver to promote de novo lipogenesis, as described in major biochemistry textbooks. On the contrary, in this study, we explored the possible involvement of gut microbiota in excess sucrose-induced lipid metabolic disorders, to validate a novel mechanism by which excess sucrose causes hepatic lipid metabolic disorders via alterations to the gut microbial community structure. Wistar male rats were fed either a control starch diet or a high-sucrose diet for 4 weeks. Half of the rats in each group were treated with an antibiotic cocktail delivered via drinking water for the entire experimental period. After 4 weeks, rats fed with the high-sucrose diet showed symptoms of fatty liver and hyperlipidemia. The architecture of cecal microbiota was altered in rats fed with high-sucrose diet as compared to the control group, with traits including increased ratios of the phyla Bacteroidetes/Firmicutes, reduced α-diversity, and diurnal oscillations changes. Antibiotic administration rescued high-sucrose diet-induced lipid accumulation in the both blood and liver. Levels of two microbial metabolites, formate and butyrate, were reduced in rats fed with the high-sucrose diet. These volatile short-chain fatty acids might be responsible for the sucrose-induced fatty liver and hyperlipidemia. Our results indicate that changes in the gut microbiota induced by a high-sucrose diet would promote the development of nonalcoholic fatty liver disease via its metabolites, such as short-chain fatty acids.

Circadian rhythm-dependent induction of hepatic lipogenic gene expression in rats fed a high-sucrose diet

Metabolic syndrome has become a global health challenge and was recently reported to be positively correlated with increased sucrose consumption. Mechanistic analyses of excess sucrose-induced progression of metabolic syndrome have been focused mainly on abnormal hepatic lipogenesis, and the exact contribution of excess sucrose to metabolic disorders remains controversial. Considering that carbohydrate and lipid metabolisms exhibit clear circadian rhythms, here we investigated the possible contribution of diurnal oscillations to responses of hepatic lipid metabolism to excess sucrose. We found that excess sucrose dose-dependently promotes fatty liver and hyperlipidemia in in rats fed a high-sucrose diet (HSD). We observed that excess sucrose enhances the oscillation amplitudes of the expression of clock genes along with the levels of hepatic lipid and carbohydrate metabolism-related mRNAs that increase lipogenesis. We did not observe similar changes in the levels of the transcription factors regulating the expression of these genes. This suggested that the excess sucrose-induced, circadian rhythm-dependent amplification of lipogenesis is post-transcriptionally regulated via the stability of metabolic gene transcripts. Of note, our findings also provide evidence that fructose causes some of the HSD-induced, circadian rhythm-dependent alterations in lipogenic gene expression. Our discovery of HSD-induced circadian rhythm-dependent alterations in lipogenesis at the post-transcriptional level may inform future studies investigating the complex relationships among sucrose uptake, circadian rhythm, and metabolic enzyme expression. Our findings could contribute to the design of chrono-nutritional interventions to prevent or manage the development of fatty liver and hyperlipidemia in sucrose-induced metabolic syndrome.

A Simplified Modification of the AOAC Official Method for Determination of Total Dietary Fiber Using Newly Developed Enzymes: Preliminary Interlaboratory Study

A preliminary interlaboratory study was conducted to evaluate the validity of the modified AOAC method for determination of total dietary fiber by Tada and Innami, in which the 3-step enzymatic digestion process in AOAC Method 991.43 is modified to a 2-step process without pH adjustment. Total dietary fiber contents in 8 representative foodstuffs were measured using both the original AOAC Method 991.43 and the modified method in 6 research facilities in Japan. Repeatability relative standard deviations, reproducibility relative standard deviations, and Horwitz ratio values from the modified method were equivalent to those from AOAC Method 991.43, except in the rice sample. However, this exceptional case shown in the modified method was entirely dissolved by the addition of α-amylase stabilizing agents. The modified method, which shortens the process of enzymatic digestion from 3 to 2 steps and in which only reaction temperature is adjusted under the same pH, was found not only to give accurate values comparable to the original method, but also to substantially reduce the labor required by the laboratory staff in the process of routine analysis. This study revealed that the validity of the modified method was further ensured by adding α-amylase stabilizing agents to the reaction system.

Delayed first active-phase meal, a breakfast-skipping model, led to increased body weight and shifted the circadian oscillation of the hepatic clock and lipid metabolism-related genes in rats fed a high-fat diet

The circadian clock is closely related to human health, such as metabolic syndrome and cardiovascular disease. Our previous study revealed that irregular feeding induced abnormal lipid metabolism with disruption of the hepatic circadian clock. We hypothesized that breakfast skipping induces lipid abnormalities, such as adiposity, by altering the hepatic circadian oscillation of clock and lipid metabolism-related genes. Here, we established a delayed first active-phase meal (DFAM) protocol as a breakfast-skipping model. Briefly, rats were fed a high-fat diet during zeitgeber time (ZT) 12-24 in a control group and ZT 16-4 in the DFAM group. The DFAM group showed increased body weight gain and perirenal adipose tissue weight without a change in total food intake. The circadian oscillations of hepatic clock and de novo fatty acid synthesis genes were delayed by 2-4 h because of DFAM. The peaks of serum insulin, a synchronizer for the liver clock, bile acids, and non-esterified fatty acid (NEFA) were delayed by 4-6 h because of DFAM. Moreover, DFAM delayed the surge in body temperature by 4 h and may have contributed to the increase in body weight gain and adipose tissue weight because of decreased energy expenditure. These data indicated a potential molecular mechanism by which breakfast skipping induces abnormal lipid metabolism, which is related to the altered circadian oscillation of hepatic gene expression. The results also suggested that the delayed peaks of serum NEFA, bile acids, and insulin entrain the circadian rhythm of hepatic clock and lipid metabolism-related genes.

Time-restricted feeding suppresses excess sucrose-induced plasma and liver lipid accumulation in rats

The etiology of metabolic syndrome involves several complicated factors. One of the main factors contributing to metabolic syndrome has been proposed to be excessive intake of sucrose, which disturbs hepatic lipid metabolism, resulting in fatty liver. However, the mechanism by which sucrose induces fatty liver remains to be elucidated. Considering feeding behavior important for metabolism, we investigated whether time-restricted feeding of high sucrose diet (HSD), only in the active phase (the dark phase of the daily light/dark cycle), would ameliorate adverse effects of sucrose on lipid homeostasis in rats. Male Wistar rats, fed either an ad libitum (ad lib.) or time-restricted control starch diet (CD) or HSD were investigated. Rats fed ad lib. (CD and HSD) completed approximately 20% of food intake in the daytime. Time-restricted feeding did not significantly suppress total food intake of rats. However, time-restricted feeding of HSD significantly suppressed the increased plasma triglyceride levels. Moreover, time-restricted feeding also ameliorated HSD-induced liver lipid accumulation, whereas circadian oscillations of liver clock gene or transcriptional factor gene expression for lipid metabolism were not altered significantly. These results demonstrated that restricting sucrose intake only during the active phase in rats ameliorates the abnormal lipid metabolism caused by excess sucrose intake.

Randomized phase III study of bevacizumab plus FOLFIRI and bevacizumab plus mFOLFOX6 as first-line treatment for patients with metastatic colorectal cancer (WJOG4407G)

BACKGROUND

FOLFIRI and FOLFOX have shown equivalent efficacy for metastatic colorectal cancer (mCRC), but their comparative effectiveness is unknown when combined with bevacizumab.

PATIENTS AND METHODS

WJOG4407G was a randomized, open-label, phase III trial conducted in Japan. Patients with previously untreated mCRC were randomized 1:1 to receive either FOLFIRI plus bevacizumab (FOLFIRI + Bev) or mFOLFOX6 plus bevacizumab (mFOLFOX6 + Bev), stratified by institution, adjuvant chemotherapy, and liver-limited disease. The primary end point was non-inferiority of FOLFIRI + Bev to mFOLFOX6 + Bev in progression-free survival (PFS), with an expected hazard ratio (HR) of 0.9 and non-inferiority margin of 1.25 (power 0.85, one-sided α-error 0.025). The secondary end points were response rate (RR), overall survival (OS), safety, and quality of life (QoL) during 18 months. This trial is registered to the University Hospital Medical Information Network, number UMIN000001396.

RESULTS

Among 402 patients enrolled from September 2008 to January 2012, 395 patients were eligible for efficacy analysis. The median PFS for FOLFIRI + Bev (n = 197) and mFOLFOX6 + Bev (n = 198) were 12.1 and 10.7 months, respectively [HR, 0.905; 95% confidence interval (CI) 0.723-1.133; P = 0.003 for non-inferiority]. The median OS for FOLFIRI + Bev and mFOLFOX6 + Bev were 31.4 and 30.1 months, respectively (HR, 0.990; 95% CI 0.785-1.249). The best overall RRs were 64% for FOLFIRI + Bev and 62% for mFOLFOX6 + Bev. The common grade 3 or higher adverse events were leukopenia (11% in FOLFIRI + Bev/5% in mFOLFOX6 + Bev), neutropenia (46%/35%), diarrhea (9%/5%), febrile neutropenia (5%/2%), peripheral neuropathy (0%/22%), and venous thromboembolism (6%/2%). The QoL assessed by FACT-C (TOI-PFC) and FACT/GOG-Ntx was favorable for FOLFIRI + Bev during 18 months.

CONCLUSION

FOLFIRI plus bevacizumab was non-inferior for PFS, compared with mFOLFOX6 plus bevacizumab, as the first-line systemic treatment for mCRC.

CLINICAL TRIALS NUMBER

UMIN000001396.

Dietary freshwater clam (Corbicula fluminea) extract suppresses accumulation of hepatic lipids and increases in serum cholesterol and aminotransferase activities induced by dietary chloretone in rats

We investigated the ameliorative effect of freshwater clam extract (FCE) on fatty liver, hypercholesterolemia, and liver injury in rats exposed to chloretone. Furthermore, we examined the effects of major FCE components (fat and protein fractions) to determine the active components in FCE. Chloretone increased serum aminotransferase activities and led to hepatic lipid accumulation. Serum aminotransferase activities and hepatic lipid content were lower in rats fed total FCE or fat/protein fractions of FCE. Expression of fatty acid synthase and fatty acid desaturase genes was upregulated by chloretone. Total FCE and fat/protein fractions of FCE suppressed the increase in gene expression involved in fatty acid synthesis. Serum cholesterol levels increased twofold upon chloretone exposure. Total FCE or fat/protein fractions of FCE showed hypocholesterolemic effects in rats with hypercholesterolemia induced by chloretone. These suggest that FCE contains at least two active components against fatty liver, hypercholesterolemia, and liver injury in rats exposed to chloretone.

Effects of Genistein, an Isoflavone, on Pregnancy Outcome and Organ Weights of Pregnant and Lactating Rats and Development of Their Suckling Pups

There is a general agreement that isoflavones can be beneficial to health in adults. However, isoflavones are well known as endocrine-disrupting chemicals. It should be considered that soy foods might adversely affect the reproductive system and infants. The aim of this study was to evaluate the effects of genistein, an isoflavone, on dams and their offspring. Maternal rats were fed diets containing genistein at levels of 0 and 0.5 g/kg diet from pregnancy day 5 to postnatal day 13. No effects of genistein on the delivery, anogenital distance, reproductive organ weight, and body weight of the infants at birth were observed. There were no consistent effects on suckling pups after continuous genistein exposure during their fetal and suckling stages through their mothers, and there was no difference in effects according to the periods of exposure during pregnancy and lactation. We also observed no significant effect on the growth of offspring after weaning. Moreover, while we observed that the serum concentration of triiodothyronine (T3) in dams decreased, the result was a tendency, not a significant decrease. Our study suggested that maternal ingestion of genistein might have not induced serious adverse effects on dams, fetuses, infants or offspring during growth. However, the results indicated in many papers suggest the necessity of further study on the safety of genistein.

Effect of Lactobacillus rhamnosus KY-3 and cellobiose as synbiotics on lipid metabolism in rats

Lactobacillus rhamnosus KY-3 is a fermentative bacterium that is used for the industrial production of L-lactic acid. We have examined the effect of L. rhamnosus KY-3 and cellobiose as synbiotics on lipid metabolism in rats. Rats were fed on a 20% casein diet (C) supplemented with either 1.7% L. rhamnosus KY-3 (KY-3), 10% cellobiose (CEB), or 1.7% L. rhamnosus KY-3 and 10% cellobiose (KY-3+CEB) for 13 d. The concentrations of serum total lipids, triacylglycerol, total cholesterol, and phospholipids were significantly reduced in rats fed a KY-3+CEB diet in comparison to those on the C, KY-3 and CEB diets. There was an increase in the weight of cecal contents and a significant increase in the amount of cecal short-chain fatty acids (SCFA). The dry weight of excretion increased additively upon the simultaneous administration of L. rhamnosus KY-3 and cellobiose (KY-3 + CEB). The amount of excreted fecal bile acids did not differ among the groups in this study. These findings support the hypothesis that the promotion of cecal fermentation can lower the level of serum lipids. These results suggest that simultaneous administration of L. rhamnosus KY-3 and cellobiose as synbiotics has a beneficial effect on lipid metabolism.

Effects of 15-deoxy-delta(12,14) prostaglandin J(2) and interleukin-4 in Toll-like receptor-4-mutant glial cells

15-Deoxy-Delta(12,14) prostaglandin J(2) and interleukin-4 are endogenous anti-inflammatory substances. In this study, we examined the effects of 15-deoxy-Delta(12,14) prostaglandin J(2) and interleukin-4 in glial cells from the Toll-like receptor-4-mutant (C3H/HeJ) and wild-type (C3H/HeN) mouse brains. The lipopolysaccharide-induced expression of inducible nitric oxide (NO) synthase and cyclooxygenase-2 in the Toll-like receptor-4-mutant glial cells have significantly lower levels (about half and quarter, respectively) than those in the wild-type cells. Treatment with both interleukin-4 (at 10 ng/ml, for 48 h) and 15-deoxy-Delta(12,14) prostaglandin J(2) (at 3 microM, for 30 min) completely inhibited the lipopolysaccharide-induced expression of inducible NO synthase and cyclooxygenase-2. In contrast, heme oxygenase-1 was induced by 15-deoxy-Delta(12,14) prostaglandin J(2) alone, but was not changed by interleukin-4 or lipopolysaccharide. The inhibitory protein of nuclear factor-kappa B was degraded by lipopolysaccharide in both mutant and wild-type glial cells, and this degradation was not inhibited by either 15-deoxy-Delta(12,14) prostaglandin J(2) or interleukin-4. These results suggest that the response to lipopolysaccharide is partially dependent on Toll-like receptor-4 in mouse glial cells, and that 15-deoxy-Delta(12,14) prostaglandin J(2) and interleukin-4 differently regulate the expression of inducible NO synthase and cyclooxygenase-2, and heme oxygenase-1.

Aryl hydrocarbon receptor nuclear translocator is induced by kainic acid in rat hippocampal glial cells

The localization and function of aryl hydrocarbon receptor nuclear translocator (ARNT) in the brain are still unclear. In this study, we examined changes of ARNT protein in rat hippocampus, by immunoblotting and immunohistochemical analysis using anti-ARNT antibody. Treatment of kainic acid (KA) induced marked increase in ARNT protein in both cytosolic and organellar fractions. ARNT immunoreactivity was markedly increased, predominantly in microglia and partly in astrocytes, similar to the immunoreactivity of heme oxygenase-1. In contrast, protein level of dioxin receptor did not change and hypoxia-inducible factor-1alpha protein was undetectable. These results suggest that ARNT expression in glial cells may participate in KA-induced episodes in the hippocampus.

Scattering of dislocated wave fronts by vertical vorticity and the Aharonov-Bohm effect. I. Shallow water

When a surface wave interacts with a vertical vortex in shallow water the latter induces a dislocation in the incident wave fronts that is analogous to what happens in the Aharonov-Bohm effect for the scattering of electrons by a confined magnetic field. In addition to this global similarity between these two physical systems there is scattering. This paper reports a detailed calculation of this scattering, which is quantitatively different from the electronic case in that a surface wave penetrates the inside of a vortex while electrons do not penetrate a solenoid. This difference, together with an additional difference in the equations that govern both physical systems, lead to a quite different scattering in the case of surface waves, whose main characteristic is a strong asymmetry in the scattering cross section. The assumptions and approximations under which these effects happen are carefully considered, and their applicability to the case of the scattering of acoustic waves by vorticity is noted.

[Lung laceration caused by penetrating chest wall injury in Hanshin & Awaji earthquake: a case report]

A 36-year-old man having a left lower lobe laceration caused by penetrating chest wall injury was operated on 5 hours after Hanshin & Awaji Earthquake. At thoracotomy, significant destruction of the left lower lobe was observed. Therefore, we gave up repairing a lung, and performed left lower lobectomy, with a satisfactory outcome. Our hospital is located on 30 km south of seismic center, but the function of our hospital was not completely paralyzed. In Awaji island, emergent treatments were done satisfactorily.

[Nineteen multiple primary cancer cases of 100 patients undergoing lung cancer resection]

In our department, half of 100 consecutive lung cancer resection cases were over the age of 70 years. In the same 100 patients, nineteen cases had multiple primary cancers. Sixteen cases had double, two cases had triple, one case had quadruple primary cancers. The incidence rate of multiple primary cancers involving the lung was 19%. This incidence of 19% is higher than the others ever reported in Japan. It was concluded, when lung cancer patients were elder, that there was increasment in the frequency of multiple cancer cases involving lung, and there was a high possibility of the occurrence of 2nd and 3rd primary cancers.

[Clinical characteristics of impacted bile duct stone in the elderly]

Acute cholangitis due to impacted bile duct stone is sometimes fatal and require prompt bile duct decompression. Particularly, AOSC (acute obstructive suppurative cholangitis) is the most serious form of bacterial cholangitis and its prognosis is usually very poor when treated conservatively. We have been treated impacted bile duct stones by decompressing the duct endoscopically. Here, we report the characteristics of our elderly patients with impacted bile duct stones who received urgent decompression treatment mainly by endoscopic techniques. In the endoscopical treatment group, the number of patients with AOSC was 5 out of 46 AC (acute cholangitis) patients (11%) under 69 years old, 14 out of 52 (27%) from 70 to 79 years old, and 12 out of 28 (43%) over 80 years old. Obviously, the severity of acute cholangitis (ratio of AOSC to AC) was higher in the elderly. This tendency was similar to the patients who received urgent transhepatic decompression treatment, although they were small in number. In all the patients treated, 7 were classified into the most serious AOSC category with Reynolds' sign, and notably 6 out of 7 were over 70 years old. More strikingly, 5 of 7 patients were over 80, and their mortality rate was indeed high. Thus, in the elderly, bacterial cholangitis by impacted bile stones was a very serious condition. Especially, the outcome of AOSC over 80 years old with Reynolds' sign was very poor, in spite of emergency endoscopic treatment.