5-Aminolevulinic acid, a precursor of heme, is utilized in a variety of applications including cancer treatment, surgery, and plant nutrition. However, 5-aminolevulinic acid itself induces oxidative stress and subsequent lipid peroxidation. Reactive oxygen species are factors in oxidative stress, not only causing cellular injury but also inducing several signal transduction pathways. Especially in cancer cells, a significant amount of signalling activation and subsequent activation of protein is caused by the enhancement of reactive oxygen species production. Reactive oxygen species levels in normal cells are low and an oxidative condition is harmful; hence, administration of 5-aminolevulinic acid to normal cells may induce oxidative stress, resulting in cell death. In this study, we investigated the effect of 5-aminolevulinic acid on normal and cancer cells with regard to oxidative stress. We used the rat normal gastric cell line RGM and its cancer-like mutant cell line RGK. 5-Aminolevulinic acid treatment of RGM cells enhanced reactive oxygen species generation and induced apoptosis associated with p53, whereas RGK cells were unaffected. In addition, RGM cell viability was recovered by application of N-acetyl-l-cysteine or p53 inhibitor. These results suggest that 5-aminolevulinic acid causes oxidative stress in normal gastric cells and induces apoptosis via the p53-dependent pathway.
Curcumin has been shown to have anti-obesity effects in animal studies. Although several molecular mechanisms of action have been reported, the initial or upstream molecular events remain to be revealed. In this study, we found that curcumin or heat shock treatment up-regulated the expression of adipose triglyceride lipase (ATGL) in Huh7 hepatoma cells, which resulted in acceleration of lipolysis. Interestingly, perturbation of protein homeostasis was seen in curcumin-treated cells, as detected by formation of numerous ubiquitinated proteins and conjugated proteins with p62 (SQSTM). Curcumin activated the protein expression of molecular chaperones, such as heat shock protein (HSP)40 and HSP70. Pre-treatment of the cells with 4-phenylbutyric acid, a chemical chaperone, suppressed proteo-stress induced by curcumin and reduced its lipolysis effect. Importantly, the cytotoxicity of curcumin was markedly alleviated when intracellular triglyceride was consumed by the polyphenol. Thus, energy supplementation from lipolysis may play substantial roles in adaptation and survival of curcumin-exposed cells. To support this notion, the cytotoxicity of curcumin was aggravated in ATGL-knockdown cells. Curcumin decreased intracellular ATP for activating AMP-activated protein kinase, which initiates catabolic pathways including ATGL-dependent lipolysis. Taken together, we propose a hypothesis that curcumin induces lipolysis to compensate for ATP reduction due to its proteo-stress effects.
4-Methylthio-3-butenyl isothiocyanate (MTBI) is a pungent bioactive constituent found in daikon. However, MTBI is immediately hydrolyzed to 3-hydroxy-methylene-2-thioxopyrrolidine in grated daikon. In this study, we evaluated whether MTBI in grated daikon complexed with α-cyclodextrin (αCD) has anti-obesity effects in mice. C57BL/6J mice were fed a normal diet (normal group), high-fat diet (HFD, control group), HFD with αCD (αCD group), or HFD with MTBI-αCD (MTBI-αCD group) for 16 weeks. The results showed that the final body weight, epididymal white adipose tissue weight, and plasma triglyceride and total cholesterol levels were significantly lower in the MTBI-αCD group than in the control group. The cell size in epididymal adipose tissue was significantly smaller and the accumulation of lipids in the liver was significantly lower in the MTBI-αCD group than in the control group. Furthermore, real-time polymerase chain reaction showed that the mRNA expression level of tumor necrosis factor-alpha was suppressed in the MTBI-αCD group. We also observed low superoxide dismutase activity in the MTBI-αCD group, possibly because MTBI-αCD has the potential to resist HFD-induced oxidative injury. In conclusion, MTBI-αCD exerted anti-inflammation and antioxidant effects to suppress lipid accumulation in epididymal adipose tissue and the liver. These effects then prevented HFD-induced obesity in mice.
Cancer cachexia is a syndrome accompanying weight loss, skeletal muscle atrophy, and loss of adipose tissue in patients with advanced cancer. Since interleukin-6 (IL-6) is one of core mediators causing cancer cachexia and kimchi can modulate IL-6 response, we hypothesized dietary intake of kimchi can ameliorate cancer cachexia. In this study, we studied preemptive administration of kimchi can ameliorate mouse colon carcinoma cells colon (C26) adenocarcinoma-induced cancer cachexia and explored anti-cachexic mechanisms of kimchi focused on the changes of muscle atrophy, cachexic inflammation, and catabolic catastrophe. As results, dietary intake of kimchi significantly attenuated the development of cancer cachexia, presented with lesser weight loss, higher muscle preservation as well as higher survival from cancer cachexia in mice. Starting from significant inhibition of IL-6 and its signaling, kimchi afforded significant inhibition of muscle specific ubiquitin-proteasome system including inhibition of atrogin-1 and muscle ring finger protein-1 (MuRF-1) with other muscle related genes including mitofusin-2 (Mfn-2) and PGC-1α. Significant inhibition of lipolysis gene such as adipose triglyceride lipase (ATGL) and hormone-sensitive ligase (HSL) accompanied with significant induction of fatty acid synthase (FAS) and sterol response element binding protein 1 (SREBP1) was achieved with kimchi. As gene regulation, IL-6 and their receptor as well as Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) were significantly attenuated with kimchi. In conclusion, dietary intake of cancer preventive kimchi can be an anticipating option to ameliorate cancer cachexia via suppressive action of IL-6 accompanied with decreased muscle atrophy and lipolysis.
The aim of the present study was to investigate elemental diet (ED)-induced alteration of the fecal and mucosal microbiome in mice. The control group was fed a normal chow and the ED group was fed normal chow containing 50% w/w Elental® (EA Pharma, Tokyo, Japan) for 28 days. Fecal and mucosal microbiome were analyzed using 16S rRNA gene sequencing. In the fecal samples, the observed species, an index for microbial richness, was significantly decreased in the ED group. Principal coordinate analysis revealed that there were significant compositional differences between the control and ED groups (PERMANOVA p = 0.0007 for unweighted and p = 0.002 for weighted UniFrac distance, respectively). In contrast, there was no significant difference in the overall structure of mucosal microbiome between the control and ED groups. In the fecal samples, abundance of the genera Adlercreutzia, Akkermansia, Streptococcus, Helicobacter, Coprobacillus and Coprococcus was significantly reduced in the ED group compared to the control group. Abundance of the genera Lactobacillus and Staphylococcus was significantly increased in the ED group. In a functional analysis using PICRUSt software, ED altered various pathways involved in amino acid metabolism of the gut microbiome. In conclusion, ED caused a reduction in bacterial diversity and altered metabolic functions.
Several outcomes have been reported on the role of gut microbiota in health promotion and disease prevention. Kyotango, one of the longevity areas with various centenarians, is a provincial city located in the northern part of Kyoto Prefecture in Japan. To understand the relationship between gut microbiota and urbanization, we compared the diversity, abundance, and function of gut microbiota in older healthy subjects between Kyotango and Kyoto cities; Kyoto is an urban city located in the southern part of Kyoto Prefecture. In total, 51 subjects at Kyotango and 51 subjects at Kyoto matched by age and gender were recruited, and their fecal samples were obtained to analyze the gut microbiota using 16S rRNA gene sequencing. Principal coordinate analysis for β-diversity revealed significant differences in the gut microbiota between two cities. In contrast, the analysis of α-diversity revealed no significant differences between the groups. On comparison at the phylum levels, the abundance of Firmicutes was decreased with the urbanization, whereas that of Proteobacteria and Bacteroidetes increased. On comparison at the genus levels, with urbanization, a significant decrease was observed in Lachnospiraceae families including genus Roseburia and Coprococcus, and significant increases was observed in Bacteroides, Oscillospira, Parabacteroides, and Ruminococcus. The most markedly increased functional pathway with urbanization was lipopolysaccharide biosynthesis proteins and lipopolysaccharide biosynthesis, and decreased pathway was transporters and ABC transporters. In conclusion, the present findings indicate significant differences in the gut microbiota between the provincial city and urban cities at Kyoto Prefecture. These alterations in the microbiota may provide new insights to consider the relationship between longevity and gut microbiota.
The mucosa-associated microbiota is an important component in human microbiota. The aim was to investigate mucosa-associated microbiota using brush samples during endoscopic procedures and compare with fecal microbiota. Seven patients who were planning to undergo a routine colonoscopy were recruited. Mucosal brushing samples were taken from 3 sites (terminal ileum, ascending and sigmoid colon), and a fecal sample was taken on the morning of colonoscopy. The samples were immediately placed in microcentrifuge tubes containing DNA stabilization reagent and analyzed using the next generation sequencer. The individual differences in microbiota were more evident than the differences of the sampling sites. Actinobacteria was more abundant and Bacteroidetes was less in the brush samples than those in the fecal samples. Taxonomic composition at the genus level and the proportion of genes responsible for some functions in the brushing samples tended to be different from those in the fecal samples. Bulleidia and Oribacteriumi were significantly more abundant and the proportions of genes responsible for transcription factors and phosphotransferase system were higher in ileal mucous than those in fecal samples. Brushing during colonoscopic procedure instead of using feces samples might be useful to analyze mucosa-associated microbiota.
Several risk scoring systems exist for acute upper gastrointestinal bleeding (UGIB). The clinical Rockall score (clinical RS) and the Glasgow-Blatchford score (GBS) are major risk scores that consider only clinical data. Computed tomography (CT) findings are equivocal in non-variceal UGIB. We compared CT findings with clinical data to predict mortality, rebleeding and need for endoscopic therapy in non-variceal UGIB patients. This retrospective, single-center study included 386 patients admitted to our emergency department with diagnosis of non-variceal UGIB by urgent endoscopy between January 2009 and March 2015. Multivariable logistic regression analysis was used to investigate CT findings and risk factors derived from clinical data. CT findings could not significantly predict mortality and rebleeding in non-variceal UGIB patients. However, upper gastrointestinal hemorrhage in CT findings better predicted the need for endoscopic therapy than clinical data. The adjusted odds ratios were 10.10 (95% CI 5.01–20.40) for clinical RS and 10.70 (95% CI 5.08–22.70) for the GBS. UGI hemorrhage in CT findings could predict the need for endoscopic therapy in non-variceal UGIB patients in our emergency department. CT findings as well as risk score systems may be useful for predicting the need for endoscopic therapy.
We compared arterial stiffness after glucose intake in active and inactive elderly people with impaired glucose tolerance and clarified whether physical activity was associated with arterial stiffness after ingestion of glucose. Twenty older adults with impaired glucose tolerance were analyzed in a cross-sectional design. Based on the international physical activity questionnaire, participants were divided into the active group (daily step count: 10,175.9 ± 837.8 steps/day, n = 10) or the inactive group (daily step count: 4,125.6 ± 485.9 steps/day, n = 10). Brachialankle (systemic) and heartbrachial (aortic) pulse wave velocity and cardio-ankle vascular index (systemic) were increased at 30, 60, and 90 min compared to baseline after a 75-g oral glucose tolerance test in the inactive but not the active group. Heartbrachial pulse wave velocity did not change compared to baseline after a 75-g oral glucose tolerance test in either group. The area under the curve for brachialankle pulse wave velocity was associated with daily living activity (r = –0.577, p = 0.008), daily step activity (r = –0.546, p = 0.013), and the daily step count (r = –0.797, p = 0.0001). The present findings indicate that physical activity or inactivity is associated with arterial stiffness following glucose ingestion.
Although some studies have indicated a correlation between Helicobacter pylori infection and the risk of colorectal neoplasms, these findings have not been consistent and are controversial. This case-control study aimed to investigate the association between endoscopic gastric mucosal atrophy and colorectal polyp occurrence. Records of 7,394 participants who underwent colonoscopy examinations from August 2008 to July 2018 were reviewed retrospectively. A total of 2,404 subjects were registered; 1,565 (65.1%) were in the gastric mucosal atrophy-positive group and 1,138 (47.3%) had colorectal polyps. The multivariate analysis adjusted by age, sex, smoking habits, alcohol habits, hemoglobin A1c, and systolic blood pressure indicated that patients in the gastric mucosal atrophy-positive group more frequently had colorectal polyps compared with patients in the gastric mucosal atrophy-negative group (odds ratio, 3.27; 95% confidence interval, 2.68–4.01; p<0.001). An analysis of the association between gastric mucosal atrophy degree and colorectal polyp status indicated that, compared with mild gastric mucosal atrophy, severe gastric mucosal atrophy was associated with a higher risk of proximal colon polyps (odds ratio, 1.47; 95% confidence interval, 1.05–2.07; p = 0.024) and two or more colorectal polyps (odds ratio, 1.80; 95% confidence interval, 1.30–2.49; p<0.001). In conclusion, gastric mucosal atrophy found during esophagogastroduodenoscopy may be an indication for complete colon screening.
Although a large body of literature reported that high intake of vitamin E played a possible role in reducing risk of cardiometabolic diseases, conflicting results were also found in some observational studies due to confounding factors. Hence, we used a Mendelian randomization study as an alternative way to examine the causality between circulating vitamin E and cardiometabolic diseases. Summary-level data were extracted from consortia and three single nucleotide polymorphisms were used as instrumental variables. Our study showed that a one-SD increase in circulating vitamin E levels was causally associated with an increased risk of coronary artery disease [odds ratio (OR) 3.16 (95%CI 1.74, 5.73); p = 1.91 × 10−3] at the Bonferroni-adjusted level of significance (p<0.005). Moreover, a one-SD increase in circulating vitamin E levels was associated with a 0.572-SD increase in low density lipoprotein cholesterol (mg/dl), a 0.693-SD increase in total cholesterol (mg/dl), and a 1.45-SD increase in triglyceride (mg/dl), but a 0.502-SD decrease in high density lipoprotein cholesterol (mg/dl) at the Bonferroni-adjusted level of significance (p<0.0028). Our findings indicated that genetically elevated vitamin E was associated with increased risk of coronary artery disease, suggesting an adverse causality between circulating vitamin E and coronary artery disease.