Treatment of Chronic Constipation using Elobixibat in a Real-World Setting: A Retrospective Cohort Study using an Electronic Medical Records Database in Japan.

Background: Chronic constipation is a common condition affecting people of all ages; therefore, the socioeconomic burden of chronic constipation is nonnegligible. Elobixibat (ELO), an ileal bail acid transport inhibitor, was launched in Japan in 2018. However, evidence of its use in diverse populations is limited. Objectives: This study aimed to evaluate the prescription of ELO, risk factors associated with ELO discontinuation, and the continuation of stimulants or saline laxatives during ELO treatment in a real-world setting using an extensive electronic medical records database that primarily includes data from acute-care hospitals. Methods: Data of patients prescribed for ELO from April 1, 2018, to March 31, 2022, were extracted from the database. The discontinuation of ELO and stimulant or saline laxatives during ELO treatment was evaluated using the Kaplan-Meier method. The Cox proportional hazards model evaluated risk factors associated with laxative discontinuation. Results: In total, 11,062 patients were evaluated. The rate of ELO discontinuation within 360 days of initiation was 78.7%. Hospitalized at the ELO initiation, stage 5 chronic kidney disease, and diagnosis of constipation by departments of obstetrics and gynecology or by departments of malignant neoplasm were identified as risk factors for discontinuation. Diagnosis of constipation, diabetes mellitus, Parkinson's disease, and previous laxative treatment was associated with a lower risk of ELO discontinuation. The prescription rate of stimulants and saline laxatives markedly decreased after ELO initiation; furthermore, nearly half of patients who were continuously prescribed ELO discontinued these laxatives within 360 days. Conclusions: The discontinuation of ELO was associated with various factors and using ELO may be beneficial in the withdrawal of concurrent stimulants and saline laxatives. These findings may help effectively manage chronic constipation.

Impact of elobixibat on serum and fecal bile acid levels and constipation symptoms in patients with chronic constipation.

BACKGROUND AND AIM: Elobixibat is a locally acting inhibitor of the ileal bile acid transporter. We compared bile acid metabolism between healthy subjects and patients with chronic constipation and assessed changes in the bile acid profile after elobixibat administration in the latter group. METHODS: Healthy subjects (n = 10) and patients with chronic constipation (n = 19) were assessed as inpatients for 7 days, during which they received meals containing ~60 g/day of fat. Patients with chronic constipation remained as inpatients for a further 7 days for once-daily elobixibat administration. Assessments included concentrations of fecal and serum bile acids, serum 7α-hydroxy-4-cholesten-3-one (C4) and fibroblast growth factor 19, and bowel movements and constipation symptoms. RESULTS: Fecal total and primary bile acids were significantly lower in patients with chronic constipation versus healthy subjects. Serum C4 and fibroblast growth factor 19 levels were comparable between groups. Elobixibat treatment increased fecal total and primary bile acids and decreased levels of fecal lithocholic acid and serum total as well as secondary bile acids in patients with chronic constipation. Bowel movements and other constipation-related symptoms were also improved by elobixibat to levels almost comparable with those of healthy subjects. CONCLUSIONS: Despite comparable C4 levels, patients with chronic constipation demonstrated decreased levels of fecal bile acids versus healthy subjects. Elobixibat treatment increased fecal bile acid excretion and reduced serum bile acid concentrations. The improvement of constipation after elobixibat treatment was associated with increased total bile acids, particularly primary bile acids.

Branched-chain amino acids inhibit the TGF-beta-induced down-regulation of taurine biosynthetic enzyme cysteine dioxygenase in HepG2 cells.

Taurine deficiency has been suggested to contribute to the pathogenesis and complications of advanced hepatic diseases. The molecular basis for a low level of taurine associated with hepatic failure is largely unknown. Using carbon tetrachloride (CCl4)-induced cirrhotic rat model, we found that the activity and expression of cysteine dioxygenase (CDO), a rate-limiting enzyme in taurine synthesis, were significantly decreased in the liver of these rats. To investigate the underlying mechanisms for the suppression, we examined the effects of pathological cytokines on CDO expression in human hepatoma HepG2 cells. Among the several cytokines, transforming growth factor-ß (TGF-ß), one of the key mediators of fibrogenesis, suppressed Cdo1 gene transcription through the MEK/ERK pathway. Finally, we further examined potential effects of branched-chain amino acids (BCAA) on CDO expression, as it has been reported that oral BCAA supplementation increased plasma taurine level in the patients with liver cirrhosis. BCAA, especially leucine, promoted Cdo1 gene transcription, and attenuated TGF-ß-mediated suppression of Cdo1 gene expression. These results indicate that the low plasma level of taurine in advanced hepatic disease is due to decreased hepatic CDO expression, which can be partly attributed to suppressive effect of TGF-ß on Cdo1 gene transcription. Furthermore, our observation that BCAA promotes Cdo1 expression suggests that BCAA may be therapeutically useful to improve hepatic taurine metabolism and further suppress dysfunctions associated with low level of taurine in hepatic diseases.

Elobixibat improves rectal sensation in patients with chronic constipation aged ≥60 years: a randomised placebo-controlled study.

OBJECTIVE: High rectal sensory thresholds (RSTs) are associated with chronic constipation (CC), especially in older patients. Bile acids (BAs) affect the RSTs of healthy individuals. Here, we aimed to investigate the effects of the BA transporter inhibitor elobixibat in patients with CC aged ≥60 years. DESIGN: We prospectively compared the RSTs of 17 patients with CC aged ≥60 years with those of 9 healthy individuals of the same age range. We next performed a prospective, randomised, parallel-group, double-blind, placebo-controlled clinical trial of 17 patients with CC who administered elobixibat or placebo daily for 1 week. Using barostat methodology, their first constant sensation volume (FCSV), defaecatory desire volume (DDV), and maximum tolerable volume (MTV) thresholds; their rectal compliance; and their faecal BA concentrations were measured before and after treatment. RESULTS: There were no significant differences in the RSTs of healthy individuals and patients with CC, but all of these tended to be higher in the latter group. Elobixibat increased the desire to defaecate, significantly reduced the threshold for FCSV (p=0.0018), and tended to reduce the threshold for DDV (p=0.0899) versus placebo. However, there were no differences in the MTV or rectal compliance of the two groups. The total faecal BA concentration increased, and particularly that of secondary BAs in the elobixibat group. Elobixibat was most efficacious in participants with a longer duration of CC and a history of treatment for CC. CONCLUSION: Elobixibat reduces the RSTs of patients with CC aged ≥60 years, which may be important for its therapeutic effects. TRIAL REGISTRATION NUMBER: jRCTs061200030.

Branched-chain amino acids prevent insulin-induced hepatic tumor cell proliferation by inducing apoptosis through mTORC1 and mTORC2-dependent mechanisms.

Branched-chain amino acids (BCAA) supplementation has been reported to suppress the incidence of liver cancer in obese patients with liver cirrhosis or in obese and diabetic model animals of carcinogenesis. Whether BCAA directly suppresses cell proliferation of hepatic tumor cells under hyperinsulinemic condition remain to be defined. The aim of this study was to investigate the effects of BCAA on insulin-induced proliferation of hepatic tumor cells and determine the underlying mechanisms. BCAA suppressed insulin-induced cell proliferation of H4IIE, HepG2 cells. In H4IIE cells, BCAA did not affect cell cycle progression but increased apoptosis by suppressing expressions of anti-apoptotic genes and inducing pro-apoptotic gene via inactivation of PI3K/Akt and NF-κB signaling pathways. Further studies demonstrated that BCAA inhibited PI3K/Akt pathway not only by promoting negative feedback loop from mammalian target of rapamycin complex 1 (mTORC1)/S6K1 to PI3K/Akt pathway, but also by suppressing mTORC2 kinase activity toward Akt. Our findings suggest that BCAA supplementation may be useful to suppress liver cancer progression by inhibiting insulin-induced PI3K/Akt and subsequent anti-apoptotic pathway, indicating the importance of BCAA supplementation to the obese patients with advanced liver disease.

Effects of Elobixibat in Patients with Diabetes and Concomitant Chronic Constipation: an 8-week, Prospective, Single-center, Single-arm Study.

AIMS: To evaluate the efficacy and safety of elobixibat in patients with diabetes and concomitant chronic constipation. METHODS: This was a single-center, single-arm study. Thirty-three patients with diabetes and chronic constipation, as defined by the Rome IV criteria, were treated with elobixibat (10 mg/day) for 8 weeks. Patients recorded stool properties, including spontaneous bowel movements (SBMs) and stool consistency, according to the Bristol Stool Form Scale (BSFS). Quality of life for constipation was evaluated with the Japanese version of the Patient Assessment of Constipation Quality of Life (JPAC-QOL). RESULTS: Of the 33 eligible patients, 30 completed the study. Elobixibat significantly increased the median (interquartile range) frequency of SBMs per week, from 5.0 (3.0-7.0) at baseline to 6.0 (4.0-7.0] at week 8 (p = 0.030). After 8 weeks, the BSFS score approached 4; the score for normal stool consistency and the JPAC-QOL score significantly improved from 1.05 ± 0.40 at baseline to 0.94 ± 0.53 (p = 0.048); and glycated albumin and serum lipid profiles significantly improved. Stratified analysis revealed that SBMs increased especially in patients with low SBM frequency, in particular in women, older adults, patients without overweight, patients with a long duration of constipation, and patients with diabetic neuropathy. No serious adverse events occurred. CONCLUSIONS: Among patients with diabetes who met the Rome IV criteria for constipation, elobixibat was effective, especially in those with few SBMs at baseline. Improvements in lipid profiles could be an advantage of elobixibat compared with other laxatives. CLINICAL TRIAL REGISTRY: Japan Registry of Clinical Trials registration number: jRCTs031190092.

Localization of polypyrimidine-tract-binding protein is involved in the regulation of albumin synthesis by branched-chain amino acids in HepG2 cells.

Long-term supplementation of branched-chain amino acids (BCAA) improves hypoalbuminemia in patients with cirrhosis. Our previous findings have suggested that the binding of polypyrimidine-tract-binding protein (PTB) to rat albumin mRNA attenuates its translation. The aim of the present study was to investigate the role of PTB in the regulation of albumin synthesis by BCAA in human hepatoma cells. HepG2 cells were cultured in a medium containing no amino acids (AA-free medium), a medium containing only 1 amino acid (a BCAA: valine, leucine or isoleucine) or a medium containing all 20 amino acids (AA-complete medium). HepG2 cells cultured in AA-complete medium secreted much more albumin than cells cultured in AA-free medium, with no difference in albumin mRNA levels. In cells cultured in AA-free medium, nuclear export of PTB was observed, and the level of the albumin mRNA-PTB complex was greater than in cells cultured in AA-complete medium. Addition of amino acids stimulated nuclear import of PTB. However, addition of amino acids with rapamycin inhibited the nuclear import of PTB. The addition of leucine, but not of valine or isoleucine, to AA-free medium increased albumin secretion and stimulated the nuclear import of PTB. These data indicate that the mammalian target of rapamycin is involved in the regulation of PTB localization and that leucine promotes albumin synthesis by inhibiting the formation of the albumin mRNA-PTB complex.

A novel diet-induced murine model of steatohepatitis with fibrosis for screening and evaluation of drug candidates for nonalcoholic steatohepatitis.

Many animal models of nonalcoholic steatohepatitis have been reported. While these models exhibit mild onset of hepatitis and fibrosis, induction is often slow. For faster screening of drug candidates, there is a compelling need for convenient animal models of steatohepatitis and nonalcoholic steatohepatitis in which fatty liver and hepatitis are stably induced within a short period. Here, we analyzed the hepatic lipid composition in nonalcoholic steatohepatitis, and used this information to successfully establish a murine model where steatohepatitis is induced within only 1 week using a novel diet (steatohepatitis-inducing high-fat diet, STHD-01) high in saturated fatty acids and cholesterol. After receiving STHD-01 for 1 week, normal mice (C57BL/6J) showed elevated markers of fatty liver and hepatitis, including hepatic triglycerides and plasma alanine aminotransferase; the administration of angiotensin receptor blockers reduced these symptoms. Furthermore, we confirmed that STHD-01 administration for 36 weeks induced not only sustained elevation of hepatic triglyceride and plasma alanine aminotransferase levels, but also fibrosis and tumor formation. Pretreatment with the carcinogen diethylnitrosamine accelerated tumor formation, and hepatic lesions were observed within 30 weeks of STHD-01 feeding following diethylnitrosamine pretreatment. Finally, branched-chain amino acids, known to reduce the risk for hepatocellular carcinoma in preclinical models, were effective in reducing the progression of liver fibrosis induced by STHD-01 feeding after diethylnitrosamine pretreatment. We concluded that STHD-01 administration successfully induces steatohepatitis within a short period of time. The proposed murine model is suitable for studying the long-term effects of pharmaceutical agents targeting steatohepatitis, fibrosis, and tumor formation.

Long-term Branched Chain Amino Acid Supplementation Ameliorates Diethylnitrosamine-induced Liver Glutathione S-transferase-p Positivity in Zucker Fatty Rats.

BACKGROUND: Obesity increases the risk of fatty liver disease and liver cancer. There are several models of obesity-associated hepatocellular carcinoma, but tumor development in these models is slow. MATERIALS AND METHODS: We investigated Zucker fatty rats, a model of obesity and insulin resistance, to discover if diethylnitrosamine (DEN), a potent liver carcinogen, might enhance liver carcinogenesis. We also investigated the effect of branched chain amino acids (BCAA) against the development of liver cancer. RESULTS: Incidence and number of hepatocellular carcinomas and adenomas were significantly greater in DEN-treated Zucker fatty rats than in DEN-treated lean rats. All treated Zucker fatty rats developed hepatocellular carcinoma within 16 weeks. Long-term BCAA supplementation significantly reduced expression of CyclinD1, PCNA, thymidine kinase, Bcl-2, and GST-p and increased expression of p21 in the liver. Furthermore, BCAA treatment significantly reduced the area of GST-p positive foci. CONCLUSION: Long-term BCAA treatment may induces cell cycle arrest and apoptotic induction, thus suppressing pre-neoplastic lesions.

Branched chain amino acid suppresses hepatocellular cancer stem cells through the activation of mammalian target of rapamycin.

Differentiation of cancer stem cells (CSCs) into cancer cells causes increased sensitivity to chemotherapeutic agents. Although inhibition of mammalian target of rapamycin (mTOR) leads to CSC survival, the effect of branched chain amino acids (BCAAs), an mTOR complex 1 (mTORC1) activator remains unknown. In this study, we examined the effects of BCAA on hepatocellular carcinoma (HCC) cells expressing a hepatic CSC marker, EpCAM. We examined the effects of BCAA and/or 5-fluorouracil (FU) on expression of EpCAM and other CSC-related markers, as well as cell proliferation in HCC cells and in a xenograft mouse model. We also characterized CSC-related and mTOR signal-related molecule expression and tumorigenicity in HCC cells with knockdown of Rictor or Raptor, or overexpression of constitutively active rheb (caRheb). mTOR signal-related molecule expression was also examined in BCAA-treated HCC cells. In-vitro BCAA reduced the frequency of EpCAM-positive cells and improved sensitivity to the anti-proliferative effect of 5-FU. Combined 5-FU and BCAA provided better antitumor efficacy than 5-FU alone in the xenograft model. Stimulation with high doses of BCAA activated mTORC1. Knockdown and overexpression experiments revealed that inhibition of mTOR complex 2 (mTORC2) or activation of mTORC1 led to decreased EpCAM expression and little or no tumorigenicity. BCAA may enhance the sensitivity to chemotherapy by reducing the population of cscs via the mTOR pathway. This result suggests the utility of BCAA in liver cancer therapy.

Possible role of visfatin in hepatoma progression and the effects of branched-chain amino acids on visfatin-induced proliferation in human hepatoma cells.

Obesity and related metabolic abnormalities, including adipocytokine dysbalance, are risk factors for hepatocellular carcinoma (HCC). Visfatin, an adipocytokine that is highly expressed in visceral fat, is suggested to play a role in the progression of human malignancies. Branched-chain amino acids (BCAA) reduce the incidence of HCC in obese patients with liver cirrhosis and prevent obesity-related liver carcinogenesis in mice. In this study, we investigated the possible role of visfatin on HCC progression and the effects of BCAA on visfatin-induced proliferation of HCC cells. In patients with HCCs, serum visfatin levels were significantly correlated with stage progression and tumor enlargement. Visfatin preferentially stimulated the proliferation of HepG2, Hep3B, and HuH7 human HCC cells compared with Hc normal hepatocytes. Visfatin phosphorylated extracellular signal-regulated kinase (ERK), Akt, and GSK-3ß proteins in HepG2 cells. LY294002 [a phosphoinositide-3-kinase (PI3K) inhibitor], PD98059 [a MAP/ERK 1 kinase (MEK1) inhibitor], CHIR99021 (a GSK-3ß inhibitor), and BCAA significantly inhibited visfatin-induced proliferation in HepG2 cells. BCAA also inhibited phosphorylation of GSK-3ß, increased cellular levels of p21(CIP1), caused cell-cycle arrest in G(0)/G(1) phase, and induced apoptosis in HCC cells in the presence of visfatin. These findings suggest that visfatin plays a critical role in the proliferation of HCC cells and may be associated with the progression of this malignancy. In addition, BCAA might inhibit obesity-related liver carcinogenesis by targeting and, possibly, by overcoming the stimulatory effects of visfatin.

Redox state of albumin is not associated with colloid osmotic pressure.

Serum albumin exists in oxidized and reduced forms. Although the oxidation of albumin affects some of its functions, the relationship between oxidized albumin and colloid osmotic pressure (COP) remains unclear. The aim of this study was to determine whether there is an association between oxidized albumin and COP. Blood samples from 20 healthy volunteers were divided into two aliquots in order to prepare reduced (n=20) and oxidized albumin samples (n=20). This was achieved by treatment with L-cysteine and a redox-stabilizing agent before and after incubation at 37°C for 24 h. The percentage of oxidized albumin was determined by high-performance liquid chromatography. COP was measured using a colloid osmometer. Reduced and oxidized albumin samples showed 100% of reduced and 100% of oxidized albumin, respectively. There were no significant differences in albumin level and total protein level between the reduced and the oxidized albumin samples. No significant change was seen in COP between the reduced and the oxidized albumin samples (reduced albumin, 17.4±0.2 mmHg; oxidized albumin, 17.3±0.2 mmHg; P=0.465). Therefore, there is no significant difference in COP between reduced and oxidized albumin samples.