Major liver resection results in a changed plasma amino acid pattern as reflected by a decreased Fischer ratio which improves by bactericidal/permeability increasing protein

Branched-chain amino acids protect the liver from cirrhotic injury via suppression of activation of lipopolysaccharide-binding protein, toll-like receptor 4, and signal transducer and activator of transcription 3, as well as Enterococcus faecalis translocation

OBJECTIVES

Branched-chain amino acids (BCAAs) are used as nutritional support and for improving prognosis in liver cirrhosis. Here we investigate the molecular mechanisms of BCAA treatment and liver damage focused on pathways related to lipopolysaccharide-binding protein (LBP).

METHODS

Serum LBP levels were measured in cirrhotic patients and in cirrhotic rats treated with BCAA to examine the correlation between liver function and survival. In cirrhotic rats, liver damage, Enterococcus faecalis translocation, serum capsular polysaccharide, and intestinal tight junction levels were assessed. Damaged HepG2 cells were cultured with BCAA-supplemented, BCAA-deficient, or control amino acid medium, followed by examination of LBP expression.

RESULTS

Serum LBP levels were significantly increased in deceased patients individuals with liver cirrhosis. The survival rate in patients with lower serum LBP (<3.48 μg/mL) was significantly improved. In BCAA-treated rat liver samples, protein expression of LBP, toll-like receptor 4 (TLR4), and phosphorylated signal transduction and activator of transcription 3 (STAT3) were significantly reduced. Also in BCAA-treated rats, intestinal zonula occludens gene expression was increased, whereas hepatic translocation of E. faecalis and serum capsular polysaccharide levels were reduced. In damaged HepG2 cells, lipopolysaccharide-induced elevation of LBP expression was rapidly and strongly repressed in BCAA-enriched medium.

CONCLUSIONS

Serum LBP level is a prognostic biomarker in liver cirrhosis. BCAA treatment reduced translocation of E. faecalis through intestinal tight junction recovery and reduced LBP expression in the liver, which repressed activation of LBP, toll-like receptor 4, and signal transduction and activator of transcription 3. Our findings suggest that BCAA supplementation protects the liver from damage via multiple pathways.

Bactericidal/permeability-increasing protein in host defense and its efficacy in the treatment of bacterial sepsis

The 55-kD bactericidal/permeability-increasing protein (BPI) is a neutrophil-derived polypeptide belonging to a family of lipid and endotoxin binding proteins. BPI is composed of two functionally distinct structural domains: a potently antibacterial and antiendotoxin ∼ 20-kD aminoterminal half, and an opsonic carboxy-terminal portion. In multiple animal models, a recombinant amino-terminal fragment of BPI (rBPI21) is nontoxic and protects against gram-negative bacteria and endotoxin. In humans, rBPI21 is also nontoxic and nonimmunogenic and has undergone phase II/III clinical trials with apparent therapeutic benefit.

Correlation between plasma amino acid profiles and the various stages of hepatitis B infection

The amino acid metabolism in patients with hepatitis B virus (HBV) infection is significantly changed. In this study, we analyzed the relationship between the amino acid profiles and varying clinical stages of HBV infection, and investigated their significance. The plasma amino acid concentrations in 115 patients with HBV infection and 32 healthy donors were detected and analyzed, and the main indicators of liver function were measured. Correlation analysis was performed between the amino acid profiles (Fischer's ratio, branched-chain amino acid to tyrosine ratio [BTR]) and the key indicators of liver function in patients with HBV infection. Fisher's ratio and the BTR of patients with HBV infection was found to differ from that of the healthy controls, and was also found to significantly correlate with the stage of HBV infection. Changes in the BTR were closely related to the level of key indicators of liver function, and a significant relationship was detected between the Fischer's ratio and the BTR (r=0.928, p<0.001). These results suggest that Fischer's ratio and the BTR can indirectly reflect the degree of liver cell injury. Determining and tracking the plasma amino acid profiles could, therefore, be used for the diagnosis, treatment selection, and prognosis of patients with varying stages of HBV infection.

Effect of Oral Supplementation with Branched-chain Amino Acid (BCAA) during Radiotherapy in Patients with Hepatocellular Carcinoma: A Double-Blind Randomized Study

Purpose

The present study evaluated whether oral supplementation with a branched-chain amino acid (BCAA) improves the biochemical and amino acid profiles of liver tumor patients undergoing radiotherapy.

Materials and Methods

Patients were randomly assigned to one of 2 groups: a group given oral supplementation with BCAA granules (LIVACT granules; Samil Pharm Co., Korea, each granule containing L-isoleucine 952 mg, L-leucine 1,904 mg, and L-valine 1,144 mg) during radiotherapy, or a placebo group. Physical and biochemical examinations and measurements, including subjective symptoms, Child-Pugh class, body mass index, plasma albumin concentration, and plasma amino acid profiles were monitored.

Results

Fifty were enrolled between November 2005 and November 2006. We also analyzed data from 37 hepatocellular carcinoma (HCC) patients in order to evaluate a more homogenous group. The two groups of patients were comparable in terms of age, gender, Child-Pugh score, and underlying hepatitis virus type. Serum albumin, total protein, liver enzymes, and cholesterol showed a tendency to increase in the BCAA group. In this group, the percentage of cases that reverted to normal serum albumin levels between 3 and 10 weeks after administration of BCAA was significantly higher (41.18%) than in the placebo group (p=0.043).

Conclusion

Oral supplementation with a BCAA preparation seems to help HCC patients undergoing radiotherapy by increasing the BCAA concentration.

Effect of Oral Supplementation with Branched-chain Amino Acid (BCAA) during Radiotherapy in Patients with Hepatocellular Carcinoma: A Double-Blind Randomized Study

PURPOSE

The present study evaluated whether oral supplementation with a branched-chain amino acid (BCAA) improves the biochemical and amino acid profiles of liver tumor patients undergoing radiotherapy.

MATERIALS AND METHODS

Patients were randomly assigned to one of 2 groups: a group given oral supplementation with BCAA granules (LIVACT granules; Samil Pharm Co., Korea, each granule containing L-isoleucine 952 mg, L-leucine 1,904 mg, and L-valine 1,144 mg) during radiotherapy, or a placebo group. Physical and biochemical examinations and measurements, including subjective symptoms, Child-Pugh class, body mass index, plasma albumin concentration, and plasma amino acid profiles were monitored.

RESULTS

Fifty were enrolled between November 2005 and November 2006. We also analyzed data from 37 hepatocellular carcinoma (HCC) patients in order to evaluate a more homogenous group. The two groups of patients were comparable in terms of age, gender, Child-Pugh score, and underlying hepatitis virus type. Serum albumin, total protein, liver enzymes, and cholesterol showed a tendency to increase in the BCAA group. In this group, the percentage of cases that reverted to normal serum albumin levels between 3 and 10 weeks after administration of BCAA was significantly higher (41.18%) than in the placebo group (p=0.043).

CONCLUSION

Oral supplementation with a BCAA preparation seems to help HCC patients undergoing radiotherapy by increasing the BCAA concentration.

Lipoic acid is 10 times more toxic in cats than reported in humans, dogs or rats

The antioxidant lipoic acid (LA) is administered to humans and pets. We described acute toxicity and maximum tolerated dose (MTD) of LA in cats. In progression, 10 healthy adult male cats received orally 60 (high), 30 (low), or 0 mg LA/kg (control). Serum enzyme activities and concentrations of bile acids, ammonia, amino acids (AA), LA and dihydrolipoic acid (DHLA) were measured, and tissues examined microscopically. Significant clinical toxicity with changes in ammonia and AA concentrations occurred in all high-dose cats. Oral LA produced hepatocellular toxicity and MTD was < 30 mg/kg in cats.

Branched chain amino acids in heptatic encephalopathy

BACKGROUND

Early theories or hepatic encephalopathy focused on ammonia-driven disruption of the Krebs cycle and cellular energy production. The "false-neurotransmitter" theory directed attention toward the interactions of amino acids, metabolism, the blood-brain barrier and neurotransmission. As they evolved, these studies revealed surprising and subtle effects of ammonia on brain amino acid uptake.

DATA SOURCES

Research over a 15-year period in Josef E. Fischer's laboratory explored many aspects of these interactions. Subsequent studies by others have confirmed and extended them into other areas. Insights from this work continue to stimulate attempts to confirm or disprove the clinical utility of branched chain amino acids.

CONCLUSIONS

Increased understanding of the factors affecting ammonia, amino acid and neurotransmitter disturbances in chronic liver failure have made a significant and ongoing contribution to the study of metabolism in health and disease.

Therapeutic potential of the bactericidal/permeability-increasing protein

Innate immune mechanisms respond rapidly to bacterial infection. A key cellular component of the innate immune response is the neutrophil, whose cytoplasmic granules contain a variety of antimicrobial proteins and peptides. Among these is the bactericidal/permeability-increasing protein (BPI), a cationic 55 kDa protein whose selective anti-infective action against Gram-negative bacteria is based on its high (nM) affinity for lipopolysaccharide (LPS, or "endotoxin"). Binding of BPI to Gram-negative bacteria results in growth inhibition, serves as an opsonin that enhances phagocytosis of bacteria and inhibits bacteria-induced inflammatory responses by blocking the interaction of LPS with host pro-inflammatory pathways. Expression of BPI appears to be developmentally regulated as human newborns apparently have lower neutrophil BPI levels than adults. BPI expression has also recently been demonstrated in human epithelial cells where it appears to be inducible by endogenous anti-inflammatory lipids (lipoxins). BPI's potent anti-endotoxic activity against a broad range of Gram-negative bacterial pathogens is manifest in biological fluids and renders it an attractive template for pharmaceutical development. Indeed, rBPI(21), an active recombinant protein derived from human BPI, has proven safe in Phase I human trials, shown promise in Phase II trials and has recently completed a Phase III trial for severe meningococcaemia with apparent benefit. Identification and evaluation of additional disease entities characterised by Gram-negative bacteraemia and/or endotoxaemia as possible targets for BPI therapy continues.