Effect of L-carnitine on liver enzymes and biochemical factors in hepatic encephalopathy: A systematic review and meta-analysis

Protective effects of exogenous melatonin therapy against oxidative stress to male reproductive tissue caused by anti-cancer chemical and radiation therapy: a systematic review and meta-analysis of animal studies

Background

Male testicular dysfunction is a considerable complication of anti-cancer therapies, including chemotherapy and radiotherapy, partly due to the increased oxidative stress caused by these treatments. Melatonin is an effective antioxidant agent that protects testicles against physical and toxic chemical stressors in animal models. This study aims to systematically review the melatonin's protective effects against anti-cancer stressors on rodential testicular tissue.

Materials and Method

An extensive search was conducted in Web of Science, Scopus, and PubMed for animal studies investigating exogenous melatonin's protective effects on rodent testicles exposed to anti-cancer chemicals and radiotherapeutic agents. Using the DerSimonian and Laird random-effect model, standardized mean differences and 95% confidence intervals were estimated from the pooled data. The protocol was prospectively registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42022355293).

Results

The meta-analysis included 38 studies from 43 studies that were eligible for the review. Rats and mice were exposed to radiotherapy (ionizing radiations such as gamma- and roentgen radiation and radioactive iodine) or chemotherapy (methotrexate, paclitaxel, busulfan, cisplatin, doxorubicin, vinblastine, bleomycin, cyclophosphamide, etoposide, Taxol, procarbazine, docetaxel, and chlorambucil). According to our meta-analysis, all outcomes were significantly improved by melatonin therapy, including sperm quantity and quality (count, motility, viability, normal morphology, number of spermatogonia, Johnsen's testicular biopsy score, seminiferous tubular diameter, and seminiferous epithelial height), serum level of reproductive hormones (Follicle-Stimulating Hormone and testosterone), tissue markers of oxidative stress (testicular tissue malondialdehyde, superoxide dismutase, glutathione peroxidase, catalase, glutathione, caspase-3, and total antioxidant capacity), and weight-related characteristics (absolute body, epididymis, testis, and relative testis to body weights). Most SYRCLE domains exhibited a high risk of bias in the included studies. Also, significant heterogeneity and small-study effects were detected.

Conclusion

In male rodents, melatonin therapy was related to improved testicular histopathology, reproductive hormones, testis and body weights, and reduced levels of oxidative markers in testicular tissues of male rodents. Future meticulous studies are recommended to provide a robust scientific backbone for human applications.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022355293, identifier CRD42022355293.

Normalization of lipid oxidation defects arising from hypoxia early posthepatectomy prevents liver failure in mouse

Surgical liver failure (SLF) develops when a marginal amount of hepatic mass is left after surgery, such as following excessive resection. SLF is the commonest cause of death due to liver surgery; however, its etiology remains obscure. Using mouse models of standard hepatectomy (sHx) (68%, resulting in full regeneration) or extended hepatectomy (eHx) (86%/91%, causing SLF), we explored the causes of early SLF related to portal hyperafflux. Assessing the levels of HIF2A with or without oxygenating agent inositol trispyrophosphate (ITPP) indicated hypoxia early after eHx. Subsequently, lipid oxidation (PPARA/PGC1α) was downregulated and associated with persisting steatosis. Mild oxidation with low-dose ITPP reduced the levels of HIF2A, restored downstream PPARA/PGC1α expression along with lipid oxidation activities (LOAs), and normalized steatosis and other metabolic or regenerative SLF deficiencies. Promotion of LOA with L-carnitine likewise normalized the SLF phenotype, and both ITPP and L-carnitine markedly raised survival in lethal SLF. In patients who underwent hepatectomy, pronounced increases in serum carnitine levels (reflecting LOA) were associated with better recovery. Lipid oxidation thus provides a link between the hyperafflux of O₂-poor portal blood, the metabolic/regenerative deficits, and the increased mortality typifying SLF. Stimulation of lipid oxidation-the prime regenerative energy source-particularly through L-carnitine may offer a safe and feasible way to reduce SLF risks in the clinic.

The effect of grape products on liver enzymes: A systematic review and meta-analysis of randomized controlled trials

The favorable influence of grape consumption on metabolic diseases has previously been shown in studies. We sought to assess the effects of grape intake on liver enzymes, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP), in adults. We performed literature search in online databases, to find eligible randomized controlled trials (RCTs). we considered RCTs that met the following criteria: RCTs consisted of use of grape products on ALT, AST, and ALP in adults (≥18 years) with at least 2 weeks intervention duration. Pooling data from 11 trials showed that grape products intake significantly reduced ALP (p = .010), without any significant changes in ALT (p = .234) and AST (p = .300). In subgroup analysis, we found a significant reduction in ALP, ALT, and AST when the duration of intervention was ≥12 weeks, and when grape seed extract (GSE) was administered. The variable duration and dosage of intervention was one of the sources of bias in our meta-analysis. Additionally, participants involved in included studies had different physiological status and various age groups. Grape products administration may significantly improve ALT, AST, and ALP in adults in long-term interventions and/or when GSE is administered. It should be noted that the favorable effects of grape consumption were small and may not reach clinical importance.

Blood Levels of Ammonia and Carnitine in Patients Treated with Valproic Acid: A Meta-analysis

Objective

Long-term valproic acid (VPA) administration is associated with adverse metabolic effects, including hyperammonemia and hypocarnitinemia. However, the pathogeneses of these adverse events remain unclear, and not enough reviews have been performed. The aim of this study was to conduct a meta-analysis of studies examining blood levels of ammonia and carnitine in patients treated with VPA.

Methods

We conducted database searches (PubMed, Web of Science) to identify studies examining blood levels of ammonia and carnitine in patients treated with VPA. A meta-analysis was performed to conduct pre- and post-VPA treatment comparisons, cross-sectional comparisons between groups with and without VPA use, and estimations of the standardized correlations between blood levels of ammonia, carnitine, and VPA.

Results

According to the cross-sectional comparisons, the blood ammonia level in the VPA group was significantly higher than that in the non-VPA group. Compared to that in the non-VPA group, the blood carnitine level in the VPA group was significantly lower. In the meta-analysis of correlation coefficients, the blood VPA level was moderately correlated with blood ammonia and blood free carnitine levels in the random effects model. Furthermore, the blood ammonia level was moderately correlated with the blood free carnitine level.

Conclusion

Although the correlation between ammonia and free carnitine levels in blood was significant, the moderate strength of the correlation does not allow clinicians to infer free carnitine levels from the results of ammonia levels. Clinicians should measure both blood ammonia and free carnitine levels, especially in patients receiving high dosages of VPA.

Effect of L-carnitine on quality of life in covert hepatic encephalopathy: a randomized, double-blind, placebo-controlled study

BACKGROUND/AIMS

L-carnitine is potentially beneficial in patients with hepatic encephalopathy (HE). We aimed to evaluate the impact of L-carnitine on the quality of life and liver function in patients with liver cirrhosis and covert HE.

METHODS

We conducted an investigator-initiated, prospective, multi-center, double- blind, randomized phase III trial in patients with covert HE. A total of 150 patients were randomized 1:1 to L-carnitine (2 g/day) or placebo for 24 weeks. Changes in quality of life and liver function were assessed at 6 months. The model for end-stage liver disease (MELD), the 36-Item Short Form Survey (SF-36), the psychometric hepatic encephalopathy score (PHES), and the Stroop Test were evaluated in all patients.

RESULTS

The total SF-36 score significantly improved in the L-carnitine group after 24 weeks (difference: median, 2; interquartile range, 0 to 11; p < 0.001); however, these values were comparable between the two groups. Furthermore, there was a significant ordinal improvement in PHES scores among patients with minimal HE who were in the L-carnitine group (p = 0.007). Changes in the total carnitine level also positively correlated with improvements in the Stroop test in the L-carnitine group (color test, r = 0.3; word test, r = 0.4; inhibition test, r = 0.5; inhibition/switching test, r = 0.3; all p < 0.05). Nevertheless, the MELD scores at week 24 did not differ between the groups.

CONCLUSION

Twenty-four weeks of L-carnitine supplementation was safe but ineffective in improving quality of life and liver function.

Dietary Administration of L-Carnitine During the Fattening Period of Early Feed Restricted Lambs Modifies Ruminal Fermentation but Does Not Improve Feed Efficiency

Early feed restriction of lambs may program animals to achieve reduced feed efficiency traits as a consequence of permanent mitochondrial dysfunction. The hypothesis at the background of the present study is that dietary administration of L-Carnitine (a compound that promotes the activation and transportation of fatty acids into the mitochondria) during the fattening period of early feed restricted lambs can: (a) improve the biochemical profile of early feed restricted lambs, (b) improve feed efficiency, (c) modulate the ruminal and intestinal microbiota, and (d) induce changes in the gastrointestinal mucosa, including the immune status. Twenty-two newborn male Merino lambs were raised under natural conditions but separated from the dams for 9 h daily to allow feed restriction during the suckling period. At weaning, lambs were assigned to a control group being fed ad libitum a complete pelleted diet during the fattening phase (CTRL, n = 11), whereas the second group (CARN, n = 11) received the same diet supplemented with 3 g of L-Carnitine/kg diet. The results revealed that even though L-Carnitine was absorbed, feed efficiency was not modified by dietary L-Carnitine during the fattening period (residual feed intake, p &gt; 0.05), whereas ruminal fermentation was improved [total short-chain fatty acids (SCFAs), 113 vs. 154 mmol/l; p = 0.036]. Moreover, a trend toward increased concentration of butyrate in the ileal content (0.568 vs. 1.194 mmol/100 ml SCFA; p = 0.074) was observed. Other effects, such as reduced heart weight, lower levels of markers related to muscle metabolism or damage, improved renal function, and increased ureagenesis, were detected in the CARN group. Limited changes in the microbiota were also detected. These findings suggest that L-Carnitine may improve ruminal fermentation parameters and maintain both the balance of gut microbiota and the health of the animals. However, the improved ruminal fermentation and the consequent greater accumulation of intramuscular fat might have hidden the effects caused by the ability of dietary L-Carnitine to increase fatty acid oxidation at the mitochondrial level. This would explain the lack of effects of L-Carnitine supplementation on feed efficiency and points toward the need of testing lower doses, probably in the context of animals being fed in excess non-protein nitrogen.

Additional L-Carnitine Reduced the Risk of Hospitalization in Patients with Overt Hepatic Encephalopathy on Rifaximin

BACKGROUND

Data regarding the additional effect on the recurrence of hepatic encephalopathy (HE) after oral L-carnitine administration are scarce.

OBJECTIVE

This study aimed to assess the additional effects of L-carnitine in patients who were receiving rifaximin for HE.

METHODS

This randomized study comprised a screening visit and a 12-week treatment period. Patients who fulfilled the eligibility criteria were randomized to either group A (additional rifaximin) or group B (additional L-carnitine and rifaximin). Group A received 1,200 mg/day of rifaximin. Group B received 1,500 mg/day of L-carnitine and rifaximin at 1,200 mg/day. The endpoints were the changes in the portal systemic encephalopathy (PSE) index and the admission rate from the baseline for the duration of the study in both groups.

RESULTS

Eighty-three patients were randomized to either group A (n = 42) or group B (n = 41). In group A, the PSE index decreased from 0.35 ± 0.09 at baseline to 0.27 ± 0.11 on the final evaluation day (p = 0.001). In group B, the PSE index decreased from 0.37 ± 0.09 at baseline to 0.24 ± 0.11 on the final evaluation day (p = 0.001). Although there was not a significant reduction in the PSE index in group A compared to that in group B (p = 0.202), the admission rates were 30.9% and 9.8% in groups A and B, respectively. Additional L-carnitine significantly reduced the admission rate (p = 0.028).

CONCLUSION

L-Carnitine addition reduced the risk of hospitalization for patients who received rifaximin for HE.

Nutraceuticals & microbiota: review

Nutraceuticals are defined as products isolated or purified from foods that are generally sold in medicinal or dosage forms not usually associated with food which is demonstrated to have a physiological benefit or provide protection against chronic disease. In this context, the products offered should be rigorously evaluated by international regulatory agencies. More recently, nutraceuticals have been proposed as a potential preventive and therapeutic option in the assessment of chronic diseases, mainly by altering the microbiome composition. However, the current lack of conclusive evidence supporting the "healthy" or "normal" microbiome, along with the dysbiosis concept paradigm, could be both contributing to the lack of homogeneous results. These issues may be solved in the next years with the use of emergent technologies in the individual's microbiome assessment and its fluctuations in time or related to many factors, such as nutraceuticals. Additionally, future research assessing the independent association between the dysbiosis modification and any "potential" nutraceutical product (including bioactive ingredient or chemical compound in food) is going to enlarge the currently reduced "established nutraceuticals" group. In this work we have assessed the nutraceutical's potential role as a microbiome-targeted manipulation therapy, and the gut-liver axis involved in the digestive diseases' pathogenesis and progression, including the chronic liver diseases. Moreover, microbiome targeted nutraceuticals that show consistent results might be further included in clinical research and trials in the therapeutic assessment of chronic diseases. Finally, the indication of these quality microbiome-targeted nutraceuticals will undoubtedly carry health benefits for individuals.

Effect of L-carnitine on health-related quality of life in patients with liver cirrhosis

L-carnitine (4-N-trimethylammonium-3-hydroxybutyric acid) is the physiologically active form of carnitine and is a natural compound that has been shown to exhibit antioxidant activity. L-carnitine is used as a supplementary treatment in patients with cirrhosis with hepatic encephalopathy, hyperammonemia or muscle cramps. In the present study, the effect of L-carnitine supplementation on health-related quality of life in 30 patients with cirrhosis was prospectively examined. L-carnitine (1,800 mg/day) was administered orally for 6 months. To assess the effects of L-carnitine on chronic fatigue, patients filled out a self-report questionnaire regarding their physical and mental health. The levels of total and free carnitine, and acylcarnitine were found to be significantly higher 1, 3 and 6 months after therapy initiation compared with before treatment. Serum albumin levels were significantly increased 3 and 6 months after initiation of therapy. L-carnitine supplementation significantly increased the BAP/d-ROM ratio, a marker of antioxidant status in patients with cirrhosis. Changes in serum carnitine concentrations were positively correlated with changes in serum albumin levels (R²=0.369; P=0.012), but not with changes in serum ammonia levels (R²= 0.005; P=0.78). Total and mental health scores improved significantly, and physical scores improved marginally 3 and 6 months after initiation of L-carnitine. These findings may be attributed to the enhanced serum albumin levels and oxidative stress rather than the reduced serum ammonia levels. Based on these results, it is suggested that L-carnitine can potentially alleviate chronic fatigue, along with the increased BAP/d-ROM ratio, which were involved in increased oxidative stress in patients with cirrhosis. The specific mechanisms by which L-carnitine ameliorates chronic fatigue is not fully understood and requires further investigation.

Effect of L-Carnitine Supplementation on Lipid Profiles of Patients with Liver Disease: A Systematic Review and Meta-Analysis

Results of previous studies regarding the effect of L-carnitine on lipid profiles in the patients with liver diseases are contradictory. This meta-analysis was performed to assess the effect of L-carnitine on serum levels of low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), and total cholesterol (TC) in overweight patients with liver diseases. A systematic search was carried out using the Web of Science, PubMed, Scopus, and Cochrane library databases to identify articles published before April 2019 investigating the effects of L-carnitine supplementation on patients with liver disease. There was no language or time limitation for the studies. A meta-analysis was carried out using both the random and fixed effects model where appropriate, and I2 index were used to evaluate heterogeneity. These results indicated that L-carnitine supplementation significantly reduces blood levels of TC and TG in patients with liver disease, whereas carnitine had no effect on the levels of HDL and LDL. The reducing effect of L-carnitine on both TC and TG was found following long-term carnitine supplementation (≥24 weeks), supplementation with doses less than or equal to 2,000 mg/d, and in patients with chronic hepatitis C. This meta-analysis indicates the beneficial effect of L-carnitine on TC and TG in overweight patients with liver disease, particularly patients with chronic hepatitis C, in both long-term and low doses.

Effect of Ginger Powder Supplementation in Patients with Non-Alcoholic Fatty Liver Disease: A Randomized Clinical Trial

Background

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders. The main causes of NAFLD are associated with insulin resistance, severe lipid metabolism disorders, oxidative stress and inflammation. Previous studies have reported that ginger has positive metabolic results.

Aim

The aim of this study was to determine the effect of ginger powder supplement on lipid profiles, insulin resistance, liver enzymes, inflammatory cytokines and antioxidant status in patients with NAFLD.

Methods

In this randomized clinical trial, 46 people with NAFLD were parted into two groups and subjected to the ginger or placebo capsules (3 capsules daily, each containing 500 mg of ginger or wheat flour) over 12 weeks. All patients received a diet with balanced energy and physical activity during the intervention period. Liver ultrasonography, anthropometric indices and biochemical parameters were measured before and after intervention.

Results

No significant difference was found between the two groups in the baseline variables at the beginning of the study. At the end of the study, serum levels of alanine aminotransferase (ALT), total cholesterol, low-density lipoprotein (LDL-C), fasting blood glucose, and insulin resistance index (HOMA), C-reactive protein (hs-CRP), and fetuin-A in the group receiving a ginger supplement significantly decreased compared to placebo. However, there was no significant difference between the two groups in body weight, fasting insulin, HDL-C, triglyceride, adiponectin, alpha-tumor necrosis factor (TNF-α), total antioxidant capacity (TAC), gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), fatty liver index (FLI), fatty liver grade and blood pressure.

Conclusion

The ginger supplement may be used as a complementary therapy along with existing therapies to reduce insulin resistance, liver enzymes and inflammation in patients with non-alcoholic fatty liver.

Case Report: Pediatric Recurrent Acute Liver Failure Caused by Neuroblastoma Amplified Sequence (NBAS) Gene Mutations

Acute liver failure (ALF) in childhood is a rapidly progressive, potentially life-threatening condition that occurs in previously healthy children of all ages. However, the etiology of ~50% of cases with pediatric ALF remains unknown. We herein report a 4-year-old Chinese girl with recurrent ALF (RALF) due to a mutation in the neuroblastoma amplified sequence (NBAS) gene. The patient had suffered from multiple episodes of fever-related ALF since early childhood. She had also suffered from acute kidney injury, hypertension, mild pulmonary hypertension, pleural effusion, and hypothyroidism. A novel compound heterozygote mutation, c.3596G> A (p.C1199Y)/ex.9del (p.216-248del), in the NBAS gene was identified by whole-exome sequencing (WES). The missense mutation c.3596G> A (p. C1199Y) was inherited from her father, and ex.9del (p.216-248del) was inherited from her mother. The patient was managed with intensive treatments, such as renal replacement therapy (CRRT), intravenous antibiotics, and glucose infusion, and was discharged after full recovery. We identified a novel compound heterozygote mutation in the NBAS gene that caused fever-related RALF in a Chinese child, which further expands the mutational spectrum of NBAS.