Effect Of L-carnitine Supplementation Research Articles

Effects of L-carnitine supplementation in diets of broiler chickens

L-carnitine is a nutritional supplement having fat-burning property and plays an important role in lipid metabolism, energy release, and also improve the production yield, immunity and blood constitute. This paper reviews the effects of L-carnitine on quantitative and qualitative characteristics of broilers. According to the reviewed literature, the application of L-carnitine (50-200 mg/kg) has no significant effect on the growth performance, however, using L-carnitine as much as 300-800 mg/kg resulted to an improvement in the body weight (2226.00-2575.00 g) compared to the control chicks (1998.40-2338.75 g). The feed conversion ratios of the chickens fed the same amount of L-carnitine were 1.66-1.86 kg/kg, which was improved in comparison with the control chicks (1.87-2.09 kg/kg). Abdominal fat of the broiler chickens fed 50-900 mg/kg L-carnitine was 0.98-1.75%, which is lower than the control chicks (1.79-2.16%). For immunity, the antibody titers against the Newcastle virus in the chickens fed 250 mg/kg L-carnitine was between 4.6- 5.5 which is more than control chicks (4.3-5.2). The antibody titer against the influenza virus in the chickens fed the same amount of L-carnitine was between 5.6-6.3, which was more than the control chicks (4.3-5.8). The use of 100-600 mg/kg L-carnitine could reduce triglyceride (90-104.4 mg/dL) compared to the control chicks (125-104.7 mg/dL) and also reduced the cholesterol (109-115 mg/dL) compared to the control chicks (129.25-131 mg/dL). The application of 100-600 mg/kg L-carnitine also could reduce low-density lipoprotein (LDL) from 19.1-72.2 mg/dL to 16.5-49.0 mg/dL. However, the application of 100-900 mg/kg L-carnitine had no significant effect on the sensory characteristics of broiler chicken meat. In general, it can be concluded that L-carnitine can be used as a dietary supplement on the health of broiler chickens without any negative effect on growth performance.

Effect of L-carnitine supplementation on renal anemia in patients on hemodialysis: a meta-analysis.

L-carnitine is an amino acid derivative that is thought to be helpful for treating renal anemia in hemodialysis patients. However, the mechanism remains to be fully elucidated. A literature search was performed on PubMed, Embase, and Cochrane Central Register of Controlled Trials to identify randomized controlled trials (RCTs) and conduct a meta-analysis for investigating the effect of L-carnitine in the treatment of renal anemia in participants receiving hemodialysis. A total of 18 eligible trials with 1090 participants were included in this study. L-carnitine can significantly increase plasma free L-carnitine levels (mean difference [MD]: 140.53, 95% confidence interval [CI] 102.22-178.85; P < 0.00001), decrease the erythropoietin responsiveness index (ERI; MD: -2.72, 95% CI -3.20 to -2.24; P < 0.00001) and the required erythropoiesis-stimulating agent (ESA) doses (MD: -1.70, 95% CI -2.04 to -1.36; P < 0.00001). However, the use of L-carnitine was not associated with a higher hemoglobin level (MD: 0.18, 95% CI -0.20 to 0.55; P = 0.35) and hematocrit level (MD: 1.07, 95% CI -0.73 to 2.87; P = 0.24). In subgroup analyses, the effects of L-carnitine supplementation on renal anemia in patients on hemodialysis were independent of the treatment duration and intervention routes. The present meta-analysis indicated that L-carnitine therapy significantly increased plasma L-carnitine concentrations, improved the response to ESA, decreased the required ESA doses in patients receiving hemodialysis, and maintained hemoglobin and hematocrit levels. L-carnitine supplementation should be supported in hemodialysis patients. However, the relationship between L-carnitine treatment and long-term outcomes is still unclear. Further high-quality RCTs are needed to verify our findings.

The effect of L-Carnitine supplementation on clinical symptoms, C-reactive protein and malondialdehyde in obese women with knee osteoarthritis: a double blind randomized controlled trial

BackgroundsL-carnitine decreases oxidation and inflammation by reducing the fatty acid in plasma and using oxygen in ATP synthesis. As such, knee osteoarthritis (KOA) can be improved by reducing apoptotic chondrocytes. This study was designed to compare the effect of L-carnitine supplementation and low-calorie diet on improving KOA among obese women. We further investigated the effect of L- carnitine on improvement of KOA in obese women on low calorie diet.MethodsTo conduct the study, 76 obese women with KOA were randomly assigned into two low-calorie diet groups: the first received 1000 mg of LCG and the second took the placebo (PLG) (n = 38). Anthropometry indices, body composition, lipid profile, C-reactive Protein (CRP), Malondialdehyde (MDA), and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) were assessed at the baseline condition and after 12 weeks.ResultsThe mean change of body mass index (BMI) (− 1.21 ± 0.84 vs. -0.79 ± 0.70; P = 0.02) and weight (− 2.76 ± 1.69 vs. -1.95 ± 1.73; P = 0.05) were significant in the LCG compared with the PLG. Likewise, LCG compared to the PLG showed insignificant improvement in waist circumference (WC) (− 5.65 ± 5.85 vs. -3.64 ± 3.37; P = 0.08). Total cholesterol (P = 0.02), MDA (P = 0.03), fat mass (P = 0.03) and visceral fat (P = 0.001) only showed decreased levels in LCG in comparison to the baseline condition. There was no significant difference between LCG and PLG, in the mean changes of hip circumference, visceral fat, free fat mass, fat mass, lipid profiles, CRP, MDA as well as stiffness, physical function, decrease of pain and total scores (P > 0.05).ConclusionThe 12-week L-carnitine supplementation could improve BMI, but had no significant effect on other anthropometric and body composition measures as well as clinical symptoms, CRP, MDA, and lipid profile in women with KOA. Further trials with higher doses and longer durations are required. IRCT registration number: IRCT2017011932026N2. Registration date: 2017-04-27.

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.

The Effect of L-Carnitine Supplementation on Weight and Body Composition in Women with Polycystic Ovary Syndrome: A Double-Blind Randomized Clinical Trial

Background: Polycystic ovarian syndrome (PCOS), one of the most common causes of endocrine disorders with irregular menstruation, is accompanied by an increase in androgen and polycystic ovarian. The aim of this study was to evaluate the effect of weight loss regimen with and without supplementation. L-carnitine affects lipid profile, insulin, and hormone resistance indices.&#x0D; Methods: This double-blind randomized clinical trial was conducted over women within the age range of 18 to 45 years, who referred to Yazd Diabetes Center in 2019. The participants were divided into the experimental and control groups. The intervention group received 1000 mg L-carnitine (LG = 28) and the placebo group (PG = 28) received the placebo daily. All people followed a low celery diet for 12 weeks. Anthropometric indices and body composition (weight, body mass index, waist circumference, hip circumference, fat mass, and free fat mass) were measured prior to and after the intervention. Data analysis was performed using SPSS software version 22. The independent sample t-test was used to compare the mean changes between the LG and PG.&#x0D; Results: At the end of the study period, patients treated with L-carnitine showed a significant decrease in waist circumference compared to the PG (change: -1 ± 3.15, P = 0.001) and no significant difference was observed between the two groups in terms of other anthropometrics indices and body composition including fat mass, body mass index, and hip circumference (P &gt; 0.05).&#x0D; Conclusion: The present study showed that 1000 mg oral L-carnitine had no significant effect on body weight, body mass index, body composition, and hip circumference, but had a significant effect on waist circumference size.

P1588CAN L-CARNITINE SUPPLEMENTATION IMPROVE CARDIOPULMONARY FUNCTION? A RANDOMIZED CONTROLLED TRIAL IN HEMODIALYSIS PATIENTS

Abstract Background and Aims It is well known that L-Carnitine is a cardioprotective agent, which balances cardiac energy metabolism, by promoting mitochondrial β-oxidation and facilitating transport of long chain fatty acids into the mitochondrial matrix. It has been shown that L-Carnitine level in plasma and tissue is lower in hemodialysis patients and they may lose the benefits of this substance. As far as our knowledge, the effect of L-Carnitine on cardiopulmonary function has not been evaluated by ergospirometry up to now. The aim of this randomized clinical trial was to assess the effects of L-carnitine supplementation on cardiopulmonary Function in hemodialysis patients through ergospirometry. Method This randomized clinical trial was conducted on 46 chronic hemodialysis patients. The patients were divided into two groups. In both groups ergospirometry parameters (VE Max, VO2-Max, VCO2 Max, AT, VE/VCO2 Slope) were recorded for a 3-month period. During this period, one group received L-Carnitine at doses of 2 gr/day orally and the other group received only placebo. After three months, all of the mentioned parameters were rechecked and statistical analysis performed by SPSS software. Results Only CRP was different between the two groups increasing in placebo group significantly after 3 months (P = 0.018). No significant difference was detected in Cardiopulmonary factors. In terms of ergospirometry factors, PET-CO2 was the only parameter significantly increased in the treatment group (P = 0.026). Conclusion The present results indicate that L-Carnitine can improve cardiopulmonary function among hemodialysis patients.

The effect of L-carnitine supplementation on blood pressure in patients with type 2 diabetes: A randomized, double-blind, placebo-controlled trial

ObjectivesDiabetic patients with hypertension are at a high risk of cardiovascular complications. The present study made an attempt to determine the effect of oral L-carnitine supplementation on blood pressure in patients with type 2 diabetes mellitus (T2DM). Materials and methodsIn this randomized, double-blind, placebo-controlled trial, 70 patients with T2DM at the age range of 41–75 years were randomly allocated to two groups: L-carnitin group (LG) (n = 35) receiving 1000 mg/day L-carnitin, and placebo group (PG) (n = 35) receiving 1000 mg/day wheat starch as placebo for 12 weeks. The systolic and diastolic blood pressures, mean arterial blood pressure and pulse pressure were examined before and after the intervention. ResultsSixty-four participants completed the study. At the end of the study period, LG compared with the PG, showed no significant difference in SBP (−1.14 ± 2.45 mmHg vs. −2.42 ± 2.79 mmHg), DBP (−3.2 ± 1.94 mmHg vs. −6±2.30 mmHg), MAP (−2.51 ± 1.84 mmHg vs. −4.80 ± 2.11 mmHg) and PP (2.05 ± 2.23 mmHg vs. 3.57 ± 2.73 mmHg). ConclusionThe oral supplementation of L-carnitine 1000 mg/day fails to affect blood pressure after 12 weeks of treatment in diabetes patients.*This was a randomized, controlled clinical trial (RCT) which was registered October 28, 2017 in the Iranian Registry of Clinical Trials (http://www.irct.ir, identifer: IRCT2017100936681N1).

Response to letter to the editor regarding: “Effect of l-carnitine supplementation on muscle cramps induced by stroke: A case report”

Response to letter to the editor regarding: “Effect of l-carnitine supplementation on muscle cramps induced by stroke: A case report”

A Local Study on the Effects of L-Carnitine Supplement on Serum Lipid Profiles in Libyan Type 2 Diabetic Patients

A Local Study on the Effects of L-Carnitine Supplement on Serum Lipid Profiles in Libyan Type 2 Diabetic Patients

Effect of L-Carnitine Supplementation on Liver Enzymes: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Possible Hepato-protective effects of L-carnitine have been reported in previous studies. Present study was conducted to systematically review the efficacy of L-carnitine supplementation on liver enzymes. The following databases were searched up to December 2018: PubMed, Scopus, ISI Web of Science, and the Cochrane library. Only randomized controlled trials (RCTs) evaluating the effects of L-carnitine supplementation on liver enzymes including alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT) were included. Pooled effect size measured using random effect model (Dersimonian-Liard). A total of 16 studies (including 1025 participants) were included in the present meta-analysis. Pooled analysis indicated that L-carnitine supplementation significantly decreased ALT (weighted mean difference (WMD): -10.729 IU/L, 95% CI: -13.787, -7.672, p<0.001; I2=95.9%), AST (WMD: -7.149 IU/L, 95% CI: -9.202, -5.096, p<0.001; I2=93.5%) and GGT (WMD: -7.395: IU/L, 95% CI: -9.171, -5.619, p<0.001; I2=80.1%). Subgroup analysis revealed that effect of L-carnitine supplementation on liver enzymes was not significant in normal weight and healthy subjects. Baseline BMI and health status were the potential source of heterogeneity. L-carnitine supplementation showed beneficial hepato-protective effects on circulating liver enzymes.

左旋肉碱补充剂对超重与肥胖人群血脂水平影响的Meta分析

左旋肉碱补充剂对超重与肥胖人群血脂水平影响的Meta分析

The Effects of L-Carnitine Supplementation on Serum Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

The findings of trials investigating the effects of L-carnitine administration on serum lipids are inconsistent. This meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effects of L-carnitine intake on serum lipids in patients and healthy individuals. Two authors independently searched electronic databases including MEDLINE, EMBASE, Cochrane Library, Web of Science, PubMed and Google Scholar from 1990 until August 1, 2019, in order to find relevant RCTs. The quality of selected RCTs was evaluated using the Cochrane Collaboration risk of bias tool. Cochrane's Q test and I-square (I2) statistic were used to determine the heterogeneity across included trials. Weight mean difference (SMD) and 95% CI between the two intervention groups were used to determine pooled effect sizes. Subgroup analyses were performed to evaluate the source of heterogeneity based on suspected variables such as, participant's health conditions, age, dosage of L-carnitine, duration of study, sample size, and study location between primary RCTs. Out of 3460 potential papers selected based on keywords search, 67 studies met the inclusion criteria and were eligible for the meta-analysis. The pooled results indicated that L-carnitine administration led to a significant decrease in triglycerides (WMD: -10.35; 95% CI: -16.43, -4.27), total cholesterol (WMD: -9.47; 95% CI: - 13.23, -5.70) and LDL-cholesterol (LDL-C) concentrations (WMD: -6.25; 95% CI: -9.30, -3.21), and a significant increase in HDL-cholesterol (HDL-C) levels (WMD: 1.39; 95% CI: 0.21, 2.57). L-carnitine supplementation did not influence VLDL-cholesterol concentrations. When we stratified studies for the predefined factors such as dosage, and age, no significant effects of the intervention on triglycerides, LDL-C, and HDL-C levels were found. This meta-analysis demonstrated that L-carnitine administration significantly reduced triglycerides, total cholesterol and LDL-cholesterol levels, and significantly increased HDL-cholesterol levels in the pooled analyses, but did not affect VLDL-cholesterol levels; however, these findings were not confirmed in our subgroup analyses by participant's health conditions, age, dosage of L-carnitine, duration of study, sample size, and study location.

Effects of l-carnitine supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials

L-carnitine plays a fundamental biological role in the metabolism of lipids and may positively affect blood pressure by decreasing insulin resistance, although the latter remains less clear. We aimed to assess the effects of L-carnitine supplementation on systolic (SBP) and diastolic blood pressure (DBP). A search was conducted using databases of EMBASE, PubMed, Scopus, Cochrane Library, and ISI web of Science from inception to February 2019 without limitations in language. A meta-analysis was conducted on a total of ten eligible randomized controlled trials using a random-effects model to estimate the pooled effect sizes of L-carnitine supplementation on SBP and DBP levels. Results were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). L-carnitine supplementation decreased DBP (-1.162 mmHg, 95% CI: -2.020, -0.303, p = 0.008) without changing SBP levels (-0.085 mmHg, 95% CI: -1.455, 1.285, p = 0.903). Results of the subgroup analyses revealed L-carnitine supplementation decreased DBP levels in participants with overweight and obesity (-1.232 mmHg, 95% CI: -2.297, -0.167, p = 0.023) and with doses of <2 g/d (-1.639 mmHg, 95% CI: -3.038, -0.240, p = 0.022). No evidence of publication bias was observed about the effects of L-carnitine supplementation on SBP (p = 0.307) and DBP (p = 0.729), as evidenced by the results of the Egger's test. In conclusion, L-carnitine supplementation decreased DBP without affecting SBP levels. Research is required to determine the molecular mechanism underlying the relationship between of L-carnitine on blood pressure.

Effects of l-carnitine supplementation on cardiovascular and bone turnover markers in patients with pemphigus vulgaris under corticosteroids treatment: A randomized, double-blind, controlled trial.

Pemphigus vulgaris (PV) is a severe, bullous, autoimmune disease of the skin and mucous membranes. Corticosteroids are usually the main core treatment for controlling PV, which could lead to several side effects such as insulin resistance, osteoporosis, and cardiovascular disorders. The aim of this study is to evaluate the protective effects of l-carnitine (LC) supplementation in PV patients under corticosteroid treatment. In this randomized, double-blind, placebo-controlled clinical trial, 48 patients with PV were divided randomly into two groups to receive 2 g LC (n = 24) or a placebo (n = 24) for 8 weeks, respectively. Serum levels of osteopontin (OPN), bone morphogenic protein 4 (BMP4), cystatin C, systolic and diastolic blood pressure, 25 hydroxyvitamin D3, and LC were evaluated at the beginning and at the end of the study. LC supplementation demonstrated a significant increase in serum carnitine (p < .001). In addition, at the end of the trial, LC supplementation significantly decreased serum BMP4 (p = .003), OPN (p = .03), and cystatin C (p = .001) levels. There was no significant effect on blood pressure in comparison with the placebo. During study, no harmful side effects were reported by patients. These findings indicate that LC supplementation significantly leads to favorable changes in OPN, BMP4, and cystatin C in PV patients under corticosteroid therapy. However, further investigations are required to confirm these results.

The effects of L-carnitine supplementation on glycemic control: a systematic review and meta-analysis of randomized controlled trials.

The findings of trials investigating the effect of L-carnitine administration on glycemic control are controversial. This meta-analysis of randomized controlled trials (RCTs) was performed to explore the effects of L-carnitine intake on glycemic control. Two authors independently searched electronic databases including MEDLINE, EMBASE, Cochrane Library, Web of Science, PubMed and Google scholar from 1990 until February 2019, in order to find relevant RCTs. 37 studies with 44 effect sizes met the inclusion criteria and were eligible for the meta-analysis. L-carnitine supplementation resulted in a significant reduction in fasting plasma glucose (FPG) (WMD: -4.57; 95 % CI: -6.88, -2.25), insulin (WMD: -1.21; 95 % CI: -1.85, -0.57), homeostatic model assessment for insulin resistance (HOMA-IR) (WMD: -0.67; 95 % CI: -0.90, -0.44) and HbA1C concentrations (WMD: -0.30; 95 % CI: -0.47, -0.13). L-Carnitine supplementation significantly reduced FPG, insulin, HOMA-IR, and HbA1c levels.

Effect of l-carnitine supplementation and sugar beet pulp inclusion in gilt gestation diets on gilt live weight, lactation feed intake, and offspring growth from birth to slaughter1.

This study evaluated the effects of l-carnitine (CAR) and sugar beet pulp (SBP) inclusion in gilt gestation diets on gilt live weight, cortisol concentration, lactation feed intake, and lifetime growth of progeny. Eighty-four pregnant gilts (Large White × Landrace) were randomly assigned to a treatment at day 38 of gestation until parturition; Control (0% SBP, 0 g CAR), CAR (0.125 g/d CAR), SBP (40% SBP), and SBP plus CAR (40% SBP, 0.125 g/d CAR). Gilts were weighed and back-fat depth was recorded on day 38, day 90, and day 108 of gestation and at weaning. Gilt saliva samples were collected pre-farrowing and fecal consistency was scored from entry to the farrowing room until day 5 post-partum. The number of piglets born (total, live, and stillborn) and individual birth weight was recorded. Piglet blood glucose concentration was measured 24 h post-partum and pigs were weighed on day 1, day 6, day 14, day 26, day 76, day 110, and day 147 of life. Carcass data were collected at slaughter. There was no interaction between CAR and SBP for any variable measured. The SBP-fed gilts were heavier on day 90 and day 108 of gestation (P < 0.05) and lost more weight during lactation (P < 0.05) than control gilts. They also had a greater fecal consistency score (P < 0.01). Total farrowing duration, piglet birth interval, and lactation feed intakes were similar between treatments (P > 0.05). The number of piglets born (total, live, and stillborn) and piglet birth weight was likewise similar between treatments (P > 0.05). Piglets from CAR-fed gilts had lower blood glucose concentrations (P < 0.01), while piglets from SBP-fed gilts had greater blood glucose concentrations (P < 0.01). Piglets from CAR gilts had a lower average daily gain between day 1 and day 6 (P < 0.05) and day 14 and day 26 post-partum (P < 0.05) compared to piglets from control gilts. However, CAR gilts weaned a greater number of pigs (P = 0.07). Live weight and carcass weight at slaughter were heavier for pigs from CAR gilts (P < 0.05) and from SBP gilts (P < 0.05). Pigs from CAR gilts (P < 0.01) and SBP gilts (P < 0.05) had increased carcass muscle depth. In conclusion, no benefit was found from the combined feeding of CAR and SBP. Fed separately, CAR increased the live weight, carcass weight, and muscle depth of progeny at slaughter. Feeding a high SBP diet increased fecal consistency in gilts pre-farrowing and increased live weight and carcass muscle depth of progeny.

Effect of l-carnitine supplementation on carnitine levels, oxidative stress and apoptotic markers in peripheral organs of aged rats

Resveratrol, a dietary polyphenol with antioxidant and anti-inflammatory activity, has been shown to provide neuroprotection in models of ischemia. However, the mechanism of action of resveratrol-induced neuroprotection remains unclear. Previous work in our laboratory has provided evidence that acute, systemic administration of resveratrol is neuroprotective in a permanent model of cerebral ischemia, an effect that was blocked when animals received the non-selective estrogen receptor antagonist, ICI, 182,780. The present study was designed to investigate whether the source of neuroprotection afforded by resveratrol action within the cerebral cortex itself is mediated preferentially via selective activation of either α or β estrogen receptor subtype. Intracortical injection of resveratrol (0.1 and 1.0 μM) 10 min prior to 30 min of ischemia followed by 5.5 h of reperfusion significantly reduced infarct volume in the prefrontal cortex. This neuroprotective effect was significantly attenuated when resveratrol injection (1.0 μM) was preceded by injection of a selective estrogen receptor α antagonist, 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1N-pyrozole dihydrochloride (MPP) or a selective estrogen receptor beta (ERβ) antagonist, 4-[2-phenyo-5,7-bis(trifluoromrthyl)pyrazolo(1,5-a)pyrimidin-3-yl]phenol (PHTPP). These results provide evidence for rapidly induced neuroprotection mediated by resveratrol activation of either estrogen receptor subtype within the ischemic cortex of rats.

Effect of addition of l-carnitine to media for oocyte maturation and embryo culture on development and cryotolerance of bovine embryos produced in vitro

The objective of these experiments was to determine the effect of l-carnitine during oocyte maturation or embryo culture on embryo development and cryosurvival. For Experiments 1–3, embryos were produced in vitro using abattoir-derived cumulus-oocyte complexes (COCs). At d 7 after insemination, embryo development was assessed, and blastocyst and expanded blastocyst stage embryos were harvested and subjected to controlled-rate freezing. Post-thaw cryosurvival was determined by re-expansion and hatching rates at 24, 48 and 72 h post-thaw. In Experiment 1, COCs were matured with or without 3.03 mM l-carnitine. There was no effect of l-carnitine supplementation during maturation on embryo development or post-thaw cryosurvival. In experiment 2, presumptive zygotes were cultured in medium supplemented with or without 5% (v/v) fetal bovine serum and l-carnitine at concentrations of 0.0, 0.75, 1.5 and 3.03 mM. There was no effect of l-carnitine treatment on embryo development, but embryos treated with l-carnitine had increased (P ≤ 0.05) post-thaw re-expansion rates, irrespective of concentration. In experiment 3, presumptive zygotes were cultured with or without 0.75 mM l-carnitine from d 1 to d 4, from d 4 to d 7 or for the entire culture period. There was no effect of l-carnitine during culture on embryo development or post-thaw cryosurvival, regardless of the timing of addition. In Experiment 4, COCs were harvested by ovum pick-up from virgin dairy heifers (n = 24) and subjected to in-vitro embryo production with presumptive zygotes cultured with or without 0.75 mM l-carnitine. At d 7 after insemination, morula and blastocyst stage embryos were harvested and subjected to controlled-rate freezing. Lactating Holstein cows (n = 102) were used as recipients and synchronized for timed embryo transfer. At d 7 after anticipated ovulation, a single embryo was thawed and transferred to the ipsilateral uterine horn of each recipient with a corpus luteum. Pregnancy was diagnosed at d 33, 44 and 72 of gestation. l-carnitine had no effect on the percentage of cows pregnant per embryo transfer (P/ET) after transfer of a frozen-thawed embryo. In conclusion, media supplementation with l-carnitine during in vitro embryo production can improve post-thaw cryotolerance as assessed in vitro but had no effect on P/ET after transfer of frozen-thawed embryos.

The effects of L-carnitine supplementation in athletic performance

Summary Objectives This review aims to analyze the available data, mainly the most recent, regarding L-carnitine supplementation and exercise performance, in order to understand if L-carnitine can still be considered an ergogenic supplement. Moreover, it also aims to briefly analyze other potential uses, more specifically the effects on weight loss, recovery after exercise and aging. News A literature search, using the online scientific databases PubMed and Scopus, was conducted to identify studies related to L-carnitine supplementation and athletic performance. The discovery that skeletal muscle carnitine content can be increased through oral supplementation in humans represented a significant progress in this area. More recently, due to this discovery, new research has been done to investigate whether L-carnitine supplementation could have an impact on fuel metabolism. However, the inconsistency of results led to a change in the focus of research, shifting towards the investigation of the impact L-carnitine could have on the process of recovery after exercise and on aging. Prospects and projects In future research, this new area needs to be more explored. Nevertheless, the study of the L-carnitine supplementation impact on fuel selection during exercise should continue and it is crucial to use athletes. Conclusion Despite some performance benefits have been demonstrated, more research needs to be done. Presently, the available data is still not enough to widely recommend the use of L-carnitine supplements with the aim of improving exercise performance.

Effects of l-Carnitine Supplementation, Botulinum Neurotoxin Injection, and Rehabilitation for a Chronic Stroke Patient

Botulinum neurotoxin injection therapy and rehabilitation have been conducted for stroke patients to reduce the spasticity of their affected limbs and improve their walking ability and daily living. Furthermore, their disability was reported to be related to muscle wasting. Supplementation of l-carnitine was reported to improve physical endurance and was used to treat sarcopenia in, for example, patients with cancer. Here, we report a case of chronic stroke with muscle wasting in a patient with improved walking endurance by l-carnitine supplementation, botulinum neurotoxin injection, and rehabilitation. A 58-year-old woman had a left putamen hemorrhage 9years before, and right spastic hemiplegia and walking disability. She could walk no more than 20m. Botulinum neurotoxin injection and rehabilitation were performed 6times every 3 months. The first time, walking speed and continuous walking distance increased as her spasticity decreased. However, the improvement declined after the second and third treatments. She had right leg pain during walking, accompanied by muscle wasting. The l-carnitine prescription contributed to the attenuation of her leg pain during walking and rapid improvement of her continuous walking distance. Walking speed and endurance further improved. In addition, the withdrawal of l-carnitine did not decrease her walking ability or induce a recurrence of her leg pain. Interestingly, creatine phosphokinase increased after l-carnitine was stopped, indicating that l-carnitine had helped to reduce muscle damage during rehabilitation. This case suggests that chronic stroke patients with muscle wasting have an abnormality in the mitochondrial energy metabolism of their muscles.