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Male infertility is an emerging health problem and there is an urgent need to search for therapeutic options. Altered metabolic states such as obesity and metabolic syndrome have been linked with male infertility. Therefore, searching for metabolic biomarkers is vital. Present work aimed to study metabolic alterations in infertile males. The seminal levels of L-Carnitine (LC), Kisspeptin (Kiss1) and Ghrelin (GHRL) were evaluated in 14 infertile and 10 fertile males. Baseline semen analysis was performed for both cases and controls. The levels of LC and Kiss1 were found to be lower in infertile patients as compared to fertile controls and the difference was found to be statistically significant. There was no significant difference observed in GHRL levels between patients and controls. The study presents a preliminary data where LC and Kiss1 levels could possibly studied further for their association with male infertility. But to confirm their association with pathogenesis of male infertility, future studies need to be conducted in larger cohorts.

Background: Doxorubicin (DOX) is a potent anthracycline chemotherapy agent widely employed to treat various malignancies, such as cancers and this study sought to determine how allicin (ALC) and or L-carnitine (LC) affect DOX-induced cardiotoxicity in rats. Methods: In this study, the possible alleviative role of ALC (20 mg/kg/day orally (PO)) or LC (100 mg/kg/day PO) or the combined treatment of both ALC and LC (with the previously mentioned dosages) was evaluated against the cardiotoxic effect of a widely used chemotherapeutic agent, DOX (20 mg DOX /kg intraperitoneal injection (IP) as a single dose) in rats in 30 days experiment. Results: The results revealed that ALC and LC significantly suppressed the DOX-induced increment in serum levels of cardiac damage biomarkers, such as lactate dehydrogenase (LDH), creatine kinase (CK) and creatine kinase-megabyte (CK-MB). Moreover, DOX-associated oxidative stress, including the elevation in malondialdehyde (MDA) level and reduced activity of antioxidant enzymes, such as catalase (CAT) and superoxide dismutase (SOD) and the level of reduced glutathione (GSH) was corrected in ALC and or LC treated groups. Furthermore, DOX-induced cardiomyopathy showed significant pathological changes, including myocyte degeneration, vacuolization, interstitial edema, and focal necrosis. Nevertheless, the histopathological lesions were corrected in the treated groups mostly in the combined treatment with ALC plus LC. Compared to ALC and LC, ALC plus LC was more effective at restoring the cardiac injury biomarkers, inhibiting cardiac oxidative damage and preserving the cardiac architecture. Conclusions: Conclusively, the study results evidenced the beneficial role of the combined treatment with ALC plus LC in mitigating DOX-induced cardiotoxicity.

This study examined the effects of L-carnitine (LC) supplementation in corn gluten meal (CGM) diets for juvenile hybrid grouper on growth, immunity, lipid metabolism, and metabolomic analysis to discover possible biomarkers and metabolites (UPLC-MS) with the aid of ultra-performance liquid chromatography-mass spectrometry. With LC levels of 0, 200, 400, 600, 1200, 1400, and 1600 mg/kg, 630 juvenile hybrid groupers with an initial weight average of 13.7 ± 0 0.09 g were randomly divided into seven groups. These groups were named control group LC0 (FM diets without LC), LC0.2, LC0.4, LC0.6, LC1.2, LC1.4, and LC1.6 respectively. Fish fed LC0.2 diets had higher final weight, weight gain (WG), and condition factor (CF) than the control group after a feeding trial for 56 days. However, they were not substantially different from the control group. Fish fed LC0.2 had the highest values of 368.09% and 1.69 g/cm3 for WG, and CF, respectively. With rising dietary LC levels, antioxidant parameters such as glutathione peroxidase (GSH-Px) in the liver substantially increased and then decreased (P < 0.05). Superoxide dismutase (SOD) and total antioxidant capacity (T-AOC), however, were unaffected (P < 0.05). Fish fed the LC0.2 diet had significantly greater pparα mRNA expression compared to fish fed the basal diet (LC0) in terms of gene expression related to lipid metabolism. Bile secretion, ABC transporters, and glycerophospholipid have been identified as the differential metabolites in the distal gut of fish, with an upregulation occurring after feeding with experimental diets. Based on the findings of the current study, we propose that LC level of 200 mg/kg in CGM diets increases fish growth and immunity and regulates hepatic metabolism. [ABSTRACT FROM AUTHOR]

Carnitines play a key physiological role in oocyte metabolism and redox homeostasis. In clinical and animal studies, carnitine administration alleviated metabolic and reproductive dysfunction associated with polycystic ovarian syndrome (PCOS). Oxidative stress (OS) at systemic, intraovarian, and intrafollicular levels is one of the main factors involved in the pathogenesis of PCOS. We investigated the ability of different acyl-carnitines to act at the oocyte level by counteracting the effects of OS on carnitine shuttle system and mitochondrial activity in mouse oocytes. Germinal vesicle (GV) oocytes were exposed to hydrogen peroxide and propionyl-l-carnitine (PLC) alone or in association with l-carnitine (LC) and acetyl-l-carnitine (ALC) under different conditions. Expression of carnitine palmitoyltransferase-1 (Cpt1) was monitored by RT-PCR. In in vitro matured oocytes, metaphase II (MII) apparatus was assessed by immunofluorescence. Oocyte mitochondrial respiration was evaluated by Seahorse Cell Mito Stress Test. We found that Cpt1a and Cpt1c isoforms increased under prooxidant conditions. PLC alone significantly improved meiosis completion and oocyte quality with a synergistic effect when combined with LC + ALC. Acyl-carnitines prevented Cpt1c increased expression, modifications of oocyte respiration, and ATP production observed upon OS. Specific effects of PLC on spare respiratory capacity were observed. Therefore, carnitine supplementation modulated the intramitochondrial transfer of fatty acids with positive effects on mitochondrial activity under OS. This knowledge contributes to defining molecular mechanism underlying carnitine efficacy on PCOS. [ABSTRACT FROM AUTHOR]

Carnitines play a key physiological role in oocyte metabolism and redox homeostasis. In clinical and animal studies, carnitine administration alleviated metabolic and reproductive dysfunction associated with polycystic ovarian syndrome (PCOS). Oxidative stress (OS) at systemic, intraovarian, and intrafollicular levels is one of the main factors involved in the pathogenesis of PCOS. We investigated the ability of different acyl-carnitines to act at the oocyte level by counteracting the effects of OS on carnitine shuttle system and mitochondrial activity in mouse oocytes. Germinal vesicle (GV) oocytes were exposed to hydrogen peroxide and propionyl-l-carnitine (PLC) alone or in association with l-carnitine (LC) and acetyl-l-carnitine (ALC) under different conditions. Expression of carnitine palmitoyltransferase-1 (Cpt1) was monitored by RT-PCR. In in vitro matured oocytes, metaphase II (MII) apparatus was assessed by immunofluorescence. Oocyte mitochondrial respiration was evaluated by Seahorse Cell Mito Stress Test. We found that Cpt1a and Cpt1c isoforms increased under prooxidant conditions. PLC alone significantly improved meiosis completion and oocyte quality with a synergistic effect when combined with LC + ALC. Acyl-carnitines prevented Cpt1c increased expression, modifications of oocyte respiration, and ATP production observed upon OS. Specific effects of PLC on spare respiratory capacity were observed. Therefore, carnitine supplementation modulated the intramitochondrial transfer of fatty acids with positive effects on mitochondrial activity under OS. This knowledge contributes to defining molecular mechanism underlying carnitine efficacy on PCOS.

The focus of this research was to assess if corn gluten meal diet supplemented with L-carinitine (LC) LC0, LC0.2, LC0.4, LC0.6, LC1.2, LC1.4, LC1.6, with LC levels of 0 for the control group, 200, 400, 600, 1200, 1400, and 1600 mg/kg, respectively, may be a viable option for juvenile hybrid grouper (♀Epinephelus fuscoguttatus × ♂E. lanceolatus). It's impact on juvenile hybrid grouper growth, immunity, gene expression, and disease resistance. Each group in the experiment had three replicates (initial weight = 13.57 ± 0.00 g) and were fed their respective diets for eight weeks. When LC0.2 was compared to LC0, it showed a significant improvement on growth (P < 0.05). The treatment groups had no differences in crude protein, moisture, or ash content. Serum acid phosphatase, alkaline phosphatase, total antioxidant capacity, and glutathione peroxidase all increased. Fish fed LC0.2 had more steatosis in their hepatocytes in the liver than fish fed LC0, however the differences were not significant in LC0 (P ˃ 0.05). In the LC0.6, LC1.2, and LC1.4 groups, FAS mRNA levels were significantly downregulated. The expression of PPARA and PPARR was higher in the LC0.2 and LC0.4 groups, but not significantly different (P ˃ 0.05) from the LC0. In comparison to LC0, the fish fed diets LC0.2 and LC0.6 had the lowest mortality rate (P < 0.05) in a bacterium challenge test. Finally, based on all of the factors, replacing FM with CGM supplemented with LC0.2 (200 mg/kg) might be used to meet the nutritional needs of fish. • The study explores the impact of incorporating corn gluten meal (CGM) and L-Carnitine (LC) into the juvenile hybrid grouper fish diet. • Inclusion of LC (200 mg/kg) in fish diet containing CGM enhances both growth performance and immunity. • Optimum dietary LC in fish diet containing CGM improves lipid metabolism and disease resistance in fish. [ABSTRACT FROM AUTHOR]

Recently, the importance of bioenergetics in the reproductive process has emerged. For its energetic demand, the oocyte relies on numerous mitochondria, whose activity increases during embryo development under a fine regulation to limit ROS production. Healthy oocyte mitochondria require a balance of pyruvate and fatty acid oxidation. Transport of activated fatty acids into mitochondria requires carnitine. In this regard, the interest in the role of carnitines as mitochondrial modulators in oocyte and embryos is increasing. Carnitine pool includes the un-esterified l-carnitine (LC) and carnitine esters, such as acetyl-l-carnitine (ALC) and propionyl-l-carnitine (PLC). In this review, carnitine medium supplementation for counteracting energetic and redox unbalance during in vitro culture and cryopreservation is reported. Although most studies have focused on LC, there is new evidence that the addition of ALC and/or PLC may boost LC effects. Pathways activated by carnitines include antiapoptotic, antiglycative, antioxidant, and antiinflammatory signaling. Nevertheless, the potential of carnitine to improve energetic metabolism and oocyte and embryo competence remains poorly investigated. The importance of carnitine as a mitochondrial modulator may suggest that this molecule may exert a beneficial role in ovarian disfunctions associated with metabolic and mitochondrial alterations, including PCOS and reproductive aging.

Polycystic ovary syndrome (PCOS) is a complex metabolic disorder associated with female infertility. Based on energy and antioxidant regulatory functions of carnitines, we investigated whether acyl-L-carnitines improve PCOS phenotype in a mouse model induced by dehydroepiandrosterone (DHEA). CD1 mice received DHEA for 20 days along with two different carnitine formulations: one containing L-carnitine (LC) and acetyl-L-carnitine (ALC), and the other one containing also propionyl-L-carnitine (PLC). We evaluated estrous cyclicity, testosterone level, ovarian follicle health, ovulation rate and oocyte quality, collagen deposition, lipid droplets, and 17ß-HSD IV (17 beta-hydroxysteroid dehydrogenase type IV) expression. Moreover, we analyzed protein expression of SIRT1, SIRT3, SOD2 (superoxide dismutase 2), mitochondrial transcriptional factor A (mtTFA), RAGE (receptor for AGEs), GLO2 (glyoxalase 2) and ovarian accumulation of MG-AGEs (advanced glycation end-products formed by methylglyoxal). Both carnitine formulations ameliorated ovarian PCOS phenotype and positively modulated antioxidant molecular pathways in the ovarian microenvironment. Addition of PLC to LC-ALC formulation mitigated intraovarian MG-AGE accumulation and increased mtTFA expression. In conclusion, our study supports the hypothesis that oral administration of acyl-L-carnitines alleviates ovarian dysfunctions associated with this syndrome and that co-administration of PLC provides better activity. Molecular mechanisms underlying these effects include anti-oxidant/glycative activity and potentiation of mitochondria.

Abstract: In recent years increasing evidence has emerged suggesting that oxidative stress is involved in the pathophysiology of a number of inherited metabolic disorders. However the clinical use of classical antioxidants in these diseases has been poorly evaluated and so far no benefit has been demonstrated. l-Carnitine is an endogenous substance that acts as a carrier for fatty acids across the inner mitochondrial membrane necessary for subsequent beta-oxidation and ATP production. Besides its important role in the metabolism of lipids, l-carnitine is also a potent antioxidant (free radical scavenger) and thus may protect tissues from oxidative damage. This review addresses recent findings obtained from patients with some inherited neurometabolic diseases showing that l-carnitine may be involved in the reduction of oxidative damage observed in these disorders. For some of these diseases, reduced concentrations of l-carnitine may occur due to the combination of this compound to the accumulating toxic metabolites, especially organic acids, or as a result of protein restricted diets. Thus, l-carnitine supplementation may be useful not only to prevent tissue deficiency of this element, but also to avoid oxidative damage secondary to increased production of reactive species in these diseases. Considering the ability of l-carnitine to easily cross the blood–brain barrier, l-carnitine supplementation may also be beneficial in preventing neurological damage derived from oxidative injury. However further studies are required to better explore this potential. [Copyright &y& Elsevier]

Abstract: Propionyl-l-carnitine (PLC) is a natural short-chain derivative of l-carnitine (LC), a natural amino acid that plays an important role in fatty acid metabolism. Recent studies suggest that PLC has vascular protective effects. Because of the importance of endothelial nitric oxide synthase (eNOS) and its product, antiatherogenic molecule nitric oxide (NO), in vascular endothelial function, we sought to elucidate that if PLC would stimulate eNOS and its upstream activators Akt and phosphatidylinositol 3-kinase (PI3 Kinase) in cultured human aortic endothelial cells (HAEC). PLC caused eNOS phosphorylation at Ser-1177, and dominant negative Akt and a novel Akt-selective inhibitor MK-2206 inhibited both PLC-mediated phosphorylation and activation of the enzyme. PI3 kinase inhibition also blocked the phosphorylation and activation of eNOS by PLC. Studies with specific drug inhibitors PD173955 and PP2 showed that the non-receptor tyrosine kinase, src, is an upstream stimulator of the PI3 kinase-Akt pathway in this pathway. In addition, PLC significantly decreased intracellular ATP/ADP ratio and activate AMPK, subsequently leading to Src activation. Finally, we demonstrated that the effects of PLC to augment eNOS activity were associated with a net increase in NO release from endothelial cells. NO production following incubation with PLC was abolished in endothelial cells coincubated with L-NAME, PD173955, LY294002, MK-2206 and compound C. In conclusion, PLC, via AMPK/Src-mediated signaling that leads to activation of PI3 kinase and Akt, stimulates eNOS, leading to increased production of NO. [Copyright &y& Elsevier]

Recently, the importance of bioenergetics in the reproductive process has emerged. For its energetic demand, the oocyte relies on numerous mitochondria, whose activity increases during embryo development under a fine regulation to limit ROS production. Healthy oocyte mitochondria require a balance of pyruvate and fatty acid oxidation. Transport of activated fatty acids into mitochondria requires carnitine. In this regard, the interest in the role of carnitines as mitochondrial modulators in oocyte and embryos is increasing. Carnitine pool includes the un-esterified l-carnitine (LC) and carnitine esters, such as acetyl-l-carnitine (ALC) and propionyl-l-carnitine (PLC). In this review, carnitine medium supplementation for counteracting energetic and redox unbalance during in vitro culture and cryopreservation is reported. Although most studies have focused on LC, there is new evidence that the addition of ALC and/or PLC may boost LC effects. Pathways activated by carnitines include antiapoptotic, antiglycative, antioxidant, and antiinflammatory signaling. Nevertheless, the potential of carnitine to improve energetic metabolism and oocyte and embryo competence remains poorly investigated. The importance of carnitine as a mitochondrial modulator may suggest that this molecule may exert a beneficial role in ovarian disfunctions associated with metabolic and mitochondrial alterations, including PCOS and reproductive aging.

Background: To study the effects of L-carnitine (LC) combined with pancreatic kininogenase on thioredoxin 2 (Trx 2), thioredoxin reductase 1 (TrxR 1), and sperm quality in patients with oligoasthenospermia., Methods: A total of 300 male infertility patients with oligoasthenospermia who were treated in the andrology clinic of our hospital from December 2019 to December 2020 were randomly divided into an LC group and combined treatment group, and 50 males with normal semen were selected as a control group. The computer-assisted semen analysis system (CASA) was used to detect the total number, vitality, and forward motility of the sperm before and after treatment, and sperm morphology was detected by the Diff-Quik method of the sperm staining kit. Sperm chromatin dispersion (SCD) method was used to detect sperm DNA fragments, and Western-blot was used to detect the protein expression of Trx 2 and TrxR 1., Results: There were no significant differences in sperm density, motility rate, forward motile sperm rate, and DNA fragmentation rate in oligoasthenospermia patients before treatment (P>0.05). However, after 1 month of treatment, the sperm density, motility rate, and forward motile sperm rate were all higher than before treatment (P<0.05), while the DNA fragmentation rate was lower than before treatment. At the same time, each index of semen in the combination group was higher than that in the LC group (P<0.05), and the total effective rate in the combination group was significantly higher than in the LC group (P<0.01). The expression of Trx2 protein in oligoasthenospermia patients was significantly increased (P<0.05), while the expression of TrxR1 protein was significantly decreased (P<0.05). After 3 months of treatment, the expression of Trx2 protein was significantly decreased (P<0.05), while the expression of TrxR1 protein was significantly increased (P<0.05)., Conclusions: The results suggest Trx 2 and TrxR 1 may be candidate protein markers for oligoasthenospermia. LC combined with pancreatic kininogenase in the treatment of male oligoasthenospermia can effectively promote sperm maturation, enhance sperm motility, and improve semen quality, which has high application value., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://dx.doi.org/10.21037/tau-21-680). The authors have no conflicts of interest to declare., (2021 Translational Andrology and Urology. All rights reserved.)

Polycystic ovary syndrome (PCOS) is a complex metabolic disorder associated with female infertility. Based on energy and antioxidant regulatory functions of carnitines, we investigated whether acyl-L-carnitines improve PCOS phenotype in a mouse model induced by dehydroepiandrosterone (DHEA). CD1 mice received DHEA for 20 days along with two different carnitine formulations: one containing L-carnitine (LC) and acetyl-L-carnitine (ALC), and the other one containing also propionyl-L-carnitine (PLC). We evaluated estrous cyclicity, testosterone level, ovarian follicle health, ovulation rate and oocyte quality, collagen deposition, lipid droplets, and 17ß-HSD IV (17 beta-hydroxysteroid dehydrogenase type IV) expression. Moreover, we analyzed protein expression of SIRT1, SIRT3, SOD2 (superoxide dismutase 2), mitochondrial transcriptional factor A (mtTFA), RAGE (receptor for AGEs), GLO2 (glyoxalase 2) and ovarian accumulation of MG-AGEs (advanced glycation end-products formed by methylglyoxal). Both carnitine formulations ameliorated ovarian PCOS phenotype and positively modulated antioxidant molecular pathways in the ovarian microenvironment. Addition of PLC to LC-ALC formulation mitigated intraovarian MG-AGE accumulation and increased mtTFA expression. In conclusion, our study supports the hypothesis that oral administration of acyl-L-carnitines alleviates ovarian dysfunctions associated with this syndrome and that co-administration of PLC provides better activity. Molecular mechanisms underlying these effects include anti-oxidant/glycative activity and potentiation of mitochondria. [ABSTRACT FROM AUTHOR]