PEGylation renders carnosine resistant to hydrolysis by serum carnosinase and increases renal carnosine levels.

Carnosine's protective effect in rodent models of glycoxidative stress have provided a rational for translation of these findings in therapeutic concepts in patient with diabetic kidney disease. In contrast to rodents however, carnosine is rapidly degraded by the carnosinase-1 enzyme. To overcome this hurdle, we sought to protect hydrolysis of carnosine by conjugation to Methoxypolyethylene glycol amine (mPEG-NH2). PEGylated carnosine (PEG-car) was used to study the hydrolysis of carnosine by human serum as well as to compare the pharmacokinetics of PEG-car and L-carnosine in mice after intravenous (IV) injection. While L-carnosine was rapidly hydrolyzed in human serum, PEG-car was highly resistant to hydrolysis. Addition of unconjugated PEG to carnosine or PEG-car did not influence hydrolysis of carnosine in serum. In mice PEG-car and L-carnosine exhibited similar pharmacokinetics in serum but differed in half-life time (t1/2) in kidney, with PEG-car showing a significantly higher t1/2 compared to L-carnosine. Hence, PEGylation of carnosine is an effective approach to prevent carnosine degradations and to achieve higher renal carnosine levels. However, further studies are warranted to test if the protective properties of carnosine are preserved after PEGylation.

A randomised trial of topical polaprezinc to prevent oral mucositis in patients undergoing haematopoietic stem cell transplantation (ToPaZ study).

PURPOSE: Oral mucositis (OM) is a common complication in haematopoietic stem cell transplantation (HSCT). Polaprezinc, an anti-ulcer drug, has been shown to be effective to prevent OM in several studies when administered topically and systemically. This study aimed to evaluate the effectiveness of topical polaprezinc in patients undergoing HSCT. METHODS: This was an open-label randomised clinical trial comparing polaprezinc and sodium bicarbonate mouthwashes for the prevention of severe OM in HSCT patients. Adult patients who received conditioning regimens at moderate to high risk of developing OM were included. The primary endpoint was the incidence of severe (WHO grades 3-4) OM. The secondary endpoints included duration of grades 3-4 OM, incidence and duration of grades 2-4 OM, patient-reported pain and functional limitations. RESULTS: In total, 108 patients (55 test arm and 53 control arm) were randomised. There was no difference in the incidence of grades 3 to 4 OM (35% test arm versus 36% control arm). The secondary endpoints were not significantly different. In both arms, patients reported more throat pain compared to mouth pain. CONCLUSIONS: Topical polaprezinc had no effect in the prevention of OM in HSCT patients. Further research is required to evaluate the effects of systemic polaprezinc. The OM assessment tool needs to be reviewed as throat mucositis was a main issue in this study. TRIAL REGISTRATION: ACTRN12320001188921 (Date Registered: 10th November 2020).

Electrophoretic Determination of L-Carnosine in Health Supplements Using an Integrated Lab-on-a-Chip Platform with Contactless Conductivity Detection.

The health supplement industry is one of the fastest growing industries in the world, but there is a lack of suitable analytical methods for the determination of active compounds in health supplements such as peptides. The present work describes an implementation of contactless conductivity detection on microchip technology as a new strategy for the electrophoretic determination of L-carnosine in complex health supplement formulations without pre-concentration and derivatization steps. The best results were obtained in the case of +1.00 kV applied for 20 s for injection and +2.75 kV applied for 260 s for the separation step. Under the selected conditions, a linear detector response of 5 × 10-6 to 5 × 10-5 M was achieved. L-carnosine retention time was 61 s. The excellent reproducibility of both migration time and detector response confirmed the high precision of the method. The applicability of the method was demonstrated by the determination of L-carnosine in three different samples of health supplements. The recoveries ranged from 91 to 105%. Subsequent analysis of the samples by CE-UV-VIS and HPLC-DAD confirmed the accuracy of the obtained results.

Characterization of a new L-carnosine synthase mined from deep-sea sediment metagenome.

L-Carnosine is a natural biologically active dipeptide with critical physiological functions, such as antioxidant, antiglycation, and cytoplasmic buffering properties. Direct enzymatic synthesis is a promising way for L-carnosine production. In this study, a new aminopeptidase (gene_236976) with synthetic activity toward L-carnosine was identified by a metagenome mining approach from deep-sea sediment and functionally expressed in Escherichia coli. The enzyme shared a low identity of 14.3% with reported L-carnosine dipeptidase (SmPepD) from Serratia marcescens. ß-Alanine methyl ester was proven to be the best substrate for the synthesis, and no ATP was needed for the enzymatic reaction. The enzyme activity was increased by structure-guided rational design. Only the mutant of G310 site gave positive results, and G310A mutant showed the best performance among the site-direct saturation mutagenesis, indicating that the additional CH3 group of mutant G310A was the main factor affecting the enzymatic activity. The engineered enzyme produced about 10 mM L-carnosine was produced from substrates of 50 mM ß-alanine methyl ester and 50 mM L-histidine, under a tentatively optimized condition. This study enriched the enzyme resources for developing the microbial synthesis process of L-carnosine production.

Anserine/Carnosine-Rich Extract from Thai Native Chicken Suppresses Melanogenesis via Activation of ERK Signaling Pathway.

Skin hyperpigmentation is an aesthetic problem that leads to psychosocial issues. Thus, skin whitening agents from agro- and poultry-industrial co-products are considered high economic value ingredients of interest for sustainable application. Therefore, this study aimed to determine the cosmeceutical potential of anserine/carnosine-rich chicken extract (ACCE) from the Thai native chicken Pradu Hang Dam Mor Kor 55 (PD) meat. The chemical composition was identified and quantified using the HPLC-UV method. Then, the antioxidation potential of the extract was compared to that of L-anserine and L-carnosine, using 1,1-diphenyl-2-picrylhydrazyl assay and shikonin-induced production of reactive oxygen species in CCD-986Sk cell models, and the anti-melanogenesis effect in the MNT-1 melanoma cell line model was investigated. Furthermore, related mechanisms were identified using colorimetric tyrosinase assay and the Western blot technique. The ACCE was composed of L-anserine and L-carnosine as two major constituents. In a dose-dependent manner, ACCE, L-anserine, and L-carnosine manifested significant antioxidation potential and significant reduction of melanin production. Activation of the extracellular signal-regulated kinase (ERK) signaling pathway and inhibition of tyrosinase activity of ACCE were demonstrated as the mechanisms of the anti-melanogenesis effect. In conclusion, ACCE has been revealed as a potential cosmeceutical agent due to its antioxidation and anti-melanogenic activity in association with L-anserine and L-carnosine composition and biomolecular regulating ability. Therefore, further studies and development should be considered to support the utilization of anserine/carnosine-rich chicken extract in the cosmetic industry for economic value creation and sustainability.

Dual l-Carnosine/Aloe vera Nanophytosomes with Synergistically Enhanced Protective Effects against Methylglyoxal-Induced Angiogenesis Impairment.

Microvascular complications are among the major outcomes of patients with type II diabetes mellitus, which are the consequences of impaired physiological functioning of small blood vessels and angiogenic responses in these patients. Overproduction and accumulation of methylglyoxal (MGO), a highly reactive dicarbonyl byproduct of glycolysis pathway, has been acclaimed as the main inducer of impaired angiogenic responses and microvascular dysfunction in diabetic patients with uncontrolled hyperglycemia. Hence, an effective approach to overcome diabetes-associated microvascular complications is to neutralize the deleterious activity of enhanced the concentration of MGO in the body. Owing to the glycation inhibitory activity of Aloe vera whole extract, and capability of l-carnosine, an endogenous dipeptide, in attenuating MGO's destructive activity, we examined whether application of a combination of l-carnosine and A. vera could be an effective way of synergistically weakening this reactive dicarbonyl's impaired angiogenic effects. Additionally, overcoming the poor cellular uptake and internalization of l-carnosine and A. vera, a nanophytosomal formulation of the physical mixture of two compounds was also established. Although l-carnosine and A. vera at whole studied combination ratios could synergistically enhance viability of human umbilical vein endothelial cells (HUVECs) treated with MGO, the 25:1 w/w ratio was the most effective one among the others (27 ± 0.5% compared to 12 ± 0.3 to 18 ± 0.4%; F (4, 15) = 183.9, P < 0.0001). Developing dual nanophytosomes of l-carnosine/A. vera (25:1) combination ratio, we demonstrated superiority of the nanophytosomal formulation in protecting HUVECs against MGO-induced toxicity following a 24-72 h incubation period (17.3, 15.8, and 12.4% respectively). Moreover, 500 µg/mL concentration of dual l-carnosine/A. vera nanophytosomes exhibited a superior free radical scavenging potency (63 ± 4 RFU vs 83 ± 5 RFU; F (5, 12) = 54.81, P < 0.0001) and nitric oxide synthesizing capacity (26.11 ± 0.19 vs 5.1 ± 0.33; F (5, 12) = 2537, P < 0.0001) compared to their physical combination counterpart. Similarly, 500 µg/mL dual l-carnosine/A. vera nanophytosome-treated HUVECs demonstrated a superior tube formation capacity (15 ± 3 vs 2 ± 0.3; F (5, 12) = 30.87, P < 0.001), wound scratch healing capability (4.92 ± 0.3 vs 3.07 ± 0.3 mm/h; F (5, 12) = 39.21, P < 0.0001), and transwell migration (586 ± 32 vs 394 ± 18; F (5, 12) = 231.8, P < 0.001) and invasion (172 ± 9 vs 115 ± 5; F (5, 12) = 581.1, P < 0.0001) activities compared to the physical combination treated ones. Further confirming the proangiogenic activity of the dual l-carnosine/A. vera nanophytosomes, a significant shift toward expression of proangiogenic genes including HIF-1α, VEGFA, bFGF, KDR, and Ang II was reported in treated HUVECs. Overall, dual l-carnosine/A. vera nanophytosomes could be a potential candidate for attenuating type II DM-associated microvascular complications with an impaired angiogenesis background.

Renovation of Intestinal Barrier by Polydatin in Experimentally Induced Ulcerative Colitis: Comparative Ultrastructural Study with L-Carnosine.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease associated with intestinal epithelial barrier impairment. Polydatin (PD), a natural product isolated from Polygonum cuspidatum, is known to have an anti-inflammatory, antioxidant, and antiapoptotic effect. We attempted to compare the protective impact of PD pretreatment on alterations to the intestinal epithelial barrier and the colonic wall's ultrastructure accompanying ulcerative colitis to other conventional drugs in practice, primarily L-carnosine, which has not been addressed before. The rats were divided into 5 groups; 3 of them were treated with sulphasalazine (500 mg/kg), L-carnosine (30 mg/kg), and PD (45 mg/kg). All groups were administered their respective drugs 3 days before the UC was induced by acetic acid intra-rectally, and the treatment was continued until the 11th day. The disease activity index (DAI) was estimated, and a macroscopic scoring was established for the harvested colonic tissue. The tissues were extracted and processed for hematoxylin and eosin staining, caspase-3 immunohistochemical staining, electron microscopy, and biochemical analysis evaluating proinflammatory markers (IL-1ß, TNF-α, and IL-6), myeloperoxidase (MPO), oxidative stress, and lipid peroxidation. Histopathological examination of colonic tissue showed that PD pretreatment effectively restored mucosal epithelial cells, intercellular tight junctions, goblet cells, and maintained the intestinal epithelial and endothelial barriers. PD suppressed MPO, proinflammatory markers, and malondialdehyde but enhanced superoxide dismutase and glutathione levels. It also hampered apoptosis, as evidenced by a reduction in caspase-3 expression. PD showed a significantly better response in preserving the intestinal epithelial barrier against acetic acid-induced colitis as compared to sulphasalazine and L-carnosine. These findings demonstrate the therapeutic role of PD for patients with UC.

Clinical Efficacy and Safety of Non-Cross-Linked Hyaluronic Acid Combined with L-carnosine for Horizontal Neck Wrinkles Treatment.

Background Horizontal neck wrinkle formation is gaining more attention among cosmetic practitioners and clients. To date, hyaluronic acid products are one of the most common treatment options for this aesthetic concern. However, different therapeutic strategies should be given to solve the problem due to multiple etiological reasons. Given that oxidative damage plays a critical role in neck wrinkle formation, anti-oxidative compounds are now considered by physicians when making a treatment plan. Aims To evaluate the efficacy and safety of a non-cross-linked hyaluronic acid filler in combination with L-carnosine in treating horizontal neck wrinkles. Methods Thirteen patients with a Wrinkle Assessment Scale (WAS) of 2-5 for horizontal neck wrinkles were treated with L-carnosine-containing non-cross-linked hyaluronic acid. Participants were followed-up for 3 months after treatment. The post-treated WAS scores evaluated by physicians were collected when patient satisfaction was surveyed. Any post-treatment adverse events were recorded. Results With a single injection of the above filler, the physician-evaluated WAS scores improved by at least one score at one month and the improvement kept consistent as far as three months after injection. According to the last follow-up visit, 11/13 patients were satisfied with the treatment effect of their neck wrinkle. Moreover, adverse events were rare after filler injection, except for local complications that were considered common reactions to the filler injection procedure. Conclusion The non-cross-linked hyaluronic acid filler containing L-carnosine is safe and effective for treating horizontal neck wrinkles.Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

L-carnosine mitigates interleukin-1α-induced dry eye disease in rabbits via its antioxidant, anti-inflammatory, antiapoptotic, and antifibrotic effects.

OBJECTIVE: To elucidate the implications of L-carnosine on interleukin-1α (IL-1α)-induced inflammation of lacrimal glands (LGs). MATERIALS AND METHODS: Forty rabbits were divided equally into four groups: control group (G1), IL-1α (G2), L-carnosine (G3), and L-carnosine plus IL-1α (G4). Several clinical, histopathological, immunohistochemical, morphometric, and biochemical investigations were performed, followed by statistical analysis to diagnose the presence of dry eye disease (DED). RESULTS: The LGs of G2 rabbits showed degeneration of the acinar cells, increased deposition of collagen fibers, and marked immunoexpression of FasL; elevated levels of interferon-γ, tumor necrosis factor-α, transforming growth factor-ß1, and malondialdehyde; and decreased levels of glutathione peroxidase, superoxide dismutase, catalase, and reactive oxygen species compared with those of G1 rabbits. In contrast, administration of L-carnosine to G4 rabbits revealed marked improvement of all previously harmful changes in G2 rabbits, indicating the cytoprotective effects of L-carnosine against IL-1α-induced inflammation of LGs. CONCLUSIONS: IL-1α induced inflammation of LGs and eye dryness via oxidative stress, proinflammatory, apoptotic, and profibrotic effects, whereas L-carnosine mitigated DED through antioxidant, anti-inflammatory, antiapoptotic, and antifibrotic effects on LGs. Therefore, this work demonstrates for the first time that L-carnosine may be used as adjuvant therapy for the preservation of visual integrity in patients with DED.HighlightsIL-1α induced dry eye disease through its oxidative stress, proinflammatory, apoptotic and profibrotic effects on the lacrimal glands of rabbit.L-carnosine has antioxidant, anti-inflammatory, antiapoptotic and antifibrotic effects.L-carnosine mitigated IL-1α induced dry eye disease via elevating the levels of FasL, IFN-γ, TNF-α, TGFß1 and MDA as well as reducing the levels of antioxidants (GPx, SOD, and catalase) and ROS in the lacrimal glands of rabbit.L-carnosine could be used as a novel adjuvant therapy for the treatment of dry eye disease.

Thermoregulatory, oxidative stress and lipid responses in prepartum ewes administered with L-carnosine during the hot-dry season.

The aim of the study was to investigate the effects of L-carnosine administration to prepartum ewes on oxidative status, lipid profile and thermoregulatory responses in the tropics during the hot-dry season. Twenty pregnant ewes were allotted each into two groups of treated and untreated ewes. The untreated ewes received orally 10 mL of water, while treated ewes were administered orally with L-carnosine (100 mg/kg) daily during the last 3 weeks of gestation. Blood samples were obtained during pre-gestation on day 0, gestation days 136 and 143 and after lambing. Dry-bulb temperatures (DBTs) of the pen were measured once per week at 06:00, 14:00 and 18:00 h as well as the thermoregulatory responses of the ewes. Birth weights of the lambs were determined 2-3 h postpartum. The DBT (37.33 ± 1.20 °C) and temperature-humidity index (85.24 ± 1.91) were above the thermoneutral zone. The results revealed no significant effect of L-carnosine on thermoregulatory responses of ewes and on the live-birth weight of their lambs. Malondialdehyde, 8-isoprostane and triglyceride concentrations were lower (P < 0.05) in treated ewes than in untreated ewes, but superoxide dismutase, catalase and glutathione peroxidase activities were higher (P < 0.05) in treated ewes compared to untreated ewes. In conclusion, L-carnosine reduced lipo-peroxidative products and augmented antioxidant enzyme activities in prepartum ewes under hot-dry conditions.

Investigation on beneficial role of l-carnosine in neuroprotective mechanism of ischemic postconditioning in mice: possible role of histidine histamine pathway.

OBJECTIVE: The present study was undertaken to investigate the possible role of histidine-histamine pathway in the neuroprotective effects produced by L-carnosine hand in hand with ischemic postconditioning in the animal model of cerebral ischemia. METHODS: Cerebral ischemia was induced in swiss albino mice by performing BCCAO surgery. Morris water-maze test was utilized to assess the learning ability and memory of the animals. The whole brain acetylcholinesterase (AChE) activity, TBARS, GSH levels and MPO activity were evaluated as the biochemical parameters. For histopathological evaluation of the cerebral infarct size, TTC staining was employed. RESULTS: Administration of L-carnosine (500 mg/kg, i.p.) successfully attenuated the manifestations of cerebral ischemia. Higher levels of AChE, TBARS, and MPO were observed in BCCAO treated animals, which were successfully attenuated by treatment with L-carnosine and ischemic postconditioning. Whereas administration of L-carnosine and ischemic postconditioning significantly increased the level of GSH in BCCAO treated animals. Moreover, treatment with ranitidine, an H2 blocker (30 NMol, i.c.v) antagonized the neuroprotective actions of L-carnosine evidenced by decrease in MWM performance, increase in the level of AChE and oxidative stress, while decrease in GSH level in brain. The cerebral infarct size was found to be more in BCCAO inflicted animals, which was improved by the administration of L-carnosine, while the cerebral infarct size worsened by treatment with ranitidine (3 nmol, i.c.v.). CONCLUSION: It is concluded that L-carnosine exerts neuroprotective effect via involvement of histidine-histamine pathway since the beneficial effects of L-carnosine were abolished by the H2-blocker.

Comparative Cerebroprotective Potential of d- and l-Carnosine Following Ischemic Stroke in Mice.

l-carnosine is an attractive therapeutic agent for acute ischemic stroke based on its robust preclinical cerebroprotective properties and wide therapeutic time window. However, large doses are needed for efficacy because carnosine is rapidly degraded in serum by carnosinases. The need for large doses could be particularly problematic when translating to human studies, as humans have much higher levels of serum carnosinases. We hypothesized that d-carnosine, which is not a substrate for carnosinases, may have a better pharmacological profile and may be more efficacious at lower doses than l-carnosine. To test our hypothesis, we explored the comparative pharmacokinetics and neuroprotective properties of d- and L-carnosine in acute ischaemic stroke in mice. We initially investigated the pharmacokinetics of d- and L-carnosine in serum and brain after intravenous (IV) injection in mice. We then investigated the comparative efficacy of d- and l-carnosine in a mouse model of transient focal cerebral ischemia followed by in vitro testing against excitotoxicity and free radical generation using primary neuronal cultures. The pharmacokinetics of d- and l-carnosine were similar in serum and brain after IV injection in mice. Both d- and l-carnosine exhibited similar efficacy against mouse focal cerebral ischemia. In vitro studies in neurons showed protection against excitotoxicity and the accumulation of free radicals. d- and l-carnosine exhibit similar pharmacokinetics and have similar efficacy against experimental stroke in mice. Since humans have far higher levels of carnosinases, d-carnosine may have more favorable pharmacokinetics in future human studies.

Contents of Functionally Bioactive Peptides, Free Amino Acids, and Biogenic Amines in Dutch-Type Cheese Models Produced with Different Lactobacilli.

Cheese ripening involves a number of biochemical processes, mainly of a proteolytic nature, which are initially triggered principally by milk-coagulating enzymes and, afterward, by microorganisms or enzymes of microbial origin. The proteolytic reactions affect, primarily, the synthesis of macro- and medium-molecular peptides from casein. In turn, the advanced proteolysis ends in the formation of short peptides and free amino acids. Further reactions may lead to the formation of nutritionally unfavorable biogenic amines. The present study aimed to determine changes in the contents of bioactive peptides (anserine and L-carnosine), free amino acids, and biogenic amines throughout the ripening of cheese models produced with the addition of Lactobacillus genus bacteria. The contents of amino acids varied considerably in the cheese models, depending on the bacterial strain added and ripening time. After five weeks of ripening, the total content of free amino acids in the cheese models ranged from 611.02 (a cheese model with Lactobacillus casei 2639) to 1596.64 mg kg-1 (a cheese model with Lb. acidophilus 2499). After the same time, the contents of the total biogenic amines in the cheese models with the addition of lactobacilli were lower than in the control cheese model (except for the model with Lb. rhamnosus 489). Anserine was detected in all cheese models (79.29-119.02 mg kg-1), whereas no L-carnosine was found over a five-week ripening period in the cheese models with Lb. delbrueckii 490 and Lb. casei 2639. After a five-week ripening, the highest total content of bioactive peptides was determined in the cheese models containing Lb. acidophilus 2499 (136.11 mg kg-1).

L-Carnosine protects against Oxaliplatin-induced peripheral neuropathy in colorectal cancer patients: A perspective on targeting Nrf-2 and NF-κB pathways.

BACKGROUND: Chemotherapy-induced peripheral neuropathy is a common side effect afflicting cancer patients treated with oxalipatin based chemotherapy. AIM: The study investigated the potential prophylactic effect of L-carnosine against acute oxaliplatin neurotoxicity in colorectal cancer patients with emphasis on the redox (Nrf-2, MDA), inflammatory (NF-κB, TNF-α), and apoptotic (caspase-3) parameters. METHODS: In this pilot study, 65 patients were recruited using a prospective randomized controlled study design and enrolled randomly into two arms; Arm A, 31 patients received FOLFOX-6 regimen (oxaliplatin, 5FU & leucovorin) and Arm B, 34 patients received FOLFOX-6 regimen and daily oral L-carnosine (500 mg) along the treatment period. Patients were followed up for three months, then both arms were analyzed for neuropathy incidence/grade and any additional toxicities according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTC version 4). RESULTS: The neuropathy grading evaluation of Arm B vs Arm A revealed that 17 patients (56.7%) vs 11 patients (35.5%) suffered grade 1, one patient (3.3%) vs 19 patients (61.3%) suffered grade 2, while 12 patients (40%) vs one patient (3.2%) were normal. In arm B, the addition of L-carnosine decreased significantly the levels/activity of NF-κB (27%) and TNF-α (36.6%); this anti-inflammatory effect entailed also its anti-oxidative and anti-apoptotic effects, thus MDA level (51.8%) and caspase-3 activity (49%) were also reduced, whereas Nrf-2 was increased (38.7%) as compared to Arm A. In both arms a significant correlation was only evident between TNF-α and the neuropathy grading score (P < .03); the correlation analysis was significantly positive between NF-κB and both Nrf-2 and caspase 3. CONCLUSION: L-Carnosine exerted a neuroprotective effect against oxaliplatin-induced peripheral neuropathy in colorectal cancer patients by targeting Nrf-2 and NF-κB pathways.

Synergistic effect of carnosine on browning of adipose tissue in exercised obese rats; a focus on circulating irisin levels.

The recent appreciation of the energy burning capacity of brown adipose tissue turns it to an attractive target for anti-obesity therapy. We sought to evaluate the effect of L-carnosine on browning of white adipose tissue in exercised obese rats. Sixty adult male Wistar albino rats, 7-8 week-old weighing 130-150 g, were allocated into six groups; with 10 rats in each, for an experimentation period of 12 weeks: (i) normal control rats fed a standard fat diet (SFD/control), (ii) normal control rats fed a standard diet and injected with L-carnosine (250 mg/kg, i.p,) for 6 weeks (SFD/CAR), (iii) high-fat diet (HFD)-induced obese rats for 12 weeks, (iv) HFD rats subjected to exercise training (HFD/EXE) for 6 weeks, (v) HFD rats injected with L-carnosine (250 mg/kg,i.p.) for 6 weeks (HFD/CAR) and, (vi) HFD rats subjected to exercise training and L-carnosine (HFD/EXE/CAR). At the end of the 12-week-experiment, the body weights and the serum levels of lipid profile, oxidative stress, and inflammatory markers as well as circulating myokines were investigated. Gastrocnemius muscles and inguinal adipose tissues were excised for the measurement of gene expression of muscle irisin, adipose tissue uncoupling protein1 (UCP1), CD137 and the protein level of p38MAPK. In addition, histopathological examination for the studied groups was performed. Both exercise training for 6 weeks and carnosine treatment significantly decreased body weight gain, ameliorated obesity-induced dyslipidemia, reduced the thiobarbituric acid reactive species (TBARS) and TNF-α, while increased total antioxidant capacity and IL-10. Furthermore, increases in serum irisin levels and the expression of adipose uncoupling protein-1 (UCP-1), adipose CD137, p38 MAPK, and muscular fibronectin type III domain-containing protein 5(FNDC5), the precursor of irisin gene expression, were correlated with these carnosine- and exercise-induced physiological improvements. The highest improvement was evident in the combined exercise and carnosine group which indicates that their beneficial effects in obese animals were synergistic. These findings suggest that L-carnosine may induce browning of adipose tissue through irisin stimulation, a phenomenon that could be related to its antioxidant, anti-inflammatory, and anti-obesity effects.

L-carnosine as an adjuvant to fluvoxamine in treatment of obsessive compulsive disorder: A randomized double-blind study.

BACKGROUND: Dysregulation of glutamate is implicated in the pathogenesis of obsessive-compulsive disorder (OCD). Consistently, glutamate-modulating agents, such as riluzole and memantine have been used in OCD treatment. Previous research has identified some neuroprotective role for L-carnosine potentially via its modulatory effect on glutamate. Here, we assessed the efficacy of L-carnosine as adjuvant to fluvoxamine in OCD treatment. METHODS: Forty-four patients diagnosed with moderate to severe OCD were recruited in a randomized double-blind trial. Patients received either L-carnosine or placebo as adjuvant to fluvoxamine for 10 weeks. The Yale- Brown Obsessive Compulsive Scale (Y-BOCS) was used for assessing the severity of symptoms at baseline and at weeks 4, 8, and 10. RESULTS: General linear model repeated measure showed significant effects for Time × Treatment interaction on total Y-BOCS [F (2.10, 88.42) = 8.66, p < 0.001], obsession [F (1.88, 79.34) = 4.96, p = 0.01] and compulsion [F (1.88, 79.11) = 4.57, p = 0.01]. At week 10, the change from baseline in Y-BOCS scores was 8.86 ± 2.89 (mean ± SD) in the L-carnosine group compared to 5.86 ± 2.88 in the placebo group. CONCLUSION: L-carnosine results in significant reduction of obsessive-compulsive symptoms when used as an adjuvant to fluvoxamine.

Zinc L-carnosine suppresses inflammatory responses in lipopolysaccharide-induced RAW 264.7 murine macrophages cell line via activation of Nrf2/HO-1 signaling pathway.

CONTEXT: Zinc L-carnosine (ZnC) is a chelate of Zn and L-carnosine and is used clinically in the treatment of peptic ulcer. OBJECTIVE: In this study, we aim to investigate the involvement of heme oxygenase-1 (HO-1) in the anti-inflammatory effects of ZnC in lipopolysaccharide (LPS)-induced RAW 264.7 murine macrophages. MATERIALS AND METHODS: We used immunoblotting analysis to evaluate the involvement of HO-1 in the anti-inflammatory effects of ZnC and the signaling pathway involved was measured using Dual luciferase reporter assay. RESULTS: Results from immunoblotting analysis demonstrated that pretreatment of cells with ZnC enhanced the expression of HO-1 in RAW 264.7 cells. Pretreatment of cells with HO-1 inhibitor (tin protoporphyrin IX dichloride) significantly attenuated the inhibitory effects of ZnC on nitric oxide (NO) production, inducible nitric oxide synthase (iNOS) expression and NF-κB activation in LPS-induced RAW 264.7 cells, suggesting that HO-1 play an important role in the suppression of inflammatory responses induced by ZnC. Furthermore, results from co-immunoprecipitation of Nrf2 and Keap1 and dual luciferase reporter assay showed that pretreatment of ZnC was able to activate the Nrf2 signaling pathway. Treatment of cells with p38 inhibitor (SB203580), c-Jun N-terminal kinase inhibitor (SP600125), and MEK 1/2 inhibitor (U0126) did not significantly suppress the induction of HO-1 by ZnC. Moreover, our present findings suggest that the effects of ZnC on NO production, HO-1 expression, and Nrf2 activation were attributed to its Zn subcomponent, but not l-carnosine. CONCLUSION: Pretreatment with ZnC was able to activate Nrf2/HO-1 signaling pathway, thus suppressing the expression of inflammatory mediators, such as NO and iNOS in LPS-induced RAW 264.7 cells.

Therapeutic efficacy of natural dipeptide carnosine against human cervical carcinoma cells.

Natural substances have been attracted several researchers in the recent years, because of its potential antioxidant, anti-inflammatory and anti-cancer properties. We have investigated the effect of carnosine on cell viability, apoptosis, DNA damage, reactive oxygen species (ROS) and caspase 3 enzyme expression in human cervical carcinoma and Madin-Darby Kidney Cells (MDCK) cells. Carnosine inhibited cancer cell growth up to 23%. ROS level was increased up to 30 and 31% in MDCK and HeLa cells respectively. Tunnel assay showed 42 and 14% of positive apoptotic cells in cancer and normal cells respectively. The alteration in mitochondrial and nuclear morphology was determined. The extended lace-like network of normal mitochondria found in control cells. Carnosine treatment significantly altered the mitochondrial morphology of normal cervical carcinoma cell. Mitochondria were condensed clump structures in carnosine treated cancer cells. Carnosine reduced the number of colonies of cervical carcinoma cells. Caspase 3 expression was corresponded to the appearance of immunofluorescence in the cytoplasm. Caspase 3 expression was gradually increased in cervical carcinoma cells. In Silico, docking study was performed to recognize the binding activity of carnosine against a subunit of the caspase 3, and carnosine was able to bind to the drug binding pocket of caspase 3. The glide energy is -5.2 kcal/mol, suggesting the high binding affinity of carnosine to caspase 3. Taking all these data together, the natural dipeptide L-carnosine could be a suitable antiproliferative agent in cervical carcinoma cells. Copyright © 2016 John Wiley & Sons, Ltd.

L-carnosine enhanced reproductive potential of the Saccharomyces cerevisiae yeast growing on medium containing glucose as a source of carbon.

Carnosine is an endogenous dipeptide composed of ß-alanine and L-histidine, which occurs in vertebrates, including humans. It has a number of favorable properties including buffering, chelating, antioxidant, anti-glycation and anti-aging activities. In our study we used the Saccharomyces cerevisiae yeast as a model organism to examine the impact of L-carnosine on the cell lifespan. We demonstrated that L-carnosine slowed down the growth and decreased the metabolic activity of cells as well as prolonged their generation time. On the other hand, it allowed for enhancement of the yeast reproductive potential and extended its reproductive lifespan. These changes may be a result of the reduced mitochondrial membrane potential and decreased ATP content in the yeast cells. However, due to reduction of the post-reproductive lifespan, L-carnosine did not have an influence on the total lifespan of yeast. In conclusion, L-carnosine does not extend the total lifespan of S. cerevisiae but rather it increases the yeast's reproductive capacity by increasing the number of daughter cells produced.

Effects of Dietary L-carnosine and Alpha-lipoic Acid on Growth Performance, Blood Thyroid Hormones and Lipid Profiles in Finishing Pigs.

The present study was conducted to determine the effects of L-carnosine (LC) and/or alpha-lipoic acid (ALA) supplementation on growth performance, blood thyroid hormones and lipid profiles in finishing pigs. A total of 40 (Landrace×Yorkshire) pigs with an initial body weight of 57.93±3.14 kg were randomly allocated to 4 experimental diets using a 2×2 factorial arrangement with 2 LC supplemental levels (0 or 0.1%) and 2 ALA supplemental levels (0 or 0.03%) in basal diets. The results showed that pigs fed LC-supplemented diets increased final live weight, average daily gain, and average daily feed intake compared to those of pigs fed without LC-supplemented diets (p<0.05). Dietary supplementation with ALA did not affect the growth performance and carcass traits of pigs (p>0.05). Additionally, LC supplementation increased serum triiodothyronine, thyroxine levels, and ALA supplementation increased serum triiodothyronine levels (p<0.05). Serum total cholesterol and triglycerides levels were significantly decreased in LC and ALA supplemented groups, respectively (p<0.05). Moreover, serum low density lipoprotein cholesterol levels were lower in the ALA-supplemented groups than those of pigs fed without ALA-supplemented diets (p<0.05). However, no significant LC×ALA interaction effect on growth performance, blood thyroid hormones and lipid profiles was found. This study suggested that dietary supplementation of LC resulted in better growth performance compared to that of ALA supplementation. L-carnosine and/or ALA supplementation positively modified blood lipid profiles, which may have the potential to prevent cardiovascular diseases.