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.

Mini-encyclopedia of mitochondria-relevant nutraceuticals protecting health in primary and secondary care-clinically relevant 3PM innovation.

Despite their subordination in humans, to a great extent, mitochondria maintain their independent status but tightly cooperate with the "host" on protecting the joint life quality and minimizing health risks. Under oxidative stress conditions, healthy mitochondria promptly increase mitophagy level to remove damaged "fellows" rejuvenating the mitochondrial population and sending fragments of mtDNA as SOS signals to all systems in the human body. As long as metabolic pathways are under systemic control and well-concerted together, adaptive mechanisms become triggered increasing systemic protection, activating antioxidant defense and repair machinery. Contextually, all attributes of mitochondrial patho-/physiology are instrumental for predictive medical approach and cost-effective treatments tailored to individualized patient profiles in primary (to protect vulnerable individuals again the health-to-disease transition) and secondary (to protect affected individuals again disease progression) care. Nutraceuticals are naturally occurring bioactive compounds demonstrating health-promoting, illness-preventing, and other health-related benefits. Keeping in mind health-promoting properties of nutraceuticals along with their great therapeutic potential and safety profile, there is a permanently growing demand on the application of mitochondria-relevant nutraceuticals. Application of nutraceuticals is beneficial only if meeting needs at individual level. Therefore, health risk assessment and creation of individualized patient profiles are of pivotal importance followed by adapted nutraceutical sets meeting individual needs. Based on the scientific evidence available for mitochondria-relevant nutraceuticals, this article presents examples of frequent medical conditions, which require protective measures targeted on mitochondria as a holistic approach following advanced concepts of predictive, preventive, and personalized medicine (PPPM/3PM) in primary and secondary care.

Identification and structure-based engineering of a dipeptidase CpPepD from Clostridium perfringens for the synthesis of l-carnosine.

l-Carnosine (l-Car), an endogenous dipeptide presents in muscle and brain tissues of various vertebrates, has a wide range of application values. The enzymatic preparation of l-Car is a promising synthetic method because it avoids the protection and deprotection steps. In the present study, a dipeptidase gene (CpPepD) from Clostridium perfringens with high l-Car synthetic activity was cloned and characterized. In an effort to improve the performance of this enzyme, we carried out site saturation mutagenesis using CpPepD as the template. By the o-phthalaldehyde (OPA)-derived high throughput screening method, mutant A171S was obtained with 2.2-fold enhanced synthetic activity. The enzymatic properties of CpPepD and mutant A171S were investigated. Under the optimized conditions, 63.94 mM (14.46 g L-1) or 67.02 mM (15.16 g L-1) l-Car was produced at the substrate concentrations of 6 M ß-Ala and 0.2 M l-His using wild-type or mutant A171S enzyme, respectively. Although the mutation enhanced the enzyme activity, the reaction equilibrium was barely affected.

Magnetic Lipid-Based hybrid nanosystems: A combined stimuli- responsive nanocarriers for enriched chemotherapeutic potential of L-carnosine in induced breast Ehrlich ascites tumor model.

Magnetic Lipid-Based Hybrid Nanosystems (M-LCNPs) is a novel nanoplatform that can respond to magnetic stimulus and are designed for delivering L-carnosine (CN), a challenging dipeptide employed in the treatment of breast cancer. CN exhibits considerable water solubility and undergoes in-vivo degradation, hence restricting its application. Consequently, it is anticipated that the developed M-LCNPs will enhance the effectiveness of CN. To ensure the physical stability of MNPs, they were initially coated with a mixture of oleic acid and oleylamine before being included in pegylated liquid crystalline nanoparticles (PLCNPs). The proposed M-LCNPs exhibited promising in-vitro characteristics, notably a small particle size (143.5 nm ± 1.25) and a high zeta potential (-39.5 mV ± 1.54), together with superparamagnetic behavior. The in-vitro release profile exhibited a prolonged release pattern. The IC50 values of M-LCNPs were 1.57 and 1.59 times lower than these of the CN solution after 24 and 48 hours, respectively. Female BALB/C female mice with an induced breast cancer (Ehrlich Ascites tumor [EAT] model) were used to study the influence of an external magnetic field on the chemotherapeutic activity and toxicity of CN loaded in the developed M-LCNPs. Stimuli-responsive M-LCNPs exhibited no apparent systemic toxicity in addition to enhanced chemotherapeutic efficacy compared to nontargeted M-LCNPs and CN solution, as evidenced by a reduction of % tumor growth (11.7%), VEGF levels (22.95 pg/g tissue), and cyclin D1 levels (27.61 ng/g tissue), and an increase in caspase-3 level (28.9 ng/g tissue). Ultimately, the developed stimuli-responsive CN loaded M-LCNPs presented a promising nanoplatform for breast cancer therapy.

The Possible Roles of ß-alanine and L-carnosine in Anti-aging.

alanine (BA), being a non-proteinogenic amino acid, is an important constituent of L-carnosine (LC), which is necessary for maintaining the muscle buffering capacity and preventing a loss of muscle mass associated with aging effects. BA is also very important for normal human metabolism due to the formation of a part of pantothenate, which is incorporated into coenzyme A. BA is synthesized in the liver, and its combination with histidine results in the formation of LC, which accumulates in the muscles and brain tissues and has a well-defined physiological role as a good buffer for the pH range of muscles that caused its rapidly increased popularity as ergogenic support to sports performance. The main antioxidant mechanisms of LC include reactive oxygen species (ROS) scavenging and chelation of metal ions. With age, the buffering capacity of muscles also declines due to reduced concentration of LC and sarcopenia. Moreover, LC acts as an antiglycation agent, ultimately reducing the development of degenerative diseases. LC has an anti-inflammatory effect in autoimmune diseases such as osteoarthritis. As histidine is always present in the human body in higher concentrations than BA, humans have to get BA from dietary sources to support the required amount of this critical constituent to supply the necessary amount of LC synthesis. Also, BA has other beneficial effects, such as preventing skin aging and intestinal damage, improving the stress-- fighting capability of the muscle cells, and managing an age-related decline in memory and learning. In this review, the results of a detailed analysis of the role and various beneficial properties of BA and LC from the anti-aging perspective.

Effects of in ovo injection of the L-carnosine on physiological indexes of neonatal broiler chicken.

The objective of the present investigation was to ascertain the impact of in ovo administration of L-carnosine on physiological indicators in neonatal broiler chickens. A total of 280 viable broiler eggs were allocated to 7 distinct groups: control, Sham in ovo injection of sterile water on d 7 of incubation. Groups 3 and 4 were subjected to in ovo injections of L-carnosine (25 and 50 µg) on d 7 of incubation. Group 5, functioning as a sham in ovo, received an injection of sterile water on d 18 of incubation. Groups 6 and 7 were in ovo injected with L-carnosine (25 and 50 µg) on d 18 of incubation. All eggs were subjected to incubation, and the hatching rate and body weight were measured post-hatch. Subsequently, blood samples were collected, and the levels of biochemical constituents in the serum were determined. Based on the outcomes, the administration of L-carnosine (50 µg) on d 7 of incubation led to a significant increase in post-hatch body weight compared to the control group (P < 0.05). The in ovo injection of L-carnosine (25 and 50 µg) on d 7 and 18 of incubation resulted in a significant decrease in the levels of serum glucose, triglyceride (TG), low-density lipoprotein (LDL), phosphorus (P), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine transaminase (ALT) in the newly hatched chickens (P < 0.05). Furthermore, the in-ovo injection of L-carnosine (25 and 50 µg) on d 7 and 18 of incubation led to a significant increase in the levels of serum high-density lipoprotein (HDL), calcium, and total protein (TP) in the newly hatched chickens (P < 0.05). Nonetheless, L-carnosine did not have a significant effect on the levels of serum IgY and IgA in the newly hatched chickens (P > 0.05). These findings indicate that the in ovo administration of L-carnosine yielded favorable outcomes in neonatal broiler chickens.

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.

Biosynthesis of Zinc Oxide Nanoparticles on l-Carnosine Biofunctionalized Polyacrylonitrile Nanofibers; a Biomimetic Wound Healing Material.

Multifunctional biohybrid nanofibers (NFs) that can simultaneously drive various cellular activities and confer antibacterial properties are considered desirable in producing advanced wound healing materials. In this study, a bionanohybrid formulation was processed as a NF wound dressing to stimulate the adhesion and proliferation of fibroblast and endothelial cells that play a major role in wound healing. Polyacrylonitrile (PAN) electrospun NFs were hydrolyzed using NaOH and biofunctionalized with l-carnosine (CAR), a dipeptide which could later biosynthesize zinc oxide (ZnO) nanoparticles (NPs) on the NFs surface. The morphological study verified that ZnO NPs are uniformly distributed on the surface of CAR/PAN NFs. Through EDX and XRD analysis, it was validated that the NPs are composed of ZnO and/or ZnO/Zn(OH)2. The presence of CAR and ZnO NPs brought about a superhydrophilicity effect and notably raised the elastic modulus and tensile strength of Zn-CAR/PAN NFs. While CAR ligands were shown to improve the viability of fibroblast (L929) and endothelial (HUVEC) cells, ZnO NPs lowered the positive impact of CAR, most likely due to their repulsive negative surface charge. A scratch assay verified that CAR/PAN NFs and Zn-CAR/PAN NFs aided HUVEC migration more than PAN NFs. Also, an antibacterial assay implied that CAR/PAN NFs and Zn-CAR/PAN NFs are significantly more effective in inhibiting Staphylococcus aureus (S. aureus) than neat PAN NFs are (1000 and 500%, respectively). Taken together, compared to the neat PAN NFs, CAR/PAN NFs with and without the biosynthesized ZnO NPs can support the cellular activities of relevance for wound healing and inactivate bacteria.

Evaluation of human skin response to solar-simulated radiation in an ex vivo model: Effects and photoprotection of L-Carnosine.

Sunlight, and more specifically the UV component, induces several skin damages, including sunburns, erythema and photoaging. The purpose of this work is to set up an ex vivo human skin model to assess the capacity of active principles in protecting skin from the deleterious effects of solar radiation. Ex vivo human skin biopsies were cultured in an air-liquid interface and exposed to solar-simulated radiation (SSR, 300-750 nm). L-Carnosine (0.2% and 2%) was applied topically to be tested as photoprotective compound. The effect on oxidative stress induction, photoaging and skin transcriptional profile was assessed by evaluating reactive oxygen species, advanced glycosylation end products formation and gene expression changes. In our model, SSR increases ROS production and AGE accumulation and affects the expression of genes related to oxidative stress, pigmentation, immunity, inflammation and photoaging. Among these pathways, 11 genes were selected as biomarkers to evaluate the skin solar radiation response. Results showed that L-Carnosine provides effective prevention against solar radiation damages reducing ROS, AGEs and mitigating the modulation of the selected biomarker genes. In conclusion, we report that our ex vivo skin model is a valuable system to assess the consequences of solar light exposure and the capacity of topically applied L-Carnosine to counteract them.

Maternal stress-induced changes in adolescent and adult offspring: Neurobehavioural improvement and telomere maintenance.

Maternal stress (MS) during gestation is known to increase the risk for the development of behavioural and physiological disorders and advances cellular aging. In this study, we investigated whether the supplementation of standardized Bacopa monnieri extract (CDRI-08/BME) or l-Carnosine (L-C) to the mother exposed to social stress during gestation modify the effect on their offspring's neurobehaviour, antioxidant defence gene expression, telomere length, and telomere biology. To test this, timed pregnant rats were subjected to social stress during the gestational day (GD) 16-18. A subset of stressed pregnant rats received either BME [80 mg/kg in 0.5% gum acacia (per-orally; p.o)] or L-C [1 mg/kg (p.o)] every day from GD-10 to until their pup's attained postnatal day (PND)-23. We observed that MS induced anxiety-like behaviour, altered inter-limb coordination, antioxidant defence genes [Superoxide dismutase (SOD1,2), Catalase (CAT), Glutathione peroxidase-3 (GPX3)], telomerase reverse transcriptase (TERT), shelterin complex subunits (TRF1, RAP1B, POT1) protein level and shorten telomere length. Notably, supplementation of BME/L-C dampens the MS, thus the effect on neurobehaviour, antioxidant defence gene expression, and telomere biology is minimized in their offspring. Together, our results suggest that supplementation of BME/L-C during gestation dampens the MS and reduced oxidative stress-mediated changes in telomere shortening/biology and associated neurobehaviour in offspring born following MS.

Combinatorial protein engineering and transporter engineering for efficient synthesis of L-Carnosine in Escherichia coli.

L-Carnosine has various physiological functions and is widely used in cosmetics, medicine, food additives, and other fields. However, the yield of L-Carnosine obtained by biological methods is far from the level of industrial production. Herein, a cell factory for efficient synthesis of L-Carnosine was constructed based on transporter engineering and protein engineering. Firstly, a dipeptidase (SmpepD) was screened from Serratia marcescens through genome mining to construct a cell factory for synthesizing L-Carnosine. Subsequently, through rationally designed SmPepD, a double mutant T168S/G148D increased the L-Carnosine yield by 41.6% was obtained. Then, yeaS, a gene encoding the exporter of L-histidine, was deleted to further increase the production of L-Carnosine. Finally, L-Carnosine was produced by one-pot biotransformation in a 5 L bioreactor under optimized conditions with a yield of 133.2 mM. This study represented the highest yield of L-Carnosine synthesized in microorganisms and provided a biosynthetic pathway for the industrial production of L-Carnosine.

The Effect of a Zinc-L-Carnosine Mouthwash in the Management of Oral Surgical Wounds: Preliminary Results of a Prospective Cohort Study.

BACKGROUND: Zinc L-carnosine promotes the transition from the inflammatory to the proliferative phase of wound healing by reducing the expression of pro-inflammatory signals and enhancing the expression of anti-inflammatory signals. This prospective cohort study aims to test the effect of a zinc-L-carnosine mouthwash in promoting oral surgical wound healing. METHODS: From October 2022 to February 2023, the authors enrolled healthy adult volunteers who needed the extraction of bilateral molars at the Unit of Dentistry of the University of Bari. The authors studied the baseline wound healing of each patient after the first extraction. Three months later, the patients underwent the second extraction and rinsed their mouths with zinc-L-carnosine mouthwash twice per day for the following 28 postoperative days. For a month after each extraction, the patients received weekly follow-up visits by an oral surgeon blinded about the study to record the modified healing index score of the wounds (range 0-6 points). For statistical analysis, we used the one-tailed t-test for paired samples with a significance level set at p < 0.05 to compare the baseline scores with those recorded during the exposure to the zinc-L-carnosine mouthwash. RESULTS: The authors enrolled four women and six men (mean age = 44.60 ± 19.22 years). On the seventh and fourteenth postoperative days, the mean difference between the modified healing index scores obtained by using the zinc-L-carnosine mouthwash and the baseline was not significant. On the twenty-first postoperative day, the mean score obtained by using the mouthwash was 5.2 ± 1.3 points and was significantly higher than the 4.7 ± 1.8 points of the baseline (p = 0.026). On the twenty-eighth postoperative day, the mean difference was significant as well (5.9 ± 0.3 points and 5.4 ± 1.1 points, respectively). CONCLUSION: The preliminary results of this study showed that the zinc-L-carnosine mouthwash improved the quality of oral surgical wound healing.

Maternal supplementation of L-carnosine improves reflexive motor behaviors in mice offspring.

This study aimed to investigate the effect of maternal supplementation of L-carnosine on improved reflexive motor behaviors in mice offspring. Forty pregnant female NMRI mice were allocated into four groups. In the control group, mice received water, while in groups 2-4, female mice received supplementation of the L-carnosine (0.001, 0.01, or 0.1 mg/kg) at gestation days (G.D.) 5, 8, 11, 14, and 17. Newborn male pups were selected, and reflexive motor behaviors were analyzed on days 5, 7, 10, and 10-15, respectively. Serum malondialdehyde(MDA), superoxide dismutase(SOD), glutathione peroxidase(GPx) and total antioxidant status(TAS) of was determined in offspring's. According to findings, prenatal supplementation of the L-carnosine significantly increased ambulation score, surface righting, hind-limb suspension score, grip strength, front-limb suspension time, and negative geotaxis in mice offspring (P < 0.05). Hind-limb foot angle decreased in mice offspring by maternal supplementation of the L-carnosine (P < 0.05). Prenatal supplementation of the L-carnosine significantly decreased the MDA and increased the SOD, GPx, and TAS levels in offspring (P < 0.05). These results suggested maternal supplementation of the L-carnosine improved reflexive motor behaviors and antioxidant status in mice offspring.

L-carnosine Attenuates Bleomycin-Induced Oxidative Stress via NFκB Pathway in the Pathogenesis of Pulmonary Fibrosis.

Idiopathic Pulmonary fibrosis (IPF), a chronic interstitial lung disease, has pulmonary manifestations clinically characterized by collagen deposition, epithelial cell injury, and a decline in lung function. L-carnosine, a dipeptide consisting of ß-alanine and L-histidine, has demonstrated a therapeutic effect on various diseases because of its pivotal function. Despite the effect of L-carnosine in experimental IPF mice, its anti-oxidative effect and associated intercellular pathway, particularly alveolar epithelial cells, remain unknown. Therefore, we demonstrated the anti-fibrotic and anti-inflammatory effects of L-carnosine via Reactive oxygen species (ROS) regulation in bleomycin (BLM)-induced IPF mice. The mice were intratracheally injected with BLM (3 mg/kg) and L-carnosine (150 mg/kg) was orally administrated for 2 weeks. BLM exposure increased the protein level of Nox2, Nox4, p53, and Caspase-3, whereas L-carnosine treatment suppressed the protein level of Nox2, Nox4, p53, and Caspase-3 cleavage in mice. In addition, the total SOD activity and mRNA level of Sod2, catalase, and Nqo1 increased in mice treated with L-carnosine. At the cellular level, a human fibroblast (MRC-5) and mouse alveolar epithelial cell (MLE-12) were exposed to TGFß1 following L-carnosine treatment to induce fibrogenesis. Moreover, MLE-12 cells were exposed to cigarette smoke extract (CSE). Consequently, L-carnosine treatment ameliorated fibrogenesis in fibroblasts and alveolar epithelial cells, and inflammation induced by ROS and CSE exposure was ameliorated. These results were associated with the inhibition of the NFκB pathway. Collectively, our data indicate that L-carnosine induces anti-inflammatory and anti-fibrotic effects on alveolar epithelial cells against the pathogenesis of IPF.

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.

Safety of zinc l-carnosine as a Novel food pursuant to Regulation (EU) 2015/2283 and the bioavailability of zinc from this source in the context of Directive 2002/46/EC on food supplements.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on zinc l-carnosine as a novel food (NF) pursuant to Regulation (EU) 2015/2283 and as a source of zinc for use in food supplements. The NF is produced by chemical synthesis and is proposed to be used in food supplements as a source of zinc. The target population proposed by the applicant is individuals above the age of 12, excluding pregnant and lactating women. The NF which is the subject of the application is a chelate-complex, formed between Zn2+ and l-carnosine and is present as a mixture of a monomer and a dimer. The material is a powder with particulate nature and is insoluble in water at neutral pH. No relevant data using an existing zinc source as comparator have been made available by the applicant and the actual bioavailability of the zinc provided by the NF at the proposed use levels remains uncharacterised. Owing to the lack of a correct characterisation of the fraction of small particles, including nanoparticles of the NF, the Panel is not in the position to evaluate specification limits for the size of the constituent particles in the NF. Owing to the lack of information on the size distribution and the physico-chemical properties of the particles constituting the NF, the Panel is not in the position to confirm whether the ADME studies and the toxicological studies provided by the applicant are appropriate to assess the safety of the NF. The Panel concludes that the NF is absorbed and provides zinc, but as it is in an insufficiently characterised particulate form, its safety has not been established and the bioavailability has not been determined.

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.

The role of Zinc L-Carnosine in the prevention and treatment of gastrointestinal mucosal disease in humans: a review.

Zinc L-carnosine is a pharmaceutical compound with direct mucosal cytoprotective and anti-inflammatory action through its antioxidative effects, cytokine modulation and membrane-stabilizing properties. Chemically, it is not an anti-secretory, antacid or raft-forming agent; its properties are mainly mediated by its higher affinity for damaged mucosa that permits the release of zinc locally by ligand exchange. Beneficial effects on various types of mucosal damage have been described in vitro and in vivo, in both animals and humans. It has been shown to promote repair of mucosal injury in human studies and has been widely used for the treatment of peptic ulcers, chemoradiotherapy-induced oral mucositis and esophagitis. More recently, the therapeutic applications of Zinc L-carnosine have been extended to the prevention and cure of various types of intestinal damage, including ulcerative colitis, iatrogenic ulcers after operative endoscopy, hemorrhoidal disease and impaired intestinal permeability. This review concentrates mainly on the current and future applications of zinc L-carnosine in gastrointestinal disease, and may be of use to gastroenterologists and endoscopists. It describes the therapeutic principles and benefits of this interesting molecule and discusses the potential future fields of interest for clinical use in humans.

Zinc carnosine: Frontiers advances of supplement for cancer therapy.

Zinc (Zn) has an existence within large quantities in the human brain, while accumulating within synaptic vesicle. There is growing evidence that Zn metabolic equilibrium breaking participates into different diseases (e.g., vascular dementia, carcinoma, Alzheimer's disease). Carnosine refers to an endogenic dipeptide abundant in skeletal muscle and brains and exerts a variety of positive influences (e.g., carcinoma resistance, crosslinking resistance, metal chelation and oxidation limitation). A complex of Zn and carnosine, called Zinc-L-carnosine (ZnC), has been extensively employed within Zn supplement therapeutic method and the treating approach for ulcers. ZnC has been shown to play a variety of roles in the body, including inhibiting intracellular reactive oxygen species(ROS) and free radical levels, inhibiting inflammation, supplementing zinc enzymes and promoting wound healing and mucosal cell repair. The present study conducting a reviewing process for the advances of ZnC in tumor adjuvant therapy.