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Free Radicals and Antioxidants
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Carnosine or L-carnosine is a dipeptide composed of two amino acids: beta-alanine and L-histidine. It is an endogenous nitrogenous water-soluble compound mainly present in the non-protein fraction of skeletal muscle and other tissues (brain, olfactory epithelium) of humans, mammals, and other vertebrates. Carnosine is an endogenous metabolic antioxidant and a non-enzymatic free radical scavenger in humans. It is also able to inactivate reactive oxygen species and chelate pro-oxidative metals (105–106). Moreover, it is a strong immunomodulator, neuroprotector against free radicals, and may be a good neurotransmitter (106). Recent data report that carnosine is able to rejuvenate senescent cells and can delay eyesight impairment for the prevention and treatment of senile cataract by eye drops (105).
Biochemistry of Buffering Capacity and Ingestion of Buffers In Exercise and Athletic Performance
Published in Peter M. Tiidus, Rebecca E. K. MacPherson, Paul J. LeBlanc, Andrea R. Josse, The Routledge Handbook on Biochemistry of Exercise, 2020
Bryan Saunders, Guilherme G. Artioli, Eimear Dolan, Rebecca L. Jones, Joseph Matthews, Craig Sale
It seems that the main determinant of carnosine content in response to supplementation is the total amount ingested. Church et al. (19) reported equivalent increases in muscle carnosine when 168 g of beta-alanine was ingested, either as 12 g.day−1 for 2 weeks or as 6 g.day−1 for 4 weeks. Similarly, Stellingwerff et al. (116) reported a 2-fold greater increase in muscle carnosine content when participants ingested 3.2 as opposed to 1.6 g.day−1 for 4 weeks. The upper limit of carnosine content attainable via beta-alanine supplementation is currently unknown. The longest trial conducted to date supplemented 6.4 g.day−1 beta-alanine for 24 weeks, with muscle carnosine content measurements taken every 4 weeks throughout the investigation (104). The greatest increases were shown in the first 4–8 weeks of supplementation, although muscle carnosine content continued to increase throughout the 24 weeks, with some individuals continuing to show increases at the final 24-week collection point, demonstrating that they may not yet have reached saturation.
Single Amino Acids
Published in Luke R. Bucci, Nutrition Applied to Injury Rehabilitation and Sports Medicine, 2020
Histidine is a conditionally essential amino acid (dietary intake viewpoint) and carnosine is the dipeptide β-alanyl-l-histidine. As with other amino acids, a dietary deficiency of histidine leads to reduced wound breaking strength and impairment of wound healing in lab animals.290 Repletion of histidine deficiency by either histidine or carnosine supplementation returned wound healing to normal, but supplemental histidine or carnosine to animals with adequate histidine intake did not enhance wound healing at doses of 1 mg/100 g body weight per day (intraperitoneal injections).290 However, higher intraperitoneal doses of carnosine (2 mg/100 g body weight per day) given to rats for longer time periods (up to 25 d postsurgery) were associated with accelerated rates of wound healing, as demonstrated by sooner peaks of glycosaminoglycan synthesis and histological development of granulation tissue in rats.291 Similar results were found after carnosine injections to guinea pigs after experimental lung injury. Acceleration of fibroblast proliferation, connective tissue regeneration, and alveolar reformation was twice that of control groups.292
L-carnosine mitigates interleukin-1α-induced dry eye disease in rabbits via its antioxidant, anti-inflammatory, antiapoptotic, and antifibrotic effects
Published in Cutaneous and Ocular Toxicology, 2021
Ayman M. Mousa, Yousef H. Aldebasi
Despite the high prevalence of DED and its association with the eyelids, Meibomian gland, and conjunctival problems, there is no gold standard therapeutic regimen. Additionally, the DED treatment protocol requires proper hygiene of the eyelids, oily eye drops, and topical antibiotics. Thus, natural antioxidants, such as L-carnosine (a natural endogenous biological antioxidant present in the muscles, kidneys, and brain), may be a novel alternative to ameliorate the hazardous side effects of DED21–25. Indeed, the antioxidant activity of L-carnosine prevents oxidative tissue damage, and its anti-inflammatory activity protects tissues from numerous inflammatory injuries26–28. Hence, this study elucidated the role of L-carnosine against IL-1α-induced inflammation of LGs in adult male rabbits through various clinical, histopathological (HP), immunohistochemical (IHC), morphometric, and biochemical investigations.
Effects of High-Dose, Short-Duration β-Alanine Supplementation on Cognitive Function, Mood, and Circulating Brain-Derived Neurotropic Factor (BDNF) in Recreationally-Active Males Before Simulated Military Operational Stress
Published in Journal of Dietary Supplements, 2021
Alyssa N. Varanoske, Adam J. Wells, David Boffey, Idan Harat, Cheyanne L. Frosti, Gregory J. Kozlowski, Yftach Gepner, Jay R. Hoffman
β-alanine (BA) supplementation is an increasingly-popular method of enhancing high-intensity exercise performance through nutritional supplementation (Blancquaert et al. 2015). Performance improvements following BA supplementation are primarily attributed to pursuant increases in intramuscular carnosine content, rather than BA itself (Harris et al. 2006). Carnosine is a dipeptide composed of the amino acids L-histidine and BA, the latter of which appears to limit the rate of carnosine synthesis in humans (Harris et al. 2006). Although carnosine and BA are regularly obtained in the diet through consumption of meat products, most of the ingested carnosine is rapidly degraded into its constituents by the enzyme carnosinase, and food products only provide sufficient BA to allow for moderate increases in carnosine content (Fritzson and Pihl 1957; Harris et al. 2006). Therefore, chronic supplementation with BA remains the most effective method of increasing intramuscular carnosine content (Harris et al. 2006). Carnosine acts as an intramuscular buffer by sequestering H+ produced during high-intensity activities, thus delaying exercise-induced acidosis and improving exercise performance (Hobson et al. 2012; Saunders et al. 2017).
Lost in translation? A critical look at the role that animal models of obsessive compulsive disorder play in current drug discovery strategies
Published in Expert Opinion on Drug Discovery, 2018
Kurt Leroy Hoffman, Hugo Cano-Ramírez
Minocycline is an antibiotic with antioxidant, anti-inflammatory, and neuroprotective effects against glutamate-mediated neurotoxicity. In a double-blind, placebo-controlled trial, minocycline as an add-on treatment to fluvoxamine significantly reduced Y-BOCS scores compared to placebo [67]. Carnosine is a naturally occurring dipeptide with antioxidant, anti-inflammatory, and neuroprotective properties. One double-blind, placebo-controlled trial showed that, in a sample of patients with moderate-to-severe OCD, l-carnosine as an adjuvant to fluvoxamine treatment significantly decreased Y-BOCS scores compared to placebo, across a 10-week treatment period [68]. We found no published information available on either minocycline or l-carnosine in animal models of OCD. On the other hand, in the mouse marble burying model, a mGluR4 receptor positive allosteric modulator (ADX88178) [69], group II mGluR antagonists (MGS0039 and LY341595) [70], and an AMPA receptor potentiator (CX546) [59] have demonstrated anti-compulsive effects, but these compounds apparently have not yet been explored in clinical studies.