Heyi Commercial Port: The Role of Carnosine and Decarboxylating Carnosine! _ Histamine _ Effect _ Peroxide Full-time Job

 Carnosine has a weak anti-inflammatory activity and a tendency to stimulate tissue repair, particularly when used after oral surgery. At higher temperature or too high or too low pH, histidine is easily oxidized and discolored, so the stability of carnosine is relatively poor. Decarboxycarnosine (β-alanyl-L-histamine), present in a variety of histamine-rich mammalian tissues (e.g., decarboxylation after extraction ,50l rotovap, heart, kidney, stomach, and intestine) in amounts as high or higher than those reported for carnosine, histamine, and 3-methylhistamine, but lower than the concentration of free histidine. In rat tissues, histidine, labeled with the radioisotope tracer 3H, is rapidly (within minutes) incorporated into decarboxylating carnosine, carnosine, and histamine, consistent with the metabolic link between the listed compounds and their potential role in histamine synthesis or degradation (see Figure 1). Thus, decarboxylated carnosine may serve as an active intermediate in the carnosine-histidine-histamine metabolic pathway and may represent an alternative means of histamine synthesis or may be a catabolite of histamine. Figure 1. Decarboxycarnosine is involved in carnosine -Histidine-histamine metabolic pathway Known reactions correspond to the following enzymes: 1. Carnosinase; 2. Carnosine synthetase; 3. Histidine decarboxylase; 4. Decarboxylating carnosine synthetase. Solid lines represent known reactions and dashed lines represent possible reactions. The figure shows the possible role of these compounds as physiological antioxidants or pro-oxidants in the presence of transition metals. 2. Antioxidant capacity of carnosine and decarboxylated carnosine Antioxidative (antiglycation) mechanism of carnosine and decarboxylate carnosine A. Carnosine, decarboxylated carnosine and other peptidomimetics containing imidazole groups can reduce lipid peroxides (LOOH) to non-toxic alcohols; B. Carnosine and decarboxylated carnosine can be complexed with transition metal ions (such as Fe2 + and Cu2 +) to prevent metal ions from catalyzing the generation of free radicals, and the complexed components have better antioxidant effect; C. React with the end products of lipid peroxidation (malondialdehyde, nonenal, etc.) to prevent these products from cross-linking with collagen and enzymes; see Figure 2 D. It can react with reducing sugar to prevent collagen glycosylation from causing yellow color, loss of elasticity and degradation. Figure 2. Schematic diagram of cross-linking between aldehyde group and amino group of protein Experimental data and comparison of carnosine and decarboxylating carnosine on anti-oxidation (anti-glycation) a. Inhibitory effect of carnosine on lipid peroxidation Fig. 3 shows data on the change in product content after lipid peroxidation catalyzed by Fe2 + (ascorbic acid protects Fe2 + from rapid oxidation), followed by protection with different concentrations of carnosine and N-acetylcarnosine. The results showed that carnosine had a good protective effect on lipid peroxidation. Figure 3. (A) Lipid peroxidation products (calculated as malondialdehyde MDA), (B) diene conjugates, (C) triene conjugates, and ketone and aldehyde products (274 nm absorption fraction), incubated separately in liposomes (1 mg/ml) for 60 min (6, dotted line) with the addition of the peroxidation-inducing system of Fe 2 + + ascorbate (1). Antioxidants N-acetylcarnosine (NAC) (10 or 20 mM) (2, 3) or L-carnosine (10 or 20 mM) (4, 5) were added to the system containing the peroxidation-inducing agent at the 5th minute of the incubation period. At 0 time and timing sampling test. b. Decarboxycarnosine-protected protein cross-linked by lipid peroxide Linoleic acid hydroperoxide (LOOH) was used to react with bovine serum albumin (BSA), and then decarboxylated carnosine was used for protection. Decarboxycarnosine can reduce LOOH to nontoxic LOH and protect BSA from cross-linking. The effect of decarboxylated carnosine is much better than that of carnosine. Compared with natural Ve, Ve can only scavenge free radicals, but it is powerless to form hydroperoxides, as shown in Figure 6. Note: Hydroperoxide is a compound containing — Ooh Figure 4. Structure and Formation of Linoleic Acid Peroxide Figure 5. (A) 13 (S) Linoleic acid hydroperoxide in phosphate buffer solution (0.1 M; HPLC chromatogram after 15 minutes incubation at 37.degree.C. (pH 7.3). Absorption wavelengths used: 234 and 205 nm. (B) 13 (S) hydroxylinoleic acid phosphate buffer solution (0.1 M; PH 7.3). Monitoring absorbance wavelength used: 234 nm. (C) HPLC monitoring of oxidative degradation of protein (BSA) by linoleic acid hydroperoxide (LOOH). (D) Correlation of natural imidazole-containing peptidomimetic protection with linoleic acid hydroperoxide (LOOH) reduction. (E) HPLC spectrum recorded at 234 nm wavelength. BSA (0.33 G/l) was incubated in 0.1 M phosphate buffer, pH = 7.3 with 1.5 mM 13 (S) -linoleic acid hydroperoxide and 5 mM decarboxylated carnosine for 60 hours at 37 ° C. Fig. 6. (A) SDS-Page of BSA exposed to 13 (S) -linoleic acid hydroperoxide. 1: BSA; 2: BSA + LOOH; 3: BSA + LOOH + decarboxylating carnosine; 4: bovine serum albumin + LOOH + L-carnosine; 5: BSA plus LOOH plus N-acetyl-h-alanylhistamine; 6: BSA plus LOOH plus L-prolylhistamine; 7: BSA plus Looh plus vitamin E. c. Decarboxylating carnosine protection Activity of superoxide dismutase after UVA/UVB irradiation Oxidative inactivation of SOD in skin cells during UV exposure represents both a reduction in part of the skin's natural antioxidant defenses and an increase in the effects of oxidative stress. The authors treated pig ears with 0%, 0.5%, 1%, and 2% decarboxylated carnosine cream, and then cut skin fragments after UVA-UVB irradiation (0.8 J/cm 2) to measure SOD activity. Fig. 7. (A) Kinetics of SOD-like activity in extracts of non-irradiated or irradiated skin previously treated with a cream containing 0% or 0.1% decarboxylating carnosine. A slope of 0.1 OD units/min was obtained for unirradiated skin. A slope of 0.17 OD units/min was obtained for irradiated skin treated with 0% decarboxylating carnosine. Irradiated skin treated with 0.1% decarboxylating carnosine obtained a slope of 0.14 OD units/min. (B) Protection of SOD activity of isolated porcine ear derm-epidermis treated with different concentrations of decarboxylating carnosine. The average TSEM of 10 independent experiments is presented. Significant difference (p < 0.001) vs control (t test). Percent protection was calculated by comparison with the SOD activity of non-irradiated skin. d. Carnosine complexe with decarboxylated carnosine Fe2 + ions, etc. The 3D models of carnosine, N-acetylcarnosine, and decarboxylating carnosine have a "claw-like" structure, similar to a "pocket", which facilitates the complexation with metal ions, and the actual data have supported the existence of this structure, as shown in Figure 8. By computer calculation, the chelation energy of decarboxylated carnosine with Fe2 + (-7725 eV) is less than that of carnosine-Fe2 + (-883 eV). Decarboxycarnosine has stronger chelating ability with Fe2 + and is more stable. Figure 8. Computer Simulation of N-Acetylcarnosine, Carnosine and Decarboxycarnosine in the Lowest Energy State of the Ball-and-Stick Model e. Hydrolysis of Carnosine and Decarboxylating Carnosine on Skin Surface Carnosine and decarboxylating carnosine are abundant in the skin. It has been proved by experiments that carnosine and decarboxylating carnosine are incubated with skin microsomes. Carnosine can be degraded by more than 60% in 10 minutes and completely decomposed in 1 hour, while decarboxylative carnosine is degraded very slowly. The main reason is that there is no corresponding enzyme on the skin surface. Figure 9. (A) Microsomal (4 mg/ml total protein) kinetics of decarboxylated carnosine (0.5 mM) and L-carnosine (0.5 mM) measured by HPLC (fluorescence on dansyl chloride reaction band). Each point represents the average of 3 experiments. (B) Kinetics of catabolism of L-carnosine and decarboxylated carnosine in the skin microsomal fraction (4 mg/ml total protein) during NADPH2-dependent enzyme activation. The kinetics of microsomal metabolism upon addition of (0.5 mM) NADPH2, decarboxylating carnosine, and L-carnosine were measured by HPLC. Each point represents the average of 3 experiments. f. Products using decarboxylated carnosine References Babizhayev M A . Biological activities of the naturalimidazole-containing peptidomimetics n-acetylcarnosine, carcinine andL-carnosine in ophthalmic and skin care products. [J]. Life Sciences, 2006,78(20):2343-2357. Babizhayev M A ,hemp extraction centrifuge, Seguin M C , Gueyne J , et al. l-carnosine(β-alanyl-l-histidine) and carcinine (β-alanylhistamine) act as naturalantioxidants with hydroxyl-radical-scavenging and lipid-peroxidase activities[J]. Biochem. J. 1994. Return to Sohu to see more Responsible Editor:. toptiontech.com