immunology & Biochemistry
Jasmin Kharazmi-Khorassani; Ahmad Asoodeh
Volume 28, Issue 1 , January and February 2021, , Pages 69-81
Abstract
Introduction: Thymosin alpha-1 (zadaxin) a 28-amino acid peptide, which was first identified in the calf thymus. This peptide is a biological modifier which leads to activation of various cells of the immune system. In the recent years, thymosin alpha-1 has been studied in in vitro and in vitro studies ...
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Introduction: Thymosin alpha-1 (zadaxin) a 28-amino acid peptide, which was first identified in the calf thymus. This peptide is a biological modifier which leads to activation of various cells of the immune system. In the recent years, thymosin alpha-1 has been studied in in vitro and in vitro studies to evaluate its biological activities and therapeutic applications. Materials and Methods: This study was done to summarize findings from the biological and clinical applications of thymosin alpha-1 peptide. We searched at the sites of Google, Google Scholar and PubMed over 1966-2019 using Thymosin alpha-1, Immunomodulatory, Cancer, Hepatitis and AIDS as keywords. Results: The results showed that thymosin alpha-1 interacts with Tolllike receptors (TLR) and brings about to activation of some intracellular pathways that ultimately stimulate the immune system by modulating cytokine production, enhancing T-cell and dendritic cells. The peptide also shows antitumor activity and a protective role against oxidative damage by increasing the level of antioxidant enzymes. Clinical studies with thymosin alpha-1 have been shown a broad effective application against many infectious diseases, including hepatitis B and C and AIDS. In addition, thymosin alpha-1 is considered as a promising and adjunctive approach for subjects suffering from some cancers such as hepatocellular carcinoma and melanoma. Conclusion: The results of this study indicate the multiple biological properties of thymosin alpha-1. However, further studies are needed to understand the mechanism of action of thymosin alpha-1.
Masood Homayoni Tabrizi; Ahmad Asoodeh; Hoda Shabestarian
Volume 22, Issue 1 , March and April 2015, , Pages 45-56
Abstract
Background & objective: Due to the side effects of synthetic antioxidants, bioactive agents derived from natural sources are of great importance. The purpose of this study was to identify and characterize an antioxidant peptide derived from enzymatic hydrolysis of β-casein in camel milk, using ...
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Background & objective: Due to the side effects of synthetic antioxidants, bioactive agents derived from natural sources are of great importance. The purpose of this study was to identify and characterize an antioxidant peptide derived from enzymatic hydrolysis of β-casein in camel milk, using pepsin and pancreatin. Materials and Methods: Enzymatic hydrolysis of camel milk had accomplished using pepsin and pancreatin. The hydrolysate was fractioned using RP-HPLC and the peptide of interest was identified with MALD-TOF/TOF technique. Antioxidant activity of isolated peptide was measured by the use of radical scavenging DPPH, ABTS, hydroxyl and superoxide and inhibition of linoleic acid oxidation. Results: The results of sequencing showed that a purified peptide, called RQ-8, has the sequence of RGLHPVPQ with molecular weight of 903.41 Da. This peptide inhibited oxidation of linoleic acid and also had scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC50=0.046 mg/ml), 2,2'-azinobis (3-ethylbenzothiazo-line-6-sulfonic acid) diammonium salt (ABTS) (IC50 = 0.085 mg/ml), superoxide (O2·-) (IC50 = 0.156 mg/ml) and hydroxyl (OH ·-) (IC50 = 0.021 mg/ml) radicals. In addition, cellular activity assays showed that the RQ-8 peptide had no toxicity on A549 lung cancer cell line. Conclusion: Results indicated that the peptide RQ-8 isolated from camel milk β-casein protein has a strong antioxidant activity.