China
Africa
Explore chapters and articles related to this topic
Nano Delivery of Antiviral Plant Bioactives as Cancer Therapeutics
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Haripriya Shanmugam, Badma Priya, Manickam Senguttuvan Swetha, Janani Semalaiyappan
Flavanoids, a kind of polyphenols, are found in a vast range of fruits, vegetables, roots, flowers, and stems. Quercetin and kaempferol are the most predominant flavanoids occurring in nature. Three aromatic amino acids, like phenylalanine, tyrosine, and tryptophan, are the source for their synthesis within the plant system. They play a major role as an antiviral bioactive and also in basic plant metabolism by inhibiting the enzymes like xanthine oxidase, cyclooxygenase, and many enzymes that produce reactive oxygen species (Pietta 2000).
Cardiovascular Risk Factors
Published in Nicole M. Farmer, Andres Victor Ardisson Korat, Cooking for Health and Disease Prevention, 2022
Investigations of specific amino acids have identified several amino acids involved in blood pressure regulation. These include branched chain amino acids (BCAA), arginine, methionine, and the aromatic amino acids, including tryptophan. Of these amino acids, the most consistent evidence in the literature is from studies on dietary supplementation of arginine for lowering blood pressure. However, studies using dietary sources for arginine have not shown consistent results.
Diseases of the Nervous System
Published in George Feuer, Felix A. de la Iglesia, Molecular Biochemistry of Human Disease, 2020
George Feuer, Felix A. de la Iglesia
The exact mechanism determining how metabolic abnormalities of these aromatic amino acids lead to the impairment of intelligence in phenylketonuria has not been firmly agreed upon. One or more of the related substances elicit toxic action on the developing brain. The overall increase of phenylalanine in the extracellular space competes with the transport of other amino acids across the blood-brain barrier, and the lack of essential amino acids causes the impairment of protein synthesis, with subsequently abnormal cognitive brain function. This is congruent with the abnormalities in the composition of cerebral proteins. Several metabolites obtained in the serum and urine of phenylketonurics inhibit important enzymes of tyrosine and tryptophan metabolism in vitro, such as aromatic amino acid decarboxylase. o-Hydroxyphenylacetic acid inhibits cerebral glutamic acid decarboxylase and the formation of glutamic and γ-aminobutyric acid may be impaired. Depletion of glutamine may potentiate the brain damage seen in phenylketonuria, and phenylpyruvic acid blocks the conversion of dihydroxyphenylalanine to epinephrine.
The gut microbiome and metabolome in kidney transplant recipients with normal and moderately decreased kidney function
Published in Renal Failure, 2023
Yang Lan, Duo Wang, Jiayang He, Hongji Yang, Yifu Hou, Wenjia Di, Hailian Wang, Xiangwei Luo, Liang Wei
Meanwhile, a non-targeted metabolomic analysis was conducted on fecal samples collected from 100 KTRs to gain insight into the alterations in their metabolomic profiles. The PLS-DA results revealed a clear separation between the two groups of recipients, it suggests that fecal metabolites can be used as molecular markers for early screening of chronic kidney failure after kidney transplantation. A total of 85 metabolites were differentially expressed in the CKD G3T patients as compared to the CKD G1-2T patients. The 85 differential metabolites were analyzed by KEGG annotation to find pathways involved in regulating these differential metabolites. Because aromatic amino acids is significantly associated with CKD progression, our study focuses on changes in amino acid-related metabolic pathways.
Stimulus-responsive peptide hydrogels: a safe and least invasive administration approach for tumor treatment
Published in Journal of Drug Targeting, 2023
Yuchen Hu, Ying Fan, Ban Chen, Hong Li, Gang Zhang, Jiangtao Su
Peptide molecules can form secondary, tertiary and quaternary structures, providing unique ideas for the design of peptide-based natural materials [23]. Various biomaterials have been designed and explored via the self-assembly property of peptides, ranging from nanoparticles to hydrogels [24,25]. As a kind of macroscale material, the formation of peptide-based hydrogels highly depends on the self-assembly process. The driving forces of self-assembly vary according to the amino acid residue composing peptide sequences, including hydrogen bonds, ionic bonds, hydrophobic interactions, and π-π stacking [26]. As the building blocks of peptides, amino acids share the same backbone structure and only differ in the side chain, which enables them to have different polarity and hydrophobicity. Therefore, the position of amino acid residues is critical for hydrogen bonding, hydrophobic interactions, π-π stacking, etc. Aromatic amino acids such as phenylalanine (Phe, F), tryptophan (Trp, W), and tyrosine (Tyr, Y) contribute to intra- and intermolecular π-π stacking interactions; acidic and basic amino acids such as lysine (Lys, K), arginine (Arg, R), and glutamic acid (Glu, E) provide electrostatic interactions; and the backbone of peptides induces hydrogen bonding capability [27].
Serum metabolomics of end-stage renal disease patients with depression: potential biomarkers for diagnosis
Published in Renal Failure, 2021
Dezhi Yuan, Tian Kuan, Hu Ling, Hongkai Wang, Liping Feng, Qiuye Zhao, Jinfang Li, Jianhua Ran
Phenylalanine, tyrosine, and tryptophan belong to aromatic amino acids, in which phenylalanine is catalyzed by phenylalanine hydroxylase to form tyrosine, and tyrosine is further metabolized to produce catecholamine (dopamine, norepinephrine, and epinephrine) [35]. Compared with the healthy controls, the tyrosine content of the ESRD patients without depression was significantly decreased, which was consistent with previous studies [36], and the significantly decreased tyrosine level was also observed in patients and animal models with CKD [37–39]. In addition, patients with ESRD had a significantly decreased kynurenine level and a significantly increased 3-hydroxyanthranilic acid (3-HANA) level than healthy controls [40]. Tryptophan is mainly metabolized by the kynurenine pathway and the serotonin metabolic pathway, the former being more than 95% in mammals [41]; kynurenine can inhibit antigen presentation, suppress the immune response, and ultimately reduce inflammation [42]. However, 3-HANA is neurotoxic and induces the formation of free radicals such as hydroxyl radicals and hydrogen peroxide, and raises the level of oxidative stress [43]. It is concluded that ESRD may be in a state of a high inflammatory response and oxidative stress [44,45].