Title:Current Landscape on Development of Phenylalanine and Toxicity of its
Metabolites - A Review
Volume: 19
Issue: 2
Author(s): Samrat Bose*, Shirsendu Mandal, Rajesh Khan, Himangshu Sekhar Maji and Sumel Ashique
Affiliation:
- Division of Pharmacology, Guru Nanak Institute of Pharmaceutical Science and Technology, 157/F, Nilgunj Road,
Kolkata, 700114, West Bengal, India
Keywords:
Phenylalanine, metabolic pathways, phenylketonuria, tyrosinemias, congenital abnormalities, dietary restriction.
Abstract: Phenylalanine, an essential amino acid, is the "building block" of protein. It has a tremendous
role in different aspects of metabolic events. The tyrosine pathway is the prime one and is typically used
to degrade dietary phenylalanine. Phenylalanine exceeds its limit in bodily fluids and the brain when the
enzyme, phenylalanine decarboxylase, phenylalanine transaminase, phenylalanine hydroxylase (PAH) or
its cofactor tetrahydrobiopterin (BH4) is deficient causes phenylketonuria, schizophrenia, attentiondeficit/
hyperactivity disorder and another neuronal effect. Tyrosine, an amino acid necessary for synthesizing
the pigments in melanin, is produced by its primary metabolic pathway. Deficiency/abnormality in
metabolic enzymes responsible for the catabolism pathway of Phenylalanine causes an accumulation of
the active intermediate metabolite, resulting in several abnormalities, such as developmental delay, tyrosinemias,
alkaptonuria, albinism, hypotension and several other undesirable conditions. Dietary restriction
of the amino acid(s) can be a therapeutic approach to avoid such undesirable conditions when
the level of metabolic enzyme is unpredictable. After properly identifying the enzymatic level, specific
pathophysiological conditions can be managed more efficiently.
