7,8‑dihydroxyflavone reduces lipid peroxidation, proinflammatory cytokines, and mediators in chemically induced‑phenylketonuria model

Abstract

Phenylketonuria (PKU) stems from a rare genetic metabolic imbalance attributed to an insufficiency in the enzyme phenylalanine hydroxylase. Within the context of PKU, brain‑derived neurotrophic factor (BDNF) plays a pivotal role in brain function. 7,8‑dihydroxyflavone (7,8‑DHF) operates as a tropomyosin receptor kinase B (TrkB) agonist, mimicking the effects of BDNF. This study aimed to examine the effects of administering 7,8‑DHF in chemically‑induced rat models specifically induced to simulate PKU chemically. The rats were subcutaneously injected with phenylalanine and p‑chlorophenylalanine, a phenylalanine hydroxylase inhibitor, along with 7,8‑DHF. The injections began on the 2nd day after birth and continued until the 10th day. Levels of interleukin‑1β (IL‑1β), interleukin‑6 (IL‑6), interleukin‑33 (IL‑33), BDNF, malondialdehyde (MDA), monoamine oxidase (MAO), and superoxide dismutase (SOD) in the brain tissues were quantified using the enzyme‑linked immunosorbent assay (ELISA). Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to assess the gene expressions of inducible nitric oxide synthase (iNOS), nuclear factor kappa beta (NF‑κB), caspase‑3, nuclear factor erythroid 2‑related factor 2 (Nrf2), heme oxygenase‑1 (HO‑1), and BDNF. The results showed a decrease in mRNA levels of iNOS, IL‑1β, IL‑6, and lipid peroxidation in the group that received 7,8‑DHF. These results indicate that administering 7,8‑DHF has the potential to reduce brain damage in PKU by lowering proinflammatory cytokine levels and lipid peroxidation in PKU models. Thus, 7,8‑DHF, as a small molecule, might offer a promising adjunct therapeutic approach for PKU.