Nrf2 activator, sulforaphane ameliorates autism-like symptoms through suppression of Th17 related signaling and rectification of oxidant-antioxidant imbalance in periphery and brain of BTBR T+tf/J mice

Autism is a neurodevelopmental disease which is characterized by its core behavioral symptoms such as impairment in social interaction and stereotyped repetitive behavior. Th17 immune responses and oxidative stress are reported to be elevated in both human autistic subjects and BTBR T + Itpr3tf/J (BTBR) mice. On the other hand, activation of nuclear factor erythroid 2 related factor (Nrf2), a master transcription factor is essential for the management of anti-inflammatory and antioxidant genes. Sulforaphane activates Nrf2 and thus is considered a potential approach to treat several neurological disorders including autism. In the current work, we used sulforaphane in asocial BTBR mice and its social counterpart C57/BL6 (C57) mice to assess its therapeutic potential and molecular mechanisms (Th17 immune responses, and oxidant-antioxidant balance) through which it acts. Our results demonstrate that BTBR treated with sulforaphane had reduced self-grooming/marble burying behavior, and increased social interaction in three chambered sociability test as compared to untreated BTBR mice. Further, sulforaphane-treated BTBR mice had reduced Th17 immune responses (STAT3, RORC, IL-17 A and IL-23R expression in CD4 + T cells), oxidative stress parameters in neutrophils/cerebellum (NFkB, iNOS, and lipid peroxides). Furthermore, sulforaphane-treated BTBR and C57 mice had upregulated enzymatic antioxidant defenses in neutrophils/cerebellum (SOD, GPx and GR expression and activity). We reason that activation of Nrf2 by sulforaphane corrected Th17 immune dysfunction and oxidant-antioxidant imbalance in periphery and brain in BTBR mice. These mechanisms lead to improvement in autism-like symptoms in BTBR mice.