Morus nigra L. Extract Mitigates Autistic-Like Behaviors in Maternally Separated Mice: Potential Involvement of Neuroinflammation, Nitric Oxide, and Oxidative Stress

Abstract

Autism spectrum disorder (ASD) is a pervasive neurodevelopmental disorder with rising global prevalence and no effective pharmacological treatments. Early-life stress, such as maternal separation (MS), is a known risk factor that can lead to neuroinflammation and oxidative stress, contributing to autistic-like behaviors. This study addresses the knowledge gap by exploring the potential of Morus nigra L. (black mulberry) extract, known for its anti-inflammatory and antioxidant properties, in mitigating these behaviors in a mouse model of MS. In this study, 40 male NMRI mice were used. Hydroalcoholic extract of M. nigra was isolated by maceration method; then, it was administered to MS-exposed mice (20, 40, or 60 mg/kg), and its effects on social interaction, memory, aggression, and spatial learning were assessed by using behavioral tests, including a three-chamber test, resident-intruder test, shuttle box test, and Morris water maze test. Oxidative stress markers in the serum and hippocampus as well as gene expression of inflammatory mediators in the hippocampus were assessed. Behavioral tests revealed significant improvements in social preference and passive avoidance memory and reduced aggressive behaviors. The Morris Water Maze test indicated enhanced spatial learning and memory. Biochemically, M. nigra extract reduced malondialdehyde levels and nitrite levels and increased total antioxidant capacity in the hippocampus. Gene expression analysis showed decreased levels of pro-inflammatory cytokines, including Tnf-α, Il-1β, and Tlr4. These findings suggest that M. nigra extract mitigates autistic-like behaviors in MS mice by possibly attenuating neuroinflammation and oxidative stress, highlighting its potential for further investigation in ASD-related behavioral phenotypes. Further research is warranted to elucidate the precise mechanisms and optimize dosing strategies.