Herbal Medicines in Autism Spectrum Disorder: A Scoping Review of Preclinical Evidence and Therapeutic Mechanisms

Herbal medicines present a promising therapeutic alternative for autism spectrum disorder (ASD), overcoming the limited efficacy and significant adverse effects associated with conventional drugs. This scoping review aims to summarize preclinical evidence on the use of herbal medicines in ASD treatment, focusing on types of animal models, intervention characteristics, behavioral outcomes, and mechanisms of action. A literature search was conducted in PubMed, Scopus, and Web of Science for studies published up to February 2025, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. This review included studies that were published in English and focused on herbal medicines in animal models of ASD, with evaluation of ASD-related behaviors. Quality assessment of the included studies was performed according to the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines 2.0. Fifty-four studies met the inclusion criteria, with 72% published from 2021 to 2025, predominantly in Asian countries (83%). Chemically induced models, particularly valproic acid-induced models (43%), were the most utilized. Single compounds (69%) were investigated more frequently than herbal extracts (22%) or traditional formulations (7%). Oral administration (48%) and therapeutic strategies (80%) were the predominant treatments. Behavioral assessments focused on social (78%) and anxiety-like behaviors (74%), with the hippocampus (43%) and cerebellum (28%) being the most frequently examined. Antioxidant (48%) and anti-inflammatory (39%) activities were the principal therapeutic mechanisms. Safety reporting was deemed to be inadequate in 81% of studies. These findings indicate that herbal medicines improve ASD symptoms primarily through modulating oxidative stress and inflammation. Future studies should address safety profiling and expanded mechanistic investigations for clinical translation.