Subacute oral toxicity of Sinopodophyllum hexandrum fruit in mice: Integrated assessment of target-organ injury and gut microbiota alteration.

ETHNOPHARMACOLOGICAL RELEVANCE: Sinopodophyllum hexandrum (Royle) T.S. Ying fruit (SHF) is recorded in the Chinese Pharmacopoeia as a Tibetan medicine for regulating menstruation and promoting blood circulation. Although its pharmacological potential (e.g., anticancer, hypolipidemic) is recognized, little is known about the subacute toxicity and the associated mechanisms, especially in relation to gut microbiota, which is crucial for evaluating its safety. AIM OF THE STUDY: This study evaluated the potential toxicological effects and underlying mechanisms behind SHF-induced subacute toxicity. MATERIALS AND METHODS: Mice were orally administered SHF at doses of 80 or 250 mg/kg/day for 60 consecutive days. Changes in body-weight, histopathological and biochemical indices, intestinal microbiota and antioxidant factors were examined. RESULTS: The low dose (80 mg/kg/day) was well-tolerated and induced the enrichment of short-chain fatty acid-producing bacteria (i.e., Ileibacterium, Romboutsia, and Erysipelotrichaceae) without apparent toxicity. In contrast, the high dose (250 mg/kg/day) caused significant weight loss, reversible pulmonary hyperinflation, hepatocellular injury, and tubular necrosis and focal interstitial inflammation with elevated blood urea nitrogen (BUN), indicating organ toxicity. Nevertheless, it also enhanced the colonic mucus barrier by expanding butyrate-producing consortia within Clostridia, Lachnospirales, and Ruminococcaceae while decreasing the abundance of Akkermansia and Bifidobacterium. Concurrently, upregulation of hepatic Nrf2/SOD1 suggested activated antioxidant responses, concomitant with ongoing tissue repair. CONCLUSION: The effects of SHF were dose-dependent. The low dose demonstrates a safe and prebiotic profile, supporting its potential development as a functional food. Conversely, the high dose is associated with toxicity risks, necessitating pulmonary, liver and renal monitoring. Future research should determine the minimum effective dose to balance efficacy and safety for clinical translation.