Sichuan Agricultural University

Resveratrol (RSV), a dietary polyphenol widely present in traditional medicinal plants and foods, exhibits antioxidant and anti-inflammatory properties that are relevant to ethnopharmacological strategies for protecting against environmental neurotoxicants. Given increasing real-world co-exposure to lead (Pb) and cadmium (Cd), elucidating RSV's capacity to preserve gut-brain axis (GBA) homeostasis has direct translational relevance for populations relying on phytochemical interventions. Sprague-Dawley rats were randomized into control, Pb-Cd model, and RSV treatment groups (10, 20, or 40 mg/kg). For 4 weeks, rats received Pb (300 mg/L) and Cd (50 mg/L) in drinking water with daily RSV. Cognitive function was assessed by Morris water maze; barrier integrity by Evans blue assay, histology, and Western blot for ZO-1/Occludin; synaptic ultrastructure by TEM; microbiota composition by 16S rRNA sequencing; and short-chain fatty acids (SCFAs) by GC-MS. Neurotransmitters (5-HT, GABA, SP, VIP) and cytokines (IL-6, IL-1β, TNF-α) were measured by ELISA. RSV improved spatial learning, reduced EB extravasation, preserved synaptic ultrastructure and proteins (BDNF, SYN, PSD-95), and restored intestinal architecture with increased ZO-1/Occludin. RSV attenuated cytokine release, normalized goblet cells, reversed dysbiosis by restoring Lactobacillaceae/Prevotellaceae, and increased acetate, propionate, and butyrate. It reinstated 5-HT and GABA while reducing SP and restoring VIP across serum, colon, and hippocampus. RSV attenuated Pb-Cd-associated neurotoxicity and was accompanied by improved intestinal and BBB-related readouts, partial normalization of gut microbiota features and SCFA levels, and preservation of synaptic and neurotransmitter-related markers, consistent with a link to gut-brain axis function. This study is among the first to test RSV in a Pb-Cd co-exposure model using a multi-dose regimen with integrated behavioral, barrier, microbial, and neurochemical endpoints.

The Hengduan Mountains (HDM), a biodiversity hotspot in Southwest China, harbour numerous endemic taxa whose diversification has been driven by the complex geological history of this region. This study investigates the diversification of the katydid genus Sichuana, endemic to the HDM, integrating mitochondrial genomics, morphology and biogeography. We sequenced complete mitochondrial genomes of all known geographic populations of Sichuana, revealing four major clades diverging during the Late Miocene (5.06-8.37 Ma). Orogeny-driven vicariance fragmented ancestral populations, while unstable barriers may facilitate mitochondrial introgression, as evidenced by paraphyletic lineages contrasting with distinct morphologies. We describe five new species (S. brevicerca sp. nov., S. fortidens sp. nov., S. qiuzhi sp. nov., S. luqiaoensis sp. nov. and S. pseudomagna sp. nov.) and two subspecies (S. pseudomagna pseudomagna subsp. nov. and S. pseudomagna borealis subsp. nov.), highlighting the taxonomic challenges posed by discordance between mitochondrial DNA-based phylogenies and morphological classifications. This study demonstrates that orogeny-driven vicariance dominates speciation in low-dispersal insects, but transient gene flow complicates species delimitation. Our findings advocate for integrative taxonomy in biodiversity hotspots and highlight the HDM as a model system for studying biogeographic complexity.