A polyphenol-rich extract (WEAC) from coffee leaf was previously shown to protect the epithelial barrier integrity. This study investigated the protective effects of WEAC in C57BL/6 mice fed a high-fat diet (HFD). WEAC supplementation (100-200 mg/kg·bw) reduced body weight and lowered TNF-α levels in serum, colon, liver, and brain in mice. WEAC improved mouse intestinal barrier integrity by upregulating the tight-junction protein and reducing intestinal d-lactic acid leakage. Liver histology revealed reduced lipid accumulation and ballooning degeneration, corresponding to decreased triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels. The WEAC intervention also decreased total bile acid levels and altered short-chain fatty acid profiles and key phytochemical metabolism. Furthermore, WEAC reduced the Firmicutes/Bacteroidetes ratio, increased the Parabacteroides, unclassified_Muribaculaceae, and Akkermansia abundance, and lowered the Blautia levels. Additionally, WEAC showed no adverse effects in mice fed a normal diet. Overall, WEAC mitigated HFD-induced intestinal barrier damage and enterohepatic function, reduced systemic inflammation, and stabilized the gut microbiome.
The rapid evolution of insecticide resistance threatens global food security, with cytochrome P450-mediated detoxification representing a key adaptive mechanism in insects. However, direct biochemical evidence linking specific P450s to pyrethroid metabolism in Plutella xylostella remains limited. Here, we investigated the molecular basis of high-level pyrethroid resistance in P. xylostella. Comparative transcriptomic analyses of a susceptible strain and two highly resistant field populations (resistance ratios >650-fold) identified PxCYP6B4 as the most strongly overexpressed P450 (>95-fold). RNA interference-mediated knockdown of PxCYP6B4 significantly increased larval susceptibility to pyrethroids, while heterologous expression in Drosophila melanogaster conferred a 5.27-fold increase in tolerance to lambda-cyhalothrin. Importantly, in vitro assays using recombinant PxCYP6B4 expressed in Sf9 cells, combined with LC-MS/MS analysis, demonstrated direct hydroxylation of lambda-cyhalothrin to 4'-hydroxy-lambda-cyhalothrin. These results establish a direct molecular and biochemical link between PxCYP6B4 overexpression and pyrethroid detoxification.

