LC-HRMS profiling of Dendrobium huoshanense aqueous extract and its therapeutic effects on nonalcoholic fatty liver disease in mice through the TLR2-NF-κB and AMPK-SREBP1-SIRT1 signaling pathways

Dendrobium huoshanense (DH) belongs to the Dendrobium genus of the Orchidaceae family and is a herbaceous plant that protects the liver and nourishes the Yin according to traditional Chinese Medicine (TCM) theory. This research aimed to determine the therapeutic effect and mechanisms of DH on a nonalcoholic fatty liver disease (NAFLD) mouse model and its chemical composition. For pharmacological research, the pathological damage and lipid accumulation in liver tissues were evaluated using HE and oil red staining, respectively. The differential proteins between the model and DHH groups were screened using 4D label-free quantitative proteomics, and the proteomic results were verified using Western blot. The potential mechanism was validated by metabolomic analysis. The main active ingredients in a DH aqueous extract were identified using UHPLC-Q Exactive HF HRMS. Pathological staining results showed that DH can reverse liver pathological damage and lipid accumulation in the NAFLD model. Quantitative proteomics revealed that the differential proteins were mainly associated with liver lipid deposition (LAL, AMPK, TM7SF2, SBCAD, and SIRT1), insulin resistance (GYS1, GYS2, PYGL, FoxO1, and PPAR-γ), and inflammation (TLR2 and MAPKAPK). Western blot verified the above-mentioned results. Metabolomic analysis also indicated that the DH aqueous extract ameliorated NAFLD in mice by affecting cholesterol metabolism and AMPK signaling pathway, proving its significant therapeutic effects on the NAFLD model. Sixty-five compounds were identified from DH aqueous extract by analyzing the precise molecular weight and MS/MS fragmentation pathway. The pharmacological mechanism of DH in treating NAFLD mainly involved the TLR2-NF-κB and AMPK-SREBP1-SIRT1 signaling pathways.