Ultrasound-Assisted Extraction of Polyphenols from Hericium erinaceus: Optimization, Bioactivities and LC-MS-Based Chemical Profiling

In this study, the Box–Behnken Design (BBD) was adopted to optimize the ultrasound-assisted extraction (UAE) conditions of polyphenols from Hericium erinaceus (H. erinaceus) on the basis of single-factor experiments, with extraction time, solid–liquid ratio and ethanol concentration as the key investigation factors. The optimal extraction parameters were determined as follows: extraction time of 56.85 min, solid–liquid ratio of 1:56.71 g/mL and ethanol concentration of 44.64%, under which the actual yield of the total polyphenol crude extract (TPCE) reached 0.9985 ± 0.03%, which was highly consistent with the theoretical predicted value of 0.9960%, verifying the good fitting degree of the established model. Taking L-ascorbic acid as the positive control, the antioxidant activity of TPCE was evaluated by determining its scavenging capacity against ABTS·+, ·OH and DPPH· free radicals, and the half-maximal effective concentration (EC50) values were measured to be 0.8850, 0.9490 and 4.198 mg/mL, respectively. With acarbose as the reference drug, the inhibitory effects of TPCE on α-amylase and α-glucosidase related to carbohydrate metabolism were assayed, and the corresponding half-maximal inhibitory concentration (IC50) values were 0.0135 and 130.3 mg/mL, respectively. Furthermore, ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was employed for the tentative identification of bioactive components in TPCE, and a total of 48 and 64 chemical constituents were characterized in negative and positive ion modes, respectively, providing a chemical basis for the biological activities of TPCE. This study confirmed that UAE is an efficient and feasible technology for extracting polyphenols from H. erinaceus, which lays a theoretical foundation for the development and utilization of its polyphenols, and also provides novel insights into the development of natural functional ingredients and potential therapeutic agents for the intervention of type 2 diabetes. Additionally, the findings further validate edible fungi as a valuable reservoir of natural bioactive substances, with promising application prospects in the research and development of functional foods and pharmaceuticals targeting metabolic diseases.