Antiradical Activity Studies of Ultrasound-Assisted Extraction of Total Flavonoids from Sanghuangporus vaninii Fruit Bodies

Abstract

Flavonoids are a class of secondary metabolites present in many plant species. Flavonoids are important active components in Sanghuangporus vaninii. It has attracted widely attention because of its unique antitumor, antioxidation, immunomodulatory, bacteriostatic, and other biological activities. In this study, the Sanghuangporus vaninii fruit bodies are used as raw materials to study the optimal extraction technology of the Sanghuangporus flavonoids. In addition, the antioxidant and bacteriostatic abilities of Sanghuangporus vaninii are analyzed through antioxidant and bacteriostatic experiments. Ultrasound-assisted ethanol extraction is used to extract Sanghuangporus flavonoids. The optimum extraction process was determined by single factor test and response surface analysis, namely, ratio of material to liquid 1 : 60, ethanol concentration 80%, ultrasonic temperature 70°C, and ultrasonic time 40 min. Under these conditions, the flavonoids content is 90.24 ± 0.89 mg/g (on dry weight basis). Using VC as the reference substance, the total flavonoid concentration was tested for its ability to scavenge free radicals such as DPPH, ABTS+, OH, and O2-. The reducing power of total crude flavonoids, the scavenging ability of NO2- , and the antibacterial and anti-inflammatory abilities are also used as evaluation indicators for this experiment. The results showed that the best scavenging rates of Sanghuangporus vaninii flavonoids for DPPH, ABTS+,· OH, and O2-.were, respectively, 92.17 ± 1.33%, 92.49 ± 1.55%, 94.85 ± 1.39%, and 86.01 ± 1.21%. In terms of reducibility, the absorbance of Sanghuangporus vaninii flavonoids at 0.008 mg/ml was 2.65 ± 0.04, which was higher than that of positive control VC at 0.90 ± 0.05. Sanghuangporus vaninii flavonoids at 200 μg/mL could effectively inhibit the NO2- content in vitro to 9.38 ± 0.23 pg/ml. The inhibitory rates of Sanghuangporus vaninii flavonoids on Escherichia coli, Staphylococcus aureus, and Bacillus subtilis were 79.48 ± 1.57%, 85.64 ± 1.22%, and 80.29 ± 0.04%. When the concentration of Sanghuangporus vaninii flavonoids was 200 μg/mL, the concentration of NO was 9.38 ± 0.23 pg/ml.