Extraction of Anthraquinone from Fermented Morinda officinalis and Its Antioxidant and Hypoglycemic Activities

Objective: Optimization of the extraction process of anthraquinone from fermented Morinda officinalis and investigated its antioxidant and hypoglycemic activities. Methods: Taking the extraction ratio of anthraquinone as the evaluation index, the optimal conditions were obtained by response surface methodology. In vitro, the antioxidant activity was evaluated by determining the scavenging ability of anthraquinone against DPPH free radical, hydroxyl free radical and superoxide anion assays. In vivo, the antioxidant activity was evaluated by measuring the effect of anthraquinone on the life span and motility of Caenorhabditis elegans. The hypoglycemic activity in vitro was evaluated by determining the inhibition rate of anthraquinone against alpha-glucosidase and alpha-amylase. The hypoglycemic activity in vivo was evaluated by measuring the effect of anthraquinone on glucose consumption of IR-HepG2 cells. Results: The optimal conditions were obtained as follows: ethanol concentration, 45%; solid-to-solvent ratio, 1:41 (g/mL); temperature, 65 ℃; and time, 1.60 h. Under these conditions, the extraction ratio of anthraquinone was 90.37%. In the antioxidant assay in vitro, anthraquinone exhibited good scavenging ability against DPPH free radicals, hydroxyl free radicals, and superoxide anions. In the antioxidant assay in vivo, anthraquinone significantly prolonged the life span (P<0.05), and enhanced the motility of Caenorhabditis elegans (P<0.05). The IC₅₀ values of anthraquinone on alpha-amylase and alpha-glucosidase were 0.588 and 0.575 mg/mL, respectively. Glucose consumption of IR-HepG2 cells in the anthraquinone group (1.2 mg/mL) was increased by 47.42% compared with the model group. Conclusion: The anthraquinone from fermented Morinda officinalis exhibited good antioxidant and hypoglycemic activities, facilitating the development of natural therapeutic agents for diabetes treatment.