title: Extraction of Flavonoids from the Flowers of Abelmoschus manihot (L.) Medic by Modified Supercritical CO₂ Extraction and Determination of Antioxidant and Anti-Adipogenic Activity.
abstract: Abelmoschus manihot (L.) Medic has been used for many years in Chinese traditional medicine. In this study, supercritical CO₂ plus a modifier was utilized to extract flavonoids from the flowers of Abelmoschus manihot (L.) Medic. The effects of temperature (40 °C-60 °C), pressure (10-30 MPa) and different concentrations of ethanol as modifier (60%-90%, ethanol:water, v/v) on major flavonol content and the antioxidant activity of the extracts were studied by response surface methodology (RSM) using a Box-Behnken design. The flavonol content was calculated as the sum of the concentrations of seven major flavonoids, namely rutin, hyperin, isoquercetin, hibifolin, myricetin, quercetin-3'-O-glucoside and quercetin, which were simultaneously determined by a HPLC method. The antioxidant activity was evaluated by a 2,2-diphenyl-1-picrylhydarzyl (DPPH) free radical-scavenging assay. The results showed that three factors and their interactions could be well fitted to second-order polynomial models (p < 0.05). At the optimal extraction conditions for flavonol content (20 MPa, 52 °C, and 85% ethanol content), the yield of flavonoids was 41.96 mg/g and the IC50 value was 0.288 mg/mL, respectively, suggesting the extract has high antioxidant activity. Furthermore, the anti-adipogenic activity of the extract on the 3T3-L1 cell line was investigated. The results indicated that it can downregulate PPARγ and C/EBPα expression at mRNA. In summary, in this study, we have established a cost-effective method for the extraction of flavonoids from the flowers of Abelmoschus manihot (L.) Medic using supercritical fluid extraction and the extracts exhibited potent antioxidant and anti-adipogenic effects, suggesting a possible therapeutic approach for the prevention and treatment of obesity.
authors.affiliation: School of Life Science and Technology, China Pharmaceutical University, #24 Tong Jia Xiang, Nanjing 210009, China. pingljj@126.com.|Department of Pharmaceutical Engineering, Zhejiang Pharmaceutical College, #888 Yin Xian Avenue Eastern Section, Ningbo 315000, China. pingljj@126.com.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Life Science and Technology, China Pharmaceutical University, #24 Tong Jia Xiang, Nanjing 210009, China. juancpu@126.com.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Life Science and Technology, China Pharmaceutical University, #24 Tong Jia Xiang, Nanjing 210009, China. Minwang@cpu.edu.cn.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
mesh_terms: D041721:3T3-L1 Cells; D028483:Abelmoschus / Q000737:chemistry*; D050156:Adipogenesis / Q000187:drug effects*; D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005419:Flavonoids / Q000737:chemistry; D035264:Flowers / Q000737:chemistry*; D005786:Gene Expression Regulation / Q000187:drug effects; D020128:Inhibitory Concentration 50; D051379:Mice; D015394:Molecular Structure; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D022762:CCAAT-Enhancer-Binding Proteins; D005419:Flavonoids; D047495:PPAR gamma; D010936:Plant Extracts
keywords: Abelmoschus manihot (L.) Medic; anti-adipogenic activity; antioxidant activity; flavonoid; modified supercritical CO2