Antioxidant, Enzyme Inhibitory and Anti-Obesity Potential of Sorrel Calyx Extracts in 3T3-L1 Adipocytes

Hibiscus sabdariffa L. (sorrel) has been widely used in the development of tropical beverages and folk medicine. This study’s objective was to investigate the anti-obesity potential of sorrel calyx extracts (methanol and water) on 3T3-L1 adipocyte cells. Phytochemical content, antioxidant potential as DPPH (1, 1-Diphenyl-2-picrylhydrazyl) radical scavenging activity and ferric reducing antioxidant power (FRAP) and enzyme (α-glucosidase, α-amylase, and pancreatic lipase) inhibitory activities were determined in sorrel methanol extracts (SME) and sorrel water extracts (SWE). Effect of SWE and SME on lipid accumulation, lipolysis and apoptosis were tested in 3T3-L1 adipocyte differentiation and maintenance stage of cells at selected concentrations (200 1000 μg/ml) was studied. The total phenolic (GAE mg/100g dry weight) and total flavonoid (mg catechin equi/ 100g dry weight) contents in SME and SWE were 158.31 and 317.27 and 90.77 and 100.08. DPPH% inhibition (IC-50-mg/ml) and FRAP (mmol Fe [II]/100g dry weight) were 0.82 and 0.33 and 1799.13 and 2296.38 for SWE and SME, respectively. SME and SWE inhibited α-glucosidase, α-amylase, and pancreatic lipase activities by more than 40% at 4mg/ml. Significant (p < 0.05) reduction in lipid accumulation and increased glycerol release in 3T3-L1 cells was observed at concentrations ranged from 600 mg/ml of both extracts. Treating cells with SME-1000 μg/ml at differentiation resulted inhibition (p < 0.05) of lipid accumulation by 45% compared to untreated cells. Highest (p < 0.05) (35%) decrease in triglyceride content as well as higher glycerol release was seen in cells exposed to SME at the differentiation stage. Sorrel extracts induced apoptosis in adipocytes at higher concentrations with prominent effect of treating cells at differentiation stage. The results of this study showed effect of sorrel extracts in reduction of lipid accumulation and increase in lipolysis of 3T3-L1 cells.