Role of Calabrian Black Rice in Metabolic Syndrome: In vitro Evaluation of Oryza sativa L. Indica Biological Properties

Background: Metabolic Syndrome is becoming more common and it is characterized by an excess intake of energy, readily available carbohydrates and fats that result in postprandial hyperglycemia and hyperlipidemia. In the treatment of Metabolic Syndrome, a diet characterized by functional food, high fiber intake and low glycemic index is recommended. Objective: The aim of this research was to study, in vitro, the beneficial and biological properties of black rice cultivated in Sibari plain, a particular area of the region of Calabria, and verify if the climatic conditions of this area influence the composition of this pigmented rice. Method: The antioxidant activity was investigated by performing the DPPH radical scavenging assay, while the free phenolic content of CBR extract was measured by Folin Ciocalteu's assay and the obtained results were expressed as mg of gallic acid equivalent/mg of extract. In order to establish the anti-inflammatory effect of CBR extract, its reactivity towards nitric oxide (NO) was evaluated, while, its anti-hypertensive activity was studied by determining the ACE activity inhibition. Results: CBR extract also suppresses pancreatic lipase activity with an IC50 value of 34.3 mu g/ml and it decreases cellular lipid accumulation by about 60%. Finally, its hypoglycemic effect was evaluated by measuring the inhibiting activity towards alpha-glucosidase and alpha-amylase enzymes. Conclusion: The obtained results demonstrate that this kind of black rice owns different beneficial properties, which make it a functional food that could improve metabolic disorders of MS.