HPLC-DAD-MS/MS profiling of phenolics from Securigera securidaca flowers and its anti-hyperglycemic and anti-hyperlipidemic activities

Abstract

Securigera securidaca (L.) Degen & Defl., Fabaceae, has been widely used in the Iranian, Indian and Egyptian folk medicine as antidiabetic and anti-hyperlipidemic remedy. Phenolic profiling of the ethanolic extract (90%) of the flowers of S. securidaca was performed via HPLC-DAD-MS/MS analysis in the positive and negative ion modes. The total polyphenols and flavonoids in the flowers were determined colorimetrically, and the quantification of their components was carried out using HPLC-UV. Total phenolics and flavonoids estimated as gallic acid and rutin equivalents were 82.39 2.79 mg/g and 48.82 1.95 mg/g of the dried powdered flowers, respectively. HPLC-DAD-MS/MS analysis of the extract allowed the identification of 39 flavonoids and eight phenolic acids. Quantitative analysis of some flavonoids and phenolics (mg/100 g powdered flowers) revealed the presence of isoquercetrin (3340 2.1), hesperidin (32.09 2.28), naringin (197.3 30.16), luteolin (10.247 0.594), chlorogenic acid (84.22 2.08), catechin (3.94 0.57) and protocatechuic acid (34.4 0.15), in the extract. Moreover, the acute toxicity, hypoglycemic and hypolipidemic effects of the extract were investigated using alloxan induced diabetes in rats in a dose of 100, 200, and 400 mg/kg bwt. The ethanolic extract was safe up to a dose of 2000 mg/kg. All tested doses of the flower extract showed marked decrease in blood glucose level by 31.78%, 66.41% and 63.8% at 100, 200 and 400 mg/kg bwt, respectively, at p < 0.05. Regarding the anti-hyperlipidemic effect, a dose of 400 mg/kg of the flower extract showed the highest reduction in serum triacylglycerides and total cholesterol levels (68.46% and 51.50%, respectively at p < 0.05). The current study proved the folk use of the flowers of S. securidaca as anti-diabetic and anti-hyperlipidemic agent which could be attributed to its high phenolic content.