In vitro inhibitory effects of Limonium contortirameum and L. virgatum extracts from Sardinia on α-amylase, α-glucosidase and pancreatic lipase

Abstract

Pancreatic triacylglycerol lipase (PL), α-amylase and α-glucosidase are interesting pharmacological targets for the management of dyslipidemia, atherosclerosis, and obesity-diabetes. Limonium spp (Plumbaginaceae) are endemic to Sardinia, Italy. Comparable with acarbose, aqueous extracts (AE) of L. contortirameum and L. virgatum, and their phytoconstituent gallic acid concentration gradients (mg/mL) were identified as in vitro potent (p<0.001, n=3) and efficacious dual inhibitors of α-amylase and α-glucosidase with respective IC50 (mg/mL) values of 0.6 ± 0.1, 1.2 ± 0.1 and 0.15 ± 0.02. Equivalent to orlistat (PL IC50 of 0.114 ± 0.004 μg/mL), L. contortirameum, L. virgatum AE and their phytoprinciple gallic acid inhibited PL substantially (p <0.001, n=3) in a dose-dependent manner in vitro with PL- IC50 (μg/mL) of 920.4 ± 105.2, 593.1 ± 56.8 and 8.4 ± 0.9, respectively. LC-MS analysis of extracts revealed the presence of several phenolic compounds in their aglycon and glycoside forms. These are catechins, flavones, epigallocatechins and flavonols. Flavonoid- and polyphenol-rich L contortirameum and L. virgatum, modulating gastrointestinal carbohydrate and lipid digestion and absorption, may be advocated as candidates for obesity-diabetes prevention and phytotherapy.