Phytochemical and Biological Evaluations of Arum hygrophilum Boiss. (Araceae)

BACKGROUND Arum hygrophilum is a traditional medicinal plant indigenous to Jordan. The present study explores its phytochemistry, antioxidative, antidiabesity, and antiproliferative potentialities. MATERIALS AND METHODS Column chromatography and HPLC-MS analysis were used for its phytochemical evaluation. Using leaf crude water and ethanol extracts, the antioxidative capacities, their modulation of pancreatic β-cell proliferation, and insulin secretion as well as glucose diffusion and enzymatic bioassays were evaluated. RESULTS Three flavonoids (luteolin, isoorientin, and vitexin) and β-sitosterol have been isolated and their structures determined. HPLC-MS analysis of the ethanol extract further revealed the presence of caffeic, ferulic, gallic, and rosmarinic acids and quercetine-3-O-rhamnoside. The ethanol extract exhibited DPPH and ABTS radical scavenging and antioxidative capacities. A. hygrophilum (1), vitexin (2), and rosmarinic acid (3) inhibited pancreatic lipase (PL) dose dependently with PL-IC50 (µg/mL) values in an ascending order: (3); 51.28 ± 7.55 < (2); 260.9 ± 21.1 < (1); 1720 ± 10. Comparable to GLP-1-enhanced β-cell proliferation in 2-day treatment wells, a dose-dependent augmentation of BrdU incorporation was obtained with the A. hygrophilum aqueous extract (AE) (0.5 and 1 mg/mL, with respective 1.33- and 1.41-folds, P < 0.001). A. hygrophilum AE was identified as an inhibitor of α-amylase/α-glucosidase with IC50 value of 30.5 ± 2.1 mg/mL but lacked antiproliferative effects in colorectal cancer cell lines (HT29, HCT116, and SW620) and insulinotropic effects in β-cell line MIN6. CONCLUSION A. hygrophilum extracts inhibited gastrointestinal enzymes involved in carbohydrate and lipid digestion and absorption. SUMMARY Phytochemical evaluation of Arum hygrophilum recovered flavonoids (luteolin, isoorientin and vitexin) and β-sitosterolHPLC-MS analysis of its antioxidative ethanol extract further revealed the presence of caffeic-, ferulic-, gallic- and rosmarinic acids and quercetine-3-O-rhamnosideA. hygrophilum inhibited α-amylase/α-glucosidase and pancreatic lipase dose-dependentlyA. hygrophilum augmented β-cell proliferation dose dependently, but it lacked antiproliferative effects in colorectal cancer cell lines (HT29, HCT116, and SW620) and insulinotropic effects in β-cell line MIN6 Abbreviations used: ABTS: 2,2'-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic Acid, AE: Aqueous Extract, ANOVA: Analysis Of Variance, AUC: Area Under Curve, BrdU: 5-Bromo-2'-Deoxyuridine, DPPH: 2,2-Diphenyl -1-Pycriylhydrazyl, ELISA: Enzyme Linked Immunosorbent Assay, GLP1: Glucagon Like Peptide 1, GSIS: Glucose Stimulated Insulin Secretion, HPLC-MS: High Performance Liquid Chromatography -Mass Spectrometry, IC50: 50% Inhibitory Concentration, KRH: Krebs/Ringer/Hepes, MTT: 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide, OGTT: Oral Glucose Tolerance Test, ORAC: Oxygen Radical Antioxidant Capacity, OSTT: Oral Starch Tolerance Test, PL: Pancreatic Lipase, SEM: Standard Error Of The Mean, SRB: Sulforhodamine B, TEAC: Trolox Equivalent Antioxidant Capacity, TLC: Thin Layer Chromatography.