RESUMO
Arum elongatum (Araceae) is widely used traditionally for the treatment of abdominal pain, arterial hypertension, diabetes mellitus, rheumatism and hemorrhoids. This study investigated the antioxidant properties, individual phenolic compounds, total phenolic and total flavonoid contents (HPLC/MS analysis), reducing power and metal chelating effects of four extracts obtained from A. elongatum (ethyl acetate (EA), methanol (MeOH), methanol/water (MeOH/water) and infusion). The inhibitory activity of the extracts were also determined against acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase and glucosidase enzymes. The MeOH/water extracts contained the highest amount of phenolic contents (28.85â mg GAE/g) while the highest total flavonoid content was obtained with MeOH extract (36.77â mg RE/g). MeOH/water demonstrated highest antioxidant activity against DPPHâ radical at 38.90â mg Trolox equivalent per gram. The infusion extract was the most active against ABTS+ â (133.08â mg TE/g). MeOH/water extract showed the highest reducing abilities with the CUPRAC value of 102.22â mg TE/g and the FRAP value of 68.50â mg TE/g. A strong metal chelating effect was observed with MeOH/water extract (35.72â mg EDTAE/g). The PBD values of the extracts ranged from 1.01 to 2.17â mmol TE/g. EA extract displayed the highest inhibitory activity against AChE (2.32â mg GALAE/g), BChE (3.80â mg GALAE/g), α-amylase (0.56â mmol ACAE/g) and α-glucosidase (9.16â mmol ACAE/g) enzymes. Infusion extract was the most active against tyrosinase enzyme with a value of 83.33â mg KAE/g. A total of 28 compounds were identified from the different extracts. The compounds present in the highest concentration were chlorogenic acids, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, isoquercitrin, delphindin 3,5-diglucoside, kaempferol-3-glucoside and hyperoside. The biological activities of A. elongatum extracts could be due to the presence of compounds such as gallic acid, chlorogenic acids, ellagic acid, epicatechin, catechin, kaempferol, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, quercetin, isoquercitrin, and hyperoside. Extracts of A. elongatum showed promising biological activities which warrants further investigations in an endeavor to develop biopharmaceuticals.