Evaluation of the in vitro antioxidant, antidiabetic and anticholinergic properties of rosmarinic acid from rosemary (Rosmarinus officinalis L.)

Abstract

In this study, antidiabetic, anticholinergic, and antioxidant abilities of rosmarinic acid were evaluated and compared to standards. To determine its antioxidant activity different in vitro bioanalytical methods, including total antioxidant activity (TAA), ABTS(center dot+) scavenging activity, O-2(center dot-) scavenging activity, DPPHmiddot scavenging activity, DMPD center dot+ scavenging activity, potassium ferric cyanide reduction ability, cupric ion (Cu2+) reduction capacity, H2O2 scavenging activity, and ferrous ions (Fe2+) binding activities were separately performed. Also, butylated hydroxyanisole (BHA), Trolox, alpha-tocopherol, and butylated hydroxytoluene (BHT) were used as the reference antioxidants. Rosmarinic acid inhibited the linoleic acid emulsion peroxidation by 89.2% while BHA, BHT, Trolox and alpha-tocopherol inhibited as 87.3, 97.6, 90.3 and 75.3%, respectively, at the same concentration (30 mu g/mL). When these results are evaluated, rosmarinic acid had effective TAA than BHA and alpha-tocopherol and close to BHT and Trolox. In addition, rosmarinic acid exhibited K-I values of 9.67 +/- 0.81 nM towards acetylcholinesterase (AChE) and 33.56 +/- 2.96 nM against alpha-glycosidase enzymes.