Durmaz_2023_Saudi.Pharm.J_31_101760

Onion contains many dietary and bioactive components including phenolics and flavonoids. Spiraeoside (quercetin-4-O-beta-D-glucoside) is one of the most putative flavonoids in onion. Several antioxidant techniques were used in this investigation to assess the antioxidant capabilities of spiraeoside, including 1,1-diphenyl-2-picrylhydrazyl radical (DPPH.) scavenging, N,N-dimethyl-p-phenylenediamine radical (DMPD(+)) scavenging, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS(+)) scavenging activities, cupric ions (Cu(2+)) reducing and potassium ferric cyanide reduction abilities. In contrast, the water-soluble alpha-tocopherol analogue trolox and the conventional antioxidants butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and alpha-tocopherol were utilized as the standards for evaluation. Spiraeoside scavenged the DPPH radicals an IC(50) of 28.51 microg/mL (r(2): 0.9705) meanwhile BHA, BHT, trolox, and alpha-tocopherol displayed IC(50) of 10.10 microg/mL (r(2): 0.9015), 25.95 microg/mL (r(2): 0.9221), 7.059 microg/mL (r(2): 0.9614) and 11.31 microg/mL (r(2): 0.9642), accordingly. The results exhibited that spiraeoside had effects similar to BHT, but less potent than alpha-tocopherol, trolox and BHA. Also, inhibitory effects of spiraeoside were evaluated toward some metabolic enzymes including acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carbonic anhydrase II (CA II) and alpha-glycosidase, which are related to a number of illnesses, such as Alzheimer's disease (AD), diabetes mellitus and glaucoma disorder. Spiraeoside exhibited IC(50) values of 4.44 nM (r(2): 0.9610), 7.88 nM (r(2): 0.9784), 19.42 nM (r(2): 0.9673) and 29.17 mM (r(2): 0.9209), respectively against these enzymes. Enzyme inhibition abilities were compared to clinical used inhibitors including acetazolamide (for CA II), tacrine (for AChE and BChE) and acarbose (for alpha-glycosidase). Spiraeoside demonstrated effective antioxidant, anticholinergic, antidiabetic and antiglaucoma activities. With these properties, it has shown that Spiraeoside has the potential to be a medicine for some metabolic diseases.