- Department of Biochemistry, Faculty of Pharmacy, Istanbul University, Istanbul, Turkey
- Received 17 March 2014, Revised 13 May 2014, Accepted 10 June 2014, Available online 27 September 2014
- Open Access funded by Taiwan Food and Drug Administration
- Under a Creative Commons license
In this study, the antioxidant and antiacetylcholinesterase activities of Sorbus torminalis (L.) Crantz fruits were evaluated. Total phenolic and flavonoid compounds, 2,2′-azino-bis (3-ethylbenzothioazoline-6-sulfonic acid), 2,2′-diphenyl-1-picrylhydrazyl, and superoxide anion radicals scavenging activities and ferric-reducing antioxidant power of water, ethyl acetate, acetone, and methanol extracts were determined for the measurement of the antioxidant activity. Quercetin and α-tocopherol were used as standard antioxidants. The inhibitory effect of the water extract on acetylcholinesterase (AChE) was evaluated using the Ellman method and galantamine was used as a standard. Water extract had the highest total phenolic concentration and the strongest antioxidant activity followed by ethyl acetate and acetone extracts whereas methanol extract has the lowest phenolics and weakest antioxidant activity. Moreover, water extract showed moderate ability to inhibit AChE. It was concluded that fruits of S. torminalis have antioxidant and anti-AChE activities and that the plant might be a natural source of antioxidants and AChE inhibitors.
- antioxidant activity;
- free radicals;
- Sorbus torminalis (L.) Crantz;
- wild service tree
Free radicals can be defined as molecules or molecular fragments containing one or more unpaired electrons in orbitals . The most important class of radical species generated in living systems is reactive oxygen species, which include superoxide anion (O2–), hydroxyl radical (OH) and hydrogen peroxide (H2O2) . Oxidative stress is a term commonly used to denote the imbalance between the concentrations of reactive oxygen and nitrogen species and the antioxidative defense mechanisms. Such an imbalance plays a pivotal role in many pathologies such as atherosclerosis, diabetes, cancer, rheumatoid arthritis, cataract, and Parkinson's diseases .
Antioxidants are substances that are capable of inhibiting oxidation. They protect the key cell components by neutralizing the damaging effects of free radicals . In plant tissues, many phenolic compounds (in addition to tocopherols) are potential antioxidants; flavonoids, tannins, and lignin precursors may work as reactive oxygen species scavenging compounds . Recently, there has been worldwide interest in finding new and safe antioxidants from natural sources, to prevent oxidative stress and to minimize oxidative injury of living cells.
Acetylcholinesterase (AChE; EC 126.96.36.199) catalyzes the hydrolysis of the neurotransmitter acetylcholine to terminate signaling events across cholinergic synapses, including those at neuromuscular junctions. Inhibition of AChE serves as a strategy for the treatment of neurodegenerative disorders such as Alzheimer's disease . Alzheimer's disease is associated with aging and characterized by progressive memory loss and cognitive deterioration . For the treatment of Alzheimer's disease, the molecular basis of the drugs used to date is as AChE inhibitors. Therefore the search for sources of effective anti-AChE compounds is extremely important. Oxidative stress has also been associated with the progression of Alzheimer's disease . The brains of patients with Alzheimer's disease show a signiﬁcant extent of oxidative damage associated with a marked accumulation of amyloid-β peptide . Some studies suggest that dietary supplements with antioxidants and free radical scavengers such as vitamin E may display some benefits in slowing the mild cognitive impairment of Alzheimer's disease  and .
Sorbus torminalis (L.) Crantz (Rosaceae) otherwise known as the “wild service tree” is a medium-sized deciduous tree native to central and southern Europe, north-western Africa, the Balkan peninsula, Asia Minor, the Crimea, Caucasus, and Transcaucasia  and . The fruits of S. torminalis are used in traditional medicine for treatment of cardiac diseases and its astringet effects  and . Also, its fruits are eaten raw  as well as consumed as jam, syrups, and wines . In Kırklareli, Turkey, S. torminalis leaves are consumed by boiling, for treatment of diabetes and stomach ache .
The antioxidant potential of some Sorbus species such as Sorbus aucuparia, Sorbus domestica, Sorbus aria, etc. has been demonstrated , , ,  and . However, there is no report about antioxidant activities of water, ethyl acetate, acetone, and methanol extracts from S. torminalis fruits. Currently, many natural antioxidants have been investigated for their inhibitory effect on AChE. In this study, anti-AChE activity of S. torminalis was examined for the first time. The aim of this study was to assess the possible antioxidant and AChE inhibitory potential of extracts of S. torminalis fruits.