Roya Karamian
1*, Mostafa Asadbegy
11 Department of Biology, Faculty of Science, Bu-Ali Sina University, Hamedan, Iran
Abstract
Background: Plant phenolic compounds are a main group of plant natural products
and flavonoids are the largest and best studied natural phenols. These
substances possess a series of biological properties and act on biological
systems as antioxidants. In present research, the aim is to determine in vitro
total phenolics content and antioxidant activity of the methanolic extracts of
three Onobrychis species belonging to the family Fabaceae, namely O. sosnovskyi
Grossh., O. viciifolia Scop. and O. melanotricha Boiss. Furthermore, an attempt
was made to identify any correlations between total phenolic content of the
extracts with their antioxidant activities
Methods:
Total phenol and flavonoid contents of the extracts were determined by
Folin-Ciocalteu and aluminum chloride methods, respectively. Antioxidant
activity was evaluated by three different test systems, namely 2,
2-diphenyl-1-picrylhydrazyl free radical scavenging (DPPH), metal-chelation
activity and ß-carotene/linoleic acid model.
Results:
Results indicated that O. viciifolia extract contains the highest total
phenolic content (10.38 ± 0.33mg GAE/g of dry extract). However, the species
are not remarkable different (P < 0.05) in total flavonoid amount. The
Onobrychis species represent strong antioxidant activity in DPPH radical
scavenging (IC50; 0.121 ± 0.005 to 0.129 ± 0.001 mg/ml), metal chelating (IC50;
1.10 ± 0.006 to 1.80 ± 0.003 mg/ml) and also β-carotene bleaching methods. In
addition, a high correlation was found between different antioxidant assays and
total phenol content of the extracts (R2 > 0.55 to 0.98).
Conclusion:
Our results showed that the examined Onobrychis extracts represent strong antioxidant
activity; hence, they can be suggested as antioxidant agents for special use in
future.