EVALUATION OF ANTIOXIDANT ACTIVITY, TOTAL PHENOLS AND FLAVONOIDS OF POMEGRANATE (PUNICA GRANATUM L.) STEM BARK

Shahpour Khangholi | Fadzilah Adibah Abdulmajid

---

URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=116927
Date :  2017/05/09
Publish in :    ششمين کنگره ملي گياهان دارويي


Keywords :Antioxidant, Stem bark, Pomegranate

Abstract :

---

Pomegranate, rich in polyphenols, traditionally has been used as a remedy for some diseases in ethnobotany. Generally,tree bark containsphytochemicals such asflavonoids, tannins and phenolic acids which possess antioxidant activity. In this study, methanol extract of pomegranate stem bark prepared by soxhlet apparatus during 8 hours was evaluated for total polyphenols content (TPC), total flavonoids content (TFC) and antioxidant activity using 2,2 diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging, metal chelating activity and trolox equivalent antioxidant capacity (TEAC). The TPC was determined by colorimetric method using Folin-Ciocalteu reagent and gallic acid as standard according to the method described by Singh et al 3. The TFC was evaluated by aluminum chloride (AlCl3) using catechin as standard as the method described by Zarin and Tan. The DPPH radicals scavenging activitywas estimated according to the method described by (Elfalleh et al., 2012). 100 μL of different concentrations of the extract (200, 100, 50, 25, 12.5, 6.25 and 3.125 μg/ml) wasmixed with 100 μL of 0.2 mM DPPH and readat 515 nm. Ascorbic acid was used as positive control. To evaluate metal chelating activity 250 μL of different concentration of extract was mixed with 20 μL 1 mM FeCl2 and 60 μL of 3 mM ferrozine and read at 570 nm according to the Aparadh, et al 1. TEAC was performed based on the method of (Loizzo, Tundis et al. 2012). 30 μL of extracts or Trolox (standard) was mixed with 330 μL of the ABTS+ solution and read at 750 nm. The results showed that extract contained 59.69 ± 2.913 mg GAE/g DW and flavonoids content 15.89 ± 0.98 mg CAT/g DW. Antioxidant activities in term ofIC50were14.99±1.18and 888.10±48.38 forDPPH and metal chelating activity respectively. TEAC value was estimated as 2.636 mM trolox equivalent /100g DW. References 1 Aaparadh, V. T., Naik, V. V. and Karadge, B. A. Annali Di Botanica Ann. Bot, 2012. (Roma)2, 49-56. 2 Elfalleh, W., Hannachi, H., Tlili, N., Yahia, Y., Nasri, N. and Ferchichi, A. Journal of Medicinal Plants Research, 2012.6, 4724-4730. 3 Singh, R. P., Chidambara Murthy, K. N. and Javaprakasha, J. K. J. Agric. Food Chem, 2002. 50, 81-86. 4 Zarina, Z. and Tan S, Y. International Food Research Journal, 2013. 20, 313-317.