Vol. 2, Issue 3 (2017)
Assessment of antioxidant potential using total phenolic content and DPPH assay of a Sri Lankan ‘spice’ mixture used to impair obesity
Author(s): Dr. MI Manuha, PA Paranagama, Dr. BM Nageeb, NZ Iqbal
Abstract: In 2012 21 % in men and 32.5 % in women were affected by excess weight in Sri Lanka. It was said that excessive oxidative stress on tissues is one of the main problems in obesity. Further, studies have also revealed that anti-oxidants impair obesity. The aim was to determine the anti-oxidant contents in a native ‘spice’ mixture that was used to impair obesity. The ‘spice’ mixture contains 5 spices commonly used in Sri Lanka: Cinnamomun zeylanicum, Cuminum cyminum, Piper nigram, Murraya koenigii and Allium sativum. Total Phenolic Content (TPC) and DPPH assays were used to determine the anti-oxidant potential of the ‘spice’ mixture. TPC was determined using Folin-Ciocalteu (FC) assay. Working standards of 100, 200, 300, 400, 500 µg / mL of concentrations of Gallic acid were prepared by diluting the stock solution with appropriate amount of distilled water to plot the standard calibration curve. A 1 mL of the samples (both extracts) was added to 5 mL of the diluted FC reagent. After 5 min 4 mL 7.5 % Na2CO3 was added, incubated and absorbance was recorded. For DPPH assay dilutions serious were prepared by aqueous, Methanol extracts of the ‘spice’ mixture. A 160 µL of each concentration (25, 50, 100, 200, 400, 800 µg) from both samples were pipetted out to the wells of the micro plate. Then a 0.25 mM DPPH (40 µL) was added to the wells and this was kept in dark at 300C for 15 minutes and the absorbance was measured. Average TPC of methanolic and aqueous extracts were 3.06 and 1.84 mg / g respectively. DPPH assay resulted that the ID 50 of the both extracts of the spice mixture are not significant different (p < 0.05) with the percentage inhibition of the standard Butylated Hydroxy Toluene (BHT). Hence, the study concludes that ‘spice’ mixture used to impair obesity possesses substantial amount of anti-oxidant potentiality.