ABSTRACT
Antioxidants are compounds that obstruct the oxidation of macromolecules in the body. In general, there are two categories of antioxidants, natural and synthetic. Recently, interest has been increased considerably for obtaining new natural antioxidants. In this study, the scavenging of free radicals such as DPPH, NO and OH by Hypericum helianthemoides extract was evaluated. Also, the antioxidant properties of this extract were evaluated by FRAP, FTC methods and determination phenolic compounds. The plant was collected from north of Fars Province and plant extraction was obtained using ethanol. In DPPH radical scavenging, different concentrations of the Hypericum extract were added to DPPH radical. In hydroxyl radical scavenging, Fenton reaction mixture, TCA and TBA were mixed with Hypericum extract. In nitric radical scavenging, nitropruside was mixed with Hypericum extract and then sulphanilic acid, naphthylene diamine were added. In determination of phenolic compounds, Folin-ciocalteu and sodium carbonate were added to Hypericum extract. In DPPH radical scavenging, the IC50 of Hypericum extract [309.35 +/- 6.5µg/ml] was higher than the antioxidant standards, BHT [IC50=81.9 +/- 2.6 µg/ml] and quercetin [IC50=60.04 +/- 6.48 µg/ml]. The highest scavenging of hydroxyl radicals was observed in Hypericum extract [70.3 +/- 0.8%, 125 µg/ml]. In gallic acid it was [73.8 +/- 3.3%]. In 200 µg/ml of Hypericum extract scavenged NO radical [85.2 +/- 2.7%]. In FRAP method, the IC50 of this extract was 109.7 +/- 10.5 µg/ml. In FTC method, the inhibition of lipid peroxidation by Hypericum extract, BHT and ascorbic acid were 59.2 +/- 2.2, 66.9 +/- 0.15, 64.06 +/- 0.02 respectively. Total phenol of the plant extract was 3 +/- 0.4 mg/g
ABSTRACT
Myrtus communis L. is a plant traditionally used as an antiseptic and disinfectant drug. In this research, the antioxidant activity of Myrtus communis was assayed by evaluating radical scavenging activity, reducing power, FRAP method and determination of phenolic compounds. The methanolic extract of leaves of Myrtus communis was fractionated by using petroleum ether, chloroform, ethyl acetate and buthanol. In reducing power, different concentrations of samples were mixed with phosphate buffer, ferrocyanate, TCA and ferric chloride. Different concentrations of samples were mixed with DPPH and after 30 min the absorbances were measured. For determination of phenolic content, 500 µl of sample was mixed with Folin-Ciocalteu and sodium carbonate. For determination of flavonoids, 500 µl of sample was mixed with 2 ml of distilled water, NaNO2 and NaOH. In reducing power method, chloroform fraction showed the highest reducing capacity. In the DPPH radical scavenging method, the highest antioxidant capacity was found in buthanol fraction [IC50=84.42 +/- 1.8 µg/ml]. In FRAP method, the highest antioxidant capacity was found in crude extract [5.4 +/- 0.3 mg/ml] and buthanol fractions [5.51 +/- 0.4 mg/ml], respectively. The highest amount of phenolic compounds was detected in ethyl acetate fraction of Myrtus communis [17.5 +/- 0.001 µg/g]. The highest amount of flavonoids was found in crude extract of Myrtus communis [171.9 +/- 7.3 µg/ml]. Overall, we can suggest that the leaves of Myrtus communis can be used as antioxidant and as a food additives to avoid oxidative degradation of foods