Total Phenolic Contents and Antioxidant Properties of Algerian Arbutus unedo L. Extracts

Arbutus unedo L. is a plant widely distributed in the Mediterranean basin and North Africa, frequently used in traditional folk medicine to treat diabetes and arterial hypertension. This study aims to evaluate the phenolic composition and antioxidant activity of ethyl acetate (EA.E) and n-butanolic (But.E) extracts prepared from leaves of Arbutus unedo. Total phenolic and flavonoids contents were determined spectrophotometrically. The antioxidant activity was evaluated using DPPH•, OH•, H2O2, O•-2, ß-carotene bleaching and AAPH-induced erythrocyte oxidative hemolysis assays. The phytochemical analysis showed the presence of polyphenols and flavonoids in both extracts. The high amount was observed in EA.E which exerted the stronger antioxidant effect, with IC50 values of 3.43 μg/mL, 323.45 µg/mL, 38.40 µg/mL and 11.56 µg/mL, in DPPH•, OH•, O•-2 and H2O2 tests, respectively. Both extracts inhibited β-carotene bleaching, but EA.E is always more potent (92%) than But.E (85%). Furthermore, the EA.E showed the highest protective effect on erythrocyte hemolysis induced by AAPH, with half time hemolysis (HT50) of 122.02 min at 40 µg/mL. Taken together, this study showed that Arbutus unedo leaf extracts possess strong antioxidant potential, which may be attributed to the presence of a high amount of polyphenolic constituents. So, this plant might be exploited as a potential source of natural antioxidant agents for pharmaceutical and food applications. Keywords: oxidative stress, antioxidant, phenolic compounds, Arbutus unedo

Free Radical Scavenging Activity, Reducing Power and Anti-Hemolytic Capacity of Algerian Drimia maritima Baker Flower Extracts

This study was undertaken to evaluate the antioxidant and anti-hemolytic properties of Algerian Drimia maritima Baker flower extracts. Determination of phenolic content was carried out to estimate the chemical composition of D. maritima extracts. Antioxidant properties were investigated in all extracts using free radical scavenging activity (against DPPH, ABTS, hydroxyl radical, and superoxide anion), reducing power, inhibition of lipid peroxidation, and anti-hemolytic capacity. Phenolic determination revealed that D. maritima flowers contain phenolic compounds, flavonoids, and tannins. Ethyl acetate extract showed the highest reducing power and scavenging activity using DPPH and ABTS assays. However, aqueous extract was the most effective against hydroxyl radical, superoxide anion, and lipid peroxidation. The half-time of hemolysis indicates that chloroform extract exhibited the best anti-hemolytic capacity in the AAPH induced hemolysis model. The results of this study suggest that D. maritima could be used as a possible source of antioxidant phenolic compounds and that further determination of these compounds may provide more information on their medicinal value.  Keywords: Drimia maritima, phenolic compounds, scavenging activity, reducing power, anti-hemolytic

ANTIOXIDANT AND ANTI-INFLAMMATORY ACTIVITIES OF RUBUS FRUTICOSUS AND ZIZYPHUS VULGARIS METHANOL EXTRACTS

Objective: This report is an attempt to study the phenolic composition of Rubus fruticosus (RFE) and Zizyphus vulgaris (ZVE) methanol extracts and evaluate their antioxidant and anti-inflammatory effects in-vitro and in-vivo.Methods: Total phenolic and total flavonoids contents of extracts were determined by spectrophotometric methods. Phenolic compounds were identified by HPLC-TOF/MS. The antioxidant activities were evaluated in vitro using DPPH, ABTS and FRAP assays. The effect of RFE and ZVE on DNA cleavage induced by H2O2 UV-photolysis was also investigated. The antioxidant effect of RFE and ZVE was tested in vivo using the blood total antioxidant capacity test in mice. On the other hand, the anti-inflammatory activity was assessed in vivo using two models of acute inflammation ear edema and vascular permeability.Results: The phytochemical analysis of these extracts showed that RFE possesses higher polyphenolic and flavonoid content than ZVE. in the same way RFE exerted the highest antioxidant capacity with IC 50 value of 14 µg/ml in DPPH assay, 1.58 mmol of Trolox E/mg extract and 3.39 of mmol FesO4/mg extract in ABTS, and FRAP assay respectively. The studied extracts showed a concentration-dependent protective effect on DNA cleavage induced by H2O2 UV-photolysis. The daily oral administration of 200 mg/kg of RFE or ZVE during three weeks showed an improvement of the blood total antioxidant capacity; the HT50 values were151.45 min and 146.72 min for the groups treated with RFE and ZVE, respectively versus 122.5 min for the control group. The topical application of 2 mg/ear of RFE inhibited the croton oil-induced ear edema by 75.72%, while the inhibition exerted by ZVE was 64.24%. These inhibitions were higher than that of indomethacin, used as a reference. Moreover, the oral administration of 400 mg/kg of RFE inhibited significantly (33.57%) acetic acid induced vascular permeability in mice. However, this effect was lower than this of indomethacin. The inhibition effect exerted by ZVE was not significant.Conclusion: The results obtained in this investigation showed that RFE possesses strong antioxidant and anti-inflammatory potential in comparison with ZVE, which may be attributed to the presence of polyphenolic phytoconstituents

Phenolic Content and Biomolecule Oxidation Protective Activity of Globularia alypum Extracts

ABSTRACT The protective activity of methanolic (Met E) and aqueous (Aq E) extracts of Globularia alypum L. (G. alypum) against DNA, lipid and protein oxidative damage was investigated. Moreover, the scavenging, chelating, and reducing power activities of the extracts were also evaluated. Phytochemical analysis was performed to determine phenolic compounds. Results showed that Met E and Aq E were rich in phenolic compounds, and were able to scavenge DPPH˙ with IC50 values of 48.61 µg/mL and 51.97 µg/mL, respectively. In addition, both extracts were able to chelate ferrous ions. At 300 μg/mL, the chelating activity was 97.53% and 91.02%, respectively. The reducing power of these extracts was also remarkable and concentration dependent. At 100 µg/mL, both extracts inhibited lipid peroxidatin by only 42.45% and 4.03%. However, the DNA oxidation damage was inhibited dose-dependently in the presence of G. alypum extracts. At 1 mg/mL, both extracts suppressed DNA cleavage by 83%-84%. The protein oxidation was also inhibited by G. alypum extracts. At 1 mg/mL, Aq E and Met E protected BSA fragmentation by 77%-99%. The overall results suggest that G. alypum extracts exerted antioxidant activity and protect biomolecules against oxidative damage; hence it may serve as a potential source of natural antioxidants

Protective activity of Hertia cheirifolia extracts against DNA damage, lipid peroxidation and protein oxidation

Context: Hertia cheirifolia L. (Asteraceae), a perennial shrub widely distributed in Northern Africa, is traditionally used to treat inflammatory disorders. Objective: The protective effect of methanol (Met E) and aqueous (Aq E) extracts of Hertia cheirifolia against DNA, lipid and protein oxidation was investigated. Materials and methods: Different concentrations (50–1000 μg/mL) of Hertia cheirifolia aerial part extracts were examined against DNA, lipid and protein oxidation induced by H2O2 + UV, FeSO4, and Fe3+/H2O2-ascorbic acid, respectively. The DPPH•, metal ion chelating, reducing power and β-carotene bleaching tests were conducted. Results: Both extracts were rich in polyphenols, flavonoids and tannins, and were able to scavenge DPPH• with IC50 values of 138 and 197 μg/mL, respectively. At 300 μg/mL, Aq E exerted stronger chelating effect (99%) than Met E (69%). However, Met E reducing power (IC50 = 61 μg/mL) was more than that of Aq E (IC50 = 193 μg/mL). Both extracts protected from β-carotene bleaching by 74% and 94%, respectively, and inhibited linoleic acid peroxidation. The inhibitory activity of Aq E extract (64%) was twice more than that of Met E (32%). Interestingly, both extracts protected DNA against the cleavage by about 96–98%. At 1 mg/mL, Met E and Aq E restored protein band intensity by 94–99%. Conclusions: Hertia cheirifolia exhibits potent antioxidant activity and protects biomolecules against oxidative damage; hence, it may serve as potential source of natural antioxidant for pharmaceutical applications and food preservation. This is the first report on the protective activity of this plant against biomolecule oxidation