Antioxidant and anti-inflammatory activities of Arbutus unedo aqueous extract

Objective: To evaluate the antioxidant and anti-inflammatory activities of aqueous extract of Arbutus unedo(A. unedo) leaves.Methods: In this context, the in vitro antioxidant activity was demonstrated by 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical and H_2O_2 radical scavenging, ferrous ion chelating, ferric reducing power, total antioxidant capacity and by the protection against peroxidation of b-carotene-linoleic acid in emulsion. The anti-inflammatory activity was evaluated first by studying the membrane of human red blood cells against different hypotonic concentrations of Na Cl and against heat, inhibiting the denaturation of albumin.Results: Total phenolic and flavonoid content were found respectively [(207.84 ± 15.03)mg gallic acid equivalent/g, and(13.070 ± 0.096) mg quercetin equivalent/g]. The extract displayed significant scavenging activity of some radicals such as 2,2-diphenyl-1-picrylhydrazyl [IC_(50)at(7.956 ± 0.278) mg/m L],OH [IC_(50)=(1 015.74 ± 46.35 mg/m L)], H_2O_2[IC_(50)=(114.77 ± 16.86) mg/m L] and showed a good antioxidant activity through ferrous ion chelating activity [IC_(50)=(1 014.30 ± 36.21) mg/m L], ferric reducing power [IC_(50)=(156.55 ± 17.40) mg/m L], total antioxidant capacity [IC_(50)=(461.67± 4.16) mg/m L] and b-carotene-linoleic acid protection against peroxidation [I% =(87.04 ± 1.21)% at 1 000 mg/m L].Conclusions: A. unedo showed in vitro anti-inflammatory activity by inhibiting the heat induced albumin denaturation and red blood cells membrane stabilization. Our results show that aqueous leaf extract of A. unedo has good antioxidant activity and interesting anti-inflammatory properties. A. unedo aqueous extract can be used to prevent oxidative and inflammatory processes.

Chemical compounds as well as antioxidant and litholytic activities of Arbutus unedo L. leaves against calcium oxalate stones

Objective: The present study aimed to quantify and identify the bioactive compounds of the Arbutus unedo L. leaves in order to evaluate both their antioxidant properties and litholytic activities against calcium oxalate stones.Methods: This survey was carried out using hydroalcoholic extract(E.FA) and infusion(I.FA) of A. unedo leaves. The quantification of phenolic compounds, flavonoids, flavonols and anthocyanins was done by spectrophotometric methods and identification of chemical components was performed by ultraperformance liquid chromatography with photodiode array and electrospray ionization tandem mass spectrometry. Antioxidant activity was measured using the 1,1-diphenyl-2-picrylhydrazyl(DPPH)method and by the ferric reducing/antioxidant power(FRAP) assay. Litholytic activity of E.FA and I.FA was studied using a special model that resembles circuitry of the urinary system.Results: E.FA showed greater antioxidant efficacy than I.FA(P < 0.05). Its higher efficiency was shown via the values of median inhibitory concentration, which was close to(76.14 ± 0.91) mg/mL for E.FA versus(202.64 ± 5.77) lg/mL for I.FA using the DPPH method, and(53.77 ± 0.81) lg/mL for E.FA versus(236.86 ± 31.90) lg/mL for I.FA, using FRAP method. I.FA exhibited significantly higher litholytic activity compared to E.FA(P < 0.05), with dissolution values of 31.03% ± 0.63% versus 14.55% ± 0.65%, respectively.Conclusion: Overall, the results suggest that the A. unedo is rich in bioactive compounds, and possesses antioxidant and litholitic abilities that are worthy of further study.