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.

<i>In Vitro</i>Sickling Inhibitory Effects and Anti-Sickle Erythrocytes Hemolysis of <i>Dicliptera colorata</i>C. B. Clarke, <i>Euphorbia hirta</i>L. and <i>Sorghum bicolor</i>(L.) Moench

Diclipteracolorata C. B. Clarke, Euphorbia hirta L. and Sorghum bicolor (L.) Moench are reported among plant species used in Congolese traditional medicine to treat Sickle Cell Disease. These medicinal plants have been investigated for their inhibitory effect on the induced sickling process of red blood cells using Emmel’s test. Aqueous plant extracts showed good antisickling activity as revealed by the observed normal biconcave form of sickle red blood cells in anoxic conditions. The calculated radius of treated red blood cells by Euphorbia hirta L., Diclipteracolorata C. B. Clarke and Sorghum biocolor (L.) Moench extracts are 3.31 ± 0.55;3.34 ± 0.53;3.17 ± 0.52, respectively. Euphorbia hirta L. is the most active with a normalization rate, more than 70%. The chemical screening performed on these plants showed the presence of anthocyanins which were then extracted. The test carried out with anthocyanin extracts showed that these phenolic compounds have a good antisickling activity and, additionally, possess an anti-hemolytic effect on SS blood. This suggests that the evidenced biological activity of these plants would be due to anthocyanins. The results hence obtained justify the use of these plants in Congolese traditional medicine.