Anti-leishmanial activities of Olea europaea subsp. laperrinei extracts.

Leishmaniasis is an infectious disease that is often fatal in affected patients and represents a major public health problem. At present, no vaccine is available, and the drug treatments used are costly, long, and have numerous side effects, they also present variable effectiveness, frequent relapses, and a more and more marked resistance towards the parasites. Thus, new therapeutic strategies are urgently needed, and they are mainly based on the research of active natural products. The objective of our study is the chemical characterization and the quantification of the polyphenol contents contained in the EAF and EAT extracts of the Laperrine olive tree and the evaluation of their antileishmania effect against Leishmania infantum. The quantification of polyphenols, flavonoids and total tannins shows a higher content in the leaf extract. We find respectively 776.76±30.64 mg gallic acid equivalent/g DR; 114.35±14.12 mg quercetin equivalent/g DR and 214.89±.17 mg tannic acid equivalent/g DR.The chemical characterization of Olea europaea subsp. laperrinei extracts show the presence of numerous antileishmanial biomolecules such as oleuropein, hydroxytyrosol, rutin, gallic acid, cafeic acid, rosmarinic acid, and quercetin.In this context, we are testing the in vitro leishmanicidal effect of Laperrine olive tree extracts. The results obtained are promising and highlight the effectiveness of the tested extracts against the promastigote form of Leishmania infantum. Indeed, the LD50 is obtained with the leaf extract at a concentration of 7.52±2.71 µl/ml.

Assessment of the Antioxidant and Anti-inflammatory Properties of Aqueous Extract of Rosa sempervirens Leaves.

The antioxidant and anti-inflammatory properties of an aqueous natural extract obtained from Rosa sempervirens leaves were assessed. The ability of the extract to scavenge DPPH, •OH, and H2O2 radicals, chelate ferrous ions, reduce ferric ions, and protect ß-carotene-linoleic acid in emulsion from peroxidation was investigated in vitro. Furthermore, the anti-inflammatory activity of the extract was evaluated by measuring the stability of the membrane of human red blood cells against different hypotonic concentrations of NaCl and heat, as well as by inhibiting the denaturation of albumin. A high total phenolic content (278.38± 11.07 mg GAE/g) and flavonoid content (34.22± 0.12 mg QE /g) were found in the extract. The extract exhibited significant scavenging activity of DPPH (IC50 6.201 ± 0.126 µg/ ml), •OH (IC50 = 894.57 ± 21.18 µg/ml), and H2O2 (IC50= 107±09.58 µg/ml) radicals, and good antioxidant activity by chelating ferrous ions (IC50 = 2499.086 ± 28.267µg/ml), reducing ferric ions (IC50=141.33±2.34 µg/ml), exhibiting total antioxidant capacity (IC50 465.65 ± 9.71 µg/ml), and protecting ß-carotene-linoleic acid against peroxidation (I% = 90.05 ± 1.65% at 1000µg/ml). R. sempervirens displayed anti-inflammatory activity in aqueous extract by inhibiting heat-induced albumin denaturation and stabilizing the membrane of human red blood cells. It was suggested from the results that R. sempervirens aqueous extract could help prevent oxidative and inflammatory processes due to its good antioxidant and anti-inflammatory properties.