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The aim of this study is to evaluate in vitro antioxidant activities of Ruta montana L.  extracts. This activity was evaluated by three methods : DPPH (2, 2'-diphenyl- 1- picrylhydrazy), bleaching of β-carotene and chelation of ferrous iron. Results showed that ethyl acetate extract (EAE) represents the highest amount of total polyphenols, tannins and flavonoids with 257,1 ± 0,703µg gallic acid equivalent/mg of extract,  251 ± 1.41 µg tannic acid equivalent /mg of extract,117,4 ± 3,451 µg quercetin equivalents/mg of extract, 139,5 ± 4,107 µg rutin equivalents/mg of extract, respectively. In the DPPH assay, ethyl acetate extract showed the higher scavenging capacity (IC50 = 0.044 ± 0.001 mg/ml) followed by methanol, aqueous and chloroform extract. Whereas, AqE showed the best chelating effect and the best inhibitory capacity of the coupled oxidation of linoleic acid/ β-carotene. Keywords: Ruta montana L; polyphenols; antioxidant activity; free radical scavenging.

Background:Rhamnus alaternus (Rhamnaceae) L. has been traditionally used for treatment of many diseases.Objective:In this study, we determined the antioxidant/free radical scavenger properties, the flavonoid profile and the cytotoxicity of aqueous and methanolic extracts obtained by maceration from Algerian R. alaternus bark, like also of aqueous extract prepared by decoction according to the traditional method. This to estimate the usefulness of the drug traditional preparation and compare it with those made in the laboratory.Materials and Methods:The antioxidant activity of the extracts was evaluated using five different redox-based assays, all involving one redox reaction with the oxidant. High-performance liquid chromatography/diode array detection/electrospray ionization mass spectrometry analysis was used to identify and quantify the flavonoids content. Cytotoxicity on human monocytic leukemia cells (U937) was also carried out.Results:All the extracts tested showed a good antioxidant/free radical scavenger activity and a similar flavonoid fingerprint. However, the methanolic one presented the best antioxidant activity that can be due to the highest flavonoid amount and significantly reduced the proliferation of leukemia cells. The results confirm that the extract prepared by decoction contains efficient antioxidant compounds and this justifies in part the therapeutic and preventive usefulness. Moreover, the methanolic extract exerted excellent cytotoxicity on U937 that could be attributed to kaempferol and rhamnocitrin glycosides.

In the present work, five hundred and sixty-seven isolates of lactic acid bacteria were recovered from raw bee pollen grains. All isolates were screened for their antagonistic activity against both Gram-positive and Gram-negative pathogenic bacteria. Neutralized supernatants of 54 lactic acid bacteria (LAB) cultures from 216 active isolates inhibited the growth of indicator bacteria. They were phenotypically characterized, based on the fermentation of 39 carbohydrates. Using the simple matching coefficient and unweighted pair group algorithm with arithmetic averages (UPGMA), seven clusters with other two members were defined at the 79% similarity level. The following species were characterized: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Pediococcus acidilactici, Pediococcus pentosaceus, and unidentified lactobacilli. Phenotypic characteristics of major and minor clusters were also identified. Partial sequencing of the 16S rRNA gene of representative isolates from each cluster was performed, and ten strains were assigned to seven species: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Lactobacillus ingluviei, Pediococcus pentosaceus, Lactobacillus acidipiscis and Weissella cibaria. The molecular method used failed to determine the exact taxonomic status of BH0900 and AH3133.

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