Nate (MMS) were purchased from Sigma-Aldrich (PO. St Louis, USA). Histidine
Nate (MMS) were purchased from Sigma-Aldrich (PO. St Louis, USA). Histidine, biotine and Agar-Agar from Difco (Paris, France). Aroclor 1254 was purchased from Supelco (USA).2.2. Plant materialsThe total sterol content was evaluated as Olumacostat glasaretilMedChemExpress Olumacostat glasaretil described by Skandrani et al. [19]. The sterol content was expressed according to the following formula:Sterols = (Psteroids /Pextract ) ?100 Where Psteroids = (Mf – MO) ?0.MO: Weight filter (mg), Mf: Weight of filter and precipitate (mg). The method described by Pearson [20], was used for the determination of tannin content of samples which is evaluated according to the following formula:Tannins = (DO extract/ ?1)/Extract concentration ?A. salicina was collected from the Arid Region Institute (IRA) situated in the south east of Tunisia in October, 2003. Botanical identification was carried out by Pr. M. Chaib [15] (Department of Botany, Faculty of Sciences of Sfax). A voucher specimen (AS-10.03) has been kept in the Laboratory of Pharmacognosy, Faculty of Pharmacy of Monastir for future reference. The leaves were shade-dried, powdered, and stored in a tightly closed container.2.3. Extraction procedure and preliminary phytochemical analysiswhere ; molar extinction coefficient (= l g-1 cm-1) of tannic acid (= 3.27 L g-1 cm-1).2.4. Radical-scavenging activity on ABTS+?One hundred twenty grams of powder, from dried leaves, were sequentially extracted in a Soxhlet apparatus (6 h) (AM Glassware, Aberdeen, Scotland, United Kingdom) with petroleum ether, chloroform and ethyl acetate. We obtained the correspondent extracts for each solvant. These types of extracts, with different polarities, were concentrated PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/28499442 to dryness and the residues were kept at 4 . Then, each extract was resuspended in the adequate solvant. Plant materials were screened for the presence of tannins, flavonoids, coumarins and sterols using the methods previously described by Boubaker et al. [16]. The polyphenol content of A. salicina leave extracts was quantified by the Folin-Ciocalteau reagent as described by Yuan et al. [17]. The Gallic acid (0.2 mg/ mL) was used as a standard.An improved ABTS radical cation decolorization assay was used. It involves the direct production of the blue/ green ABTS+. chromophore through the reaction between ABTS and potassium persulfate. Addition of antioxidants to the preformed radical cation reduces it to ABTS, to an extent and on a timescale depending on the antioxidant activity, the concentration of the antioxidant and the duration of the reaction. ABTS was dissolved in water to a 7 mM concentration. ABTS+. was produced by reacting ABTS stock solution with 2.45 mM potassium persulfate (final concentration) and allowing the mixture to stand in the dark at room temperature for 12-16 h before use. The ABTS+. solution was diluted with ethanol to an absorbance of 0.7 (?0.02) at 734 nm. In order to measure the antioxidant activity of extracts, 10 l of each sample at various concentrations (0.5, 2.5, 4.5, 7.5 and 9.5 mg/ml) was added to 990 l of diluted ABTS +?and the absorbance was recorded every 1 min. We stop the kinetic reaction after 30 min. Each concentration was analysed in triplicate. The percentage decrease of absorbance at 734 nm was calculated for each point and the antioxidant capacity of the test compounds was expressed as percent inhibitionBoubaker et al. Annals of Clinical Microbiology and Antimicrobials 2011, 10:37 http://www.ann-clinmicrob.com/content/10/1/Page 3 of( ). Trolox (6-hydroxy-2,5,7,8-te.