Polyphenols, antioxidant activity and mode of action of antimicrobial compounds of Dittrichia viscosa extracts

In order to promote the spontaneous plant Dittrichia viscosa known by its use in traditional medicine, the content of phenolic compound in the aqueous and ethanolic extracts was determined according to the colorimetric method based on the Folin-Ciocalteu reagent, and the antioxidant activity which was evaluated by two methods: DPPH and FRAP. For antimicrobial activity, the microtiter microplate method was applied to the yeast Candida albicans and to two bacteria Staphylococcus aureus and Escherichia coli. Regarding the mode of action of the extracts of tested germs, an evaluation of the nucleic acids released during the lysis of the treated cells was carried by the spectrophotometric assay at wave length 260 nm. The results revealed that the extracts have an interesting content of polyphenols, which is higher in the ethanolic extract. Antioxidant and antimicrobial activities are higher for the alcoholic extract than the decoction. The MIC for E. coli is 0.28 ± 0.05 mg / ml, 2.290 ± 0.20 mg / ml for Staphylococcus aureus and 33.33 ± 0.33 mg / ml for C. albicans. The alcoholic extract  and decocted of  D. viscosa act  respectively by damaging the bacterial and yeast wall

Effect of heat treatment on bioelectronic coordinates and antibacterial activities of natural and synthetic clays

Our work consists in studying the effect of the thermal treatment at 900°C of three clays “two anionic clays of synthesis ' Double lamellar hydroxide' Zn3Al-CO3 and Mg3Al-CO3, and another natural cationic: Ghassoul (Gh)”, on their antibacterial and bioelectronic power. Their chemical characteristics such as pH at zero charge point (pHzcp), redox potential (Eh), index of oxidizing/reducing power (rH2), and electrochemical potential to dissipate energy (W), as well as the type of oxide formed as a result of this treatment; were also determined. The materials were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), and scanning electron microscopy (SEM). Antibacterial activity was tested for four bacteria: two Gram positive (Staphylococcus aureus, Enterococcus faecalis) and two Gram negative (Escherichia coli, Salmonella spp). The antibacterial power of the three clays was evaluated by their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), using the microtiter plate technique. The results showed that the pHzcp, rH2, W and antibacterial power of the two lamellar double hydroxides increased as a result of heat treatment. While the test on the heat treated cationic clay showed an opposite result. It thus appears that the changes in the physicochemical and electrochemical characteristics of the clays following their calcination at 900°C; are at the origin of the change in their antibacterial powe

Acinos alpinus and Ziziphora hispanica: Phenolic Profile, Antioxidant and Antibacterial Properties of Hydromethanolic Extracts from Aerial Parts

Acinos alpinus and Ziziphora hispanica belonging to the Lamiaceae family are well-known for their biological properties. The phenolic composition was characterized using HPLC coupled to photodiode array and electrospray ionization mass spectrometry. The antioxidant capacity was assessed by 2,2′-diphenyl-1-picrylhydrazyl radical and ferric reducing antioxidant power assays. The antibacterial activity was evaluated by disc-diffusion and broth micro-dilution methods. A total of 53 phenolic compounds were identified in both extracts, with the predominance of caffeoylquinic acid isomers with a content of 2.09 mg/g in A. alpinus extract, while coumarylquinic acid isomers with a content of 17.33 mg/g was determined in Z. hispanica extract. The Acinos alpinus extract displayed the highest radical scavenging activity (IC50 DPPH = 3.226±0.035 mg/mL) and reducing power (EC50 FRAP = 3.792±0.001 mg/mL), followed by Z. hispanica extract with IC50 DPPH value of 7.265±0.209 mg/mL, and EC50 FRAP value of 24.689± 0.106 mg/mL. Furthermore, both A. alpinus and Z. hispanica extracts exhibited a bactericidal effect against six pathogenic bacteria with a MIC value from 4.16 to 33.33 mg/mL. On the basis of the results achieved, the aerial parts of Moroccan Acinos alpinus and Ziziphora hispanica might be used as natural agents in the food and pharmaceutical field

Impact des opérations d'abattage dans les tueries traditionnelles sur la qualité bactériologique de la viande de volaille à Meknès (Maroc)

Impact of Slaughtering Operations in Traditional Slaughterhouses on the Bacteriological Quality of Poultry Meat in Meknès. The aim of the present study was to determine the critical control points during operations of slaughtering in the traditional slaughterhouses in Meknès (Morocco). For this reason, fifteen visits have been done in three sites of poultry slaughtering. In all visit, eleven samples (ten grams of neck skin) were collected from poultry carcass after every operation. Aerobic total, total coliform, enterobacteria and staphylococcus were counted by the spread-plate method. Results indicated that the microbiological quality of poultry meat is associated to hygiene level in slaughterhouses. Therefore, scalding, plucking and eviscerating were noted as critical operations

Etude toxicologique des phosphogypses sur la croissance des chlorelles et l'activité locomotrice des daphnies

L'industrie des phosphates rejette un sous-produit le phosphogypse. Ce produit est riche en sulfate de calcium, il contient le magnésium, le potassium, le fer et les métaux lourds. L'étude écotoxicologique du phosphogypse sur deux espèces aquatiques ; une algue Chlorella vulgaris et un microcrustacé planctonique Daphnia magna a montré, une inhibition de la croissance de cette algue à partir d'une concentration de 3,2g / l et une immobilisation de plus 50 % de la population des Daphnies en 24 heures, à partir de la concentration de 4,4g / l