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Propolis is a resinous substance produced by honeybees and used to protect their hives from outside attackers including microorganisms. In present study, propolis sample was collected from adjacent to Jazan city, Saudi Arabia and the chemical constituents of the ethanolic extract was evaluated by GC-MS. The ethanolic extract was tested against selected strains of microorganisms for its antibacterial and antifungal activities. The major classes of compounds indentified in the extract were fatty acid esters and aliphatic hydrocarbons. Methyl-(7Z)-7-hexadecenoate, methyl-(9E)-octadecenoate and methyl tetracosanoate were found to be the principal fatty acid esters, while E-pentatriacont-17-ene and 2,4-dimethylpentane were identified as predominant aliphatic hydrocarbon compounds. The propolis extract has exhibited remarkable antimicrobial activity against certain strains of bacteria and yeasts. In general, significant antimicrobial activity was recorded against gram positive bacteria (zone of inhibition: 16.3±0.35–30.6±0.11 mm; MICs: 1–4 μg/ml); while gram negative bacteria (zone of inhibition: 10.1±0.23–17.2±0.13 mm; MICs: 4–16 μg/ml) and yeasts (zone of inhibition: 9.1±0.23–18.7±0.10 mm; MICs: 2–16 μg/ml) showed comparatively lower susceptibility to propolis extract. The antimicrobial potential of propolis extract could be therapeutically significant and may allow substituting for some antimicrobial agents or synergizing the antimicrobial action, when used in combination. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the possible occurrence of some selected pharmaceutical compounds in the groundwater of Jazan area, Saudi Arabia. Methods: Water samples from 46 wells were collected from different sites covering Jazan area of Saudi Arabia between February and March 2017. These samples were first analyzed to investigate the presence of eleven drugs mostly used in the study area. Thereafter, samples were subjected to liquid chromatography-mass spectrometry (LC-MS/MS) by direct injection and external standard calibration. Results: Despite the low detection limit (0.001 - 0.02 µg/L) applied to the investigated compounds with a variety chemical groups (acetylsalicylic acid, paracetamol, ibuprofen, metronidazole, caffeine, olmesartan, omeprazole, nifedipine, diclofenac sodium, glibenclamide and loratidine), none of these compounds was detected in any of the analyzed samples. Conclusion: The main source of environmental contamination with pharmaceuticals and personal care products (PPCPs) is wastewater. The results obtained reveal the absence of groundwater contamination by these compounds in Jazan area. However, further extended investigations and monitoring are recommended. [ABSTRACT FROM AUTHOR]

Presence of heavy metals at high concentrations in edible fish might lead to some health issues for consumers. The current work determined the concentrations of four heavy metals Cd, Pb, Zn and Cu in seawater, gills and muscles of two common fishes, Mugil cephalus and Lethrinus miniatus, collected in summer 2014 from two different areas of Red Sea, Jazan, Saudi Arabia, using ICP-AES after microwave digestion procedure. The concentrations of investigated metals were higher in the gills than in muscles for the two fish species. However, the concentration of zinc was higher than other metals in all samples, in the following order Zn>Cu>Pb>Cd. The average of maximum metal concentration was measured for Zn (11.087 ± 1.672 mg kg-1w.w) in the gills of Lethrinus miniatus, Cu (0.548 ± 0.249 mg kg-1w.w) in the gills of Mugilcephalu, Pb (0.131 ± 0.092 mg kg-1w.w) in the gills of Mugilcephalu, and Cd (0.064 ± 0.017 mg kg-1w.w) in the gills of Lethrinus miniatus. Concentration of investigated metals in water was following the same order in the fish tissues Zn>Cu>Pb>Cd, with a maximum detected concentrations of 0.0233, 0.0085, 0.0059, and 0.0023 mg L-1, respectively. Despite the detection of heavy metals in the edible tissues of investigated fish, the concentrations were within the recommended maximum residual level of FAO/WHO and EU. Therefore, the investigated fish might be considered safe for human consumption. More extended investigations are highly recommended. [ABSTRACT FROM AUTHOR]

Clotrimazole is a broad-spectrum antimycotic drug used for the treatment of dermatological and gynecological infections; it is incompletely broken down during sewage treatment and could potentially reach agricultural land through the application of municipal biosolids or wastewater. In the absence of any environmental fate data, we evaluated the persistence and dissipation pathways of H-clotrimazole during laboratory incubations of agricultural soils. Clotrimazole was removed from a loam (time to dissipate 50% = 68 d), a sandy loam (time to dissipate 50% = 36 d), and a clay loam (time to dissipate 50% = 55 d), with formation of nonextractable residues being the major sink for H. Their parent compound had no significant mineralization, as evidenced by the lack of formation of HO. Up to 15% of the applied radioactivity was recovered in the form of [H]-(2-chlorophenyl)diphenyl methanol. The rate of clotrimazole dissipation in the loam soil did not vary with moisture content, but it was slower at a lower temperature (number of days to dissipate 50% = 275.6 d at 4°C). Addition of municipal biosolids to the loam soil did not vary the clotrimazole dissipation rate. In summary, the present study has established that clotrimazole is dissipated in soil, at rates that varied with soil texture and temperature. Clotrimazole dissipation was accompanied by the formation of nonextractable residues and detectable extractable residues of the transformation product (2-chlorophenyl)diphenyl methanol. Environ. Toxicol. Chem. 2011; 30:582-587. © 2010 SETAC [ABSTRACT FROM AUTHOR]

Glyphosate (N-(phosphonomethyl)glycine) is one of the most widely used herbicides in the world to control weeds in agricultural and urban areas. Its increasing use requires special attention to its transfer from terrestrial to aquatic environments. However, knowledge on the leaching of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) is scarce. Here we aimed to assess the dynamic interactions between glyphosate sorption and leaching; and to identify the main factors that influence the two processes in three undisturbed agricultural soils using microlysimeters under outdoor conditions. We studied the sorption, desorption and leaching of 14C-labelled glyphosate on three soils using batch experiments in the laboratory and lysimeters under natural conditions for 11 months. The laboratory results showed that glyphosate was strongly adsorbed, yielding empirical constants of Freundlich sorption isotherms (Kf) of 16.6 for the clay loam soil, 33.6 for the silt clay loam soil and 34.5 for the sandy loam soil, with nf close to 1 in all three cases. Glyphosate was also weakly desorbed, i.e. 5 to 24% (w) of initially sorbed glyphosate. Sorption and desorption were only pH-dependent. The outdoor results showed that nearly 70% of the initial glyphosate was present in the soil in a non-extractable form at the beginning of the experiment. Conversely, only less than 20% of the initial glyphosate is present in the soil in a non-extractable form after 11 months. These findings suggest that the non-extractable residues become available and take part in biodegradation and leaching. The amounts of 14C-glyphosate derivatives leached were less than 0.28% of the initially applied glyphosate. HPLC analyses showed that the AMPA metabolite generally represented up to 100% of the residues present in the leachates. The results of leaching were highly influenced by the hydrodynamic properties and the biodegradation capacities of the soils. Although glyphosate residues were found in low concentrations in the leachates for almost a year, the contamination of groundwater does not seem to be a concern, regardless of the soil type, if the herbicide is used in accordance with good agricultural practice. [ABSTRACT FROM AUTHOR]