Antimicrobial and antibiofilm activities of phenolic compounds extracted from Populus nigra and Populus alba buds (Algeria)

The interest of this work is the discovery of new antimicrobial agents of plant origin to inhibit the formation of microbial biofilms. The present research was conducted to identify and quantify the phenolic compounds extracted from Populus nigra and Populus alba buds harvested in the area of Tizi-Ouzou (Algeria), and to evaluate their antimicrobial and antibiofilm activity. High performance liquid chromatography (HPLC) was performed to identify the phenolic compounds in the ethyl acetate fraction of P. nigra and the methanolic extracts of P. nigra and P. alba. The antimicrobial activity of the crude extracts and the fractions of these two species was tested against 11 microorganisms, using the disk diffusion method, while the antibiofilm effect of certain extracts was carried out in a 96-well microplate and on a biomaterial (catheter). HPLC analysis revealed the presence of 10 bioactive compounds. The main phenolic compounds identified in the three extracts were p-coumaric acid, ellagic acid, and Kaempferol. This study was able to demonstrate that the extracts of P. nigra and P. alba buds have interesting antimicrobial properties, with diameters ranging from 6.6 to 21.3 mm. In addition, extracts of P. nigra exhibited antibiofilm effects greater than 70%. Our results provide evidence for the antimicrobial and antibiofilm potential of bud extracts from both poplar species. Thus, these results will pave the way for further research on these two plants.

Evaluation of nutritional status and body composition of young Tunisian weightlifters

Aim: The aim of this study was to study the quantitative and qualitative aspects of daily spontaneous nutrition as well as anthropometric characteristics and body composition of young Tunisian weightlifters

Methods: Thirty one boys aged between 14 and 18 years, practicing for two hours a day, six days a week in the four weightlifting clubs in Tunis were invited to attend an evaluation session for a food survey [3 days recall, with consumption frequency over a period of 7 days] and the assessment of anthropometric measurements [Weight, height and skinfolds]

Results: Energy intake was acceptable. However, an imbalance nutrient intake was revealed. Concerning macronutrient, fat and protein were above the recommended allowances [p<0.01]. Further, the percentage of saturated fatty acids was significantly above the recommended values while the percentages of polyunsaturated fatty acids and monounsaturated fatty acids were restricted. Regarding the micronutrient, the intake of calcium, magnesium and potassium were restrictive [p<0.01]. As for the fluid intake, a limited contribution was observed [p<0.01]. Several correlations between body composition and dietary intake have been found

Conclusion: Nutritional education may lead these young weightlifters to adopt appropriate nutritional habits to optimize dietary intake. This fact could be compromising of a more suitable body composition and could have a positive bearing on athletic performance

Antioxidant activity profiling by spectrophotometric methods of aqueous methanolic extracts of Helichrysum stoechas subsp. rupestre and Phagnalon saxatile subsp. saxatile / 中国天然药物

AIM@#The aqueous methanolic extracts of two plants from Algeria, Helichrysum stoechas subsp. rupestre and Phagnalon saxatile subsp. saxatile, were investigated for their antioxidant activity.@*METHOD@#Total phenolics, flavonoids, and tannins were determined by spectrophotometric techniques. In vitro antioxidant and radical scavenging profiling was determined by spectrophotometric methods, through: Total antioxidant capacity, and radical scavenging effects by the DPPH and ABTS methods, reducing and chelating power, and blanching inhibition of the β-carotene.@*RESULTS@#All of the extracts showed interesting antioxidant and radical scavenging activity. The highest contents in phenolics, tannins, and the highest total antioxidant capacity as gallic acid equivalents of 97.5 ± 0.33 mg GAE/g DW was obtained for the flowers of H. stoechas subsp. rupestre extract in the phosphomolybdenum assay. An extract of the leafy stems of P. saxatile subsp. saxatile revealed the highest content of flavonoids, and the highest antioxidant activity by the radical scavenging and β-carotene assays when compared with standards. The best activity was by the scavenging radical DPPH with an IC50 value of 5.65 ± 0.10 μg·mL(-1).@*CONCLUSION@#The studied medicinal plants could provide scientific evidence for some traditional uses in the treatment of diseases related to the production of reactive oxygen species (ROS) and oxidative stress.