Seasonal Variation in the Biological Effects of PM2.5 from Greater Cairo

Greater Cairo (Egypt) is a megalopolis where the studies of the air pollution events are of extremely high relevance, for the geographical-climatological aspects, the anthropogenic emissions and the health impact. While preliminary studies on the particulate matter (PM) chemical composition in Greater Cairo have been performed, no data are yet available on the PM’s toxicity. In this work, the in vitro toxicity of the fine PM (PM2.5) sampled in an urban area of Greater Cairo during 2017–2018 was studied. The PM2.5 samples collected during spring, summer, autumn and winter were preliminary characterized to determine the concentrations of ionic species, elements and organic PM (Polycyclic Aromatic Hydrocarbons, PAHs). After particle extraction from filters, the cytotoxic and pro-inflammatory effects were evaluated in human lung A549 cells. The results showed that particles collected during the colder seasons mainly induced the xenobiotic metabolizing system and the consequent antioxidant and pro-inflammatory cytokine release responses. Biological events positively correlated to PAHs and metals representative of a combustion-derived pollution. PM2.5 from the warmer seasons displayed a direct effect on cell cycle progression, suggesting possible genotoxic effects. In conclusion, a correlation between the biological effects and PM2.5 physico-chemical properties in the area of study might be useful for planning future strategies aiming to improve air quality and lower health hazards.

Supercritical extraction of bioactive compounds from Cocoa husk: study of the main parameters

Cocoa is a product of natural origin rich in polyphenols, mainly procyanidins and flavan-3-ols, which has a high antioxidant power. Its regular consumption brings positive health effects. The objective of the present study was to evaluate the effects of diameter of particle, extraction time, temperature, pressure and ethanol concentration in the supercritical fluid extraction (SFE) of bioactive compounds from cocoa husk. This work was developed in two stages. The first stage was aimed to study the impact of the particle size and extraction time. Extractions were carried out under constant conditions. Once particle size and extraction time were defined, it gave way to the second stage, where the effect of three levels of temperature (308.15, 313.15 and 318.15 K), pressure (10, 15 and 20 MPa) and concentration of ethanol (2, 11, and 20% ethanol) were evaluated. The results of this study suggest that particle sizes less than 0.26mm and extraction times exceeding 147min could increase the total polyphenol content (TPC). Finally, a multivariate statistical analysis was developed, showing that the most favorable conditions for obtaining extracts rich in polyphenols corresponded to 308.15K, 20MPa and 20% ethanol, under which the TPC was 35.11(±1.57)EAGmg/LEg, a total flavan-3-oles content (TFC) of 12.89 (±0.51)EEPmg/gLE and total carotenoids content (TCC) of 64.35(±1.54)EBC mg/gLE. The results obtained suggest that SFE favors the extraction of apolar compounds (carotenoids) from cocoa husk. Likewise, for the optimal extraction point, husk cocoa showed antioxidant capacity of 489.58μmol ET/LEg.