Investigation of the relaxing effect of a camphor nanoemulsion on rat isolated trachea.

Asthma is a chronic inflammatory disease that targeting lower airways, being characterized by bronchial smooth muscle hyper responsiveness and mucus hypersecretion. Asthma is considered the most common respiratory disease in the world, affecting approximately 235 million individuals. The main therapy sometimes fails to establish clinical improvement in patients, which leads to a constant search for new alternatives. Camphor is a transparent solid monoterpene with a strong aroma, which due to its high lipophilicity is insoluble in water. Nanostructured carrier systems have shown promise as a delivery system for lipophilic compounds such as monoterpenes. Therefore, the objective of this work was to evaluate the relaxant effect of nanoemulsified camphor (NEC), as well as the mechanism of action of that monoterpene, in isolated rat trachea. The results obtained demonstrated that NEC promote relaxation of the isolated rat trachea when smooth muscle contraction was induced by both carbachol (CCh) and KCl, presenting a pCE50 of 2.25 ± 0.27 and 3.30 ± 0.07, respectively. In the presence of dexamethasone (DEXA), tetraethylammonium (TEA), glibenclamide (GLIB), 1H-[1,2,4]-oxadiazole-[4,3,-a]-quinoxaline-1-one (ODQ) and ruthenium red (RR) there was a significant difference in at least one of the evaluated pharmacological parameters, such as concentration-response curves shape, Emax or pCE50. As conclusion, NEC may be involved with ß-adrenergic receptors, channels for K+ sensitive to ATP (KATP) or Channels for K+ opened by Ca2+ (KCa), increase in prostanoids and with receptor channel with transient potential (TRPv). In conclusion, ß-adrenergic receptors, prostanoids, nitric oxide (NO), ATP-sensitive K+ channels (KATP), Ca2+-opened K+ channels (KCa), and transient receptor potential cation channel subfamily V (TRPV) are involved in the relaxing effect of NEC. In addition, the mechanism of action of NEC may be involved with the signal transduction pathway Nitric Oxide/soluble guanylyl cyclase/cGMP/cGMP-activated protein kinase. NEC, therefore, demonstrates spasmolytic activity when presenting tracheal relaxation compared to CCh and KCl contracturants.

Removal of recalcitrant organic matter content in wastewater by means of AOPs aiming industrial water reuse.

This paper comes out from the need to provide an improvement in the current oil refinery wastewater treatment plant (WWTP) aiming to generate water for reuse. The wastewater was pretreated and collected in the WWTP after the biological treatment unit (bio-disks) followed by sand filtration. Ozonation (ozone concentration from 3.0-60 mgO3 L-1), UV (power lamp from 15 to 95 W), H2O2 (carbon:H2O2 molar ratio of 1:1, 1:2, and 1:4), and two advanced oxidation processes (UV/O3 and UV/H2O2) were investigated aiming to reduce the wastewater organic matter and generate water with suitable characteristics for the reverse osmosis operation and subsequent industrial reuse. Even after the biological and filtration treatments, the oil refinery wastewater still presented an appreciable amount of recalcitrant organic matter (TOC of 12-19 mgC L-1) and silt density index (SDI) higher than 4, which is considered high for subsequent reverse osmosis due to membrane fouling risks. Experiments using non combined processes (O3, H2O2, and UV only) showed a low degree of mineralization after 60 min of reaction, although the pretreatment with ozone had promoted the oxidation of aromatic compounds originally found in the real matrix, which suggests the formation of recalcitrant compounds. When the combined processes were applied, a considerable increase in the TOC removal was observed (max of 95 % for UV/O3 process, 55 W, 60 mgO3 L-1), likely due the presence of higher amounts of reactive species, specially hydroxyl radicals, confirming the important role of these species on the photochemical degradation of the wastewater compounds. A zero-order kinetic model was fitted to the experimental data and the rate constant values (k, mgC L-1 h-1) ranged from 4.8 < k UV/O3 < 11 ([O3]0 = 30-60 mg L-1), and 8.6 < k UV/H2O2 < 11 (C:H2O2 from 1:1 to 1:4). The minimum and maximum electrical energy per order (E EO) required for 60 min of treatment were calculated as 5.4 and 81 Wh L-1, respectively, for UV/O3 (15 W, 60 mgO3 L-1) and UV/H2O2 (95 W, 1C:1H2O2). Good results in terms of water conditioning for reverse osmosis operation were obtained using UV/H2O2 process with initial molar ratio of 1 C:2 H2O2 (UV lamp 55 W) and 1 C:4 H2O2 (UV lamp 95 W), and total organic carbon (TOC) removals of 62 % (SDI15 = 1.8) and 74 % (SDI15 = 2.0) were achieved, respectively, after 60 min. The treated wastewater followed to the reverse osmosis system, which operated with an adequate flux of permeate, was very efficient to remove salt and generate a permeate water with the required quality for industrial reuse.