Nanostructured Systems Containing Rutin: In Vitro Antioxidant Activity and Photostability Studies.

The improvement of the rutin photostability and its prolonged in vitro antioxidant activity were studied by means of its association with nanostructured aqueous dispersions. Rutin-loaded nanocapsules and rutin-loaded nanoemulsion showed mean particle size of 124.30 ± 2.06 and 124.17 ± 1.79, respectively, polydispersity index below 0.20, negative zeta potential, and encapsulation efficiency close to 100%. The in vitro antioxidant activity was evaluated by the formation of free radical ·OH after the exposure of hydrogen peroxide to a UV irradiation system. Rutin-loaded nanostructures showed lower rutin decay rates [(6.1 ± 0.6) 10(-3) and (5.1 ± 0.4) 10(-3) for nanocapsules and nanoemulsion, respectively] compared to the ethanolic solution [(35.0 ± 3.7) 10(-3) min(-1)] and exposed solution [(40.1 ± 1.7) 10(-3) min(-1)] as well as compared to exposed nanostructured dispersions [(19.5 ± 0.5) 10(-3) and (26.6 ± 2.6) 10(-3), for nanocapsules and nanoemulsion, respectively]. The presence of the polymeric layer in nanocapsules was fundamental to obtain a prolonged antioxidant activity, even if the mathematical modeling of the in vitro release profiles showed high adsorption of rutin to the particle/droplet surface for both formulations. Rutin-loaded nanostructures represent alternatives to the development of innovative nanomedicines.

Acute effects of sediments taken from an urban stream on physiological and biochemical parameters of the neotropical fish Prochilodus lineatus.

Juveniles of Prochilodus lineatus were exposed to sediments collected from one of five sites along an urban stream into which various types of contaminants are discharged. After 24 or 96 h fish were examined and the results compared with those from control groups (fish exposed only to water, for the same period). Plasma ion levels varied significantly and fish exposed to site 5 sediment showed a transient increase in both sodium and chloride concentrations. Plasma glucose was significantly higher in fish exposed to sediment from sites 2 and 5. The higher liver glutathione-S-transferase activity registered in fish exposed to sediment from sites 1, 4 and 5 suggests the presence of organic contaminants at these sites and the enhancement of liver catalase activity in fish exposed to sediment from sites 3 and 4 may be due to contaminant-mediated oxyradical production. The overall results revealed that sites 4 and 5 are more severely contaminated, probably due to organic contaminants from agricultural sources and municipal landfill.