Genotoxic and mutagenic effects of methyl ether dillapiole on the development of Aedes aegypti (Diptera: Culicidae).

Dillapiole, extracted from Piper aduncum essential oil and its derivatives, has been shown to be a potential alternative to the control of Aedes aegypti, which has become resistant to synthetic insecticides. Methyl ether dillapiole (MED) and temephos (TM) were compared to complement the data on the genotoxicity and developmental changes of Ae. aegypti. Over four generations (G1 -G4 ), third stage larvae were treated with MED at 60, 80 and 100 µg/mL and TM at 0.002, 0.005 and 0.007 µg/mL for 4 h. Adult females were separated to estimate oviposition and hatching rates, and total egg length. Over the four generations, a significant reduction was recorded in oviposition and hatching rates, and in mean egg length (Tukey, P < 0.05), compared with the negative control (NC). Cytological slide preparations were done from adult oocytes and larval neuroblasts. The cumulative effects of genotoxic (bridges, budding and nuclear fragmentation) and mutagenic (micronucleus and chromosomal breakage) damage was observed in the neuroblasts and oocytes of exposed mosquitoes. Developmental changes and damage to the genome of MED-treated Ae. aegypti were greater than those caused by TM. Further studies should focus on understanding the effects of the MED molecule on Ae. aegypti.

Physical properties of films based on pectin and babassu coconut mesocarp.

The objective of this research was to study the physical properties, water sorption, thermal and structure of films made from citrus pectin (CP), babassu coconut mesocarp (BCM) and glycerol (G). Seventeen formulations were prepared according to a central compound rotational design combining different proportions of the materials and evaluating the films produced according to their moisture contents, solubility, thicknesses and water vapor permeability. The results showed a direct relationship between the composition of the film and each physical property, providing films with unique mechanical characteristics and barrier properties. In the second phase, the films were reformulated, maintaining the proportions of CP and BCM constant and altering the G content. The results showed films with permeable structures, thus favoring the use of high drying temperatures (up to 70 °C) for the confection of films, without altering their physical and structural properties.