Cypermethrin elicited responses in heat shock protein and feeding in Caenorhabditis elegans

Heat shock proteins (Hsp) are a family of stress proteins, which are elicited in response to a variety of stressors in organisms. The objective of this study was to explore the potential of cypermethrin, a synthetic pyrethroid insecticide, on induction of small heat shock proteins (Hsp16) and feeding response in transgenic Caenorhabditis elegans PC72 (Hsp16-LacZ). A concentration-dependent inhibition in feeding was evident in worms exposed to cypermethrin (31%, 46% and 56% at 5, 10, 15 mM, respectively) beyond 4 h while marked induction of heat shock protein-16 expression was evident after 12 h exposure (as evident from quantitative analysis). Maximum expression of Hsp16 was observed throughout the body of the worms 24 h after exposure similar to that evident in the worms exposed to heat shock at 30°C. These data suggest that cypermethrin possesses the potential to induce Hsp16 as well as inhibit feeding in C. elegans at non-lethal concentrations. C. elegans (PC72) thus could serve as a convenient model to study the early toxic effects of xenobiotics.