Effects Of Capsaicin On Growth And Behavior In Caenorhabditis Elegans

Chili pepper(Capsicum annuum L.)is not only a common food but also a traditional medicine.Capsaicin,a main active component of chili,has been developed to prevent and treat several diseases.Caenorhabditis elegans as a model organism has well-annotated genome and many genes orthologous to human disease genes and has been extensively used in studies of genetics,development,behavior and neurobiology.Here C.elegans was used to investigate the effects of capsaicin on growth and behavior.(1)Locomotion behavior.The avoidance,body bends,body-bend amplitude and moving speed assays were used to study the effect of capsaicin on C.elegans locomotion behavior.The nematodes were found not to avoid capsaicin,indicating that capsaicin can be fed in food.The body bends and speed were increased but body-bend amplitude was not affected,demonstrating an improved locomotion behavior.(2)Feeding behavior.Pharyngeal pumping and food clearance assays were used to investigate the effect of capsaicin on C.elegans feeding behavior,in which capsaicin was found to increase pharyngeal pumping rate of the nematodes but not affect food intake.(3)Growth and development.Body size,body fat,lifespan and brood size assays were used to investigate the effect of capsaicin on C.elegans growth and development.The body size of nematodes was increased by capsaicin but body length was not affected,while body fat was reduced.The lifespan of the nematodes was extended by capsaicin at lower concentrations,but reproduction was not affected.(4)Memory behavior.Learning assay experiments revealed that the C.elegans was able to form memory to capsaicin in a favorable fashion.Taken together,capsaicin was found to affect growth and behavior of C.elegans,demonstrating the feasibility of C.elegans as a model to study the effect of capsaicin on phenotypes,which provide an important insight into future investigations of capsaicin,e.g.epigenetic alterations.