Do ROS really slow down aging in C. elegans?

It was shown in C. elegans that life-long treatments with low level of the prooxidant paraquat increased reactive oxygen species (ROS), which then acted as the signal to slow down aging by activating the intrinsic apoptosis pathway. And deficiencies of the electron transport chain subunits increased longevity through similar mechanisms. We surprisingly found that ROS were downand up-regulated respectively upon chronic and transient paraquat treatments although the same ROS measuring approaches were applied. Adaptive responses were shown to be responsible for the reduction under chronic stresses. Post young adult stage started treatments shortened lifespan at all concentrations tested and mild extension was only observed by treating with “proper” concentration of paraquat from egg hatching. However, the extension in the latter case could be explained by growth retardation. Thus, sometimes the extension of the post growth span rather than the whole lifespan should be considered as evidence for “real” slowing down of aging. We also believe that aging was affected by the synthetic effects of multiple secondary responses rather than that of ROS alone. If the protective elements such as antioxidants are beneficial then ROS should be not considering that the former fight against the latter. The view that ROS are “good” for aging would also produce a false impression that antioxidants are bad. We hope the alternative perspective proposed here will bring about beneficial discussions in correlated areas.