From In the Pipeline: "there's a report out in PNAS that the longtime treatment for leprosy (Hansen's disease), diaminodiphenylsulfone (DDS or dapsone), also prolongs life in the nematode C. elegans. ... The treated animals showed a significantly longer lifespan, faster body movements compared to untreated controls, and a delay in accumulating the 'aging pigment' lipofuscin. Now, DDS kills bacteria by inhibiting folate synthesis, but that doesn't seem to have anything to do with lifespan extension. The authors found that one of its key targets might be pyruvate kinase - and this might be the source for the mild anemia that's sometimes seen as a side effect in human patients. Nematodes have two isoforms of the enzyme, one mostly in muscle, and the other mostly in the digestive tract. Further study (with RNAi, etc.) showed that the lifespan extension seems to be working through the former, but not the latter. But it also showed that this probably can't be responsible for the whole lifespan effect, either: mutant nematodes with that isoform deleted live longer than wild type, but treating them with DDS makes them live longer still."