It can be stated that potent alkylating properties
of STZ are the main reason of its toxicity. However, the
synergistic action of both NO and reactive oxygen
species may also contribute to DNA fragmentation and
other deleterious changes caused by STZ. NO and
reactive oxygen species can act separately or form the
highly toxic peroxynitrate (ONOO; Fig. 2). Therefore,
intracellular antioxidants or NO scavengers substantially
attenuate STZ toxicity