Nitric oxide (NO) is an important endogenously produced signaling molecule . This gaseous messenger is critical for the regulation of vascular and muscle tone, neurotransmission, wound healing, platelet aggregation and many other physiological processes. Furthermore, nitric oxide plays a significant role in tumor biology participating in cell death, angiogenesis, and antitumoral immune response . Dysregulation of NO production leads to various pathological processes. For instance, impaired NO production causes diabetic vascular complications .