Arginine is not responsible for the activation of nitric oxide synthase by garlic

Garlic (Allium sativum L., Liliaceae) has had an important dietary and medicinal role for centuries. Its chemical constituents have beneficial effects on cardiovascular risk factors and other medicinal effects in the body. Several components of garlic are known but the individual compounds responsible for its divergent properties have yet to be established. There is a link between garlic and the L-arginine-nitric oxide pathway. Amino acid analysis of garlic powder demonstrates that it is a rich source of arginine, the precursor for nitric oxide. However, neither arginine nor alliin-derived products were found to be responsible for the activation of nitric oxide synthase by garlic in cell-free homogenates. Heat treatment of garlic preserved its capacity for enzyme activation.