Fig. 4.

Proposed model of garlic-induced H₂S production and H₂S function in the vascular system. Garlic-derived organic polysulfides with allyl moieties and more than two sulfur atoms (see Fig. 5) react with exofacial membrane thiols and cross the cell membrane to react with GSH to produce H₂S. Glucose is the main energy source of RBCs, supporting glycolysis and pentose phosphate pathway (PPP) reduction of NADP⁺ to NADPH, a cofactor of GSH reductase (GR), which maintains the intracellular GSH pool. GSH may also participate in transmembrane electron transfer to reduce exofacial thiols (16). H₂S production then leads to vasorelaxation via vascular smooth muscle cell K_ATP-linked hyperpolarization (8).