What is DHLA?
Is it pharmacologically active? DHLA is the reduced form of a-Lipoic acid, an effective biological antioxidant. The chemical structure of the a-lipoic acid molecule (Figure 1) is responsible for its wide range of actions and its active involvement in metabolic processes, particularly the glycolytic or "energy" cycle.
The molecule consists of an 8 carbon fatty acid chain with two interlinked sulfur atoms attached. When each sulfur atom picks up a hydrogen , breaking the bond between the sulfur atoms, the molecule is "reduced" to dihydrolipoic acid, DHLA, which can be readily oxidized to lipoic acid (LA) (Figure 2). The "redox couple" formed by DHLA and LA can transfer hydrogen atoms or electrons back and forth and therefore help in complex enzymatic processes and also assist in regenerating other antioxidants. In the glycolytic energy production cycle, the -COOH group in the molecule releases and recovers carbon dioxide.
DHLA is a potent reducing agent. It scavenges hypochlorous acid and peroxyl radicals and probably scavenges hydroxyl radicals. DHLA is known to regenerate ascorbate and (indirectly) vitamin E from their radical forms. DHLA is also believed to prevent lipid peroxidation by reducing glutathione. Current evidence suggests that DHLA can recycle vitamin E through glutathione, vitamin C, ubiquinol, NADPH, or NADH1
- Ref: 1. Packer, L. (1995) Free Radical Biology and Medicine, 19(2):227-250