Lipoamide is the neutral amide of α-lipoic acid (LA) [1].

Unlike LA, lipoamide does not occur naturally in either animals or plants. Compared with free LA, lipoamide is a better cofactor for α-oxo-acid dehydrogenase enzymes, and acts as a more efficient antioxidant, with potential therapeutic application in obesity and diabetes [1].

In 3T3-L1 adipocytes, lipoamide (1 ~ 10 µM) increased the number and mitochondrial mass per cell. Lipoamide treatment also increased the copy number of mitochondrial DNA, as well as protein levels and expression of various transcription factors in mitochondrial biogenesis, such as mitochondrial transcription factor A, peroxisome proliferator-activated receptor-γ co-activator-1α, and nuclear respiratory factor 1. In addition, lipoamide (0.1 ~ 100 µM) increased expression of endothelial nitric oxide synthase and formation of cGMP in a dose-dependent manner [1]. In post-ischaemic perfused rat hearts, lipoamide at 0.25 mM increased the lactate utilization. Furthermore, lipoamide activated pyruvate dehydrogenase by 50% in post-ischaemic myocardium [2].

References:

[1]. Shen W, Hao J, Feng Z, et al. Lipoamide or lipoic acid stimulates mitochondrial biogenesis in 3T3-L1 adipocytes via the endothelial NO synthase-cGMP-protein kinase G signalling pathway. British Journal of Pharmacology, 2011, 162(5): 1213-1224.

[2]. Sumegi B, Butwell N B, Malloy C R, et al. Lipoamide influences substrate selection in post-ischaemic perfused rat hearts. Biochemical Journal, 1994, 297: 109-113.