Please, if you would, elaborate on the characteristics to these varieties, and why I would want to use either. Aside from being "potent" what properties do either R-ALA or Na-RALA have that cannot be produce with a greater volume of plain ALA.....
Great question! The benefits of lipoic acid supplementation are well known, so I will concentrate on why the S-enantiomer is highly undesirable on its own and how it may even inhibit the action of the R-enantiomer.
As I mentioned earlier, standard alpha lipoic acid (what you described as
plain ALA) is usually 50% nautral (R-Lipoic Acid or R-LA) and 50% unnatural (S-Lipoic Acid or S-LA). S-LA, being an unnatural lipoic acid form, is not only poorly absorbed in the body, but may also constrain natural lipoic acid (R-LA) from eliciting its most important properties. In particular, S-LA inhibits the pyruvate dehydrogenase (PDH) enzyme, a mitochondrial enzyme involved in the regulation of glucose metabolism. This leads to mitochondrial dysfunction as the TCA (Krebs) Cycle, an important process in the mitochondria and responsible for producing most of cellular ATP, may be disrupted. This is so because the production of ATP requires the chemical conversion of pyruvate molecules into carbon dioxide, water, and ATP. The main enzyme responsible for the breakdown of pyruvate is pyruvate dehydrogenase (PDH). Although two other enzymes (dihydrolipoyl transacetylase and deihydrolipoyl dehydrogenase) and five coenzymes (TPP, lipoic acid, FAD+, NAD+, and CoA) are needed in this process, without PDH the process will break down.
Apart from PDH inhibition, S-LA in high amounts can hinder mitochondrial action through a structural limitation. As is well known, alpha lipoic acid's role in ATP synthesis also requires that it binds with key enzymes in the mitochondria. However, S-LA's unnatural form inhibits its ability to bind to these mitochondrial enzymes, leading to a compromise of ATP production. Furthermore, and still on ATP, ATP production in the presence of R-LA and S-LA may be limited through another mechanism. In particular, ALA seeks to
permeate the inner membrane of the mitochondria to positively influence ATP production. This function, however, may be hindered due to S-LA metabolization in the outer cellular membrane, leading to a structural weakening of the R-enantiomer.
Furthermore, S-LA may inhibit the action of R-LA by competitively inhibiting the bioactivity of transcription factors and signalling proteins. Beyond this, S-LA increases HbA1c levels, where HbA1c is a specific type of hemoglobin A, a binding site for glucose. Still on glucose metabolism, S-LA reduces the cellular expression of GLUT-4 proteins, negatively impacting glucose disposal.
The above is why R-LA, D-HLA, or Na-RALA, is strongly preferred to S-LA or plain ALA (mixture of R-LA and S-LA).
R-ALA and Na-RALA are more effective that plain ALA because they do not have the S-enantiomer.
Compared to Na-RALA, however, R-LA is more unstable, has poorer solubility and absorption, and is consequently less bioavailable. Na-RALA, however, is a highly aqueous soluble, heat stable and extremely low polymer salt of R-LA. It is by far the most bioactive lipoic acid form currently available.
So, Na-RALA should be preferred. Then R-LA/D-HLA. Plain ALA, of course, is an option, but hardly compares to R-LA and Na-RALA.
