Pantethine is a combination of the vitamin pantothenic acid and the low-molecular-weight aminothiol cysteamine. Pantethine is the biologically active form of pantothenic acid (vitamin B5). Pantethine is the disulfide dimer of pantetheine, the 4'-phosphate derivative of which is an intermediate in the conversion of the B vitamin pantothenic acid to coenzyme A (see Pantothenic Acid). Pantethine is found naturally in small quantities in most forms of life, and therefore, in food sources. Very large doses of pantethine have been found to have lipid-lowering effects, and pantethine is used in Europe and Japan as a lipid-lowering agent.
Pantethine is also known as D-bis(N-pantothenyl-beta-aminoethyl)disulfide and (R)-N,N'-[dithiobis(ethyleneimino-carbonylethylene] bis (2 , 4-dihydroxy-3, 3-dimethylbutyramide). Its molecular formula is C22H42N4O8S2 and its molecular weight is 554.73 daltons. Pantethine has been found to decrease serum levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C), apolipoprotein B and triglycerides. It has also been found to increase high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 levels. The mechanism of the possible lipid-modulating activity of pantethine is not understood. In isolated hepatocytes, pantethine has been shown to inhibit both cholesterol and fatty acid synthesis. It is speculated that pantethine, by acting as a precursor of coenzyme A, may enhance the beta-oxidation of fatty acids. However, this has not been confirmed. Another hypothesis is that the lipid-modulating effect of pantethine may be mediated via its metabolite cysteamine. It is argued that there is little pantethine found in the serum following its ingestion and that most of a dose is metabolized to pantothenic acid and cysteamine. Since pantothenic acid does not possess lipid-modulatory activity, cysteamine might. This lipid-modulatory activity could occur via the inhibition of acetyl coenzyme A carboxylase activity and the stimulation of hepatic fatty acid oxidation, resulting in lowered triglyceride levels, and via the inhibition of HMG-CoA reductase activity, resulting in lowered cholesterol levels. Again, this has not been confirmed. Further, cysteamine, a treatment for cystinosis, has not been found to have lipid-lowering activity in those with this rare genetic disorder. Nor, does pantethine appear to be efficacious in the treatment of cystinosis. Parenterally administered pantethine has been demonstrated to inhibit lens opacification, in some animal studies. The mechanism of this possible ophthalmoprotective effect is not understood. One possibility is that pantethine may inhibit the formation of protein aggregates in the lens of the eye by forming mixed disulfides with cysteine residues of certain lens proteins. There is no evidence that orally administered pantethine has any activity in inhibiting lens opacification.
Pantethine is the active form of pantothenic acid. It has been shown to significantly reduce serum triglycerides, total cholesterol, and LDL-cholesterol (the so-called "bad cholesterol") levels while increasing HDL ("good cholestrerol") levels in several clinical trials. Pantethine has the advantage of being an effective treatment for high cholesterol while avoiding the undesirable side effects of synthetic lipid-lowering drugs. In fact, there appear to be no toxicity or side effects from to pantethine, making an attractive and natural treatment alternative. Pantethine has been used for the past 30 years in Japan, where it is approved as a pharmaceutical agent for the purpose of increasing HDL-C, the "good cholesterol" needed by the body to maintain a healthy heart.