ACTIMAG

Indications

• Used as a skin or hair conditioning agent
• Metabolic disorders related to glutamine and glutathione metabolism
• Potential treatment target in conditions associated with elevated organic acids

Mechanism of action

Pidolic acid is generated through the cyclization of the free amino group of glutamic acid or glutamine, and can be formed enzymatically by glutaminyl cyclases. It participates in the glutathione cycle and is metabolized to glutamate by 5-oxoprolinase. As a humectant, it attracts and retains moisture due to its hydrophilic properties, forming hydrogen bonds with water molecules.

Pharmacodynamics

As a naturally occurring amino acid derivative, pidolic acid is involved in various metabolic pathways. Elevated levels of pidolic acid in the blood can indicate issues related to glutamine and glutathione metabolism, and its accumulation may lead to metabolic acidosis. This compound is present in significant amounts in brain tissue and serves as a biological intermediate. Chronic elevations are linked to several metabolic disorders, highlighting its relevance in clinical contexts.

Pharmacokinetics

Pidolic acid is primarily found in bound form in tissues. Its formation and metabolism are closely tied to the metabolic pathways of glutamic acid and glutamine. The compound's levels can fluctuate based on metabolic conditions, and abnormal concentrations can lead to acidosis, especially when accompanied by a decline in arterial pH. The pharmacokinetics of pidolic acid itself is not fully characterized due to limited research.

Adverse effects

• Metabolic acidosis
• Neurological symptoms
• Poor feeding
• Vomiting
• Loss of appetite

Precautions

• Monitor levels in patients with known metabolic disorders
• Use caution in patients with kidney or liver impairment

Pregnancy

Safety during pregnancy has not been established. Use only if clearly needed.

Breast-feeding

Use with caution, as effects in nursing infants are unknown.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• Calcium pidolate
• Magnesium pidolate
• Potassium pidolate

Mechanism of action

Pidolic acid is an endogenous amino acid derivative where the free amino group of glutamic acid or glutamine cyclizes to generate a lactam. Subsequently it is also a metabolite in the glutathione cycle that is converted to glutamate by the enzyme 5-oxoprolinase. Moreover, N-terminal glutamic acid and glutamine residues can either spontaneously cyclize to become pidolic acid, or be enzymatically transformed by glutaminyl cyclases. In particular, this is ultimately a form of N-termini that is a challenge for N-terminal sequencing using Edman chemistry, which necessitates a free primary amino group that is not present in pidolic acid. Pyroglutamate aminopeptidase can restore a free N-terminus by cleaving off the pyroglutamate residue, however. Additionally, pidolic acid and certain pidolic acid salts like calcium, magnesium, and potassium pidolic acid are sometimes used as skin or hair conditioning agents because of their humectant effects. In such humectant formulations, hydrophilic amine, hydroxyl, or even carboxyl groups possess high affinities for forming hydrogen bonds with molecules of water, allowing the hygroscopic formulations to attract and retain moisture in the air nearby through absorption, therefore drawing the water vapor into the formulation.

Pharmacodynamics

Pidolic acid is a naturally occurring but little-studied amino acid derivative that can be formed enzymatically or non-enzymatically and participates as a biological intermediate in various chemical pathways. Elevations of the acid in blood levels may be associated with problems of glutamine or glutathione metabolism. Pidolic acid, in general, is found in large quantities in brain tissue and other tissues in bound form, like skin. Moreover, pidolic acid in high enough levels can act as an acidogen capable of inducing acidosis and a metabotoxin that can result in adverse health effects. Chronically elevated levels of pidolic acid are associated with at least five inborn errors of metabolism including 5-oxoprolinuria (where 5-oxoproline is otherwise known as pidolic acid), 5-oxoprolinase deficiency, glutathione synthetase deficiency, hawkinsinuria, and propionic acidemia. In particular, abnormally high levels of organic acids like pidolic acid in the blood, urine, brain, and/or other tissues results in general metabolic acidosis. Such acidosis generally occurs when arterial pH falls below 7.35. In infants, the initial symptoms of acidosis consist of poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy. Eventually, acidosis and the symptoms of acidosis can lead to heart, liver, and kidney abnormalities, seizures, coma, and possibly even death. Many children who are afflicted with organic acidemias experience intellectual disability or delayed development. In adults, acidosis or acidemia is characterized by headaches, confusion, feeling tired, tremors, sleepiness, and seizures. High levels of pidolic acid in the blood have also been demonstrated following acetaminophen overdose, causing an increased level of acidity called a high anion gap metabolic acidosis.