What are the properties of Levodopa in supplements?

Levodopa

Levodopa is a prodrug of dopamine that is administered to patients with Parkinson's due to its ability to cross the blood-brain barrier[Label]. Levodopa can be metabolised to dopamine on either side of the blood-brain barrier and so it is generally administered with a dopa decarboxylase inhibitor like carbidopa to prevent metabolism until after it has crossed the blood-brain barrier[Label,A177781]. Once past the blood-brain barrier, levodopa is metabolized to dopamine and supplements the low endogenous levels of dopamine to treat symptoms of Parkinson's[Label]. The first developed drug product that was approved by the FDA was a levodopa and carbidopa combined product called Sinemet that was approved on May 2, 1975[A177781,L6133]. Read more about Levodopa on DrugBank: DB01235.

Levodopa

Levodopa is an amino acid precursor of dopamine with antiparkinsonian properties. Levodopa is a prodrug that is converted to dopamine by DOPA decarboxylase and can cross the blood-brain barrier. When in the brain, levodopa is decarboxylated to dopamine and stimulates the dopaminergic receptors, thereby compensating for the depleted supply of endogenous dopamine seen in Parkinson's disease. To assure that adequate concentrations of levodopa reach the central nervous system, it is administered with carbidopa, a decarboxylase inhibitor that does not cross the blood-brain barrier, thereby diminishing the decarboxylation and inactivation of levodopa in peripheral tissues and increasing the delivery of dopamine to the CNS. Read more about Levodopa on NCI Thesaurus: C611.

Levodopa

L-Dopa, also known as dopar or levodopa, belongs to the class of organic compounds known as tyrosine and derivatives. Tyrosine and derivatives are compounds containing tyrosine or a derivative thereof resulting from reaction of tyrosine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. Dopamine is formed by the decarboxylation of L-DOPA by aromatic L-amino acid decarboxylase (AADC). L-Dopa is a drug. L-Dopa is a very strong basic compound (based on its pKa). L-Dopa exists in all living organisms, ranging from bacteria to humans. Within humans, L-dopa participates in a number of enzymatic reactions. In particular, L-dopa and dihydrobiopterin can be biosynthesized from L-tyrosine and sapropterin through the action of the enzyme tyrosine 3-monooxygenase. In addition, L-dopa can be converted into dopamine through the action of the enzyme aromatic-L-amino-acid decarboxylase. In humans, L-dopa is involved in the metabolic disorder called the aromatic l-aminoacid decarboxylase deficiency pathway. In work that earned him a Nobel Prize in 2000, Swedish scientist Arvid Carlsson first showed in the 1950s that administering L-DOPA to animals with drug-induced (reserpine) Parkinsonian symptoms caused a reduction in the intensity of the animals' symptoms. L-Dopa is an odorless tasting compound. Outside of the human body, L-dopa is found, on average, in the highest concentration in a few different foods, such as broad beans, swiss chards, and yellow wax beans and in a lower concentration in garden onions, yellow zucchinis, and dills. L-dopa has also been detected, but not quantified in, several different foods, such as amaranths, garden onion (var.), winged beans, new zealand spinachs, and pot marjorams. This could make L-dopa a potential biomarker for the consumption of these foods. L-Dopa is a potentially toxic compound. L-Dopa has been found to be associated with several diseases such as alzheimer's disease and eosinophilic esophagitis; also L-dopa has been linked to several inborn metabolic disorders including sepiapterin reductase deficiency and aromatic l-amino acid decarboxylase deficiency. Excessive peripheral dopamine signaling is undesirable as it causes many of the adverse side effects seen with sole L-DOPA administration. Read more about Levodopa on HMDB: HMDB0000181.