Repositioning Candidate Details

Candidate ID: R1397
Source ID: DB11735
Source Type: approved; investigational
Compound Type: small molecule
Compound Name: Galactose
Synonyms: D-Galactose; D(+)-Galactose; Galactose
Molecular Formula: C6H12O6
SMILES: [H]C(=O)[C@H](O)[C@@H](O)[C@@H](O)[C@H](O)CO
Structure:
DrugBank Description: Galactose has been used in trials studying the treatment and diagnosis of Hepatitis C, Hepatic Cancer, Wilsons Disease, Diabetic Macular Oedema, and Focal Segmental Glomerulosclerosis, among others. There are even proposals for its use in accelerating senescence in mice, rats, and Drosophila, for its association with ovarian cancer, or even for the potential treatment of focal segmental glomerulosclerosis. Nevertheless, none of these ongoing studies have yet provided formal elucidation for their proposals. As a naturally occurring sugar, it may be found in a number dairy products. Even then, however, it is not generally used as a sweetener considering it is only about 30% as sweet as sucrose. Regardless, although it is predominantly used as a pathway to generate glucose fuel for the human body, galactose is involved as an ingredient in some commonly used vaccines and non-prescription products.
CAS Number: 59-23-4
Molecular Weight: 180.1559
DrugBank Indication: There are limited therapeutic uses for which galactose is formally indicated. Some predominant indications include (a) the use of galactose to facilitate the construction of structurally and immunologically effective attenuated vaccines , and (b) the role galactose plays as an essential element in the formation of lactulose - a synthetic disaccharide indicated for the treatment of constipation and/or hepatic encephalopathy (HE); hepatic coma . Nevertheless, there are many studies looking into a variety of possible uses for galactose, including the use of the monosaccharide sugar for accelerating senescence in mice, rats, and Drosophila , the proposed association between galactose in consumed milk and ovarian cancer , a possible role in the therapy of focal segmental glomerulosclerosis , among various others. Regardless, none of these proposed indications have yet been formally elucidated for practical use.
DrugBank Pharmacology: Galactose is a naturally occurring monosaccharide that forms the disaccharide lactose when combined with glucose (another monosaccharide) . Subsequently, when lactose or small amounts of free galactose found in various common dairy products (and other foods) are consumed, the hydrolysis of lactose to glucose and galactose occurs and galactose is itself further metabolized to generate glucose . Such glucose is, of course, ultimately relied upon and used as the primary metabolic fuel for humans in a variety of biological reactions. Conversely, however, the ways in which galactose is commonly used in therapeutic agents generally do not rely upon such pharmacodynamics, even though they ultimately remain the most important ways in which galactose exerts or elicits useful biological actions for the human body.
DrugBank MoA: In the development of typhoid Ty21a live oral vaccine, the use of exogenous galactose is critical. When dealing with Salmonella typhimurium, it has been shown that rough strains with incomplete lipopolysaccharide (LPS) lacking O-specific side chains are much less virulent than smooth strains with complete LPS with O-specific side chains . Salmonella typhimurium gal E mutants used to produce the vaccine are effectively avirulent and highly protective but lack the specific UDP-galactose 4-epimerase enzyme which allows for the normal synthesis of UDP-galactose from UDP-glucose . The consequence of this mutant defect is that the gal E mutants can only generate incomplete LPS without O-specific antigen side chains, which are not capable enough as the complete LPS with O-specific side chains at generating an immunologic response . When exogenous galactose is added to the vaccine medium, however, it allows the mutants to generate UDP-galactose via galactose 1-phosphate . This ultimately allows the mutants to form smooth-type LPS with O-specific side chains . Regardless, the mutant's epimerase defect ultimately results in the accumulation of such intermediary products like galactose 1-phosphate and UDP-galactose, which consequently causes lysis of the mutant cells. The resultant vaccine is subsequently effective enough to elicit an immunologic response while the bacteriolysis prevents the mutant cells from regaining virulence under conditions where smooth type LPS similar to the active parental strain is synthesized . Galactose is also an essential element to the chemical structure of the commonly used laxative solution lactulose. Lactulose itself is a synthetic disaccharide that is made in parts from lactose, galactose, and various other sugars . It is poorly absorbed from the gastrointestinal tract and no enzyme capable of hydrolysis of lactulose is present in human gastrointestinal tissue . Oral doses of lactulose subsequently arrive at the colon largely unchanged . At the colon, lactulose is finally broken down predominantly to lactic acid, and also small amounts of formic and acetic acids by the action of colonic bacteria, which results in an increase in osmotic pressure and slight acidification of the colonic contents . This action consequently causes an increase in stool water content and softens the stool for a laxative effect .
Targets: --
Inclusion Criteria: Indication associated