Lithocholic acid, also known as 3α-hydroxy-5β-cholan-24-oic acid or LCA, is a

bile acid Bile acids are steroid acids found predominantly in the bile of mammals and other vertebrates. Diverse bile acids are synthesized in the liver in peroxisomes. Bile acids are conjugated with taurine or glycine residues to give anions called bile ...

that acts as a detergent to solubilize fats for absorption. Bacterial action in the colon produces LCA from

chenodeoxycholic acid Chenodeoxycholic acid (CDCA; also known as chenodesoxycholic acid, chenocholic acid and 3α,7α-dihydroxy-5β-cholan-24-oic acid) is a bile acid. Salts of this carboxylic acid are called chenodeoxycholates. Chenodeoxycholic acid is one of the ...

by reduction of the

hydroxyl In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...

functional group at carbon-7 in the "B" ring of the

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

framework. It has been implicated in human and experimental animal

carcinogenesis Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cell (biology), cells are malignant transformation, transformed into cancer cells. The process is characterized by changes at the cellular, G ...

. Preliminary ''

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

'' research suggests that LCA selectively kills

neuroblastoma Neuroblastoma (NB) is a type of cancer that forms in certain types of nerve tissue. It most frequently starts from one of the adrenal glands but can also develop in the head, neck, chest, abdomen, or Vertebral column, spine. Symptoms may include ...

cells, while sparing normal neuronal cells and is cytotoxic to numerous other malignant cell types at physiologically relevant concentrations.

Dietary fiber Dietary fiber (fibre in English in the Commonwealth of Nations, Commonwealth English) or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical co ...

can bind to lithocholic acid and aid in its excretion in stool; as such, fiber can protect against colon cancer. LCA (and LCA acetate and LCA propionate) can activate the

vitamin D receptor The vitamin D receptor (VDR also known as the calcitriol receptor) is a member of the nuclear receptor family of transcription factors. Calcitriol (the active form of vitamin D, 1,25-(OH)2vitamin D3) binds to VDR, which then forms a heterodi ...

without raising calcium levels as much as

vitamin D Vitamin D is a group of structurally related, fat-soluble compounds responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, along with numerous other biological functions. In humans, the most important compo ...

itself. LCA binds with 20 μM affinity to the human membrane enzyme

NAPE-PLD NAPE-PLD may refer to: * * N-acyl phosphatidylethanolamine-specific phospholipase D, an enzyme * N-acetylphosphatidylethanolamine-hydrolysing phospholipase D, an enzyme {{enzyme index ...

, enhancing dimer assembly and enabling catalysis. NAPE-PLD catalyzes the release of

anandamide Anandamide (ANA), also referred to as ''N''-arachidonoylethanolamine (AEA) is a fatty acid neurotransmitter belonging to the fatty acid derivative group known as N-acylethanolamine (NAE). Anandamide takes its name from the Sanskrit word ''ananda ...

and other ''N''-acylethanolamines (NAE) from the membrane precursor ''N''-acylphosphatidylethanolamine (NAPE). NAPE-PLD facilitates crosstalk between

signals and lipid amide signals. LCA has been reported to have anti-aging effects in yeast, and more recently fruit flies, nematodes, and mice.

References

{{DEFAULTSORT:Lithocholic Acid Bile acids Secondary alcohols Cholanes