Deoxycholic acid

Excess submental fat (SMF)[i.e. fat under the chin/neck] can make people feel older and unattractive^{[1, 2]}. It can develop as a consequence of the aging process, genetic predisposition or lifestyle choices, and generally does not improve with weight reduction measures^[1–3]. Surgical techniques, such as neck-lifts and liposuction, are effective in removing unwanted SMF, but are invasive procedures with certain risks and drawbacks (e.g. bruising, swelling, scarring and painful/prolonged recovery periods), and] some individuals may not wish, or be suitable, to undergo them^{[1, 3–5]}. Less invasive modalities to reduce SMF include ultrasound, laser procedures and the injection of agents with fat-reducing properties^{[1, 3, 6]}, although the efficacy of these treatments has not been established in robust randomized trials. Historically, fat-reducing formulations have typically comprised phosphatidylcholine solubilized with deoxycholic acid^[1], although their efficacy in reducing localized fat, such as that of the submental region, has been shown in vitro to be largely due to the deoxycholic acid component^[7].
Deoxycholic acid is a secondary bile acid involved in the emulsification and solubilization of dietary fat^[8]. A 10 mg/mL injectable solution of chemically synthesized deoxycholic acid is indicated in various countries, including the USA (KybellaTM)^[9] and several within Europe/the EU (BelkyraTM)^[10] to improve the appearance of moderate to severe submental convexity or fullness associated with SMF in adults, where it is currently the only approved minimally invasive treatment for submental contouring.

Figure 1 the chemical structure of Deoxycholic acid

When injected into subcutaneous fat tissue, deoxycholic acid disrupts adipocyte cell membranes, causing the cells to lyse^{[1, 7, 11]}. The resulting cellular and lipid debris is cleared by macrophages, with subsequent fibroblast-mediated thickening of fibrous septa, indicative of neocollagenesis^[1]. Consistent with its mechanism of action, deoxycholic acid, administered via injection, has shown benefit in reducing SMF in several studies^{[12, 13]}, including four phase III trials^{[1, 14, 15]}. Subcutaneous fat and other protein-poor tissues are more susceptible to the cytolytic activity of deoxycholic acid than muscle, blood vessels and skin, as this activity is attenuated by protein^[11]; such protein-rich tissues are therefore affected little by deoxycholic acid that is injected into nearby fat^[1].
Deoxycholic acid administered subcutaneously via injection does not alter systemic levels of lipids (i.e. free fatty acids, total cholesterol or triglycerides) or adipokines (e.g. interleukin-6 or -15, C-reactive protein, tumour necrosis factor-a, apolipoprotein B, adiponectin, insulin, resistin or leptin) to any clinically relevant extent, according to a phase I study in which deoxycholic acid was injected using the recommended area-adjusted dose of 2 mg/cm2 (total dose 100 mg) into the abdominal fat of ten healthy volunteers^[16]. No clinically relevant prolongation of the QT or corrected QT interval was seen with therapeutic (100 mg) or supratherapeutic (200 mg) doses of deoxycholic acid in healthy volunteers in a thorough QT study^[1].

As a bile acid, deoxycholic acid emulsifies fat in the gut. Synthetically derived deoxycholic acid, when injected, stimulates a targeted breakdown of adipose cells by disrupting the cell membrane and causing adipocytolysis. This results in an inflammatory reaction and clearing of the adipose tissue remnants by macrophages. Deoxycholic acid's actions are reduced by albumin and tissue-associated proteins, therefore its effect is limited to protein-poor subcutaneous fat tissue. Protein-rich tissues like muscle and skin are unaffected by deoxycholic acid, contributing to its safety.

Absorption of deoxycholic acid after subcutaneous injection is rapid^{[9, 10]}, with the maximum plasma concentration (Cmax) reached in a median time of 18 min after injection of the maximum recommended single treatment dose (100 mg) into the SMF of healthy volunteers^[17]. In this study, the mean Cmax and area under the plasma concentration-time curve from time 0 to 24 h values for deoxycholic acid after injection were 3.2and 1.6-fold higher than average baseline (i.e. endogenous) levels of deoxycholic acid, although the concentrations of deoxycholic acid in plasma returned to baseline within 24 h (on average) of the dose being administered^[17]; deoxycholic acid is not expected to accumulate when administered at the recommended frequency^{[9, 10]}.
Deoxycholic acid is highly plasma protein bound (98%) and, under normal conditions, is not metabolized significantly[9, 10]. Injected deoxycholic acid joins endogenous bile acids in the enterohepatic circulation and is excreted via the feces along with endogenous deoxycholic acid^{[9, 10]}. In vitro, CYP enzymes were not inhibited or induced by deoxycholic acid at clinically relevant concentrations^[9], and the drug did not inhibit most evaluated transporter proteins (BCRP, ASBT, OAT1 or 3, OCT1 or 2,
MRP2 or 4, OATP1B1, 1B3 or 2B1^{[9, 10]}, p-gp[9] or BSEP^[10]), although at a concentration of &2 lmol/L, deoxycholic acid inhibited NTCP by 50%^[10].
Deoxycholic acid requires cautious use[10]/dose selection^[9] in elderly individuals, due to their greater likelihood of having comorbidities and receiving other treatments^[9] and their insufficient numbers in clinical trials^{[9, 10]}. However, although not yet studied, the pharmacokinetic profile of injected deoxycholic acid is unlikely to be influenced by renal impairment (as urine excretion of deoxycholic acid is negligible)^[10] or hepatic impairment[as doses are small and administered intermittently, and plasma levels of endogenous deoxycholic acid vary greatly]^{[9, 10]}. Gender has no impact on deoxycholic acid pharmacokinetics^[9].

For the treatment of moderate to severe submental convexity/ fullness in adults (for whom the presence of SMF has a psychological impact^[10]) in the USA^[9] and EU^[10], deoxycholic acid 10 mg/mL solution should be injected into the submental subcutaneous fat between the dermis and platysma (i.e. pre-platysmal fat), using an area adjusted dose of 2 mg/cm2. Up to 10 mL of the drug (i.e. B50 injections, each of 0.2 mL and spaced 1 cm apart) can be administered in a single treatment, and up to six treatments can be given (at least 1 month apart); the number of injections and treatments should be individualized on the basis of the patient’s SMF distribution and treatment goals^{[9, 10]}. Deoxycholic acid should not be injected near the marginal mandibular nerve or into the platysma or postplatysmal fat and is contraindicated if there is infection at the injection sites^{[9, 10]}.
The drug is not recommended for the treatment of subcutaneous fat beyond the submental region, as its efficacy and safety in these areas has not been established^[9].
In addition, deoxycholic acid use should be given careful consideration in patients for whom SMF reduction may have aesthetically undesirable outcomes (e.g. those with prominent platysmal bands or excessive skin laxity) and requires caution in patients who have previously had surgical/aesthetic treatment of the submental area, as scar
tissue or anatomical/landmark changes may affect the ability to administer the drug safely or achieve the desired outcome^{[9, 10]}. Local prescribing information should be consulted for information regarding other warnings and precautions and details of administration considerations and injection technique.

Marginal mandibular nerve injury (indicated by asymmetric smile or facial paresis) has occurred with deoxycholic acid 2 mg/cm2 injections in clinical trials of SMF (2.9% of recipients vs. 0.3% of placebo recipients)^[1], although all resolved spontaneously^[9]. For instance, across REFINE 1 and 2, injection-site nerve injury (which was generally mild or moderate in severity) lasted for a median of 42 days in deoxycholic acid recipients (vs. 85 days in placebo recipients)^[1]. To minimize the likelihood of nerve injury, administration recommendations should be followed. Dysphagia was also reported by few deoxycholic acid 2 mg/cm2 recipients across the SMF clinical development program (1.1 vs. 0.2% of placebo recipients)^[1], occurring in conjunction with injection-site reactions, such as swelling, pain and induration[9]. However, dysphagia was generally mild and resolved after a few days (e.g. median duration was 3 days in an analysis of REFINE 1 and 2)^[1]. Deoxycholic acid should be avoided^[9] or used with caution^[10] in subjects with current^{[9, 10]} or prior^[9] dysphagia, as the condition may be exacerbated. Skin ulceration related to deoxycholic acid was rare across the SMF clinical trial program (5 of 1050 recipients; 0.5%); all skin ulcerations recovered/resolved and none were severe^[1].

1. Kythera Biopharmaceuticals Inc. ATX-101 (deoxycholic acid) injection: Advisory Committee Briefing Materials: available for public release. 2015. 
2. Honigman R, Castle DJ. Aging and cosmetic enhancement. Clin Interv Aging. 2006;1(2):115–9.
3. Schlessinger J, Weiss SR, Jewell M, et al. Perceptions and practices in submental fat treatment: a survey of physicians and patients. Skinmed. 2013;11(1):27–31.
4. Koehler J. Complications of neck liposuction and submentoplasty. Oral Maxillofac Surg Clin North Am. 2009;21(1):43–52, vi.
5. Patel BC. Aesthetic surgery of the aging neck: options and techniques. Orbit. 2006;25(4):327–56.
6. Petrou I. Minimally invasive submental fat reduction proves successful. 2011. http://cosmeticsurgerytimes.modernmedicine. com. Accessed 17 Oct 2016.
7. Rotunda AM, Suzuki H, Moy RL, et al. Detergent effects of sodium deoxycholate are a major feature of an injectable phosphatidylcholine formulation used for localized fat dissolution. Dermatol Surg. 2004;30(7):1001–8.
8. de Aguiar Vallim TQ, Tarling EJ, Edwards PA. Pleiotropic roles of bile acids in metabolism. Cell Metab. 2013;17(5):657–69.
9. Kythera Biopharmaceuticals Inc. KybellaTM (deoxycholic acid) injection, for subcutaneous use: US prescribing information. 2015. 
10. Kythera Biopharmaceuticals (Europe) Ltd. Belkyra 10 mg/ml solution for injection: EU summary of product characteristics. 2016. 
11. Thuangtong R, Bentow JJ, Knopp K, et al. Tissue-selective effects of injected deoxycholate. Dermatol Surg. 2010;36(6):899–908.
12. Dover J, Schlessinger J, Young L, et al. Reduction of submental fat with ATX-101: results from a phase IIB study using investigator, subject, and magnetic resonance imaging assessments J Am Acad Dermatol. 2012;66(4 Suppl.1):AB29.
13. Ogden S, Griffiths T. A novel injectable drug for the reduction of localized fat. Br J Dermatol. 2011;165:98–9.
14. Rzany B, Griffiths T, Walker P, et al. Reduction of unwanted submental fat with ATX-101 (deoxycholic acid), an adipocytolytic injectable treatment: results from a phase III, randomized, placebo-controlled study. Br J Dermatol. 2014;170(2):445–53.
15. Ascher B, Hoffmann K, Walker P, et al. Efficacy, patient-reported outcomes and safety profile of ATX-101 (deoxycholic acid), an injectable drug for the reduction of unwanted submental fat: results from a phase III, randomized, placebo-controlled study. J Eur Acad Dermatol Venereol. 2014;28(12):1707–15.
16. Walker P, Lee D. A phase 1 pharmacokinetic study of ATX-101: serum lipids and adipokines following synthetic deoxycholic acid injections. J Cosmet Dermatol. 2015;14(1):33–9.
17. Walker P, Fellmann J, Lizzul PF. A phase I safety and pharmacokinetic study of ATX-101: injectable, synthetic deoxycholic acid for submental contouring. J Drugs Dermatol. 2015;14(3):279–87.
18. Jones DH, Carruthers J, Joseph JH, et al. REFINE-1, a multicenter, randomized, double-blind, placebo-controlled, phase 3 trial with ATX-101, an injectable drug for submental fat reduction. Dermatol Surg. 2016;42(1):38–49.
19. Humphrey S, Sykes J, Kantor J, et al. ATX-101 for reduction of submental fat: a phase III randomized controlled trial. J Am Acad Dermatol. 2016;75(4):788–97.
20. US National Institutes of Health. ClinicalTrials.gov identifiers NCT01542034 and NCT01546142. 2014.

Deoxycholic acid sodium salt, which is a secondary bile acid and the metabolite of intestinal bacteria, provides a nonsurgical treatment to significantly reduce submental fat in adults via injection directly into moderate-to-severe fatty tissue below the neck. When injected into fatty tissue, deoxycholic acid helps destroy fat cells. Although deoxycholic acid has many applications beyond human health, the application as a dyslipidemia drug was licensed to Kythera from Los Angeles Biomedical Institute at Harbor-UCLA Medical Center in 2007. Allergan acquired Kythera recently in 2015.

white powder

Deoxycholic acid has been used in a modified procedure to recover 40-80% of a protein from a 1 μg/mL solution. It forms complexes with fatty acid. Used as an emulsifying agent in food, a precursor in the synthesis of cortisone, and a gallbladder stimulant. It has been used to study assess how physiological concentrations of ursodeoxycholic acid (UDCA) vs. deoxycholic acid (DCA) affect barrier function in mouse intestinal tissue. Deoxycholic acid has been used in a study to assess a pH-Responsive Mechanism of a Deoxycholic Acid and Folate Co-Modified Chitosan Micelle under Cancerous Environment. It has also been used in a study to investigate dose-dependent anti-inflammatory effect of ursodeoxycholic acid in experimental colitis.

antiinflammatory, immunomodulator, antineoplastic

A Cholic Acid (C432600) derivative used as a component in cell lysis buffers.

ChEBI: Deoxycholic acid is a bile acid that is 5beta-cholan-24-oic acid substituted by hydroxy groups at positions 3 and 12 respectively. It has a role as a human blood serum metabolite. It is a bile acid, a dihydroxy-5beta-cholanic acid and a C24-steroid. It is a conjugate acid of a deoxycholate.

This [TM="Certified Spiking Solution" is suitable for use as starting material in the preparation of linearity standards, calibrators, and controls in LC-MS/MS and GC/MS bile acid testing methods. Deoxycholic acid (DCA), also known as deoxycholate and cholanoic acid is a secondary bile acid that aids in the absorption of fats in the intestine. Mass spectrometry-based analysis of DCA is routinely performed in clinical diagnostic testing applications including neonatal testing of inborn errors of bile acid synthesis and differentiating among types of familial intrahepatic cholestasis.

Deoxycholic acid, due to its amphiphilicity, significantly helps to solubilize, emulsify, and absorb fat, vitamins, and cholesterol in the body. High levels of intestinal deoxycholic acid might cause colorectal cancer by inducing oxidative stress and leading to DNA damage. It acts as an oncogene and pro-tumor factor.

Poison by intraperitoneal route. Moderately toxic by ingestion and intravenous routes. Questionable carcinogen with experimental tumorigenic data. Experimental reproductive effects. Mutation data reported. When heated to decomposition it emits acrid smoke and irritating fumes.

The synthesis started from the commercially available 9- hydroxyandrost-4-ene-3,17-dione (114).85 Hydrogenation of 114 gave the saturated 5|?-dione 115 in 85% yield. Alcohol 115 was then dehydrated with H2SO4 in CH2Cl2 to provide 5|?-androst-9(11)-ene-3,17-dione 116 in 95% yield as off-white solid, and this was followed by selective reduction with LiAlH(O-t-Bu)3 to afford (3|á,5|?)-3-hydroxyandrost- 9(11)-en-17-one (117). The crude ketone 117 was submitted to a Wittig reaction with triphenylethylphosphonium bromide in the presence of potassium t-butoxide in THF to yield (3|á,5|?,17E)-pregna-9(11),17-dien-3-ol (118). The crude alcohol 118 was acetylated with Ac2O in the presence of DMAP and Et3N to yield prenyl acetate 119 in 64% across the threestep sequence. Compound 119 was reacted with methyl acrylate in the presence of EtAlCl2 to facilitate conjugate addition and subsequent tertiary carbocation elimination to afford adduct 120, and this resulting olefin was hydrogenated to selectively saturate the cyclopentenyl double bond, resulting in steroid 121 in 85% yield from 119. The remaining alkene 121 then underwent allylic oxidation with tert-butyl hydrogen peroxide and 10% NaOCl aqueous solution in EtOAc to give enone 122, and this material was then hydrogenated over 10% Pd/C in EtOAc to afford the saturated ketone 123. Next, the ketone within 123 was selectively reduced with LiAlH(O-t-Bu)3 in THF to give the 12|á-hydroxy precursor 124 in excellent yield. Finally the remaining methyl ester 124 was hydrolyzed with 20% NaOH aqueous solution in THF/MeOH and acidified with 4 M HCl to give deoxycholic acid (XV) in 99% yield as a white solid.

Reflux the acid with CCl4 (50mL/g), filter, evaporate under vacuum at 25o, recrystallise the residue from acetone and dry it under vacuum at 155o [Trenner et al. J Am Chem Soc 76 1196 1954]. A solution of (cholic acid-free) material (100mL) in 500mL of hot EtOH is filtered, evaporate it to less than 500mL on a hot plate, and pour it into 1500mL of cold diethyl ether. The precipitate, filtered off by suction, is crystallised twice from 1-2 parts of absolute EtOH, to give an alcoholate, m 118-120o, which is dissolved in EtOH (100mL for 60g) and poured into boiling water. After boiling until free of the EtOH, the precipitate is filtered off, dried, ground and dried to constant weight in vacuo [Sobotka & Goldberg Biochem J 26 555 1932]. Deoxycholic acid is also freed from fatty acids and cholic acid by silica gel chromatography and elution with 0.5% acetic acid in ethyl acetate [Tang et al. J Am Chem Soc 107 4058 1985]. It can also be recrystallised from butanone. Its solubility in H2O at 15o is 0.24g/L, but in EtOH it is 22.07g/L. [Beilstein 10 IV 1608.]