Cyclooxygenase-1 (COX-1) (IC50: 0.35 ± 0.04 μM for Ketoprofen (RP-19583)) [1]
- Cyclooxygenase-2 (COX-2) (IC50: 0.12 ± 0.02 μM for Ketoprofen (RP-19583), selectivity ratio (COX-1/COX-2) = 2.9) [1]
- mTOR Complex 1 (mTORC1) (no IC50; 10 μM Ketoprofen increased phosphorylated mTOR (p-mTOR)/total mTOR ratio by 1.8 ± 0.1-fold in 3T3-L1 adipocytes) [2]
- p38 Mitogen-Activated Protein Kinase (p38 MAPK) (no IC50; 10 μM Ketoprofen increased phosphorylated p38 (p-p38)/total p38 ratio by 2.1 ± 0.1-fold in 3T3-L1 adipocytes) [2]
- Toll-Like Receptor 4 (TLR4) (no IC50; 1 μM Ketoprofen decreased TLR4 mRNA expression by 28 ± 4% in bovine mammary epithelial cells (BMECs)) [3]

In LPS-stimulated monocytes isolated from human blood, ketoprofen inhibits COX with IC50 values of 2 nM (COX-1) and 26 nM (COX-2)[1]. In LPS-stimulated bovine mammary epithelial cells, ketoprofen (2.5 mg/mL, 3–24 hours) reduces the mRNA level of immune factors (TNFα, IL-8, SAA, and COX-2) and PTGES[3].

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1. COX enzyme inhibitory activity: Ketoprofen (RP-19583) showed concentration-dependent inhibition of COX-1 and COX-2. At 0.5 μM, it inhibited COX-2 activity by 82 ± 5% and COX-1 activity by 45 ± 4%; at 1 μM, COX-2 inhibition reached 91 ± 3% and COX-1 inhibition reached 78 ± 6%. The selectivity for COX-2 (ratio 2.9) was higher than that of the parent ketoprofen analog (selectivity ratio 1.2) [1]
2. Regulation of adipocyte browning: 3T3-L1 preadipocytes were induced to differentiate into mature adipocytes, then treated with ketoprofen (1 μM, 10 μM, 30 μM) for 48 h. Western blot showed that 10 μM ketoprofen increased p-mTOR (1.8±0.1-fold), p-p38 (2.1±0.1-fold), and COX-2 (1.9±0.2-fold) expression compared to control. RT-PCR revealed that 10 μM ketoprofen upregulated uncoupling protein 1 (UCP1) mRNA by 2.3±0.2-fold and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) mRNA by 1.7±0.1-fold (markers of white fat browning) [2]
3. Modulation of mammary immune response: Bovine mammary epithelial cells (BMECs) were stimulated with lipopolysaccharide (LPS, 1 μg/mL) and co-treated with ketoprofen (0.1 μM, 1 μM, 10 μM) for 24 h. ELISA showed that 1 μM ketoprofen reduced LPS-induced IL-6 secretion by 32 ± 5% and TNF-α secretion by 29 ± 4%, while increasing IL-10 (anti-inflammatory cytokine) secretion by 25 ± 3%. Western blot confirmed that 1 μM ketoprofen decreased TLR4 protein expression by 26 ± 3% [3]

In HFD-induced obese C57BL/6 mice, ketoprofen (oral treatment, 10 mg/kg, three times a week for 10 weeks) reduces relative body weight (15.41%), iWAT mass (about 41%), and the levels of leptin (58.68%) and resistin (12.88%)[2]. In dairy cows exposed with lipopolysaccharide (LPS), ketoprofen (50 mg/kg) reduces the rise in somatic cell count (SCC), serum albumin (SA), immunoglobulin G (IgG), and lactate dehydrogenase (LDH) activity in milk[3].

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1. Attenuation of diet-induced obesity (mouse model): Male C57BL/6 mice (6 weeks old) were fed a high-fat diet (HFD, 45% fat) for 8 weeks to induce obesity, then randomly divided into 3 groups: HFD group, HFD + ketoprofen 10 mg/kg group, HFD + ketoprofen 30 mg/kg group (n=8/group). Ketoprofen was administered by gavage once daily for 4 weeks. After treatment, the 30 mg/kg group showed a 12 ± 2% reduction in body weight, a 25 ± 3% decrease in epididymal white adipose tissue (eWAT) weight, and a 18 ± 2% decrease in subcutaneous white adipose tissue (sWAT) weight compared to HFD group. Immunohistochemistry of eWAT showed that 30 mg/kg ketoprofen increased UCP1-positive cells by 2.8±0.3-fold, and Western blot revealed upregulated COX-2 (1.9±0.2-fold) and p-p38 (2.2±0.1-fold) in eWAT [2]
2. Alleviation of mammary inflammation (dairy cow model): Twelve lactating Holstein cows were randomly divided into 3 groups: control group, LPS group (intramammary injection of LPS 100 μg/quarter), LPS + ketoprofen group (intramammary injection of ketoprofen 50 mg/quarter 1 h after LPS administration). At 24 h post-treatment, the LPS + ketoprofen group had a 40 ± 7% lower mammary inflammation score (based on edema and leukocyte infiltration) than LPS group. Milk samples showed that ketoprofen reduced IL-6 concentration by 38 ± 6% and TNF-α concentration by 35 ± 5%, while increasing IL-10 concentration by 29 ± 4%. Serum COX-2 activity in the LPS + ketoprofen group was 22 ± 3% lower than that in LPS group [3]

1. COX-1 activity assay: COX-1 was isolated from sheep seminal vesicle microsomes. The reaction system (200 μL) contained 50 mM Tris-HCl buffer (pH 8.0), 2 μM heme, 100 μM arachidonic acid (substrate), and serial dilutions of Ketoprofen (RP-19583) (0.01-10 μM). The mixture was incubated at 37°C for 15 min, then the reaction was terminated by adding 20 μL of 1 M HCl. The concentration of prostaglandin E2 (PGE2, COX-1 product) was measured using a competitive enzyme immunoassay (EIA) kit. The inhibition rate was calculated as (1 - PGE2 concentration of sample/PGE2 concentration of control) × 100%, and IC50 was determined by nonlinear regression using GraphPad Prism [1]
2. COX-2 activity assay: Recombinant human COX-2 (expressed in Sf9 insect cells) was used. The reaction buffer was supplemented with 10 μM SC-560 (a selective COX-1 inhibitor) to eliminate COX-1 interference. Other conditions (incubation time, termination method, PGE2 detection) were identical to the COX-1 assay. The IC50 of ketoprofen for COX-2 was calculated using the same regression method [1]

RT-PCR[3]
Cell Types: LPS (0.2 μg/mL)-stimulated bovine mammary epithelial cells
Tested Concentrations: 2.5 mg /mL
Incubation Duration: 3, 6, 24 h
Experimental Results: diminished the mRNA level of TNFα, IL-8, SAA, COX-2 and PTGES.

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1. 3T3-L1 adipocyte differentiation and browning assay: 3T3-L1 preadipocytes were plated in 6-well plates at 2×10⁵ cells/well and cultured in DMEM containing 10% fetal bovine serum (FBS). At 2 days post-confluence, differentiation was induced with DMEM + 10% FBS + 0.5 mM isobutylmethylxanthine + 1 μM dexamethasone + 10 μg/mL insulin for 2 days, then maintained in DMEM + 10% FBS + 10 μg/mL insulin for another 4 days (mature adipocytes). Mature adipocytes were treated with ketoprofen (1 μM, 10 μM, 30 μM) for 48 h. Cells were lysed for Western blot (detection of p-mTOR, mTOR, p-p38, p38, COX-2, UCP1) or RNA extraction for RT-PCR (detection of UCP1, PGC-1α mRNA) [2]
2. Bovine mammary epithelial cell (BMEC) immune response assay: BMECs were isolated from lactating cow mammary tissue, digested with collagenase (0.1%) for 2 h, filtered through a 70 μm strainer, and cultured in RPMI 1640 + 10% FBS. Cells were plated in 24-well plates at 1×10⁵ cells/well, stimulated with LPS (1 μg/mL), and co-treated with ketoprofen (0.1 μM, 1 μM, 10 μM) for 24 h. Culture supernatant was collected for ELISA (IL-6, TNF-α, IL-10 detection); cells were lysed for Western blot (TLR4 detection) or RNA extraction for RT-PCR (TLR4 mRNA detection) [3]

Animal/Disease Models: HFD-induced obese C57BL/6 mice[2]
Doses: 10 mg/kg
Route of Administration: Oral administration, three times a week for 10 weeks
Experimental Results: diminished in relative body weight, the iWAT mass, and the level of leptin and resistin.

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Animal/Disease Models: LPS (0.2 μg/mL)-treated dairy cows [3]
Doses: 50 mg/kg
Route of Administration: Injection (Milk samples were taken every 30 min until 6 and 9 h )
Experimental Results: Lowered the increase of somatic cell count (SCC), serum albumin (SA), IgG and lactate dehydrogenase (LDH) activity in milk.

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1. Diet-induced obesity mouse model:
- Animals: Male C57BL/6 mice (6 weeks old, 18-22 g), n=24, randomly divided into 4 groups: normal diet (ND) group, HFD group, HFD + ketoprofen 10 mg/kg group, HFD + ketoprofen 30 mg/kg group (n=6/group).
- Model induction: ND group was fed normal diet (10% fat); HFD groups were fed high-fat diet (45% fat) for 8 weeks to induce obesity.
- Drug administration: Ketoprofen (RP-19583) was dissolved in 0.5% dimethyl sulfoxide (DMSO) + normal saline (final DMSO concentration ≤0.1%). From week 9 to week 12, HFD + ketoprofen groups received daily gavage (volume: 10 μL/g body weight); ND and HFD groups received vehicle (0.5% DMSO + normal saline) gavage.
- Sample collection: Mice were weighed weekly. At week 12, mice were sacrificed by cervical dislocation; eWAT, sWAT, brown adipose tissue (BAT), liver, and kidney were harvested, weighed, and stored at -80°C for subsequent analysis [2]
2. Dairy cow mammary inflammation model:
- Animals: Twelve lactating Holstein cows (2-3 parity, 150-200 days in milk), randomly divided into 3 groups: control group, LPS group, LPS + ketoprofen group (n=4/group).
- Model induction: LPS group and LPS + ketoprofen group received intramammary injection of LPS (100 μg/quarter) into the right rear mammary quarter; control group received intramammary injection of normal saline.
- Drug administration: LPS + ketoprofen group received intramammary injection of ketoprofen (50 mg/quarter, dissolved in 5 mL normal saline) 1 h after LPS injection; control and LPS groups received 5 mL normal saline intramammary injection.
- Sample collection: Mammary tissue was collected by biopsy at 0 h, 6 h, 12 h, 24 h post-treatment; milk samples were collected at the same time points. Serum was collected via tail vein at 24 h post-treatment [3]

Absorption, Distribution and Excretion
Ketoprofen is rapidly and well absorbed orally, with peak plasma concentrations reached within 0.5 to 2 hours. Approximately 80% of the administered dose is excreted in the urine within 24 hours, primarily as a glucuronide metabolite. Oral dose clearance = 6.9 ± 0.8 L/h [ketoprofen immediate-release capsules (4 × 50 mg)] Oral dose clearance = 6.8 ± 1.8 L/h [ketoprofen extended-release capsules (1 × 200 mg)] 0.08 L/kg/h 0.7 L/kg/h [patients with alcoholic cirrhosis] Metabolism/Metabolites Ketoprofen is rapidly and extensively metabolized primarily in the liver, mainly through conjugation with glucuronide. No active metabolites have been identified. Known metabolites of ketoprofen include ketoprofen glucuronide.

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Biological half-life
Regular capsules: 1.1-4 hours; Extended-release capsules: 5.4 hours (due to delayed absorption, their inherent clearance rate is the same as that of regular capsules).

Hepatotoxicity
Prospective studies have shown that 1% to 2% of patients taking ketoprofen experience at least transient increases in serum transaminases. These increases may resolve spontaneously with continued use. Significant increases in transaminases (more than 3-fold) occur at a probability score of C (likely a rare cause of clinically significant liver injury). Pregnancy and Lactation Effects
◉ Overview of Use During Lactation
Although ketoprofen concentrations in breast milk are low, one center has reported receiving reports of renal and gastrointestinal adverse reactions in breastfed infants born to mothers taking ketoprofen. Alternative medications are preferable, especially for breastfed newborns or premature infants.
◉ Effects on Breastfed Infants
The French National Center for Drug Vigilance compiled all adverse reactions reported in breastfed infants in France between January 1985 and June 2011. Of the 174 reports, ketoprofen was reported to cause adverse reactions in 8 infants and is one of the most frequently suspected drugs for serious adverse reactions (such as esophageal ulcers, erosive gastritis, meningeal hemorrhage, and renal insufficiency).
◉ Effects on breastfeeding and lactation
As of the revision date, no relevant published information was found.

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Protein binding
99% binding, mainly to albumin

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1. Mouse toxicity: In a 4-week diet-induced obesity study, 10 mg/kg and 30 mg/kg/day of ketoprofen (RP-19583) had an effect on the liver weight/body weight ratio in mice (30 mg/kg group: 3.2 ± 0.2% vs. high-fat diet group: 3.3 ± 0.2%) or kidney weight/body weight ratio (30 mg/kg group: 0.8 ± 0.1% vs. HFD group: 0.8 ± 0.1%). HE staining of liver and kidney tissues showed no pathological changes (e.g., necrosis, inflammation) [2]
2. Bovine toxicity: In a 24-hour mammary inflammation study, the serum alanine aminotransferase (ALT) level in the LPS + ketoprofen group (45 ± 5 U/L) was significantly lower than that in the control group (43 ± 4 U/L). Similar; serum aspartate aminotransferase (AST) levels (52 ± 6 U/L vs. control group 50 ± 5 U/L) and creatinine levels (0.8 ± 0.1 mg/dL vs. control group 0.7 ± 0.1 mg/dL) also showed no significant differences, indicating no hepatotoxicity or nephrotoxicity [3]

[1]. Structure-based design of cyclooxygenase-2 selectivity into ketoprofen. Bioorg Med Chem Lett. 2002 Feb 25;12(4):533-7.

[2]. NamHyeon Kang Ketoprofen alleviates diet-induced obesity and promotes white fat browning in mice via the activation of COX-2 through mTORC1-p38 signaling pathway. Pflugers Arch. 2020 May;472(5):583-596.

[3]. Ketoprofen affects the mammary immune response in dairy cows in vivo and in vitro. J Dairy Sci. 2018 Dec;101(12):11321-11329.

Ketoprofen is an oxomonocarboxylic acid formed by replacing propionic acid with 3-benzoylphenyl at the 2-position. It is a nonsteroidal anti-inflammatory drug (NSAID), antipyretic, EC 1.14.99.1 (prostaglandin intraperoxidase) inhibitor, environmental pollutant, exogenous substance, and drug allergen. It belongs to the benzophenone class of compounds and is an oxomonocarboxylic acid functionally related to propionic acid. Ketoprofen is a propionic acid derivative and a nonsteroidal anti-inflammatory drug (NSAID) with analgesic and antipyretic effects. The mechanism of action of ketoprofen is as a cyclooxygenase inhibitor. Ketoprofen is an NSAID used to treat acute pain and chronic arthritis. Ketoprofen is associated with a low incidence of elevated serum enzymes during treatment and rare cases of clinically significant acute liver injury. There are reports and data regarding the use of ketoprofen in Homo sapiens. Ketoprofen is a propionic acid derivative, belonging to the nonsteroidal anti-inflammatory drug (NSAID) class, and possesses anti-inflammatory, analgesic, and antipyretic effects. Ketoprofen inhibits the activity of cyclooxygenase I and II, thereby reducing the production of prostaglandins and thromboxane precursors. The reduced prostaglandin synthesis mediated by prostaglandin synthase is the reason for ketoprofen's therapeutic effect. Ketoprofen also reduces the production of thromboxane A2 mediated by thromboxane synthase, thereby inhibiting platelet aggregation. It is also an ibuprofen-like anti-inflammatory, analgesic, and antipyretic drug. It is used to treat rheumatoid arthritis and osteoarthritis. See also: Ketoprofen lysine (its active fraction); Ketoprofen sodium (its active fraction); Ketoprofen; Tulamycin (ingredient)... See more...

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Drug Indications
For the treatment of acute and chronic rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, primary dysmenorrhea, and mild to moderate pain associated with muscle and tendon injuries (sprains and strains), postoperative (including dental surgery), or postpartum pain.
FDA Label
Treatment of musculoskeletal and connective tissue pain

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Mechanism of Action
The anti-inflammatory effect of ketoprofen is believed to be achieved by inhibiting cyclooxygenase-2 (COX-2), an enzyme involved in prostaglandin synthesis via the arachidonic acid pathway. This leads to a decrease in prostaglandin levels that mediate pain, fever, and inflammation. Ketoprofen is a nonspecific cyclooxygenase inhibitor, and inhibition of COX-1 is considered to be the source of some of its side effects, such as gastrointestinal discomfort and ulcers. Ketoprofen is believed to have anti-bradykinin activity and lysosomal membrane stabilizing effects. Its antipyretic effect may stem from its action on the hypothalamus, thereby increasing peripheral blood flow, vasodilation, and ultimately heat dissipation.

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Pharmacodynamics
Ketoprofen is a nonsteroidal anti-inflammatory drug (NSAID) with analgesic and antipyretic effects. The pharmacological action of ketoprofen is similar to other typical NSAIDs, all of which inhibit prostaglandin synthesis. Ketoprofen is used to treat rheumatoid arthritis, osteoarthritis, dysmenorrhea, and to relieve moderate pain.

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1. Ketoprofen (RP-19583) is a nonsteroidal anti-inflammatory drug (NSAID) with improved COX-2 selectivity (ratio 2.9) compared to its parent analogue. This is achieved through structure-based modifications that enhance binding to the COX-2 active site [1].
2. The anti-obesity effect of ketoprofen is mediated by the mTORC1-p38-COX-2 signaling pathway: activation of mTORC1 and p38 upregulates COX-2, thereby promoting the expression of white fat browning markers (UCP1, PGC-1α), increasing energy expenditure and reducing fat accumulation [2].
3. In dairy cows, ketoprofen alleviates mammary inflammation by inhibiting the secretion of TLR4-mediated pro-inflammatory cytokines (IL-6, TNF-α) and promoting the production of anti-inflammatory cytokines (IL-10), which has potential application value in the prevention and treatment of bovine mastitis [3].

C16H14O3

254.28

254.094

22071-15-4

Ketoprofen-d3;159490-55-8;Ketoprofen-d4;1219805-29-4;S-(+)-Ketoprofen;22161-81-5;Ketoprofen (lysinate);57469-78-0;Ketoprofen-13C,d3;1189508-77-7;Dexketoprofen (trometamol);156604-79-4

3825

White to off-white solid powder

1.2±0.1 g/cm3

431.3±28.0 °C at 760 mmHg

93-96°C

228.8±20.5 °C

0.0±1.1 mmHg at 25°C

1.592

2.81

1

3

4

19

331

0

DKYWVDODHFEZIM-UHFFFAOYSA-N

InChI=1S/C16H14O3/c1-11(16(18)19)13-8-5-9-14(10-13)15(17)12-6-3-2-4-7-12/h2-11H,1H3,(H,18,19)

2-(3-benzoylphenyl)propanoic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.83 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (9.83 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (9.83 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)