Diacerein targets the inflammatory cytokine interleukin-1 (IL-1). Its active metabolite, rhein, inhibits the production of IL-1β and also blocks the IL-1 receptor. By inhibiting IL-1, it reduces the inflammatory response in the joint and decreases the activity of matrix metalloproteinases (MMPs), which are enzymes that degrade cartilage. This mechanism contributes to its anti-inflammatory and cartilage-protective effects in osteoarthritis. It also inhibits the synthesis of nitric oxide and prostaglandin E2.

Diacerein significantly inhibits LPS-induced IL-1beta production by synovial tissue and cartilage. Diacerein (1 μM) has a significantly less inhibitory effect on cartilage synthesis than culture media containing LPS only. Diacerein (1 μM) decreases NO release in synovial tissue and cartilage media and increases IL-1ra levels in cartilage culture media. Diacerein (10 μM) enhances the expression of TGF-beta1 and TGF-beta2 in cultured bovine articular chondrocytes. Diacerein reduces, in a dose-dependent manner, the interleukin-1-beta (IL-1beta)-induced MMP-13 production in osteoarthritic subchondral bone. Diacerein significantly reduces the activity of MMP-13 and cathepsin K in osteoclasts. Diacerein effectively blocks the IL-1beta effect on the osteoclast differentiation process and the survival of mature osteoclasts.

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In human OA synovial tissue cultures stimulated with LPS (1 μg/ml), Diacerein at 10⁻⁶ M significantly inhibited IL-1β secretion (P<0.05 vs LPS). [1]
In human OA cartilage cultures stimulated with LPS, Diacerein at 10⁻⁶ M and 10⁻⁵ M induced a dose-dependent decrease of IL-1β production (P<0.05 vs LPS at both concentrations). [1]
Diacerein at 10⁻⁶ M reversed the inhibitory effect of LPS on cartilage ³⁵S-GAG synthesis (proteoglycan synthesis), being 89±24% as effective as rhein at equivalent concentrations. [1]
Conditioned media from synovial tissue cultured with LPS plus Diacerein (10⁻⁶ M) significantly reversed the inhibitory effect of LPS-conditioned media on ³⁵S uptake by human cartilage cultures (P<0.02 vs LPS). [1]
Diacerein at 10⁻⁵ M decreased LPS-stimulated NO release in human synovial tissue cultures (P<0.002 vs LPS) and in human cartilage cultures (P<0.001 vs LPS). [1]
Diacerein at 10⁻⁵ M significantly inhibited LPS-induced IL-1ra production in synovial tissue cultures (P<0.001 vs LPS). [1]
Diacerein at 10⁻⁶ M and 10⁻⁵ M significantly stimulated IL-1ra secretion in human cartilage cultures (P<0.05 and P<0.002 respectively vs LPS). [1]
Diacerein at 10⁻⁵ M and 10⁻⁶ M did not show any deleterious effect on synovial fibroblast viability (>90% compared to controls). [1]
In vitro, Diacerein and its active metabolite rhein have been shown to inhibit the production of IL-1β and other pro-inflammatory cytokines in chondrocytes and synovial cells. They also inhibit the activity of matrix metalloproteinases (MMPs), which are responsible for cartilage degradation. These in vitro studies confirm its mechanism of action and its potential to protect cartilage from inflammatory damage. Its activity is well-characterized in cell culture models.

Diacerein (100 mg/kg/day) significantly suppresses the paw edema and the increase in serum mucoprotein in the adjuvant-induced arthritic rats. Diacerein (30 mg/kg/day) combined with Naproxen (3 mg/kg/day) results in significantly greater anti-inflammatory activity than with naproxen alone in the adjuvant-induced arthritic rats. Diacerein (100 mg/kg/day) also significantly prevents bone loss and reduces the serum alkaline phosphatase and decreases the excretion of urinary hydroxyproline in the ovariectomized rats. Diacerein (25 mg/kg) decreases the thickness of cartilage and subchondral bone in the lesion (middle) zone of the lateral tibial plateau in Merino wethers.
In vivo, Diacerein has been shown to slow the progression of osteoarthritis in animal models and in clinical studies. It reduces the production of IL-1 and other inflammatory mediators in the joint, leading to a decrease in inflammation and cartilage degradation. It is used as a symptomatic treatment for osteoarthritis, providing pain relief and improving joint function. Its effects are slow-acting, and it takes several weeks to achieve maximal benefit.

Non-cellular assays for Diacerein typically involve measuring its effects on IL-1 production or on the activity of MMPs. These assays may use purified enzymes or cell-free systems to study the compound's inhibitory effects. For example, the inhibition of MMP activity can be measured using synthetic substrates. These experiments help to characterize its mechanism of action at a biochemical level.

Synovial tissue organ culture: Human OA synovial tissue was cut into small pieces (few mm diameter, approx. 80 mg per sample) and cultured in 2 ml RPMI 1640 supplemented with L-glutamine (2 mM), penicillin (100 U/ml) and streptomycin sulphate (100 μg/ml). Test materials including Diacerein (10⁻⁷ to 10⁻⁵ M) were added, and after 48 h incubation (37°C, 5% CO₂), supernates were collected for IL-1β, NO, and IL-1ra assays. [1]
Cartilage culture: Human OA cartilage was finely diced, randomized, and distributed in 96-well plates (approx. 15 mg cartilage per well) in 0.2 ml DMEM with 1% FCS, penicillin, and streptomycin. Test materials including Diacerein (10⁻⁷ to 10⁻⁵ M) were added. After 24 h, ³⁵SO₄ (final 40 μCi/ml) was added, and after two more days of incubation, supernates and cartilage were collected for ³⁵S-GAG determination. Separate cultures without radioactive material were used for IL-1β, IL-1ra, and NO assays after 48 h incubation. [1]
Cell viability assay: Human synovial fibroblast monolayer cultures were exposed to Diacerein (10⁻⁵ to 10⁻⁷ M) for 72 h, and viability was determined by trypan blue exclusion test. Toxicity was also evaluated by tritiated thymidine incorporation into DNA. [1]
In vitro cell-based assays for Diacerein are used to study its effects on chondrocytes and synovial cells. Cells are treated with the compound or its active metabolite, rhein, and the production of inflammatory cytokines and MMPs is measured. These studies help to confirm its anti-inflammatory and cartilage-protective effects at the cellular level.

30, 100 mg/kg Rats

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In vivo animal studies for Diacerein are conducted in models of osteoarthritis. The compound is typically administered orally to animals with induced joint inflammation. Endpoints include measurements of joint swelling, pain behavior, and histopathological analysis of cartilage degradation. These studies are crucial for validating its efficacy in vivo and for understanding its mechanism of action.

Absorption, Distribution and Excretion
Bioavailability is 50-60%. It is completely converted to the active metabolite emodin [DB13174] before entering systemic circulation. Estimated in rats, 37% is excreted in the urine and 53% in the feces. Volume: 15-60 L. Total clearance: 1.5 L/h; renal clearance: 0.1 L/h. Metabolism/Metabolite Before entering systemic circulation, it is completely converted to emodin [DB13174] via double deacetylation. Emodin [DB13174] is further metabolized to emodin glucuronide and emodin sulfate. Biological Half-Life 4-10 hours.

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In humans, the maximum plasma concentration of Diacerein was 11 μM after a single oral dose of 50 mg. [1]
Following daily administration of 50 mg Diacerein every 12 h for one month, its active metabolite rhein was found in synovial fluid at concentrations in the 1–10 μM plasma range. [1]
Diacerein is an orally active compound with a molecular weight of 368.29 g/mol. It is a prodrug that is metabolized to its active form, rhein, in the liver. Its pharmacokinetic properties have been studied in clinical settings. It is absorbed from the gastrointestinal tract and has a half-life that supports twice-daily dosing. It is excreted primarily via the kidneys.

Protein Binding
99% of emodin binds to plasma proteins.

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Diacerein at concentrations of 10⁻⁵ to 10⁻⁷ M added to synovial fibroblast monolayer cultures for 72 h showed no deleterious effect on cell viability, which remained >90% compared to controls. [1]
Diacerein used at concentrations up to 10⁻⁵ M was devoid of cell toxicity. [1]
Diacerein has an established safety profile from its clinical use. It is generally well-tolerated, but its use is associated with gastrointestinal side effects, such as diarrhea and abdominal pain. Comprehensive toxicological data are available from its clinical use. Diacerein is an approved drug in some countries for the treatment of osteoarthritis.

Osteoarthritis Cartilage.1999 May;7(3):272-80;Osteoarthritis Cartilage.1999 May;7(3):255-64.

4,5-Diaacetoxy-9,10-dioxo-2-anthracarboxylic acid is an anthraquinone compound. Diacerein is a prodrug that is metabolized to emodin. Currently, diacerein is approved in France for the treatment of osteoarthritis, but its use is limited due to its side effects, including severe diarrhea. Diacerein is being investigated for the treatment of insulin resistance, type 2 diabetes, and its complications. Drug Indications For the treatment of osteoarthritis of the hip or knee. Mechanism of Action The active metabolite of diacerein, emodin [DB13174], reduces cartilage destruction by decreasing the expression of matrix metalloproteinases (MMPs)-1 and -3, and by upregulating the expression of tissue inhibitors of matrix metalloproteinases (TIMPs), which can reduce the activity of multiple MMPs. The anti-inflammatory effects of emodin can reduce the activity level of interleukin-1β, which plays an important role in reducing extracellular matrix production, MMP activity, and persistent inflammation. Emodin reduces the synthetic activity of abnormal osteoblasts through an unknown mechanism.

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Pharmacodynamics
Reduces inflammation and cartilage destruction, and corrects abnormal osteoblast activity.

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Diacerein (ART 50) is marketed in France by Negma for the treatment of osteoarthritis. It is currently under evaluation as a disease-modifying OA drug (DMOAD) in a 3-year, randomized, double-blind, placebo-controlled clinical study of 500 patients with OA of the hip (ECHODIAH study). [1]
Diacerein showed anti-OA effects in experimental animal OA models (references cited but not part of this study's own data). [1]
The mechanism of action of Diacerein involves antagonism of IL-1 effects on cartilage matrix components and collagenolytic activity, with no effect on phospholipase A2, cyclo-oxygenase, and 5-lipoxygenase. [1]
Diacerein (Diacerhein) is a slow-acting drug used for the symptomatic treatment of osteoarthritis. Its active metabolite, rhein, inhibits the production and activity of IL-1, a key inflammatory cytokine. This reduces inflammation and cartilage degradation. Diacerein is an approved drug in some countries for osteoarthritis.

C19H12O8

368.29

368.053

13739-02-1

Diacerein-d6;1325559-27-0

26248

Light yellow to yellow solid powder

1.5±0.1 g/cm3

631.5±55.0 °C at 760 mmHg

217-2180C

231.8±25.0 °C

0.0±1.9 mmHg at 25°C

1.634

1.99

1

8

5

27

683

0

TYNLGDBUJLVSMA-UHFFFAOYSA-N

InChI=1S/C19H12O8/c1-8(20)26-13-5-3-4-11-15(13)18(23)16-12(17(11)22)6-10(19(24)25)7-14(16)27-9(2)21/h3-7H,1-2H3,(H,24,25)

4,5-diacetyloxy-9,10-dioxoanthracene-2-carboxylic 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: 5 mg/mL (13.58 mM) in 1% (w/v) carboxymethylcellulose (CMC) (add these co-solvents sequentially from left to right, and one by one), suspension solution.

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Solubility in Formulation 2: 1%CMC Na : 30mg/mL

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