COMBINATION THERAPY COMPRISING A POLYUNSATURATED

KETONE AND A FOLIC ACID PARTNER

This invention relates to a pharmaceutical composition comprising certain polyunsaturated long-chain ketones in combination with folic acid or the folic acid derivatives methotrexate, aminopterin or a pharmaceutically acceptable salt, or a hydrate or solvate thereof. The invention also relates to the use of said pharmaceutical composition for the treatment or prevention of skin conditions such as dermatitis and psoriasis.

Background

This invention is concerned with a combination therapy for the treatment of certain skin conditions such as psoriasis and dermatitis. In its broadest sense, dermatitis is inflammation of the skin. It is a common and disfiguring skin condition which requires quick and efficient treatment. Dermatitis symptoms vary, however, with the different forms of the condition. Symptoms vary from skin rashes to bumpy rashes through to flaky skin and blisters. Although different types of dermatitis have varying symptoms, there are certain signs that are common for all of them, including redness of the skin, swelling, itching, skin lesions and sometimes oozing and scarring.

Also, the area of the skin on which the symptoms appear tends to be different with every type of dermatitis. Types of dermatitis are classified according to the cause of the condition. Contact dermatitis is caused by an allergen or an irritating substance. Irritant contact dermatitis accounts for 80% of all cases of contact dermatitis.

Atopic dermatitis is very common worldwide and increasing in prevalence. Atopic dermatitis is a type of eczema and is an inflammatory, chronically relapsing, noncontagious and itchy skin disorder.

Other less common forms of dermatitis include dermatitis herpetiformis. It is characterized by intensely itchy, chronic papulovesicular eruptions, usually distributed symmetrically on extensor surfaces such as the back of neck, scalp, elbows, knees, back, hairline, groin or face. Seborrheic dermatitis is a dermatitis that occurs in the vicinity of sebaceous glands and is caused by sebum over production. The condition tends to give a scaly, flaky skin condition.

Stasis dermatitis is an inflammation on the lower legs which is caused by build-up of blood and fluid and it is more likely to occur in people with varicose veins.

Other common skin disorders include psoriasis. This is an autoimmune induced, chronic disease of skin characterised by red, itchy and scaly skin patches. Skin disorders n general and dermatitis and psoriasis in particular are disfiguring and can lead to reluctance of a sufferer to let people see their condition. Successful treatments of these skin disorders are therefore sought.

A common treatment for skin disorders is administration of one or more topical folic acid derivatives. The present inventors have now found that the combination of certain polyunsaturated ketones and folic acid or certain derivatives thereof such as methotrexate and aminopterin or a pharmaceutically acceptable salt, or a hydrate or solvate thereof results in a synergistic improvement in performance.

Summary of Invention

Thus, viewed from one aspect the invention provides a pharmaceutical composition comprising:

(A) one or more a compound of formula (I):

R-L-CO-X CD wherein R is a C 10-24 unsaturated hydrocarbon group optionally interrupted by one or more heteroatoms or groups of heteroatoms selected from S, O, N, SO, S0 ₂ , said hydrocarbon group comprising at least 4 non-conjugated double bonds;

L is a linking group forming a bridge of 1 to 5 atoms between the R group and the carbonyl CO wherein L comprises at least one heteroatom in the backbone of the linking group; and

X is an electron withdrawing group;

or a pharmaceutically acceptable salt, or a hydrate or solvate thereof; and (B) one or more folic acid partners selected from methotrexate, folic acid or aminopterin, or a pharmaceutically acceptable salt, or a hydrate or solvate thereof, especially methotrexate or aminopterin or a pharmaceutically acceptable salt, or a hydrate or solvate thereof.

In a preferred embodiment, methotrexate or a pharmaceutically acceptable salt, or a hydrate or solvate thereof is the compound (B) partner.

Viewed from another aspect the invention provides a pharmaceutical kit composition for simultaneous, in parallel, sequential or separate use comprising a first composition comprising a compound (I) as herein defined and a pharmaceutically- acceptable diluent or carrier, and a second composition comprising a compound (B) as the folic acid partner as herein defined such as methotrexate or aminopterin or a

pharmaceutically acceptable salt, or a hydrate or solvate thereof and a pharmaceutically- acceptable diluent or carrier.

In particular, the invention relates to a pharmaceutical composition or kit as herein before defined in which the compound of formula (I) is:

or a pharmaceutically acceptable salt, or a hydrate or solvate thereof. In particular, the folic acid partner (B) is methotrexate or aminopterin or a salt, hydrate or solvate thereof.

At least one other folic acid partner may be combined with the methotrexate to achieve intended results, for example, 1 or 2 of such compounds. Alternatively, the methotrexate (including a pharmaceutically acceptable salt, or a hydrate or solvate thereof thereof) may be substituted by at least one other folic acid partner, for example, 1 or 2 of such other compounds (including salts, hydrates and solvates of such compounds). Viewed from another aspect the invention provides a pharmaceutical composition as hereinbefore defined for use in the treatment or prevention of a skin disorder such as psoriasis or dermatitis.

Viewed from another aspect the invention provides a method of treating or preventing a skin disorder such as psoriasis or dermatitis in an animal subject, for example, a mammal such as rodent (mouse, rat, rabbit), monkey (or other non-human primate), pig or other laboratory animal used as a model to study skin disorders. Another suitable mammalian subject is a patient in need thereof. In one embodiment, the nvention comprises administering to said subject (e.g. a human patient) an effective amount of a pharmaceutical composition as herein before defined.

Viewed from another aspect the invention provides a method of treating, such as reducing symptoms of, or preventing a skin disorder such as psoriasis or dermatitis, in a patient in need thereof comprising administering to said patient, preferably a human, an effective amount of at least one compound of formula (I) and simultaneously, in parallel, separately or sequentially administering to said patient an effective amount of at least one compound (B) (e.g., 1, 2 or 3 of such compounds) as herein defined. In sequential administration either compound can be administered first.

Viewed from another aspect the invention provides a method of treating, such as educing symptoms of, or preventing a skin disorder such as psoriasis or dermatitis, in a patient in need thereof comprising:

(i) identifying a patient who has received either a compound of formula (I) or a compound (B);

(ii) administering to said patient an effective amount of either at least one of at least one compound (B) as herein defined or at least one compound of formula (I) as herein before defined so that said patient is administered with both at least one compound of formula (I) and at least one compound (B).

In preferred embodiments, 1, 2 or 3 of compound B will be suitable for use withhe invention with 1 or 2 of compound B being preferred for many invention applications.

Viewed from another aspect the invention provides use of a pharmaceutical omposition as hereinbefore defined in the manufacture of a medicament for treating or reventing a skin disorder such as psoriasis or dermatitis. Viewed from another aspect the invention provides a process for the preparation of a pharmaceutical composition as hereinbefore defined comprising blending at least one compound of formula (I) or a pharmaceutically acceptable salt, or a hydrate or solvate thereof and at least one compound (B) or a pharmaceutically acceptable salt, or a hydrate or solvate thereof in the presence of at least one pharmaceutical excipient.

Definitions

The term lower alkyl is used herein to refer to C1 -6 alkyl groups, preferably C1 -4 alkyl groups, especially C1-3 alkyl groups. These alkyl groups can be linear or branched, preferably linear.

In one embodiment, the invention relates to a pharmaceutical composition in which at least one compound (I) and at least one folic acid partner (e.g. 1, 2, or 3 of such compounds) are blended together in a single composition. The invention also relates to a pharmaceutical composition in the form of a kit in which the active compounds are provided in separate compositions but are designed for administration simultaneously (in parallel), separately or sequentially. Any method for treating or preventing a skin disorder as defined herein encompasses simultaneous, in parallel, separate or sequential administration of the active components or administration of the composition of the invention.

The pharmaceutical composition of the invention is a "combination", which means either a fixed combination in one dosage unit form, or non fixed combination such as a kit of parts for combined adrninistration where at least one compound of the formula (I) and at least one folic acid partner (e.g. 1, 2 or 3 of such compounds) may be administered independently at the same time (e.g. in parallel) or separately within time intervals, especially where these time intervals allow that the combination partners show a cooperative and preferably a synergistic effect.

Thus a "pharmaceutical composition" as used herein means a product suitable for pharmaceutical use that results from the mixing, admixing or combining more than one active ingredient and includes both fixed and non-fixed combinations of the active ingredients. The term "fixed combination" or "fixed dose" means that the active ingredients, e.g. a compound of formula (I) and a folic acid partner such as methotrexate, are both administered to a patient simultaneously in the form of a single entity or dosage. The pharmaceutical composition can also be a "non-fixed combination" which means that the active ingredients, e.g. a compound of formula (I) and the combination partner are both administered to a patient as separate entities either simultaneously, in parallel, concurrently or sequentially with no specific time limits, wherein such adrninistration provides therapeutically effective levels of the two compounds in the body of the animal in need thereof.

The term folic acid partner as used herein means folic acid or a derivative of folic acid generally suitable for intended goals of the invention. Preferred partners include the following: methotrexate or aminopterin. Methotrexate and its pharmaceutically acceptable salts, hydrates and solvates thereof are especially preferred folic acid partners.

All discussion below relating to preferred compounds of the invention is equally applicable to both these aspects of the invention. Detailed Description

This invention concerns a combination therapy of at least compound of formula I) and at least one folic acid partner, in particular 1, 2 or 3 of such compounds with 1 or 2 compounds being preferred for many invention applications. In a preferred embodiment methotrexate or aminopterin or a salt, hydrate or solvate thereof is the folic acid partner. We have surprisingly found that this combination therapy results in synergy. Our results demonstrate a reduction in the proliferation and viability of HaCaT cells, the composition offering a larger decrease than could have been expected from the use of compoundsndividually, i.e. the combination of the compounds produces an overall effect that is greater than the sum of the individual elements.

Pharmaceutical Composition of the invention

The invention relies on the therapeutic combination of at least one compound of ormula (I) or a pharmaceutically acceptable salt, or a hydrate or solvate thereof and ateast one folic acid partner such as methotrexate. The compound of formula (I) is

wherein R is a C _10-24 unsaturated hydrocarbon group optionally interrupted by one or more heteroatoms or groups of heteroatoms selected from S, O, N, SO, SO ₂ , said hydrocarbon group comprising at least 4 non-conjugated double bonds;

L is a linking group forming a bridge of 1 to 5 atoms between the R group and the carbonyl CO wherein L comprises at least one heteroatom in the backbone of the linking group; and

X is an electron withdrawing group; or a pharmaceutically acceptable salt, or a hydrate or solvate thereof.

The group R preferably comprises 5 to 9 double bonds, preferably 5 or 8 double bonds, e.g. 5 to 7 double bonds such as 5 or 6 double bonds. These bonds should be non- conjugated. It is also preferred if the double bonds do not conjugate with the carbonyl functionality.

The double bonds present in the group R may be in the cis or trans configuration however, it is preferred if the majority of the double bonds present (i.e. at least 50%) are in the cis configuration. In further advantageous embodiments all the double bonds in the group R are in the cis configuration or all double bonds are in the cis configuration except the double bond nearest the carbonyl group which may be in the trans configuration.

The group R may have between 10 and 24 carbon atoms, preferably 12 to 20 carbon atoms, especially 17 to 19 carbon atoms.

Whilst the R group can be interrupted by at least one heteroatom or group of heteroatoms, this is not preferred and the R group backbone preferably contains only carbon atoms.

The R group may carry up to three substituents, e.g. selected from halo, Ci^ alkyl e.g. methyl, or Ci-6 alkoxy. If present, the substituents are preferably non-polar, and small, e.g. a methyl group. It is preferred however, if the R group remains unsubstituted.

The R group is preferably an alkylene group.

The R group is preferably linear. It preferably derives from a natural source such as a long chain fatty acid or ester. In particular, the R group may derive from AA, EPA or DHA. Thus, viewed from another aspect the invention employs a compound of formula

CD

wherein R is a C)o-24 unsubstituted unsaturated alkylene group said group comprising at least 4 non-conjugated double bonds;

L is a linking group forming a bridge of 1 to 5 atoms between the R group and the carbonyl CO wherein L comprises at least one heteroatom in the backbone of the linking group; and

X is an electron withdrawing group or a pharmaceutically acceptable salt, or a hydrate or solvate thereof.

Ideally R is linear. R is therefore preferably an unsaturated C 10-24 polyalkylene chain.

The linking group L provides a bridging group of 1 to 5 backbone atoms, preferably 2 to 4 backbone atoms between the R group and the carbonyl, such as 2 atoms. The atoms in the backbone of the linker may be carbon and/or be heteroatoms such as N, O, S, SO, SO ₂ . The atoms should not form part of a ring and the backbone atoms of the inking group can be substituted with side chains, e.g. with groups such as C^ alkyl, oxo, alkoxy, or halo.

Preferred components of the linking group are -C¾-, -CH(Ci^alkyl)-, -N(Ci. alkyl)-, -NH-, -S-, -0-, -CH=CH-, -CO- , -SO-, -S0 ₂ - which can be combined with each other in any (chemically meaningful) order to form the linking group. Thus, by using two methylene groups and an -S- group the linker -SCH ₂ CH ₂ - is formed. It will be appreciated that at least one component of the linker provides a heteroatom in the backbone.

The linking group L contains at least one heteroatom in the backbone. It is also preferred if the first backbone atom of the linking group attached to the R group is a heteroatom or group of heteroatoms.

It is highly preferred if the linking group L contains at least one -C¾- link in the backbone. Ideally the atoms of the linking group adjacent the carbonyl are

CH ₂ -. It is preferred that the group R or the group L (depending on the size of the L group) provides a heteroatom or group of heteroatoms positioned α, β, γ, or δ to the carbonyl, preferably β or γ to the carbonyl. Preferably the heteroatom is O, N or S or a sulphur derivative such as SO.

Highly preferred linking groups L therefore are -NH ₂ CH ₂ , -NH(Me)CH ₂ -, -SCH ₂ -,

-SOCH ₂ -, or -COCH ₂ -

The linking group should not comprise a ring.

Highly preferred linking groups L are SCH ₂ , NHCH ₂ , and N(Me)CH ₂ .

Viewed from another aspect the invention employs a compound of formula (II) wherein R is a linear C _10-24 unsubstituted unsaturated alkylene group said group comprising at least 4 non-conjugated double bonds;

and

X is an electron withdrawing group or a salt thereof.

The group X is an electron withdrawing group. Suitable groups in this regard includ ₂ wherein Hal

represents a halogen, e. g. fluorine, chlorine, bromine or iodine, preferably fluorine.

In a preferred embodiment the electron withdrawing group is CHal ₃ , especially

CF ₃ .

Thus, preferred compounds of formula (I) are those of formula (III)

More, preferred compounds of formula (I) are those of formula (TV) wherein R is a linear C _10-24 unsubstituted unsaturated alkylene group said comprising at least 4 non-conjugated double bonds;

X is as hereinbefore defined (e.g. CF ₃ ); and

Yl is selected from O, S, SO or SO ₂

Highly preferred compounds for use in the invention are depicted below.

where X is as hereinbefore defined such as CF ₃ .

The following compounds are highly preferred for use in the invention:

Salts, hydrates or solvates of any of these compounds could also be used. It will be appreciated that the pharmaceutical composition of the invention may comprise one or more than one compound of formula (I) as herein before defined, for example, 1 , 2 or 3 of such compounds with 1 or 2 of such compounds being preferred for many invention applications.

Compound (B)

The second component (compound B, i.e. the folic acid partner) of the composition of the invention is folic acid or the folic acid derivatives methotrexate or aminopterin or a pharmaceutically acceptable salt, or a hydrate or solvate thereof. Methotrexate is a compound of formula:

Aminopterin is depicted above. In any composition of the invention the folic acid partner may be present in a salt or non salt form. In particular, in any composition of the invention, the compound (B) such as methotrexate or arninopterin may be present in a salt or non-salt form. If a salt form is used, any conventional salt form is possible. The salt may be a monosalt form, or disalt form, given the presence of multiple hydroxy groups on which salts can be formed.

Methotrexate is a known commercial product and any known commercial form of methotrexate can be used, such as methotrexate sodium or methotrexate hydrate.

Arninopterin is a known commercial product and any known commercial form of methotrexate can be used arninopterin sodium.

The use of methotrexate or a salt thereof is especially preferred.

In one embodiment, the invention provides a composition comprising:

(A) a compound of formula (I):

or a salt thereof; and

(B) folic acid or derivative thereof selected from the group consisting of methotrexate, arninopterin or a pharmaceutically acceptable salt, or a hydrate or solvate hereof, especially arninopterin or methotrexate or a pharmaceutically acceptable salt, or a hydrate or solvate thereof, most especially methotrexate or a pharmaceutically acceptable salt, or a hydrate or solvate thereof.

Alternatively, the compositions of the invention could comprise methotrexate or arninopterin and additionally comprise further folic acid partners to augment the properties of the composition of the invention. Suitable additional folic acid partners nclude folic acid itself.

It is also within the scope of the invention to combine the composition of the nvention with other compounds conventionally used in conjunction with folic acid or derivatives thereof such as methotrexate. For example, compound (B) may be combined with cyclosporin, etanercept, alafacept, puvasol, acetretin or zinc sulphate.

The amounts of each compound present in the composition of the invention are determined in molar terms, and the ratio of each is preferably folic acid partner to compound of formula (I) of 10:1 to 1:10 moles, such as 5 : 1 to 1 :5 moles, or such as 3 : 1 to 1:1 moles.

The amount of the compounds of the invention in the composition will often be determined by the physician depending on the dosage required. Skin Disorders

As noted above, the invention targets skin disorders, especially psoriasis and dermatitis. In particular, it is envisaged that the composition of the invention can reduce inflammation and/or itchiness associated with the skin condition in question.

The combination therapy of the invention may have utility in treating a variety of different forms of dermatitis, such as atopic dermatitis or contact dermatitis. Thus, the compounds of the invention may be used to treat contact dermatitis such as allergic contact dermatitis or irritant contact dermatitis.

The nature of the allergan or irritant which causes the contact dermatitis can vary a lot and many people have different reactions to different allergans/irritants.

One of the most common causes of allergic contact dermatitis are plants of the Toxicodendron genus: poison ivy, poison oak, and poison sumac. Certain alkyl resorcinols such as bilobol found in Gingko biloba fruits are strong skin irritants.

Other allergens include nickel, gold, balsam of Peru (Myroxylon pereirae), and chromium.

Common causes of irritant contact dermatitis are harsh (highly alkaline) soaps, detergents, and cleaning products. Irritant contact dermatitis can be divided into forms caused by chemical irritants and those caused by physical irritants. Common chemical irritants implicated include solvents (alcohol, xylene, turpentine, esters, acetone, ketones, and others); metalworking fluids (neat oils, water-based metalworking fluids with surfactants); latex; kerosene; ethylene oxide; surfactants in topical medications and cosmetics (sodium lauryl sulfate); alkalis (drain cleaners, strong soap with lye residues). Physical irritant contact dermatitis may most commonly be caused by low humidity from air conditioning. Also, many plants directly irritate the skin.

A further form of contact dermatitis is photocontact dermatitis. The skin condition is caused by exposure to ultraviolet light (320-400 nm UVA).

The invention may also lead to a treatment of atopic dermatitis. Atopic dermatitis is a type of eczema and is an inflammatory, chronically relapsing, non-contagious and itchy skin disorder.

Other less common forms of dermatitis to be treated include dermatitis herpetiformis, seborrheic dermatitis and stasis dermatitis. The composition may also be used to treat eczema.

By treating or treatment is meant at least one of:

(i) . inhibiting the disease i.e. arresting, reducing or delaying the development of he disease or a relapse thereof or at least one clinical or subclinical symptom thereof, or

(ii) . relieving or attenuating one or more of the clinical or subclinical symptoms of he disease.

By prevention is meant (i) preventing or delaying the appearance of clinical symptoms of the disease developing in a mammal.

The benefit to a subject to be treated is either statistically significant or at least perceptible to the patient or to the physician. In general a skilled man can appreciate when "treatment" occurs. It is particularly preferred if the pharmaceutical compositions of the invention are used therapeutically, i.e. to treat a condition which has manifested ather than prophylactically. It may be that the pharmaceutical composition of the nvention is more effective when used therapeutically than prophylactically.

The pharmaceutical composition of the invention can be used on any animal ubject, in particular a mammal and more particularly a human or an animal serving as a model for a disease (e.g., rat, mouse, pig, monkey, etc.). For example, in one use a pharmaceutical composition of the invention is used as a positive control in the animal ubject to test other compounds for activity and/or side effects.

In order to treat a disease an effective amount of the active pharmaceutical omposition needs to be administered to a patient. A "therapeutically effective amount" means the amount of a pharmaceutical composition that, when administered to an animal or treating a state, disorder or condition, is sufficient to effect such treatment. The "therapeutically effective amount" will vary depending on the pharmaceutical composition, the disease and its severity and the age, weight, physical condition and responsiveness of the subject to be treated and will be ultimately at the discretion of the attendant doctor.

It may be that to treat skin disorders according to the invention that the pharmaceutical composition of the invention has to be readministered at certain intervals. Suitable dosage regimes can be prescribed by a physician.

The pharmaceutical composition of the invention typically comprises the active components in admixture with at least one pharmaceutically acceptable carrier selected with regard to the intended route of administration and standard pharmaceutical practice.

The term "carrier" refers to a diluent, excipient, and/or vehicle with which an active compound is administered. The pharmaceutical compositions of the invention may contain combinations of more than one carrier. Such pharmaceutical carriers are well known in the art. The pharmaceutical compositions may also comprise any suitable binders), lubricant(s), suspending agent(s), coating agent(s), and/or solubilizing agent(s) and so on. The pharmaceutical composition can also contain other active components, e.g. other drugs for the treatment of skin disorders.

It will be appreciated that pharmaceutical compositions for use in accordance with the present invention may be in the form of oral, parenteral, transdermal, sublingual, topical, implant, nasal, or enterally administered (or other muco sally administered) suspensions, capsules or tablets, which may be formulated in conventional manner using one or more pharmaceutically acceptable carriers or excipients. The pharmaceutical compositions of the invention could also be formulated as nanoparticle formulations.

However, for the treatment of skin disorders, the pharmaceutical composition of the invention will preferably be administered topically. The pharmaceutical composition may therefore be provided in the form of a cream, gel, foam, salve or ointment.

The pharmaceutical composition of the invention may contain from 0.01 to 99% weight - per volume of the active material. The therapeutic doses will generally be between about 10 and 2000 mg/day and preferably between about 30 and 1500 mg/day of active components combined. Other ranges may be used, including, for example, 50-500 mg day, 50-300 mg/day, 100-200 mg/day or active components combined. Administration may be once a day, twice a day, or more often, and may be decreased during a maintenance phase of the disease or disorder, e.g. once every second or third day instead of every day or twice a day. The dose and the administration frequency will depend on the clinical signs, which confirm maintenance of the remission phase, with the reduction or absence of at least one or more preferably more than one clinical signs of the acute phase known to the person skilled in the art.

The invention is described further below with reference to the following non- limiting examples and figures. Description of Figures:

Figure 1 :Co-treatment with cPLA2a inhibitor Compound Al and methotrexate shows synergistic effects on decreasing keratinocyte cell proliferation and viability compared to each inhibitor alone. Average and standard deviation of 2-4 independent experiments performed in series of 8 technical replicates per treatment

In Figure 2a to c, synergistic reduction of the proinflammatory mediators PGE2, TNF and IL-lb are observed when suboptimal concentrations of Compound Al (5 μΜ) and MTX (1 μΜ) is combined. (1x10 ⁶ PBMC, 72h stimulation with 10 ng/mL LPS.) A) PGE2, B) TNF, C) ILl-β.

Example 1

The following compounds were used in the Experiments:

Co-treatment Compound Al &M ethotrexate:

Methods:

Cell culture:

The spontaneously immortalized, nontumorigenic skin keratinocyte cell line HaCaT was maintained in DMEM supplemented with 5 % (v/v) FBS, 0.3 mg/ml glutamine and 0.1 mg/ml gentamicin at 37°C with S % CO ₂ in a humidified atmosphere. Subculture using trypsin-EDTA was performed every 3-4 days with split ratio of 1:3 - 1:4 to ensure actively proliferating cells. Resazurin Assay:

Cells were seeded in 96 well plates in fully supplemented medium at a density of 2S00 cells per well. Following 72 hours of cultivation, the cells were starved of serum in 0.25% FBS/DMEM overnight to halt proliferation, synchronize and to increase cell sensitivity to treatment. On day 4, the cells were treated with cPLA2a inhibitor Compound Al and folic acid analogue methotrexate hydrate (MTX)(Sigma Aldrich #A6770) and left to incubate for 2 hour in incubator at 37°C with 5 % C0 ₂ in a humidified atmosphere before fluorescence was read at 544 nm excitation and 590 nm emission wavelength. The cells were observed under the microscope to evaluate possible morphology changes and signs of stress before addition of resazurin. The experiments were performed in series of 8 wells per treatment and repeated 2-3 times.

Results:

Co-treatment with cPLA2a inhibitor Compound Al and folic acid analogue methotrexate hydrate shows synergistic effects on decreasing keratinocyte cell proliferation and viability compared to each inhibitor alone.

Following 24 hours of treatment, 10μΜ of MTX resulted in a modest reduction of -15% and 5μΜ Compound Al alone showed little or no effect on reducing proliferation and viability of HaCaT cells (fig 1). However, when combining sub-effective doses of Compound Al and MTX, a significant ~25% reduction of proliferation and viability was observed (Fig. 1). This observed trend of synergistic effects on cell proliferation and viability indicates beneficial effects of co-treatment of on skin disorders.

Example 2 PBMC isolation and experimentation:

Blood was recruited from healthy donors at St. Olavs Hospital HF, the Bloodbank. Peripheral blood mononuclear cells (PBMC) were isolated using SepMate™ separation tubes with LymphoPrep density gradient medium according to the STEMCELL Technology recommendations. For experiments, lxl 0 ⁶ cells/well/1 mL RPMI medium supplemented with 5%FBS, 0.3 mg/ml glutamine and 0.1 mg/ml gentamicin with or without inhibitors Compound Al, methotrexate hydrate (MTX) (Sigma-Aldrich, #A6770) or a combination of the two inhibitors, prior to the addition of lipopolysaccharides as a potent inducer of inflammation (LPS from E. coli 026:B6 γ-irradiated, Sigma-Aldrich, #L2654). Following treatment (72 hrs., 37°C, 5% C02), the cell suspensions were centrifuged to isolate the supernatant from the cell fraction. Samples were stored at -80°C until analysis.

Enzyme linked immunoassay detection of PGE2, TNF and ILl-β:

Cell supernatant samples were analyzed by enzyme-linked immunosorbent assay (EIA) for PGE2 (Cayman #514010), TNF and ILl-β (RnD Systems, DuoSet # DY210 and # DY201) according to the manufacturers protocols. Cell supernatants were assayed at dilutions 1:1 for TNF; 1:10 for ILl-β and 1:100 for PGE2, except supernatants from untreated PBMC (negative control) that were assayed undiluted in all assays. Supernatants were hybridized over-night incubation, enzymatic conversion of substrate were read at OD420 nm. Data were processed using a 4-parameter logistic fit model. Results:

Co-treatment with cPLA2a inhibitor Compound Al and folic acid analogue methotrexate hydrate shows synergistic effects on decreasing peripheral blood mononuclear cell production of the proinflammatory mediators PGE2, TNF and IL-Ιβ compared to eachnhibitor alone.

Following 72 hours of treatment, ΙμΜ of MTX and 5 μΜ of Compound Al both esulted in a reduction of -35-40% of LPS-induced PGE2 in PBMC. However, when ombining sub-effective doses of Compound Al and MTX, a ~80% reduction of PGE2evels was observed (Fig. 2A). For LPS-induced production of TNF, 1 μΜ of MTX educed TNF levels by ~20% whereas 5 μΜ of Compound Al had no effect at all. When ombining these doses of MTX and Compound Al, a reduction of -90% was observedFig. 2B). For IL-Ιβ, the same doses of MTX and Compound Al reduced the LPS- induced IL-lb levels by -20 % when given alone, but when given in combination a reduction of ~75% was observed (Fig. 2C).

This observed trend of synergistic effects on reducing several key proinflammatory mediators indicates beneficial effects of co-treatment of on skin disorders.

Several key pathways are dysregulated in skin disorders such as psoriasis and atopic dermatitis. With this preliminary result, cPLA2a inhibitors represent a promising adjuvant treatment to other drugs in treatment of the inflammation and itching caused by a number of skin conditions such as psoriasis and dermatitis.