Presenr invention concern aroma-ic aldehydes and derivatives thereof, which are useful for the treatment of diseases which arise due to an elevated cellular proliferation (i.e. the rapid and repeated reproduction by cell division) , such as psoriasis, inflammatory diseases, rheumatic diseases and allergic deππatologic reactions.

Psoriasis, for example, is a dermatologic disease which is characterized by rapid turnover of the epidermis. In addition patients suffering from psoriasis may also suffer from auto¬ immune and rheumatic diseases, such as for instance lupus and arthritis. Presently, psoriasis is treated with hydrocortison derivatives, ditranole, tar salve cr, in serious cases, with immuno-depressants such as cytostatica, cycloεporinε or the like. All these treatments give rise to unwanted secondary effects.

It has now according to present invention been found that compounds, previously known as anti-cancer agents may be used for combatting diseases resulting from an abnormally elevated cell proliferation.

The compounds according to present invention are aromatic benzaldehydes or derivatives thereof of the following formula (I) :

Ar - C - (I)

X-

wherein Y is H or D; wherein X^ and X ₂ may be the same or different and may be OR,

SR, NRτ_R _2r whereby R, R ₁ and R ₂ may be H or an alkyl of 1-5

C-atoms; or Xτ_ and X ₂ may together with the C-atom to which they are bound constitute a C=0 group or a cyclic acetal

(20) , thioacetal (0,S) , dithiane (2S) , aminale (2N) , oxazoli- dine (0,N) or thiazolidine (N,S) ;

wherein Ar is phenyl which may be unsubstituted or sub¬ stituted in one or several positions by one or more of the following substituents which may be alkyl with 1-5 C-atoms, cycloalkyl of 3-6 C-atomε, halogen, nitro, amino, monoalkyl- amino or dialkylamino, wherein the alkylgroups have 1-5 C- atoms, OR wherein R may be H or an alkylgroup of l-5C-aton.s; or pharmaceutically acceptable salts thereof.

The alkyl groups herein may be straight-chained or branched, and especially preferred are methyl, ethyl, propyl and t- butyl. The halogens may be any of chlorine, bromine, fluorine and iodine.

The pharmaceutically acceptable salts may be alkali metal salts, such as sodium salts, earth alkali metal salts, such as magnesium or calsium salts, ammoniumsaltε, salts with organic a inobases or the like.

Some of the compounds according to present invention are known as anticancer agents among other from EP215395, J63264411, J88009490, J55069510 and EP283139.

From the prior art it is known that the administration of compounds of formula I at a high dosage over a prolonged periode of time becomes lethal to cancer cells. The compounds of formula I have an inhibitory effect on the synthesis cf proteins within the cells. For cancer cells, the rate cf protein accumulation is so low that the shortage of vital

proteins induced by treatment with compounds cf formula _. will lead to cell death.

It has now been found that these compounds also exert an effect on cells having an abnormally elevated cellular proli¬ feration rate, and thus according to present invention the compounds of formula I may be used for the treatment of diseases such as psoriasis, inflammatory diseases, rheumatic diseases and allergic dermatologic reactions.

Dermatologic abnormalities such as psoriasis are often char¬ acterized by rapid turnover of the epidermis. While normal skin produces ca. 1250 new cells/day/cm ² of skin consisting of about 27,000 cells, psoriatic skin produces 35,000 new cells/day/cm ² from 52,000 cells. The cells involved in these diseases are however "normal" cells reproducing rapidly and repeatedly by cell division. While the cell cycle of normal skin cellε iε approximately 311 hours, this progression through the division cycle is reduced to about 10 to 36 hours for psoriatic skin.

It is known that benzaldehydes and certain acetal derivatives therof have a growth-inhibitory effect on human cellε which is by its nature reversible. Growth inhibition induced by these compounds is primarily due to a reduction in the prc- tein syntheεis by cells. (Pettersen et al . , Eur.J.Clin. Oncolo. 19, 935-940 (1983) and Cancer Res. 4_5, 2085-2091 (1985)). The inhibition of protein synthesis iε only effec¬ tive as long as these agents are present in the cellular microenvironment. The synthesis of cellular protein iε, for instance, rapidly restored to its normal level within one hour from the time when the agent is removed from the cells.

This leads to the surprising effect that the normal cellε are left without damage after treatment with the compounds ac¬ cording to formula I. Furthermore, the inhibition cf protein synthesis achieved induces a prolonged cell cycle duration

such that a reduction of the cell production as well as a reduction of protein synthesis iε achieved during treatment. Therefore diseases for which the symptomatic cause is an enhanced cell proliferation rate can be treated with the compounds of formula I without this leading to cell death - a condition unwanted since the cells involved are normal cells with an abnormal cell proliferation rate.

Examples of diseaseε which may be treated by the compounάε cf formula I are rheumatoid arthritiε, psoriatic arthritis, systemic lupus erythematosuε (SLE) , diεcoid lupus erythemato- sus (DLE) , acne, Bechterew's arthritis, systemic selerodema and seborrhea.

In the following in vitro experiments it iε shown that a representative of the compounds of formula I, Zilaεcorb( ² H ■ , haε a protein εyntheεis inhibitory effect en cellε with a short cell cycle time (Table 1) , which effect is reverεibie (Table 2) and surprisingly leaves the cells unharmed after treatment. The protein εyntheεiε inhibition further induces a median cell division delay (Table 3) . It is also shown that other compounds of formula I have a protein inhibitory effect (Table 4) , which will lead to the corresponding cell divisio delay as shown in Tables 1-3.

BIOLOGICAL MATERIALS AND METHODS USED TO DEMONSTRATE THE EFFECT

In the following ^' biological experiments, the compound used is 5,6-O-benzylidene-L-ascorbic acid-d^ (Zilascorb[ ² K] ) cf formula II

Cell Culturing Techniques and synchronization

Human cells of the established line NHIK 3025, originating from a cervical carcinoma in situ (Nordbye, K. and Oftebro, R. , Exp. Cell Res., 58: 458, 1969), Oftebro, R. and Nordbye, K. , Exp. Cell Res., 58: 459-460, 1969) were cultivated in medium E2a (Puck et al., J. Exp. Med. , 106: 145-165, 1957) supplemented with 20% human (prepared at the laboratory) and 10% horse serum (Grand Island Biological Co.).

These cells were considered relevant for the present studies since they are of an epithelial type having a relatively short cell cycle time and lacking some malignant characteris¬ tics such as tumor formation in nude mice.

The cells are routinely grown as monolayers in tissue culture flasks. The cells do not move around after they have at¬ tached, a quality which enables us to observe the same cells in an inverted microscope for several cell generations. The cells were kept in continuous exponential growth by frequent reculturing, i.e. every second and third day, and were obtained by repeated selection of mitotic cellε (Pettersen et al., Cell Tissue Kinet., 10: 511-522, 1977). During the synchronization procedure the cells were kept in medium E2a, and the whole experiment took place in a walk-ir. incubator at 37°C. Under growth conditions as uεed here, the NHIK 3025 cells have a medium cell-cycle time of -18 hr, with median G^, S^ _^ and G ₂ durations of -7, -8 and -2.5 hr, res¬ pectively.

Duration of cell cycle-time (Table 3) :

For detection of the drug effects on cell-cycle kinetics, the same methods were used as described previously (Lindmo, T. and Pettersen, E.O. , Cell Tissue Kinet., 12: 43-57, 1979; Pettersen et al., Eur. J. Cancer Clin. Oncol., 19: 507-514, 1983; Rβnning et al., J. Cell. Physioi., 109: 411-419, 1981).

Briefly, the selected mitotic cells were seeded into 8 tissue culture flasks (25 sq cm) , 5000 cells per flask. The cells divided within 1 hr and attached as doublets to the bottom cf the flasks. The cells within a delineated area of the flask (100 cells) were observed repeatedly in an inverted micro¬ scope, and the time of entrance into mitosis, as well as the time of division, were noted for each separate cell.

Protein Synthesis:

The rate of protein synthesis was calculated as described previously (Ronning et al., J. Cell Physiol., 107: 47-57, 1981) . Briefly, cellular protein was labeled to saturatior. during a 2-day preincubation with [ ¹⁴ C]valine of constant specific radioactivity (0.5 Ci/mol) prior to the experiment. This was achieved by using a high concentration of valine so that the dilution of [ ¹⁴ C]valine by intracellular valine and by proteolytically generated valine will be negligible (Ronning et al., Exp. Cell Res., 123: 63-72, 1979) , thus keeping the specific radioactivity at a constant level. The rate of protein synthesis was calculated from the incorpora¬ tion of [ ³ H]valine of constant specific activity. The incor¬ porated measurements were related to the total of [ ¹ C] radioactivity in protein at the beginning of the respective measurement periods and expressed as percentage per hr (Rønning et al., J. Cell. Physiol., 107: 47-57, 1981) .

Results

The primary effect on protein synthesis of human NKIK 3025 cells by Zilascorb( ² H) is shown in table 1. A drug dose of 0.5 mM is sufficient to reduce protein synthesis from about 3.7 %/h to about 2.4 %/h and higher doses strengthens the inhibition.

Data:

Table 1 .

Rate of protein synthesis during the first hour of treatment with Zilascorb( ² H)

concentration (mM) ps (%/H)

0 (control) 3.68 r 0.08

0.5 2.36 r 0.16

1.0 1.73 - 0.06

1.5 1.38 r 0.02

2.0 1.40 ± 0.08

3.0 1.21 ± 0.11

In table 2 the reversibility of the protein synthesis inhibi¬ tion is illustrated. The cells were treated with a dose of 2 mM Zilascorb( ² H) for up to 3 h before Zilascorb( ² H) was removed. During treatment protein εynthesis was 1.2 - 1.4 %/h as compared to 4.41 %/h in the control. After removal of Z ⁱ lascorb( H) _t protein synthesiε increased rapidly back to the control level.

Table 2 .

Rate of protein synthesis of 2 mM Zilascorb( ² H) during a 3 ; treatment and during the first 2 h after removal of the age:

Time interval * PS (%/h)

Control 4.41 ± 0.08

0-1 h during treatment 1.40 ± 0.08

1-2 h " " 1.21 Q.11

2-3 h " " 1.32 ± 0.02

3-4 h after removal 2.57 r 0.06

4-5 h " " 4.32 ± 0.08

* Measurement waε performed by incorporation of ³ κ- -valine during 1 h pulses indicated by start ana end time points. The time when Zilascorb( ² H) waε added waε taken as time zero.

To get a more detailed study concerning the degree cf damage to the cells after a limited Zilascorb( ² H) , treatment NHIK 3025 cells were synchronized and an 8 h treatment with 1 m

Zilascor ( ² H) was given in the Gl- to early S-phases cf the cell cycle. Thereafter the time of cell division was record¬ ed.

Table 3.

The median cell division delay induced by 8 h treatment of synchronized cells with 1 mM Zilascorb( ² H) . Treatment waε started when the cells were in early Gl-phase.

Zilascorb( ² H) Median cell cycle treatment duration

Control 18.5 h

1 mM for 8 h in Gl 25.0 h

From table 3 the division delay was 6.5 h.

By flow cytometric recordings of DNA-histogra ε of the trea¬ ted cells it was found that initiation of DNA synthesis waε delayed in these cellε as compared to control cellε by about 6 h. Thus, as the treated cells progresεed through S and G2 , i.e. after Zilascorb ( ² H) was removed, the rate of progress was almost similar to that cf the untreated control.

The data of table 3 should be evaluated on baεiε of those cf table 1 shoving that 1 mM Zilascorb( ² H) reduces protein synthesis to 1.73 %/h from 3.68 %/h which was the protein synthesis in the control. Since NHIK 3025 cells usually have a protein degradation just above 1 %/h, net protein accumula¬ tion iε not more than 0.7 %/h in the treated cellε during treatment. Thus, during treatment the protein doubling time is

τ _D = in ² . = 99

0.007

Since the protein doubling time of these cells is normally about 18 h one can conclude that the rate of protein accumu¬ lation during treatment waε reduced to about 18% of that cf the control. Our previous studies have shown that a primary

protein synthesis inhibition reduces the cell cycle progres¬ sion in all phases of the cell cycle to the same extent as the reduction in protein accumulation (i.e. the cell cycle time equals the protein doubling time) (see Rønning et al. , J. Cell Physiol. 109. 411-418 (1981)). Therefore one must expect that the cell-cycle delay induced by an 8 h treatment with 1 mM Zilascorb( ² H) _WO uld be about 8 h - ₁ .5 (i.e. 18% of 8h) = 6.5 h which is exactly what we found. Since this delay is induced during treatment, and no extra delay iε accumu¬ lated after treatment, the cell cycle inhibition as induced by this agent is reversible.

Generally cell cycle progression is a sensitive parameter which is easily disturbed by various types of cell damage. Since this parameter is left completely undisturbed after an 8 h treatment with such a high concentration of Zilascorb( ² H) , that it was sufficient to stop cell cycling almost completely during treatment, it iε judged to be a strong evidence that the cells are unharmed by the treatment. It is, therefore, not probable that the treatment has induced any damage even of sublethal nature.

Table 4

Examples of other compounds of formula I inducing protein synthesis inhibition

Measurement was performed in human NHIK 3025 cellε during the first hour after addition of the compound of formula I to the cells:

Drug Formula Cone. (mM) Rate of protein synthesis % of control

Niiro-BΛSS-d,

-F-ba-d- ° 2.0 -U.j±2.0

F

The compounds may according to the present invention be ad inistrered in any pharmaceutical formulation suitable for topical or systemic therapy.

The pharmaceutical preparations may be administrered enteral- ly, parenterally or topically.

When administrered enterally, the compounds cf formula I may be formulated e.g. as soft or hard gelatine capsules, tab¬ lets, granules, grains or powders, drageeε, εyrupε, suspen¬ sions, solutions or suppositorieε.

When adminiεtrered parentally, preparations of the compounds of formula I as injection or infusion solutions are suitable.

When administrered topically the compounds of formula I may be formulated as a lotion, salve, ointment, cream, gel, tinc¬ ture, spray, lotion or the like containing the compounds of formula I in admixture with non-toxic, inert, solid or liquid carriers which are usual in topical preparations. It iε especially suitable to use a formulation which protects the active ingredient against air, water and the like.

The preparations can contain inert or pharmacodynamically active additives. Tablets or granulates e.g. can contain a series of binding agents, filler materials, carrier sub¬ stances or diluents. Liquid preparations may be present, for example, in the form of a sterile solution. Capsules can contain a filler material or thickening agent in addition to the active ingredient. Furthermore, flavour-improving addi¬ tives as well as the substances usually used as preserving, stabilizing, moisture-retaining and emulsifying agents, salts for varying the osmotic pressure, buffers and other additives may also be present.

The dosages in which the preparations are administered can vary according to the mode of use and the route of use, as well as to the requirements of the patient. In general a daily dosage for a systemic therapy for an adult average patient of 70 kg body weight will be about 0.1-50 mg/kg/day preferably 1-15 mg/kg/day. For topic administration, the suitable salve or ointment can contain from 0.1-20% by weight of the active ingredient, especially 1-5%.

The proportion of active ingredient in the pharmaceutical composition will vary depending upon the type of preparation, but may generally be within the range of approximately 0.1 to 20% by weight for oral administration and for absorption through mucous membranes, and about 0.01 to 10% by weight for parenteral administration.

If desired the pharmaceutical preparation of the compound cf formula I can contain an antioxidant, e.r. tocopherol, N- methyl-tocopheramine, butylated hydroxyanisole, ascorbic acid or butylated hydroxytoluene.