FR2705030A1 - Use of sterol compounds for the production of an anti-inflammatory medicament - Google Patents

Abstract

The invention relates to the use of a sterol compound, chosen from derivatives or precursors of cholesterol and of cholestane, comprising plant sterols, for the production of an anti-inflammatory medicament.

Description

 The invention relates to the use of a sterol compound chosen from the derivatives or precursors of cholesterol and cholestane, including plant sterols, as anti-inflammatory.

 The importance of interactions between cholesterol and lipids at air-water interfaces has been described by F. VILALLONGA and his collaborators in Biochim. Biophys. Acta, vol. 135, p. 557-559 (1967).

The influence of these interactions in the structure of some biological membranes has been demonstrated by CA ROTUNNO et al. in "The structure of membrane in introduction to study of biological membranes" (GORDON and BREACH, Science Publishers, New
York, p. 7-48). JB FINEAN suggested the formation of a stable complex between cholesterol molecules and the fatty acid part of phospholipids or cerebrosides, which he described in "Experientia" vol. 9, p. 17-19 (1953).

Previous research has been done on the interactions between unsaturated fatty acids and cholesterol, but none of them report the inhibition of lipoxygenation of fatty acids by cholesterol or other sterols. The results of this research are presented in the following publications
E. LUND, U. DICZFALUSY, I. BJORKHEM (1992) J. Biol. Chem.

Flight. 267, p. 12462-12467 1.1. TENG, LL SMITH (1976), Bioorg. Chem., Vol. 5, p. 99-119
II TENG, LL SMITH (1973), J. Arn. Chem. Soc., Vol 95, p. 4060-4061.

 It has now been discovered that sterol compounds selected from cholesterol and cholestane derivatives or precursors can act as inhibitors of lipoxygenase by preventing the dioxygenation of fatty acids normally catalyzed by this enzyme.

 The inventors believe that the inhibitory activity of these compounds results from the formation of a complex between the fatty acid, substrate of the enzyme, and the said compound. They found that lipoxygenase did not recognize the complexed fatty acid and therefore was unable to catalyze its oxidation.

 This property confers on the compounds used according to the invention an anti-inflammatory activity, given the known pro-inflammatory action of the lipoxygenase derivatives.

 The invention therefore relates to the use of sterol compounds selected from the derivatives or precursors of cholesterol and cholestane, including plant sterols, for the formation of an anti-inflammatory drug. Examples of precursors and derivatives of said sterols are unsaturated or hydroxylated derivatives or precursors.

 A first group of preferred sterol compounds comprises all sterol-derived sterol nucleus molecules selected from cholesterol and cholestane, not carrying a hydroxyl group at the sterol nucleus, with the exception of hydroxyl at position 3p. or of a hydroxyl group at the side chain grafted at 17.

 A second group of preferred compounds are Sa-cholestane, 7-oxo-cholesterol, 3,5-cholestadiene, cholesterol acetate, 19-hydroxycholesterol, 5p-cholestane, cholesterol and 5- Cholestene.

 Of these compounds, Sa-cholestane, 7-oxo-cholesterol, 3,5-cholestadiene, 19-hydroxy-cholesterol, and cholesterol acetate are particularly preferred.

 These compounds are commercially available or readily prepared by those skilled in the art using known methods.

 The medicament used according to the invention may in particular be in a form suitable for external use, for example in the form of cream, milk, gel, ointment, solution or in liposomal form.

 It may contain as active ingredient one or more steric compounds chosen from the derivatives or precursors of cholesterol and cholestane, in combination with a pharmaceutically acceptable vehicle, such as excipients, perfumes, dyes and surfactants.

 The sterols according to the invention inhibit the enzymatic activity of lipoxygenase, by formation of a complex between the sterol or precursor compound, and the fatty acid, substrate of the enzyme. The compounds used according to the invention are intended to combat all forms of inflammation encountered in mammals. They find their application in the pharmaceutical field.

 Biological test results for the purpose of determining the inhibition of lipoxygenase are given below.

 Inhibition of lipoxygenase has been demonstrated in vitro by studying the kinetics of inhibition of linoleic acid oxidation by various sterol compounds derived from cholesterol or cholestane, in the presence of lipoxygenase-1 extracted from soybean.

 This lipoxygenase is stable and commercially available. It represents a good model of lipoxygenase of animal origin since it contains many amino acid sequences similar to those found in animal lipoxygenases.

 Measurements of the absorbance of the linoleic acid oxidation products in U.V. absorption spectrometry made it possible to follow the kinetics of inhibition of the oxidation reaction.

 The test method was as follows.

 In 3 ml of a potassium phosphate buffer solution (at pH = 7.4), 100 WM of linoleic acid and an equimolar amount of the compound of which it is desired to measure the inhibitory activity, as well as 12 g of lipoxygenase- 1 extracted from soy. The buffer solution makes it possible, by fixing the pH of the solution, to reproduce the physico-chemical conditions encountered in vivo in mammals.

 The variation of the U.V. absorption of the resulting solution was studied at 235 mm as a function of time and compared with that of a sample containing no compounds used according to the invention.

 The inhibition percentages were recorded after 5 minutes for a number of compounds selected from cholesterol and cholestane derivatives.

Table I summarizes all the results obtained

<tb> Test <SEP> Compound <SEP> tested <SEP> Percentage
<tb><SEP> inhibition
<tb><SEP> 1 <SEP> Sa-Cholestane <SEP> 24
<tb><SEP> 2 <SEP> 7-oxo-cholesterol <SEP> 43
<tb><SEP> 3 <SEP> 3,5-cholestadiene <SEP> 41
<tb><SEP> 4 <SEP> acetate <SEP> of <SEP> cholesterol <SEP> 41
<tb><SEP> 5 <SEP> 19-hydroxy-cholesterol <SEP> 34
<tb><SEP> 6 <SEP> 5-cholestene <SEP> 17
<tb><SEP> 7 <SEP> SP-cholestane <SEP> 22
<tb><SEP> 8 <SEP> cholesterol <SEP> 20
<Tb>

Claims (7)

 1. Use of a sterol compound selected from the derivatives or precursors of cholesterol and cholestane, including plant sterols, for the manufacture of an anti-inflammatory drug.  2. Use of a compound according to claim 1, said compound being a sterol nucleus molecule having no hydroxyl group at the sterol nucleus, with the exception of the hydroxyl at position 3p, nor of hydroxyl group at the of the side chain grafted at 17.  3. Use of a compound according to claim 1, wherein said compound is selected from Sa-cholestane, 7-oxo-cholesterol, 3,5-cholestadiene, cholesterol acetate, 19-hydroxy-cholesterol .  4. Use of a compound according to claim 1, said compound being selected from 5p-cholestane, cholesterol and 5-cholestene.  5. Use of a compound according to any one of claims 1 to 4 in association with a pharmaceutically acceptable carrier.  6. Use of a compound according to any one of claims 1 to 4 for the manufacture of a medicament for external use.  7. Use of a compound according to any one of claims 1 to 4 for the manufacture of a medicament in the form of cream, milk, gel, ointment or solution, or in liposomal form.