Use of 20-hydroxyecdysone and the derivatives thereof in the treatment of myopathies

1. A method of treatment of Duchenne muscular dystrophy (DMD) and/or Becker muscular dystrophy (BMD), comprising the step of administering to a subject in need thereof an effective amount of a compound selected from:

a) 20-hydroxyeedysone;

a compound of formula (II):

wherein:

R 1 is chosen from: a group (C 1 -C 6 )W(C 1 -C 6 ); a group (C 1 -C 6 )W(C 1 -C 6 )W(C 1 -C 6 ); a group (C 1 -C 6 )W(C 1 -C 6 )CO 2 (C 1 -C 6 ); a group (C 1 -C 6 )A, A representing a heterocycle optionally substituted by a group of the type OH, OMe, (C 1 -C 6 ), N(C 1 -C 6 ), CO 2 (C 1 -C 6 ); a CH 2 Br group;

W being a heteroatom chosen from N, O, and S; and a compound of formula (III):

2. The method according to claim 1 , wherein the Duchenne muscular dystrophy (DMD) and/or the Becker muscular dystrophy (BMD) induces an impairment of a muscle function.

3. The method according to claim 2 , wherein the muscle function is striated skeletal muscle function or myocardium function.

4. The method according to claim 2 , wherein the impairment is myocardial hypertrophy.

5. The method according to claim 2 , wherein the muscle function is at least in part impaired by a progressive onset of fibrosis.

6. The method according to claim 1 , wherein mitochondrial respiration of muscle cells is increased.

7. The method according to claim 1 , wherein a number of vessels per muscle fibre is increased.

8. The method according to claim 1 , wherein myoblast differentiation into myotubes is increased.

9. The method according to claim 1 , wherein the 20-hydroxyecdysone is a compound of formula (I):

10. The method according to claim 1 , wherein the 20-hydroxyecdysone is a plant extract, or an extract from a part of a plant, said plant being chosen from plants containing at least 0.5% 20-hydroxyecdysone of formula (I) in dry weight of said plant, said plant extract, or said extract from said part of said plant, comprising at least 95% 20-hydroxyecdysone of formula (I);

wherein the 20-hydroxyecdysone of formula (I) is:

11. The method according to claim 10 , wherein the extract comprises between 0 and 0.05%, in dry weight of the extract, of impurities liable to affect the safety, availability or efficacy of a pharmaceutical application of said extract.

12. The method according to claim 10 , wherein the plant is chosen from Stemmacantha carthamoides, Cyanotis arachnoidea and Cyanotis vaga.

13. The method according to claim 1 , wherein the 20-hydroxyecdysone is a Stemmacantha carthamoides root extract comprising at least 95% 20-hydroxyecdysone of formula (I).

14. The method according to claim 1 , wherein in the compound of formula (II):

R 1 is chosen from: a group (C 1 -C 6 )W(C 1 -C 6 ); a group (C 1 -C 6 )W(C 1 -C 6 )W(C 1 -C 6 ); a group (C 1 -C 6 )W(C 1 -C 6 )CO 2 (C 1 -C 6 ); a group (C 1 -C 6 )A, A representing a heterocycle optionally substituted by a group of the type OH, OMe, (C 1 -C 6 ), N(C 1 -C 6 ), CO 2 (C 1 -C 6 ),

W being a heteroatom chosen from N, O and S.

15. The method according to claim 1 , wherein the compound of formula (II) is chosen from:

No. 1: (2S,3R,5R,10R,13R,14S,17S)-2,3,14-trihydroxy-10,13-dimethyl-17-(2-morpholinoacetyl)-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one;

No. 2: (2S,3R,5R,10R,13R,14S,17S)-2,3,14-trihydroxy-17-[2-(3-hydroxypyrrolidin-1-yl)acetyl]-10,13-dimethyl-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one;

No. 3: (2S,3R,5R,10R,13R,14S,17S)-2,3,14-trihydroxy-17-[2-(4-hydroxy-1-piperidyl)acetyl]-10,13-dimethyl-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one;

No. 4: (2S,3R,5R,10R,13R,14S,17S)-2,3,14-trihydroxy-17-[2-[4-(2-hydroxyethyl)-1-piperidyflacetyl]-10,13-dimethyl-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one;

No. 5: (2S,3R,5R,10R,13R,14S,17S)-17-[2-(3-dimethylaminopropyl(methyl)amino)acetyl]-2,3,14-trihydroxy-10,13-dimethyl-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one;

No. 6: 2-[2-oxo-2-[(2S,3R,5R,10R,13R,14S,17S)-2,3,14-trihydroxy-10,13-dimethyl-6-oxo-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-l′17-yl[ethyl]ethyl sulfanylacetate;

No. 7: (2S,3R,5R,10R,13R,14S,17S)-17-(2-ethylsulfanylacetyl)-2,3,14-trihydroxy-10,13-dimethyl-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one; and

No. 8: (2S,3R,5R,10R,13R,14S,17S)-2,3,14-trihydroxy-17-[2-(2-hydroxyethylsulfanyl)acetyl]-10,13-dimethyl-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one.

16. The method according to claim 10 , wherein said plant extract, or said extract from said part of said plant, comprises at least 97% 20-hydroxyecdysone of formula (I).

17. The method according to claim 13 , wherein the Stemmacantha carthamoides root extract comprises at least 97% 20-hydroxyecdysone of formula (I).