Estudo preliminar do BN 82270 no tratamento da distrofia muscular experimental (18/03/2006)
Itália – BN 82270 é uma nova molécula formada da união de duas outras e que apresenta dois mecanismos de ação importantes para o tratamento da distrofia muscular; a droga tem efeito antioxidante e inibidor da calpaína. O estudo desta droga demonstrou claramente efeitos benéficos com redução da CK, redução da citocina pró-fibrótica TGF-beta 1. O efeito positivo não foi uniforme em todos os músculos e os pesquisadores deste grupo liderado por Annamaria de Lucca ainda estão estudando em camundongos a dose que poderia oferecer melhores resultados sem efeitos colaterais tóxicos para o organismo. O resumo em inglês deste artigo que será publicado em breve na revista Neuromuscular Disorders pode ser lido abaixo:
First evaluation of the potential effectiveness in muscular dystrophy of a novel chimeric compound, BN 82270, acting as calpain-inhibitor and anti-oxidant
Rosa Burdi, Maria Paola Didonna, Bernadette Pignol, Beatrice Nico, Domenica Mangieri , Jean-Francois Rolland, Claudia Camerino, Alberta Zallone , Paolo Ferro , Francesca Andreetta, Paolo Confalonieri, Annamaria De Luca – Italy
BN 82270 is a membrane-permeable prodrug of a chimeric compound (BN 82204) dually acting as calpain inhibitor and anti-oxidant. Acute in vivo injection of dystrophic mdx mice (30 mg/kg, s.c.) fully counteracted calpain overactivity in diaphragm. A chronic 4–6 weeks administration significantly prevented in vivo the fore limb force drop occurring in mdx mice exercised on treadmill. Ex vivo electrophysiological recordings showed that BN 82270 treatment contrasted the decrease in chloride channel function (gCl) in diaphragm, an index of spontaneous degeneration, while it was less effective on both exercise-impaired gCl and calcium-dependent mechanical threshold of the hind limb extensor digitorum longus (EDL) muscle fibres. The BN 82270 treated mdx mice showed a marked reduction of plasma creatine kinase and of the pro-fibrotic cytokine TGF-b1 in both hind limb muscles and diaphragm; however, the histopathological profile of gastrocnemious muscle was poorly ameliorated. In hind limb muscles of treated mice, the active form was detected by HPLC in the low therapeutic concentration range. In vitro exposure to 100 mM BN 82270 led to higher active form in diaphragm than in EDL muscle. This is the first demonstration that this class of chimeric compounds, dually targeting pathology-related events, exerts beneficial effects in muscular dystrophy. The drug/prodrug system may require posology adjustment to produce wider beneficial effects on all muscle types.
