Effect of the extract from salvia miltiorrhiza radix (SMR) on skeletal muscle ischemia and reperfusion injury in rabbits

Abstract

T he development of microsurgical techniques for replantation of amputated digits and limbs has led to longer periods of ischemia in the clinical setting. In addition, transplantation of skeletal muscle is employed to treat facial paralysis and Volkmann's ischemic contracture. To restore function to replanted extremities and transplanted muscle, not only should the ischemic period be shorter than that required for successful replantation and transplantation, but also reperfusion injury of skeletal muscle should be avoided. White cell inhibitors, enriched substrates and controlled rates of reperfusion, or combinations of these, have been shown to improve muscle viability and recover potentially viable muscle, oxygen and hydroxyl radical scavengers after prolonged ischemia and variable periods of reperfusion (1-4).Salvia miltiorrhizae radix (Chinese crude drug named 'danshen') has been used in China as a therapeutic modality for The extract of salvia miltiorrhiza radix (SMR) is a well known Chinese herbal medicine known as danshen. It has been found in several experimental studies, published mostly in China, to have antioxidant properties. The purpose of this experiment was, therefore, to compare the effects of danshen injection with those of superoxide dismutase (SOD) and mannitol on skeletal muscle ischemia and reperfusion injury in rabbits. The authors used a rabbit limb replantation model subjected to 5 h of global ischemia. Immediately before reperfusion, the animals received SOD (16,000 U/kg), mannitol (1 g/kg) or danshen injection (2 g/kg) intravenously. Both danshen and mannitol significantly increased limb survival (P<0.01). Increased limb survival was observed in the SOD-treated group compared with the saline-treated group (P<0.05) but not with the ischemic group (P>0.05). Light and transmission electron microscopy revealed that the pathologic and ultrastructural changes in skeletal muscles, which were subjected to 5 h of ischemia followed by 2 h of reperfusion, were reduced with SOD, mannitol and danshen injection. These results suggest that the hydroxyl radical seems to be the most important factor in ischemia and reperfusion injury to skeletal muscle and that danshen, like mannitol, may have a role in antioxidation as a hydroxyl radical scavenger. Key Words: Antioxidant, Ischemia/reperfusion injury, Rabbit, Salvia miltiorrhiza radixEffet d'un extrait de racine de salvia miltiorrhiza sur l'ischémie du muscle squelettique et la lésion de reperfusion chez le lapin RÉSUMÉ : L'extrait de racine de salvia miltiorrhiza est bien connu comme plante médicinale en Chine, sous le nom de danshen. Selon plusieurs études expérimentales publiées surtout en Chine, cette plante aurait des propriétés antioxydantes. Le but de l'expérience était donc de comparer les effets d'une injection de danshen à ceux de la superoxyde dismutase (SOD) et du mannitol sur l'ischémie du muscle squelettique et sur la lésion de reperfusion chez le lapin. Les auteurs ont utilisé un modèle de réimplantation de membre chez le lapin soumis à ...