Antioxidants prevented oxidative injury of SR induced by Fe²⁺/H₂O₂/ascorbate system but failed to prevent Ca²⁺‐ATPase activity decrease

Abstract

Dysfunction of sarcoplasmic reticulum (SR) Ca2+-ATPase induced by oxidative stress may be a contributing factor to the development of serious age related diseases. Incubation of sarcoplasmic reticulum (SR) vesicles of rabbit skeletal muscles with Fe2+/H2O2/ascorbate decreased the SH group content of SR approximately to 35% and Ca2+-ATPase activity to 50% of control not oxidized sample. Protein carbonyls increased twofold, lipid peroxidation was also significantly elevated. The antioxidant effects of trolox, the pyridoindole derivative stobadine and of the standardized extracts from bark of Pinus Pinaster PycnogenolR (Pyc) and from leaves of Ginkgo biloba (EGb 761) were studied on oxidatively injured SR. All antioxidants exerted preventive effects against the oxidized lipids and protein SH groups of SR vesicles. Trolox and stobadine did not influence protein carbonyl formation, while flavonoid extracts prevented carbonyl generation, probably by binding to protein. The preventive effects of the antioxidants studied on lipids and protein SH groups were however not associated with protection of Ca2+-ATPase activity. Stobadine and trolox exerted no effect on enzyme activity, Pyc and EGb 761 enhanced the inhibitory effect of Ca2+-ATPase activity in oxidatively injured SR. Concluding, under the conditions of oxidative stress induced by Fe2+/H2O2/ascorbate against SR of rabbit skeletal muscle, the agents studied demonstrated antioxidant effects yet failed to protect Ca2+-ATPase activity.

Italian consensus conference on guidelines for conservative treatment on lower limb muscle injuries in athlete

“… 9 11–15 Furthermore, the significance of overlapping mechanical causes 11–18 and metabolic pathways was discussed. 19–21 The importance of the calcium overload stage and the consequent self-aggravation of the lesion in the immediate postinjury period was stressed. 21–23 Finally, the importance of the role of stem cells (SC) in skeletal muscle repair and regeneration processes was also discussed 24–29 and, in agreement with other studies, 28 29 the use of stem cells as treatment for MIs was disapproved because scientific evidence does not confirm its effectiveness and safety.…”