RÉSUMÉ
<p><b>OBJECTIVE</b>To study effects of three pentacyclic triterpenoids, oleanolic acid (OA), ursolic acid (UA) and asiatic acid (AA) on Ca(2+)-induced liver mitochondrial permeability transition (MPT).</p><p><b>METHOD</b>Effects of three compounds on liver MPT induced by Ca2+ were assessed by measuring the change in mitochondrial swelling, mitochondrial membrane potential and release of matrix Ca2+ in vitro.</p><p><b>RESULT</b>Obvious mitochondrial swelling, loss of mitochondrial membrane potential and release of matrix Ca2+ occurred after the addition of 50 micromol x L(-1) Ca2+. However, preincubation with 50 mg x L(-1) OA, UA or AA significantly blocked the above changes. In addition, it was also found that there are differences in the inhibitions of three compounds on liver MPT induced by Ca2+.</p><p><b>CONCLUSION</b>Three pentacyclic triterpenoids, OA, UA and AA, have significant mitochondrial protection through blocking on liver MPT and the inhibition on liver MPT of AA is stronger than that of UA and OA.</p>