beta-Amyloid　protein　(A　beta),　a　major　protein　component　of　brain　senile　plaques　in　Alzheimer＇s　disease,　is　known　to　be　directly　responsible　for　the　production　of　reactive　oxygen　species　(ROS)　and　induction　of　apoptosis.　In　this　study,　the　protective　effect　of　puerarin,　an　isoflavone　purified　from　the　radix　of　the　Chinese　herb　Pueraria　lobata,　on　A　beta-induced　rat　pheochromocytoma　(PC12)　cultures　was　investigated.　Although　exposure　of　PC12　cells　to　50　mu　M　A　beta(25-35)　caused　significant　viability　loss　and　apoptotic　rate　increase,　pretreatment　of　the　cells　with　puerarin　for　24　h　reduced　the　viability　loss　and　apoptotic　rate.　Puerarin　(1　mu　M)　significantly　inhibited　A　beta(25-35)-induced　apoptosis　of　PC12　cells.　Preincubation　of　the　cell　with　puerarin　also　restored　the　ROS　and　mitochondrial　membrane　potential　levels　that　had　been　altered　as　a　result　of　A　beta(25-35)　treatment.　Puerarin　was　also　found　to　increase　the　Bcl-2/Bax　ratio　and　reduce　caspase-3　activation.　These　results　suggest　that　puerarin　could　attenuate　A　beta(25-35)-induced　PC12　cell　injure　and　apoptosis　and　could　also　promote　the　survival　of　PC12　cells.　Therefore,　puerarin　may　act　as　an　intracellular　ROS　scavenger,　and　its　antioxidant　properties　may　protect　against　A　beta(25-35)-induced　cell　injury.　(c)　2008　International　Federation　for　Cell　Biology.　Published　by　Elsevier　Ltd.　All　rights　reserved.