Neuroprotective properties of catalpol in transient global cerebral ischemia in gerbils: dose-response, therapeutic time-window and long-term efficacy.

The present study evaluated for the first time the dose-effectiveness, therapeutic time-window and long-term efficacy of the neuroprotection of catalpol by behavioral and histological measures in gerbils subjected to transient global cerebral ischemia. Catalpol (1 mg/kg ip) used immediately after reperfusion and repeatedly at 12, 24, 48 and 72 h significantly rescued neurons in the hippocampal CA1 subfield and reduced cognitive impairment. The neuroprotective efficacy of catalpol became more evident at the doses of 5 and 10 mg/kg. Of great importance were the findings that the neuroprotective efficacy of catalpol still could be seen even when the treatment was delayed 3 h and when the observational period was lasted out 35 days after ischemia. It was reasonable to draw the conclusion that catalpol was truly neuroprotective rather than simply delayed the onset of neuronal damage. These results suggested that catalpol might be of therapeutic value for global cerebral ischemia.