Effect of olibanum on a rat model of Alzheimer's disease induced by intracerebroventricular injection of streptozotocin

Olibanum improves memory in different models of learning. However, the effect of olibanum on models of Alzheimer’s disease has been less studied. In the present study, the effect of olibanum on memory in normal rats and in a rat model of Alzheimer disease induced by intracerebroventricular injections of streptozotocin was evaluated. Rats received an aqueous extract of olibanum (50, 100 and 300 mg/kg) via gavage, acutely 30 minutes before the test and chronically for 21 consecutive days before assessment of memory racall. In two other groups of animals, two guide cannulas were inserted into the lateral ventricles under stereotaxic surgery. One group received bilateral injections of streptozotocin (1.5 mg/kg/2 μl/side) in the first and third days of surgery. The other group received artificial cerebrospinal fluid. Fourteen days after surgery, learning was evaluated. Two other groups of animals received olibanum (50 mg/kg) or its solvent, for 21 days beginning from one week before injections of streptozotocin. Acute administration of olibanum did not affect learning parameters, but chronic administration of it (50 mg/kg) improved memory retrieval. Streptozotocin increased number of necessary stimulations for induction of short term memory, but decreased step through latency, significantly. In animals which received streptozotocin, olibanum increased step through latency, significantly. Olibanum reduces the risk of Alzheimer’s disease induced by streptozotocin. Further studies with emphasis on active constituents of olibanum may result in development of drugs capable of decreasing probability of Alzheimer’s disease occurrence.