Therapeutic effect of frankincense in a rat model of Alzheimer’s disease

Objective: Frankincense improves memory in different models of learning. However, its influence on models of Alzheimer s disease (AD) has not been studied widely. In the present study, the therapeutic effect of frankincense was evaluated in a model of AD induced by i.c.v administration of streptozotocin. Materials and Methods: Under stereotaxic surgery, two guide cannulas were implanted in the lateral ventricles of adult male Wistar rats weighing 230-270 g. One group received streptozotocin (1.5 mg/kg/2μl/side) bilaterally on the first and third day of surgery. Another group received artificial cerebro-spinal fluid. Fourteen days after surgery, learning was evaluated using the passive avoidance paradigm. Four other groups of animals received frankincense (50 mg/kg) or its solvent after establishment of AD for 21 or 42 consecutive days, and then, memory retrieval was assessed. Results: Streptozotocin increased the number of stimulations required for induction of short-term memory and decreased step-through latency on the test day, significantly (p<0.05). Chronic injection of the aqueous extract of frankincense for 21 days did not affect learning parameters, but injection of it for 42 days, significantly increased step-through latency (p<0.05), decreased the number of step-through into the dark compartment (p<0.01) and decreased the time spent in the dark compartment (p<0.05). Conclusion: The results indicate that chronic administration of frankincense has the potential to improve dementia type of AD induced by i.c.v injection of streptozotocin in a time-dependent manner.

Keywords:

Streptozotocin , Alzheimer’s disease , Frankincense , Memory , Rat