Effect of Pentoxifylline on Apoptotic-Related Gene Expression Profile, Learning and Memory Impairment Induced by Systemic Lipopolysaccharide Administration in the Rat Hippocampus

BACKGROUND: Inflammation is one of the effective factors, in the development of functional disorders of the nervous system. Pentoxifylline (PTX) has an inhibitory effect on inflammatory factors. Therefore the aim of this study was to evaluate the effect of PTX on learning, memory and expression of genes, involved in neuronal survival in the rat hippocampus, following systemic lipopolysaccharide (LPS) injection. METHODS: Male rats were randomly divided into 5 groups of control, LPS and LPS + PTX, receiving doses of 10, 25 and 50 mg/kg of PTX, respectively. In LPS groups, LPS was injected (5 mg/kg; intraperitoneal), and after one week, rats received intraperitoneal PTX for 14 days, in the treatment groups. Learning and memory were evaluated by object location task (OLT) and novel object recognition (NOR). Then, the hippocampus was dissected in order to measure the expression of the associated genes. RESULTS: The results showed that peripheral LPS injection caused significant damage (P < 0.01) to learning and memory with respect to controls, but PTX with doses of 10 and 50 mg/kg prevented these impairments. Results from reverse transcription polymerase chain reaction (RT-PCR) showed that LPS significantly increased the expression of Bax and TNF- α with respect to controls. PTX in the LPS + PTX group significantly increased the expression of Bcl-2, BAD and Caspase-3. CONCLUSIONS: Other than the increased Bcl-2 expression, PTX had no significant effect on the expression of other genes, therefore further studies are needed to find out how PTX improves the learning and memory impairments, following the peripheral inflammation.