Antidepressant and cognitive activities of intranasal piperine-encapsulated liposomes

Antidepressant and cognitive effects of piperine -encapsulated liposomes (PL) were investigated in male Wistar rats. Oral piperine (5 mg/kg body weight/day) and intranasal PL (7.2 µg/day) were randomly assigned to daily administer for 14 days to rats which were subjected to forced swimming, Mor-ris water maze and spontaneous motor behavior tests. PL significantly exhibited anti-depression like activity and cognitive enhancing effects, in comparison to the control groups after the first dose (p < 0.01) and the effects could be maintained throughout the period of study. Quantitative analysis of the brain homogenates by HPLC indicated that piperine, delivered either orally or nasally, distributed to the hippocampus at a higher extent than the cortex and that the time to peak concentration of nasal PL was shorter than for the oral piperine. Intranasal PL was, thus, potential in delivery of piperine, at a low dose, to exert its an-tidepressant and cognitive enhancing activities.