title: Effect of breastfeeding piperine on the learning of offspring mice: interaction with caffeine and diazepam.
abstract: Piperine, the main alkaloid of black pepper (Piper nigrum), has been suggested to display several pharmacological properties, including pain relief, anticonvulsant, antidepressant-like, antianxiety, sedative, and anti-inflammatory effects. This study was designed to investigate the effect of piperine on learning in mice and the interaction of the effect with caffeine and diazepam. Piperine (100 mg/kg intraperitoneally) was injected into the mouse mothers or nursing dams during breastfeeding for 25 days at five-day intervals. After feeding the newborn mice, their learning was evaluated using a step-through passive avoidance task. Mouse learning was assessed 1 hr and 24 hr and 1 week after a training session. Piperine increased learning in the first (1 hr: 243.33 s vs 55.17 s, P = 0.002) and third assessments (1 week: 226 s vs 97 s, P < 0.05) post-training, but no significant change was seen at the second (24 hr) assessment. Piperine improved the effect of a low dose of caffeine (25 mg/kg intraperitoneally after a shock of 2 s duration) in a first assessment (295.17 s vs 149.17 s, P = 0.026) compared to a higher dose of caffeine. Piperine reversed diazepam (1 mg/kg intraperitoneally) suppression of learning 24 hours after training by a 4 s shock (298 s vs 135.67 s, P = 0.03). According to the results, piperine alone significantly increased learning 1 hour and 1 week after training assessments, and learning can be improved in the short term when followed by piperine administration. It was also shown that piperine can potentiate the effect of a low dose of caffeine and can reverse the effect of diazepam.
authors.affiliation: Cellular and Molecular Biology Research Center, Department of Pharmacology, Alzzahra University, Babol University of Medical Sciences, Tehran, Iran; Department of Pharmacology, Alzzahra University, Babol University of Medical Sciences, Tehran, Iran.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Moghadamnia
authors.affiliation: Department of Pharmacology, Alzzahra University, Babol University of Medical Sciences, Tehran, Iran.
authors.forename: Vahid
authors.initials: V
authors.lastname: Zangoori
authors.affiliation: Department of Pharmacology, Alzzahra University, Babol University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed Sadegh
authors.initials: SS
authors.lastname: Zargar-Nattaj
authors.affiliation: Department of Pharmacology, Alzzahra University, Babol University of Medical Sciences, Tehran, Iran.
authors.forename: Pooya
authors.initials: P
authors.lastname: Tayebi
authors.affiliation: Department of Physics, Alzzahra University, Babol University of Medical Sciences, Tehran, Iran.
authors.forename: Yasaman
authors.initials: Y
authors.lastname: Moghadamnia
authors.affiliation: Department of Anatomical Iran; Sciences and Embryology, Tehran, Iran.
authors.forename: Seyed Gholam Ali
authors.initials: SG
authors.lastname: Jorsaraei
keywords: breastfeeding; caffeine; diazepam; learning; memory; piper nigrum; piperine; step-through passive avoidance task