title: Naringin and Rutin Alleviates Episodic Memory Deficits in Two Differentially Challenged Object Recognition Tasks.
abstract: BACKGROUND
  Cognitive decline or dementia is a debilitating problem of neurological disorders such as Alzheimer's and Parkinson's disease, including special conditions like chemobrain. Dietary flavonoids proved to be efficacious in delaying the incidence of neurodegenerative diseases. Two such flavonoids, naringin (NAR) and rutin (RUT) were reported to have neuroprotective potential with beneficial effects on spatial and emotional memories in particular. However, the efficacy of these flavonoids is poorly understood on episodic memory, which comprises an important form of autobiographical memory.
  
  
  OBJECTIVE
  This study objective is to evaluate NAR and RUT to reverse time-delay-induced long-term and scopolamine-induced short-term episodic memory deficits in Wistar rats.
  
  
  METHODS
  We have evaluated both short-term and long-term episodic memory forms using novel object recognition task. Open field paradigm was used to assess locomotor activity for any confounding influence on memory assessment. Donepezil was used as positive control and was effective in both models at 1 mg/kg, i.p.
  
  
  RESULTS
  Animals treated with NAR and RUT at 50 and 100 mg/kg, p.o. spent significantly more time exploring novel object compared to familiar one, whereas control animals spent almost equal time with both objects in choice trial. NAR and RUT dose-dependently increased recognition and discriminative indices in time-induced long-term as well as scopolamine-induced short-term episodic memory deficit models without interfering with the locomotor activity.
  
  
  CONCLUSIONS
  We conclude that, NAR and RUT averted both short- and long-term episodic memory deficits in Wistar rats, which may be potential interventions for neurodegenerative diseases as well as chemobrain condition.
  
  
  CONCLUSIONS
  Incidence of Alzheimer's disease is increasing globally and the current therapy is only symptomatic. Curative treatment is a major lacuna. NAR and RUT are natural flavonoids proven for their pleiotropic pharmacological effects with potential neuroprotective benefits. The study evaluated these flavonoids for their potential to improve the most common form of episodic memory (memory of autobiographical events in relation to time, places etc.) in two differential animal models assessing short-term and long-term memory, respectively. We also found that NAR and RUT were able to reverse both short-term and long-term memory deficits dose dependently in female Wistar rats. Abbreviations used: AD: Alzheimer's disease, AChE: Acetylcholinesterase, COX: Cyclooxygenase, DI: Discriminative index, ITI: Inter trial interval, NAR: Naringin, RUT: Rutin, NORT: Novel object recognition task, NOS: Nitric oxide synthase, QOL: Quality of life, RI: Recognition index, WFI: Water for injection.
authors.affiliation: Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Grandhi Venkata
authors.initials: GV
authors.lastname: Ramalingayya
authors.affiliation: Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Madhavan
authors.initials: M
authors.lastname: Nampoothiri
authors.affiliation: Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Pawan G
authors.initials: PG
authors.lastname: Nayak
authors.affiliation: Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Anoop
authors.initials: A
authors.lastname: Kishore
authors.affiliation: Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Rekha R
authors.initials: RR
authors.lastname: Shenoy
authors.affiliation: Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Chamallamudi
authors.initials: C
authors.lastname: Mallikarjuna Rao
authors.affiliation: Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Krishnadas
authors.initials: K
authors.lastname: Nandakumar
keywords: Alzheimer's disease; chemobrain; cognition; episodic memory; flavonoids; neurodegenerative disease; novel object recognition task