Antioxidant, Antistress, Nootropic activity and its Correlation studies of aqueous extract of Punica granatum fruit estimated by Noninvasive biomarkers and Y-maze test in rodents

Abstract

The memory loss associated with increased oxidative stress due to increased level of free radicals. Oxidative stress has been involved in several diseases includes cancer, atherosclerosis and neurodegenerative diseases.This study aimed to estimate the correlation of antioxidant and antistress activity with nootropic activity of aqueous extract of pomegranate (Punica granatum) by in-vivo noninvasive studies using rats. The in-vitro antioxidant activity was determined based on the ability of the Punica granatum to scavenge free radicals and lipid peroxidation inhibiting activity. The antistress effect of the aqueous extract of Punica granatum for 24h treatment (100 and 300mg/kg, p.o.) was evaluated by using the forced swim stress test in rats. The 24h urinary excretion of vanillylmandellic acid (VMA), 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and ascorbic acid (AA) was determined in all groups under normal and stressed conditions by HPLC and spectrophotometric methods in all groups, were selected as noninvasive biomarkers. Nootropic activity activities of Punica granatum fruit extract were estimated as locomotor and working memory in rats in a Y-maze apparatus. Administration of aqueous extract of Punica granatum at a dose of 100 and 300mg/kg reduced the urinary metabolite levels. Punica granatum treatment showed significant dose dependent variation in non-invasive biomarker levels in urine samples of rats taken after 24h. The treatment with Punica granatum extracts improved the percentage entry of rats into safer zone, it means acquisition (learning) retention and retrieval (memory) were improved in rats compared to stress controls. Cognition determined by working memory and locomotor activity results were shown to be dose-dependent. The results of this study strongly suggestedantioxidant, antistress and nootropic activity effect of Punica granatumin rodents were correlated. The data obtained were analyzed by one-way ANOVA followed bytukey test. p<0.05 was considered to be significant. There is substantial evidence that flavonoids play an active role in providing antioxidant, antistress and nootropic activities of Punica granatum extracts. The findings of the present investigations indicate that the Punica granatum has significant antistress activity, which may be due to the immunostimulating property and increased resistance, nonspecifically, against all experimental stress conditions. The study provided scientific evidence for their utility as nootropic agents and to advocate their use in foods.