Evaluation of Neuroprotective Activity of Carica papaya Seeds Extract in Okadaic Acid Induced Alzheimer’s Disease in Zebra Fish Model (Danio rerio)

Abstract

Aim: In the present study, Carica papaya seeds ethanol extract on the memory impairment and enhancing activity in zebrafish is studied using Rivastigmine as the standard drug and Okadaic acid as the memory impairing agent. Methods: Zebrafishes were procured from Marine institute Bangalore. The Alzheimer’s properties of Carica papaya seeds were evaluated. The fresh seeds were isolated and air-dried before pulverized to a course powder with and electric grinder. Extraction were carried out with 70% ethanol by Soxhlet apparatus. Preliminary phytochemical screening of the extract was investigated in this study. Two doses of herbal extract of Carica papaya seeds (50 and 100mg/kg) were used in this study. Whereas Rivastigmine as a standard drug and Okadaic acid were used as to induce memory impairment. Two behavioural tests namely, Colour-Biased Appetite Conditioning T-Maze test and light/dark chamber test. Histopathological studies of brain were also performed. Detection of estimation of cholinergic neurotransmitter acetylcholinesterase (AchE) using Enzyme-linked immunosorbent assay. Results: The extract contains phytochemicals, including alkaloids, flavonoids, glycosides, steroids, saponins and terpenoids. For the, zebrafish that received Carica papaya seeds extract at doses of 100mg/kg had significantly increased time spent and total number of entries into the green arm and decreased in red arm in T-maze and had significantly increased in time spent and total number of entries into the light chamber and decreased in dark chamber in light/dark chamber respectively. The amount of acetylcholinesterase was found to be more in the negative control (Okadiac acid) and low dose (50mg/kg) Carica papaya seeds extract. A significant purkinje cells were also observed from the histological study after treatment with Carica papaya seeds extract. Nucleus elongation of oligodendrocytes from zebrafish model of AD induced with Okadaic acid were improved when treated with the Carica papaya seeds extract. The results of the present study contribute to the ability ofCarica papaya seeds extract in ameliorating the memory impairment effects of Okadaic and can be used as a potential drug for neurodegenerative diseases like Alzheimer’s Disease.