Scopolamine

Background: Memory and cognitive decline represent hallmark manifestations of Alzheimer's disease and related neurodegenerative conditions. Current pharmacological management relies predominantly on synthetic cognitive enhancers and cholinesterase inhibitors, whose long-term administration raises concerns regarding tolerability, systemic toxicity, and patient adherence. Consequently, attention has shifted toward plant-derived therapies — particularly those rich in neuroprotective and antioxidant constituents — as more sustainable and well-tolerated options for maintaining brain health. Annona reticulata, a member of the Annonaceae family, has attracted scientific interest owing to its phytochemical complexity and historically documented medicinal applications. Objective: The present investigation aimed to evaluate the cognitive-enhancing potential of the hydroalcoholic fruit extract of Annona reticulata in a scopolamine-induced murine model of cholinergic cognitive impairment. Methods: A total of thirty-six male Wistar mice were randomly allocated into six experimental groups, each comprising six animals. Group I served as the vehicle-treated normal control, while Group II received the reference nootropic, piracetam (400 mg/kg, per oral), administered daily for six consecutive days. Cholinergic cognitive impairment was established in Group III through intraperitoneal administration of scopolamine (1 mg/kg). Groups IV, V, and VI were co-administered scopolamine alongside graded doses of the hydroalcoholic fruit extract at 100, 200, and 400 mg/kg orally, respectively. Spatial learning and memory were evaluated employing the Morris Water Maze paradigm over six days. Following behavioural assessment, hippocampal tissues were harvested and processed for histopathological examination. Data were statistically analysed using one-way and two-way ANOVA, and values were reported as mean ± SEM. Results: Hydroalcoholic fruit extract of Annona reticulata elicited a statistically significant and dose-related amelioration of spatial learning and memory deficits in scopolamine-challenged animals. Extract-treated groups exhibited progressive reductions in escape latency and augmented target quadrant occupancy across training days. At the highest tested dose (400 mg/kg), cognitive performance closely approached that observed in the piracetam reference group, underscoring the extract's potent nootropic efficacy. Conclusion: Collectively, these findings indicate that Annona reticulata fruit extract harbours appreciable cognitive-enhancing and neuroprotective capabilities. The extract warrants further mechanistic and translational investigation to delineate its precise mode of action and validate its therapeutic applicability in cognitive dysfunction disorders.

This study was designed to evaluate, learning and memory enhancing activity of aqueous and ethanolic extracts of whole plant of Sida veronicaefolia in rats using Elevated plus maze(EPM), Hebb William Maze(HWM), and Morris water maze(MWM) and to evaluate brain Acetylcholine esterase activity ,lipid peroxidation, superoxide dismutase activity, catalase and glutathione level. Rats were divided into 7 groups of 6 no each. Group 1(control) animals received vehicle , Group 2 animals received scopolamine (0.4mg/kg i.p.), on 19th and 27th day only, Groups 3 and 4 animals received 200mg/kg and 400mg/kg p.o. of aqueous extraction of Sida veronicaefolia. Group 5 and 6 animals received 200mg/kg and 400mg/kg p.o. of ethanolic extraction of Sida veronicaefolia and Group 7 animals received piracetam (400mg/kg i.p.) for 27 days, followed by scopolamine (0.4mg/kg i.p.) single dose on 19th and 27th day only. Assessment of transfer latency (TL), time taken to reach reward chamber (TRC) and assessment of swim latency (SL) was one on 19th and 27th day using elevated plus maze, Hebb William maze and Morris water maze. Animals were sacrificed on 27th day, brain acetylcholine esterase activity, lipid peroxidation, superoxide dismutase activity, catalase activity and glutathione level were estimated. The data was expressed as mean ± S.E.M. The statistical analysis was done by means of ANOVA followed by Dunnett’s post hock test. The aqueous and ethanolic extracts of Sida veronicaefolia decreased Tranfer Latency, Time taken to reach Reward Chamber and Sim Latency in comparison to scopolamine treated rats, decreased acetylcholine esterase activity and lipid peroxidation and increased super oxide dismutase, glutathione and catalase activity in brain.