Objective: This study aims to investigate the neuroprotective, memory enhancement effects and phytochemical profile of Rhizophora apiculata.
Materials and Methods: Ethanolic and aqueous extracts of R. apiculata leaves were prepared and screened for their antioxidant potential. In vitro studies were performed to assess the neuroprotective effects of R. apiculata extracts against scopolamine-induced neurotoxicity in SH-SY5Y cells. Further, in vivo, memory-enhancing effects of the extracts were evaluated in a scopolamine-induced amnesia model in rats by measuring brain acetylcholinesterase (AChE) levels, lipid peroxidation, and glutathione (GSH) activity. Furthermore, phytochemicals were identified through HR-LCMS analysis, and their binding interactions with the target protein AChE were investigated through in silico studies.
Results: Treatment with ethanolic (100 µg/ml) and aqueous extracts (100 µg/ml) significantly reduced oxidative stress up to 89.386±2.37% in DPPH assay and 84.167±5.80% ABTS assays, respectively. The extracts (100 μg/ml) notably increased the viability (97.49%) of SH-SY5Y neuroblastoma cells against scopolamine-induced neurotoxicity. In vivo, studies revealed that both extracts improved memory function in scopolamine-induced amnesia by inhibiting the AChE activity and enhancing brain GSH levels while reducing lipid peroxidation. HR-LCMS analysis identified 54 distinct phytochemicals, with several compounds showing promising binding affinities like olitorin (-11.5 kcal) and gambiriin A3 (-10.7 kcal) for AChE in in-silico studies.
Conclusion: Based on the findings of this study, R. apiculata leaves may be considered a promising source of neuroprotective compounds, with potential therapeutic applications for various neurological diseases.