<i>In vitro</i> antiaggregation and deaggregation potential of <i>Rhizophora mucronata</i> and its bioactive compound (+)- catechin against Alzheimer’s beta amyloid peptide (25–35)
<p><b>Objective:</b> Amyloid hypothesis states that endogenous <i>β</i>-amyloid peptides (A<i>β</i>), especially its aggregated oligomers and fibrils are the key pathogenic factors leading to Alzheimer’s disease (AD). Therefore, inhibition of A<i>β</i> fibrillation rather than blocking its production is considered promising therapeutic intervention. Hence, the present study was carried out to assess the effect of methanolic leaf extract of <i>R. mucronata</i> (MERM) and its bioactive compound catechin on <i>in vitro</i> fibrillation of A<i>β</i> (25–35).</p> <p><b>Methodology:</b> Antiaggregation and disaggregation effect by MERM and (+)- catechin against A<i>β</i> (25–35) were assessed in three different phases by thioflavin T (ThT) fluorescence assay and confocal microscopic analysis. The conformational changes in the aggregated A<i>β</i> fibrils in the presence and absence of MERM and catechin were analysed by Fourier transform infrared (FTIR), transmission electron microscopy (TEM) and CD spectroscopy.</p> <p><b>Results:</b> Results of ThT and confocal microscopic studies showed decrease in fluorescence intensity in MERM and catechin-treated groups illustrating that both MERM and catechin effectively inhibited fibril aggregation as well as destabilized preformed A<i>β</i> fibril. TEM revealed that MERM incubated samples were virtually devoid of structured fibrils but had an amorphous-like consistency, whereas the control contained structured fibrils of various width and length. FTIR analysis showed decrease in absorbance at 1630 cm<sup>−1</sup> (amide I region) in MERM-treated groups substantiating the results of ThT assay. Circular dichroism data indicate that catechin prevents the formation of <i>β</i>-structured aggregates of A<i>β</i> peptide.</p> <p><b>Conclusion:</b> Results suggest that MERM and catechin might have direct interaction with A<i>β</i> peptide preventing its fibrillation.</p
