BPC-157 and Its Novel Hybrid Analogs as Inhibitors of Acetylcholinesterase.
This study investigated whether the gastric pentadecapeptide BPC-157 and two newly designed hybrid analogs (CIARA-1 and CIARA-2) could inhibit acetylcholinesterase (AChE), an enzyme targeted in the treatment of neurodegenerative conditions such as Alzheimer's disease. The hybrid peptides were rationally designed by combining a BPC-157-derived fragment with an arginine-rich C-terminal sequence intended to enhance binding at both the catalytic and peripheral sites of AChE. Inhibitory activity was measured in vitro using a modified Ellman colorimetric assay, with kinetic parameters derived from Lineweaver-Burk plots. All three compounds showed competitive inhibition—meaning they raised the Michaelis-Menten constant (Km) without affecting maximum velocity (Vmax)—indicating direct competition with the substrate at the enzyme's active site. CIARA-1 showed the strongest inhibition (Ki = 0.24 mM; IC50 = 2.52 mM), followed by CIARA-2 and then BPC-157 itself. Results were supported by molecular docking predictions. A key limitation is that inhibitory potencies were substantially lower than those of approved AChE inhibitors. No animal or human data were included. The authors suggest these peptides represent a structural scaffold for further optimization rather than immediate therapeutic candidates.
Why this grade: All experimental work was conducted in cell-free enzymatic assays with no animal or human subjects, providing only preliminary mechanistic data that cannot be directly extrapolated to clinical efficacy.
Acetylcholinesterase (AChE) inhibition remains a key therapeutic strategy in the management of neurodegenerative disorders such as Alzheimer's disease. In this study, the inhibitory potential of the gastric pentadecapeptide BPC-157 and two newly designed hybrid analogs, CIARA-1 and CIARA-2, was investigated for the first time. The hybrid peptides were rationally designed by combining a BPC-157-derived fragment with an arginine-containing C-terminal sequence to enhance interactions with the enzyme's active and peripheral binding sites. Enzyme kinetics were evaluated using a modified Ellman assay, and inhibition parameters were determined through Lineweaver-Burk analysis. All tested compounds exhibited a competitive mechanism of inhibition, as evidenced by increased Michaelis-Menten constant ( K m ) values with unchanged maximum velocity ( V max ), indicating competition with the substrate at the catalytic site of AChE. Among the tested compounds, CIARA-1 demonstrated the highest inhibitory potency, reflected by the lowest inhibition constant ( K i = 0.24 mM) and IC 50 value (2.52 mM), followed by CIARA-2 ( K i = 0.29 mM; IC 50 = 2.73 mM) and BPC-157 ( K i = 0.48 mM; IC 50 = 2.80 mM). These findings were consistent with molecular modeling predictions, supporting stronger binding interactions for CIARA-1. Despite significantly lower potency compared to clinically used AChE inhibitors, the studied peptides represent a promising scaffold for further optimization. Overall, this work demonstrates that BPC-157 and its hybrid analogs act as reversible competitive AChE inhibitors, with enhanced activity observed for structurally modified derivatives. The results highlight the potential of peptide-based hybrid molecules as multifunctional candidates in the development of novel therapeutics targeting cholinergic dysfunction.
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