Neuroprotective effect of chrysophanol in Alzheimer disease via modulating the Ca²⁺/EGFR-PLCγ pathway

Chrysophanol (CHR) is an anthraquinone compound found in rhubarb, and it possesses neuroprotective properties. The purpose of this study was to gain a better understanding of its role in Alzheimer's disease (AD). In vivo study, D-galactose combined with intracerebral injection of β-protein 25-35(Aβ25-35) were used to establish AD model rats. In vitro study, Aβ_25-35 was used to induce AD model cells. Our results indicated that CHR improves learning and memory in AD model rats and provides protection against neuronal damage in both AD model rats and cells. Additionally, we observed that CHR suppressed the protein expression of p-tau, EGFR, PLCγ, IP3R, and CAM, as well as the mRNA levels of tau, EGFR, PLCγ, IP3R, and CAM. Furthermore, we have confirmed that CHR inhibited the fluorescence expression of calcium ions (Ca²⁺). In conclusion, the CHR may exert neuroprotective effects in AD by reducing tau phosphorylation through the Ca²⁺/EGFR-PLCγ pathway.