Comprehensive Metabolomic Profiling and Biological Activity Analysis of <scp> <i>Eschscholzia californica</i> </scp> Extracts Using <scp>LC</scp> ‐ <scp>ESI</scp> ‐ <scp>QTOF</scp> ‐ <scp>MS</scp>

The current investigation was designed to explore the chemical composition, antioxidant capacity, enzyme inhibitory activity, and cytotoxic potential of four different extracts (Ethyl Acetate, Ethanol, Ethanol/Water (70%) and Water) derived from the aerial parts of <i>Eschscholzia californica</i>. In vitro, assessments were performed utilizing diverse antioxidant assays, along with evaluations of neuroprotective enzyme inhibition targeting acetylcholine and butyl choline enzymes, as well as antidiabetic activities against α-amylase and α-glucosidase and a potential candidate for a tyrosinase inhibitor. LC-ESI-QTOF-MS identification provided a total of 70 compounds in the extracted samples of <i>E. californica</i>, including kaempferol 3-(deoxyhexosyl-hexoside)-7-hexoside, rutin, quercetin dideoxyhexoside, caffeic acid hexoside, quinoline alkaloids, morphine derivatives, and scoulerine. Moreover, the ethanol extract exhibited the highest anti-AChE (2.39 mg GALAE/g), while ethyl acetate exhibited anti-BChE (3.31 mg GALAE/g), Ethanol/Water (70%) anti-tyrosinase (53.09 mg KAE/g) and anti-glucosidase (1.09 mmol ACAE/g) activities. Additionally, the ethyl acetate extract effectively inhibited carbonic anhydrase I and II isoenzymes. Furthermore, the ethanol and ethanol/water extracts demonstrated significant cytotoxicity against A549 lung cancer cells. However, <i>E. californica</i> partially/weakly triggers the apoptosis of cancer cells. Furthermore, the investigation identified 885 target genes for <i>E. californica</i>'s phytochemicals, 31 of which were familiar to insomnia. In silico studies demonstrated that protopine, rutin, eschscholtzidine, boldine, and (S)-scoulerine exhibited notable inhibitory effects on insomnia-related DRD5, DRD4, and SERT proteins. These findings highlight the potential pharmacological applications of the aerial parts of <i>E. californica</i> as a source for developing novel phytopharmaceuticals targeting various oxidative stress-related conditions, including diabetes, cancer, Alzheimer's disease, and insomnia.