Integrative Study of <i>Plantago lanceolata</i> L.: Phytochemical Properties and Therapeutic Effects on Cancer, Diabetes, and Alzheimer’s Disease

Alzheimer’s disease is linked with diabetes and cancer, emphasising the need for effective treatments. <i>Plantago lanceolata</i>, recognised as safe by various pharmacopeias, was investigated in this study for therapeutic potential. We examined the effects of its leaf extracts and sub-extracts (methanol, hexane, dichloromethane, ethyl acetate, butanol, aqueous) on AChE, BChE, α-amylase, α-glucosidase enzymes, as well as their impact on HDF-a and U87-MG cancer cells. The phytochemical characterisation was performed using ICP-MS and LC–MS/MS. Cytotoxic effects were evaluated on HDF-a and U87-MG cell lines, along with assessments for nuclear abnormalities. Na and K were detected in extracts, with isoleucine and cyanidin-3-O-glucoside being the most concentrated compounds. Extracts at concentrations exceeding 25 µg/mL significantly increased cytotoxicity in HDF-a cell lines compared to the control group, without inducing nuclear abnormalities. Methanol extract demonstrated moderate inhibition against AChE and BChE at concentrations of 100 µg/mL and 500 µg/mL, respectively. These findings suggest that extracts exhibit potential therapeutic effects.