Functional potential of Valeriana extracts: Spectroscopic characterization, biological activities and heavy metal...

This study aimed to characterize and evaluate the bioactive properties of Valeriana alanyense (VA) and Valeriana speluncaria (VS) extracts obtained using water and methanol. The antioxidant, antibacterial, anticancer, antidiabetic activities, as well as metal ion binding capacities, were systematically investigated. The extracts exhibited total phenolic contents ranging from 12.61 to 47.23 mg GAE/L. Antioxidant assays revealed DPPH scavenging capacities between 2.80 and 34.50 mg/mL and ABTS scavenging capacities between 0.66 and 5.18 mg/mL. All extracts demonstrated notable α-glucosidase inhibitory activity. HPLC/UV-Vis profiling identified chlorogenic acid (475.50 mg/g, VAWE), quercetin (429.37 mg/g, VSWE), rutin (355.10 mg/g, VAME), and benzoic acid (109.77 mg/g, VSME) as the predominant phenolic compounds. Significant antibacterial effects were recorded against Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, and Salmonella enteritidis. Furthermore, the extracts exhibited cytotoxic activity against HT-29 and CaCo-2 cancer cell lines. Spectroscopic analyses revealed strong binding affinities, with fluorescence quenching observed in water extracts upon Cu²⁺ addition and in methanol extracts upon Hg²⁺ addition. These findings demonstrate that Valeriana extracts, particularly VAWE, possess potent bioactive properties and selective heavy metal sensing ability, supporting their potential as functional ingredients in food and pharmaceutical applications as well as in environmental monitoring.