Exploring alternative methods for producing extracts with antioxidant and antimicrobial properties from Cercis siliquastrum L. and safety assessment

Cercis siliquastrum L. is considered an important medicinal herb. To provide knowledge that can contribute to scientific literature, the present study focuses on the identification of bioactive compounds of different Cercis siliquastrum L. extracts using GC-MS. Furthermore, the antibacterial activity of Cercis siliquastrum L. extracts against the gram-negative bacterium Escherichia coli (E. coli) was examined. Moreover, a safety evaluation against human cells was performed. A combination of maceration and percolation was used for the extraction of leaves. Additionally, the reuse of the biomass was evaluated through sequential extractions using organic solvents of different polarity to obtain a wide range of secondary metabolites. In total, fourteen bioactive compounds were detected using GC-MS. However, some differences, especially in the compounds identified in each extract as well as in their abundance were observed. The major components of the extracts obtained from the hydroethanolic and methanolic extracts were γ-sitosterol, α-tocopherol and phytol. In the case of the hexane extract octacosane, γ-sitosterol and α-tocopherol were the most abundant constituents. The hydroethanolic extract possessed the most significant antibacterial activity against Escherichia coli, as well as the highest antioxidant activity. Regarding the cytogenotoxic potential of the hydroethanolic extract, none of the tested concentrations led to cytotoxic effects. Although the highest tested concentration (1.50 % v/v) induced micronucleus (MN) formation compared to the control cultures, the difference was not statistically significant, confirming the absence of genotoxic effects. The reuse of the secondary biomass also led to extracts consisting of compounds with beneficial properties and aligns with the circular economy concept.