Characterization of Liposomal and Free Aqueous Extracts of Ceratonia siliqua : Evaluation of Phenolic Contents and Antimicrobial, Antimutagenic, Enzyme Inhibitory, and Antiproliferative Activities

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Ceratonia siliqua (carob) is a Mediterranean medicinal plant rich in phenolic contents but limited by poor bioavailability. To address this, an aqueous carob extract was formulated into liposomes and characterized. Phenolic profiles of the free (CBE) and the liposomal extracts (LCBE) were compared by the HPLC. Genotoxic safety and biological activities of both extracts were evaluated. HPLC analysis identified key phenolic acids in both formulations; while the concentration of gallic acid was determined as 23.5 ppm in CBE and 18.5 ppm in LCBE, caffeic acid levels were determined as 43.5 ppm in CBE and 24.5 ppm in LCBE. In addition, protocatechuic acid followed a similar trend, with concentrations of 55.1 ppm in CBE and 35.1 ppm in LCBE. Biologically, the LCBE showed enhanced antibacterial activity, particularly against Escherichia coli. The LCBE demonstrated stronger competitive inhibition of AChE and α-amylase when compared with the free extract, suggesting potential relevance for enzyme-modulating and glycemic support. In preliminary MTT-based cell viability screening, LCBE showed relatively greater activity than CBE in MCF-7 cells; however, this effect was weak, while PC-3 and MDA-MB-231 cells showed limited responsiveness under the tested conditions. Further selectivity and mechanistic studies should be done in vivo bioavailability/pharmacokinetics.