Plant Extracts in Focus: Chemical Characterization, Biological Activity, and Their Significance in Ethnomedicine and Practical Applications

Dear Colleagues,

We are pleased to invite you to contribute to the Special Issue of Plants, a renowned journal of botany.

Plant extracts are complex mixtures of secondary metabolites with beneficial properties, extracted from plant tissues using various solvents and extraction techniques. They can be obtained from both whole plants and specific plant parts. Due to their diverse bioactivities, they are widely applied in food, pharmacy, and cosmetics industries.

Plant extracts have been used for thousands of years in traditional herbal formulations. Recent research trends have enabled us to enhance our understanding of many traditionally used plants through modern techniques for the characterization of pure bioactive compounds. One or more of these compounds are synergistically responsible for the biological activity of the plant extract. To better understand the properties of bioactive compounds and their mechanisms of action, they should be isolated, identified, and characterized, before being applied as bioactive agents.

This Special Issue of Plants focuses on, but is not limited to, techniques for the isolation, separation and identification of bioactive compounds, chemical characterization and the evaluation of biological activities of plant extracts. We also welcome contributions addressing advancements in extraction methods, synergy between compounds, and innovative applications in industry, including functional foods, nutraceuticals, and sustainable cosmetics.

We encourage authors to submit both original research articles and comprehensive reviews that provide deeper insight into this dynamic field.

We look forward to receiving your contributions.

Dr. Ana Alimpić Aradski
Dr. Katarina Šavikin
Dr. Mariana Oalđe Pavlović
Dr. Ivona Veličković
Guest Editors

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• plant extract
• extraction
• chemical characterization
• bioactive compounds
• biological activity
• ethnomedicine
• natural products
• standardization

Title: Exploring the therapeutic potential of Rosmarinus officinalis: Chemical composition and biological insights of different extracts, with a focus on the synergistic effect of rosmarinic acid with 5-FU
Authors: Mariana Oalđe Pavlović¹, Milena Milutinović², Ana Alimpić Aradski¹, Uroš Gašić³, Danijela Mišić³, Petar D. Marin¹, Sonja Duletić-Laušević¹†
Affiliation: 1 University of Belgrade, Faculty of Biology, Institute of Botany and Botanical Garden “Jevremovac”, Studentski trg 16, Belgrade, Serbia; 2 University of Kragujevac, Faculty of Science, Department of Biology and Ecology, Radoja Domanovića 12, 34000 Kragujevac, Serbia; 3 University of Belgrade, Institute for Biological Research “Siniša Stanković”, National Institute of the Republic of Serbia, Bulevar Despota Stefana 142, Belgrade, Serbia;
Abstract: Rosmarinus officinalis (rosemary) is a medicinal and aromatic Lamiaceae plant of historical and modern importance, and it plays a significant role in both traditional and contemporary medicinal practices. Hence, this study aimed to evaluate the therapeutic properties of extracts of rosemary from two Serbian continental climates (L1 and L2) and one Montenegrin Mediterranean climate (L3), harvested in March (M), July (J), and November (N). Extracts were prepared using 70% methanol, 70% ethanol, and water, and analyzed for chemical composition through spectrophotometry, LC-MS, and GC-MS. The biological potential was tested using antioxidant (DPPH, FRAP, TRP, and β-carotene bleaching), enzyme-inhibitory assays (α-glucosidase, AChE, and TYR), and MTT assay to determine the cytotoxicity against HCT-116 colorectal cancer cells and the synergistic effects of rosmarinic acid and the chemotherapy drug 5-FU. The results showed that L3 extracts had the highest content of various groups of polyphenolics. Specifically, the L3M methanolic extract exhibited the highest total phenolic and phenolic acid contents, the L3M ethanolic extract had the highest flavonoid content, while the L3N ethanolic extract had the highest flavonol content. Compounds identified adopting the LC/MS non-targeted metabolomics approach, mainly belonged to the groups of hydroxycinnamic acid derivatives and flavonoid O-glycosides, and their amounts did not significantly change in relation to the type of the extraction agent. Not surprisingly, water was the least efficient in extracting volatile compounds, and rosemary alcoholic samples were predominated by 1,8-cineole, camphor, borneol, terpinen-4-ol, and verbenone. The L3N methanolic extract exhibited strong DPPH and FRAP activities; L3M methanolic extract had the highest TRP, while the L1J ethanolic extract was the most effective in protecting β-carotene from bleaching. In α-glucosidase inhibition, the L3N ethanolic extract was the most effective. The AChE inhibition peaked in L2J and L1J aqueous extracts, while TYR inhibition in L2J methanolic extract. Furthermore, the methanolic extracts had the highest anticancer potential, with L3J showing the highest cytotoxicity, and rosmarinic acid displayed a strong synergistic effect with 5-FU. Overall, this study confirmed the impact of solvent, locality, and season on the bioactivity of rosemary extracts, and highlighted the efficacy of rosemary especially from the Mediterranean climate, and rosmarinic acid’s potential to enhance 5-FU cytotoxicity.