Phytochemical Characterization and Antibacterial Activity of Lantana camara L. Seed Extracts

Background and Objective: Lantana camara L. is a medicinal plant rich in bioactive phytochemicals traditionally used for treating infections and various ailments. The main objective was to characterize the bioactive compounds present in Lantana camara seeds and to evaluate their antioxidant and antibacterial activities. Materials and Methods: Two solvents were used for extraction from 100 g of seed powder: Pure ethanol and a hydroethanolic mixture containing 70% water and 30% ethanol. The extracts were the subjected to phytochemical screening, quantitative analysis of phenolic compounds, flavonoids, and tannins, as well as antioxidant activity assays using DPPH and ABTS, and antibacterial susceptibility tests. Data were analyzed in GraphPadPrism 8, with results as Mean±SD at p≤0.05. Results: The hydroethanolic mixture produced a higher extraction yield (10.30%) compared to pure ethanol (4.736%). However, the ethanolic extract was richer in phenolic compounds (67.10 mg gallic acid equivalents per gram of dry extract), flavonoids (354.83 mg quercetin equivalents per gram of dry extract), and tannins (234.50 mg catechin equivalents per gram of dry extract). It also showed stronger antioxidant activity, with an IC₅₀ of 2942.83 μg/mL for DPPH and 2100.27 μg/mL for ABTS, compared to the hydroethanolic extract, which had IC₅₀ values of 3173.84 μg/mL for DPPH and 2832.71 μg/mL for ABTS, although both were less effective than quercetin. Finally, only the ethanolic extract demonstrated significant antibacterial activity against all six tested strains, including Pseudomonas aeruginosa and Klebsiella pneumoniae. Conclusion: Ethanol appears to be the most effective solvent for extracting bioactive compounds from Lantana camara seeds, due to its ability to concentrate the secondary metabolites responsible for antioxidant and antibacterial activities. These findings confirm the pharmacological potential of this plant and support its use in traditional medicine.