Phytochemical Analysis and Biological Activity of Ricinus Communis: Investigating Antioxidant and Antibacterial Properties

Introduction: Castor oil bean (Ricinus communis) belongs to the Euphorbiaceae family and is valued for its oil and medicinal uses. It contains several bioactive compounds including ricin, ricinine and flavonoids, and has attracted considerable attention for its various biological effects, including antioxidant and anti-inflammatory effects. The aim of this article was to investigate the antioxidant, antibacterial effects, and phenolic and flavonoid bioactive compounds of castor bean seeds from different regions. Methods: In this study, methanol and hexane extracts from castor bean seeds were prepared via two different extraction methods (stirring and Soxhlet). The antioxidant effect of these extracts was measured using the DPPH (2, 2-diphenyl-1-picrylhydrazyl) method. For antibacterial effect, both disk diffusion and minimum inhibitory concentration (MIC)/minimum bactericidal concentration (MBC) methods were employed across several types of bacteria. The study also evaluated the total phenolic and flavonoid contents. Results: The results indicated that the stirring extraction method using methanol yielded the highest level of total phenolic and flavonoid content from castor bean seeds sourced from the Mazandaran region. In contrast, the soxhlet- methanolic extraction of castor bean seeds from the Qom region exhibited the most significant free radical scavenging activity. Notably, Bacillus cereus and Staphylococcus aureus strains depicted the highest sensitivity, with mean diameters 21.16 ± 0.84 mm and 15.33 ± 0.47 mm, respectively, at a concentration of 400 mg/mL of stirring-methanolic extraction. Additionally, the methanol extract from the Mazandaran region displayed strong inhibitory and bactericidal effects against various bacterial strains. Conclusion: The results revealed that the cultivation region of the seeds, the used solvent, and the extraction method had a substantial impact on the bioactive properties of the castor bean seeds.