Antioxidant and antibacterial activities of geranium (pelargonium graveolens L'Hr.) essential oil as affected by the growing biotope

This study investigated the variability of antioxidant and antibacterial activities of essential oil (EO) from geranium (Pelargonium graveolens) aerial parts, collected from four Tunisian regions. The highest EO yield was obtained in Korba, followed by Beja, Tozeur and Sfax. In all regions, geranium EO was rich in oxygenated monoterpenes mainly due to the predominance of citronellol and geraniol. Antioxidant potential of geranium EO was evaluated by DPPH, ABTS, iron reducing power and beta-carotene bleaching assays. Independently of region, geranium EO showed a weak antioxidant potential as compared to the positive control BHT. However, geranium EO was endowed with important antibacterial properties. In fact, Escherichia coli and Staphylococcus aureus were the most sensitive strains than Serratia marcescens, Pseudomonas aeruginosa, Pseudomonas aeruginosa and Enterococcus hirae. These findings suggested that geranium EO could be used as new and rich potential sources of many future multipurpose products for food preservation, pharmaceutical, and industrial applications.