Chemical composition, antioxidant and antibacterial activities of the essential oil of Pelargonium graveolens L’Hér

Abstract

Pelargonium graveolens L’Hér. (PG) is an aromatic and flowering plant, cultivated in Algeria. The purpose of this research was to determine the chemical composition, antioxidant activity and antibacterial properties of the essential oil from aerial parts of Pelargonium graveolens L’Hér. cultivated in the West of Algeria. The chemical composition was analyzed by gas chromatography–mass spectrometry GC–MS; the active components were mainly geraniol (23.5%) and citronellol (19.4%). Antioxidant activity of Pelargonium graveolens L’Hér. essential oil (PGEO) was evaluated by measuring the free radical scavenging activities of DPPH, ABTS and the ferric-reducing power methods. Results show antiradicalar power with IC₅₀ equal to 19.66 ± 0.31 mg/mL and 10.79 ± 0.054 µg/mL against DPPH and ABTS, respectively. The antibacterial activity of PGEO on five bacteria was tested by measuring the minimum inhibitory concentration, and inhibition zone diameter. The Inhibition zones showed that PGEO was active against all the studied bacteria, with Gram-positive being more sensitive to the oil than Gram-negative bacteria; the most susceptible strain against this essential oil was Staphylococcus aureus with the strongest inhibition zone (21 mm). Furthermore, PGEO was tested for its acute toxicity in Wistar rats and the result showed no mortality with a normal behavior. The antioxidant and antibacterial activities might not be primarily attributed to geraniol and citronellol, but rather to their combined action.