ANTIOXIDANT AND ANTIMICROBIAL ACTIVITY OF GRANGEA MADERASPATANA (L.) POIR. EXTRACT

Abstract

The extract of aerial parts of Grangea maderaspatana (L.) Poir., obtained by steam distillation was analyzed by gas chromatography and gas chromatography coupled with mass spectroscopy. Twenty one constituents were identified, constituting 91.5 % of the oil. It was characterized by the dominant presence of sesquiterpenoids (sesquiterpenoid hydrocarbons 36.1 % and oxygenated sesquiterpenoids 28.4 %). Most abundant compounds are γ-gurjunene (26.5%), terpinyl acetate (20.8%) and hinesol (11.7%). The in vitro antioxidant potential of the oil was evaluated using, DPPH radical scavenging, metal chelating and reducing power assays. The oil showed antioxidant potential with significant reducing power (ASE/mL 2.01 ± 0.00), chelating activity (IC₅₀ 1.80 ± 0.15) and DPPH radical scavenging activity (IC₅₀ 2.90 ± 0.96). Antimicrobial activity of the oil was tested against one gram positive, four gram negative bacteria and two fungi using agar well diffusion method. The ZOI values of the oil were in the range of 2.67 ± 0.58 to 11.00 ± 0.00 mm and MIC of the oil was ranged from 5 to 30 µL/ mL for tested microorganisms. The activity was more pronounced against Candida albicans (ZOI = 11.00 ± 0.00 mm, MIC = 5 µL/mL) followed by Streptomyces candidus (ZOI = 9.33 ± 0.58 mm, MIC = 5 µL/mL), while the oil was least effective against Aeromonas hydrophila and Klebsiella pneumoniae.

KEY WORDS: Grangea maderaspatana, essential oil, antioxidant activity, antimicrobial activity, terpenoid composition.