Chemical Composition, Antioxidant and Anti-inflammatory Activities of Essential Oils of Three Cymbopogon Plants

The chemical constituents of the essential oils from three Cymbopogon plants (C. winteranus, C. citratus and C. distans) were detected by GC-MS. Their antioxidant activity was investigated by the scavenging rate of DPPH free radicals and anti-inflammatory activity were evaluated by inhibition of lipopolysaccharide (LPS)-induced NO production in RAW264.7 cells. The results showed that terpenoids were the main chemical constituents of essential oils from three Cymbopogon plants, with the content of 76.35%~90.52%, of which terpene aldehydes and terpene alcohols were the highest. The main components of C. winteranus, C. citratus and C. distans were (+)-citronellal (37.85%), trans-citral (36.12%) and geraniol (34.76%), respectively. The DPPH radical scavenging activity of the three essential oils was dose-dependent, but lower than that of ascorbic acid (IC₅₀=(0.005±0.002) mg/mL). At a lower concentration (2~4 μg/mL), the ability of three essential oil to reduce NO production was similar to dexamethasone (Dex, 10 μmol/L). The results showed that the three essential oils of Cymbopogon had significant anti-inflammatory activity, C. citratus (IC₅₀ =(0.472±0.121) μg/mL) had the best anti-inflammatory activity, followed by C. winteranus (IC₅₀ = (0.632±0.147) μg/mL) and C. distans (IC₅₀ =(0.669±0.131) μg/mL). Thus they have great development potential as anti-inflammatory drugs and anti-inflammatory products.