Chemical composition, antioxidant and myorelaxant activity of essential oils of Globba sessiliflora Sims

The volatile constituents of the rhizomes and aerial parts of Globba sessiliflora Sims were analyzed by a combination of gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The major constituents identified in the rhizome oil were beta-caryophyllene (20.1%), alpha-cadinol (14.7%), selin-11-en-4 alpha-ol (12.0%), caryophyllene oxide (8.6%), gamma-eudesmol (7.1%) and myrcene (4.7%). The oil from aerial part contained myrcene (15.8%), beta-caryophyllene (12.3%), selin-11-en-4 alpha-ol (11.0%), beta-longipinene (10.9), manool (8.1%), germacrene D (5.2%) and beta-eudesmol (4.1%) as major constituents. Both the oils showed significant myorelaxant effect on isolated duodenum smooth muscles of Wistar rats. The antioxidant activity of the oils were evaluated by different methods, namely reducing power assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and the chelating effect on Fe2+. The oils exhibited good to moderate antioxidant activity in a dose-dependent manner.