Essential Oil Constituents and Biological Activities of the Halophytic Plants, Suaeda Vermiculata Forssk and Salsola Cyclophylla Bakera Growing in Saudi Arabia

Suaeda vermiculata Forssk and Salsola cyclophylla Bakera are two halophytic plants growing in marsh salted areas of central Saudi Arabia and are used for both medicinal and feeding camel's purposes. Essential oil analysis for the plants was achieved for the first time and offered seventeen compounds from S. vermiculata (100 %) and thirty-three volatile compounds (98.16 %) from S. cyclophylla. Camphor (28.74 %), borneol (33.77 %) and alpha-Terpineol (22.78 %) constitute the majority of essential oils of S. vermiculata while hexahydrofarnesyl acetone (27.14 %) and benzoic acid esters (27.97 %) constitute the majority of essential oils of S. cyclophylla. The scavenging effect of S. vermiculata and S. cyclophylla essential oils at 10 mg/ml 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical was 47 % and 32 %, respectively. S. vermiculata essential oil demonstrated a strong growth inhibition for Candida albicans by 19 mm inhibition zone diameter (IZD) and 5.2 mg/ml minimal inhibitory concentration (MIC) and a moderate growth inhibition for Pseudomonas aeruginosa; while essential oil of S. cyclophylla inhibited the growth of Staphylococcus aureus and Candida albicans by 16 mm IZD and MIC equal to 45 and 14.5 mg/ml, respectively. In conclusion, both essential oils demonstrated a significant antioxidant activity compared with the standard Trolox. The significant antioxidant and antimicrobial activity were confirmed which is remarkable from the viewpoint of this herb being regular camel feed.