Volatile oil composition, antioxidant and antimicrobial properties of Boerhavia erecta L. and Euphorbia hirta L.

This study investigated the volatile oil composition of Boerhavia erecta L. and Euphorbia hirta L. along with the corresponding antioxidant and antimicrobial properties. In this regard, stems and roots of Boerhavia erecta together with aerial parts of Euphorbia hirta L. were used. Essential oils were obtained by hydrodistillation method using Clevenger-type apparatus, while identification and characterization were done by gas chromatography-mass spectrometry (GC-MS) technique. Antioxidant activities were evaluated by 2,2 -diphenyl-1-picrylhydrazyl (DPPH•) method and the antimicrobial properties were assessed by agar diffusion method. GC-MS analyses revealed seven and twenty-four components in stem and root oils of Boerhavia erecta L., respectively representing 81.84% and 76.93% of the total oil contents with phytol (61.31%) and 9-octadecenamide (33.95%) as the most abundant components, respectively. Eleven compounds were identified in E. hirta L. oil representing 92.79% of the oil. The major compound of this essential oil was (Z)-9-octadecenamide (60.71%). The other minor components were methyl hexadecanoate (7.02%) and phytol (4.80%). B. erecta and E. hirta oils showed significant antioxidant activities compared to α-tocopherol. B. erecta L. stem oil inhibited the growth of Escherichia coli and Staphylococcus aureus bacterial strains, while root oil showed moderate inhibition against Salmonella typhi and Bacillus subtilis at inhibition zones of 14-20 mm over a concentration of 12.5-50%. The three oil samples displayed significant antifungal activities against Candida albicans. Chemical constituents of B. erecta L. and E. hirta L. oils may be responsible for these biological activities. These evaluations are reported for the first time.