Composition and biological activity of essential oil from Artemisia roxburghiana Besser and Elsholtzia fruticosa Rehder cultivated in Italy

Artemisia roxburghiana Besser and Elsholtzia fruticosa Rehder plants were evaluated as innovative crops for the production of essential oil with valuable biological activity. A high essential oil content resulted for both species, that is 0.31% for A. roxburghiana and 0.46% for E. fruticosa. The composition of essential oil of A. roxburghiana is characterized by higher amount of cis-thujone, 1-8 cineole and camphor, while E. fruticosa oil is rich in 1,8-cineole and -terpinene. The biocidal activities of both oils were evaluated against some pathogenic Gram-positive and Gram-negative bacterial strains and as natural insecticides against aphids. E. fruticosa oil showed higher microbiologic activity compared to A. roxburghiana one, particularly against Staphylocosus aureus, Enterococcus faecium, Salmonella sp. and Escherichia coli. Both plant species revealed a high aphicidal activity against the polyphagous pest Myzus persicae, assessed by nymph mortality and fecundity reduction, and their efficacy resulted to be comparable to that of azadyrachtin. Due to the high content and the biocidal activity of these oils, the two investigated species represent a possible innovative crop for the production of essential oils to be employed in the food and the agro-industry.