Chemical composition, Larvicidal and Antibacterial Activity of the Essential Oil of Trachyspermum ammi Fruit

Trachyspermum ammi fruits (T. ammi) are widely sold and used in the Arabian herbal markets, which requires scientific investigations about its biological activities. The GC-MS analysis of the essential oil revealed that it contains 20 compounds, of which the main components are aromatic and monocyclic terpenes. Thymol was present in the higher amounts (36.00%) followed by γ-terpinene (26.01%) and m-cymene (21.44%). The essential oil of T. ammi contains about 9.77% of bicyclic terpenes of which β-pinene is about 6.70%. The anti-bacterial activity (in vitro) was performed by disc diffusion, MIC and MBC methods. The essential oil of the fruits of T. ammi exhibited significant dose-dependent antibacterial activity against all tested microorganisms (three Gram-positive and four Gram-negative bacteria) and it was comparable to the positive control (Chloramphenicol), with a remarkable MIC and MBC values. Water extract of T. ammi exhibited promising larvicidal activity against S. littoralis and the lethal concentration, LC50 was found to be 6.21%. The current study provides some scientific support to the application of T. ammi fruits in traditional medicine and suggests it as a source of antibacterial drug and natural larvicidal agents for crops as biocontrols.