Microscopical examination, essential oil composition and evaluation leaves extract as antibacterial activity of Zanthoxylum odoratum L. cultivated in Iraq

Rutaceae family, especially genus Zanthoxylum L., are well-known for its occupancy diverse chemical components with significant pharmacological proficiency. This study aims to evaluate the leaf surface under a microscope, analysis of essential oil ingredients and estimate antibacterial activity of ethanol extracts from the leaves of Zanthoxylum odoratum L. cultivated In Iraq. Fresh leaves of Z. odoratum were collected from the Pharmacy Collage Botanical Garden, in February 2023.Using free-hand sections, the anatomy of the leaf was analysed and stomata and their types were identified. Hydrodistilling in a claviger apparatus was used to extract the essential oil and then the GC/MS system was used to determine its chemical composition. Antibacterial efficacy of ethanol extracts of Z. odoratum leaves was evaluated against two Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa using the well diffusion method and determining the minimum inhibitory concentrations (MIC). The leaves have a single layer of epidermis. Lower epidermis was stomatiferous and the stomata are anomocytic. By hydrodistillation, the essential oils of Z. odoratum L. leaves were obtained and analyzed using gas chromatography-mass spectroscopy. The most plentiful category of compounds found in leaf oils is acyclic and non-cyclic monoterpenes. Additionally, monocyclic and bicyclical sesquiterpene. In general, D-Limonene, Methyl cinnamate, β-Myrcene and Humulene are the main constituents of this species. Minimum inhibitory concentrations (MIC) of ethanol extracts of leaves were estimated against two Gram negative bacteria. While the extracts at lower concentrations exhibit considerable inhibitory action against E. coli, the extracts at all doses show different degrees of inhibitory activity against all P. aeruginosa bacteria.