Growth inhibitory activity of Rosa × damascena flower extract on Acinetobacter baumannii Open Access

Zhong, Jiabao (Spring 2020)

Permanent URL:


The emergence of Acinetobacter baumannii, a common nosocomial, opportunistic pathogen, has caused more and more infection cases around the world. The virulence of the species – tolerance for desiccation and disinfection, motility and biofilm formation – allows it to persist and spread in healthcare settings. Due to the high mortality rate and high multidrug-resistance rate, effective treatments against the pathogen are becoming limited, while the resistance genes are rapidly spread via horizontal-gene transfer between strains of A. baumannii. The most commonly used antibiotics against A. baumannii infection is carbapenem, and the last-line treatment is colistin, but strains resistant to the two antibiotics are reported around the world. The need for novel treatment is urgent and one of the promising novel treatments is chemical compounds extracted from medicinal plants.

The flower of the Damask rose, Rosa × damascena, has a long history of medicinal use in Lebanon, besides its various commercial use. It is commonly used to relieve gastrointestinal problems, cough and dermatitis by Lebanese, and is believed to function as cardiotonic, antirheumatic, antioxidant and antimicrobial. The essential oil of the flower is also documented to be a relaxant that heals depression, stress, anxiety and migraine. Previous research had demonstrated certain antimicrobial effect of R. damascena extract.

Through bioassay-guide fractionation, extraction of the Rosa × damascena flower was fractionated and determined to have growth inhibitory activity against Acinetobacter baumannii strains ATCC 17978 and AB5075. The growth inhibitory effect was determined by broth microdilution MIC assay, and the most potent fractions, 1921D-F7~9, were confirmed with TLC-agar overlay bioautography assay of inhibiting growth of AB5075. Cytotoxicity test show that the potent extracts have low toxicity to human skin cells. Therefore, further separation of the potent extracts 1921D-F7~9 of R. damascena flower is a promising direction for treatment against multidrug-resistant A. baumannii.

Table of Contents

Chapter 1: Introduction                                                                                                                    1

            Acinetobacter baumannii: emerging infection, virulence, antimicrobial resistance

            Rosa × damascena mill L.: traditional use, chemical profile, pharmacological properties

            Research question and project aims

Chapter 2: Materials and Methods                                                                                              11

           Overview of Bioassay-guided fractionation

            Plant collection and processing

            Plant Maceration

            Fractionation of plant extracts

            Analysis of plant extracts

            Bioactivity assays

Chapter 3: Results                                                                                                                          23

           Overall fractionation scheme

            Extracts 1921 and 1921B~E

            Extracts 1921D and 1921D-Fs

            Extracts 1921D-F7~9

Chapter 4: Discussion                                                                                                                     39

            Overall fractionation scheme

            Chemical Properties of Rosa × damascena Potent Extracts

            Biological Activity of Rosa × damascena Potent Extracts


            Future directions

About this Honors Thesis

Rights statement
  • Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.
  • English
Research Field
Committee Chair / Thesis Advisor
Committee Members
Last modified

Primary PDF

Supplemental Files