eucalyptus oil review. the antibacterial effect of eucalyptus oil

Eucalyptus oil Review: Antibacterial Effects of Eucalyptus oil




The extraction of oil from eucalyptus citriodora HOOK and its antibacterial effect on Escherichia coli was carried out to evaluate and determine the usefulness of eucalyptus oil in treating infectious diseases caused by Escherichia coli. This is a scientific research project aim at finding solution to pathogenic diseases.



The fresh leaves of eucalyptus citriodora hook were collected from five different locations. The oil was extracted immediately after sample collection by steam distillation. 40g of the leaves was placed into 250ml 0f water and heated in a conical flask .The temperature was maintained at about 98 ̊C. The process lasted for three and half hours. The distillate was yellowish in color. Antibacterial screening was carried out using Mueller-Hinton-Agar. The Agar disc diffusion method was employed. The result of the antibacterial activity test revealed that the essential oil of eucalyptus citriodora has an antibacterial activity against Escherichia coli with inhibition zone ranging from 6mm to 15mm of both low and high concentration respectively.



The essential oil of eucalyptus citriodora is yellowish in colour with a lemon scented aromatic smell. The leaves have antibacterial and antifungal properties. The spread of drug resistant pathogens has caused a serious threat to the treatments of infectious diseases. Escherichia coli, which is a gram negative anaerobic bacteria has prevailed in infectious diseases. With the right application of eucalyptus oil, such diseases can be suppressed.



  • The research is of immense importance because it looks into the extraction of oil from eucalyptus citriodora leaves by steam distillation.
  • It enables us to know the antibacterial property of eucalyptus oil.


AIMS AND OBJECTIVE                   

This academic research project is centre on;

  • The extraction of eucalyptus oil from Eucalyptus citriodora Hook from five different locations, and

  • Its antibacterial effect using Escherichia Coli.



Eucalyptus plant is a tall tree that grows wild in warmer climate with diverse genius of trees. They are about several hundred species of eucalyptus plants. Eucalyptus oil is an essential oil distilled from the leaves of eucalyptus plant with a sweet smell by steam distillation. The oil is a photochemical extracted from the plant leaves. Its usefulness is seen in a variety of ways and in its medicinal value. Eucalyptus oil is divided into three classes;

  • Medicinal

  • Industrial

  • Aromatic

The essential oil of eucalyptus plant finds many uses in aromatherapy and in allelopathic effects.


Eucalyptus citriodora plants are naturally ever green with oil glands, but lose its leaves during summer. They are commonly laceolate, petiolate and glossy green.


Review on eucalyptus citriodora

Scientific classification

  • Kingdom: Plantae
  • (unranked): Angiosperms
  • (unranked): Eudicots
  • (unranked): Rosids
  • Order: Myrtales
  • Family: Myrtaceae
  • Tribe: Eucalypteae
  • Genus: Corymbia
  • Species: C. citriodora
  • Corymbiacitriodor



The most conspicuous features of eucalyptus citriodora are the flowers and fruits (capsules and gumnuts). All matured  eucalypts put on an annual layer of bark which varies with the age of the plant, the manner of the bark shed, the length of the bark fibres, the degree of furrowing, the thickness, the hardness and the colour. The types of bark include;


  • Stringy bark
  • Iron bark
  • Tessellated bark
  • Ribbon bark


The lemon scented gum mainly consists of citronellal, is used as insect repellents. Eucalyptus oil has anti-inflammatory effect and analgesic qualities. The cineole-based oil is used as a component in pharmaceutical preparations to relieve the symptoms of influenza and cold. The essential oil is used in personal hygiene, dental care, soaps and in wounds to prevent infections.


Eucalyptus oil is used in flavorings in beverages, confectionery, baked goods and meat products at low concentration (0.002%). It’s dangerous when taken by mouth. Eucalyptus oil about 5% of mixture prevents the separation problem with ethanol and petrol fuel blends. It has a variety of industrial applications.


It’s difficult to obtain reliable references concerning their pharmacological merits, but studies have shown that certain essential oil may have the ability to prevent the transmission of some drug resistant strains of pathogens specially staphylococcus, streptococcus and Candida.


Eucalyptus oil has a wide range of therapeutic properties including antimicrobial, diuretic, deodorant and stimulant. Download the file by clicking here