Antimicrobial activity of tulsi

1. THE OXFORD COLLEGE OF
SCIENCE
Antimicorobial activity of tulsi (ocimum tenuiflorum)
essential oil and their major constituents
against three species of bacteria
TEAM: ANIL KUMAR C
SHARMILA
PAVITHRA
HARSHITA
CHANDANA
ANUSHA

2. INTRODUCTION
• In recent years scientists worldwide have realized that the effective life span of any
antimicrobial agent is limited, due to increasing development of resistance by
micoorganisms.
• Consequently, numerous studies have been conducted to find new alternative sources of
antimicrobial agents, especially from plants.
• The aims of this project were to examine the antimicrobial properties of essential oils
distilled from Australian-grown ocimum tenuiflorum (tulsi) to quantify the volatile
components present in flower spikes, leaves and the essential oil, and to investigate the
compounds responsible for any activity.
• Broth micor-dilution was used to determine the minimum inhibitory concentration (MIC) of
tulsi essential oil against selected micorobial pathogens.
• The oils, at concentrations of 4.5 and 2.25% completely inhibited the growth of
staphylococcus aureus (including MRSA) and Escherichia coli, while the same concentration
only partly inhibited the growth of pseudomonas aeruginosa.

3. • 54 comopunds identified in tulsi leaves, flower spikes, or essential oil
three are proposed to be responsible for this activity; camphor,
eucalyptol and eugenol.
• Since S.aureus (including MRSA), P.aeruginosa and E.coli are major
pathogens causing skin and soft tissue infections, tulsi essential oli
could be a valuable topical antimicrobial agent for management of
skin infections by these organisms.

4. MATERIALS AND METHODS
• Tulsi obtained from medicinal plant herbarium at southern cross
university
• Fresh leaves were steamed distilled for 6 hrs in an steam distiller
• The yield of volatile oil was 0.57%
• Yellow colored volatile oil was store at 4 celcius dark until needed
• BACTERIAL STAINS : S. auresus , E. coli , P. aeruginosa

6. Procedure:
• Extracted oil was emulsified in muller- hinton broth
• 90µl of oil and 10µl of DMSO were added
• Solution mixed by vortexing and added 900µl of MHB
• From that 30µl aliquots with brief vortexing
• Determined minimal inhnitory concentration of tulsi essential oil
• Two fold dilution of essential oil dilute and solubilized
• 9% of 50µl were prepared in MHB in 96 well
• 50µl of bacterial suspension was added ( final concentration 5*10)
• Further diluted 1:2 by bacterial suspension was incubated for 24 at 37
celcius
• O.D at 620 nm

7. Extraction of volatile compounds by HS- SPME
• extraction volatile compounds was performed by headspace solid
phase micro extraction
• 85µm polycrylate fiber fitted to sampling fiber holder was placing into
the gas chromotograph injection port at 250 celcius for 30 minutes
• PA fiber was cooled then inserted into headspace of vial containing
sample , then whole system was placed in a heating block for 40
celcius for 50 min
• Volatile were then desorbed by placing the fiber in the GC injection
for 5 min

8. RESULT:
1.Nineteen major compounds were
present in all samples from all parts of the plant, but
at different concentrations.
2. The cell viability decreased by less
than 20% when the cells were treated with a concentration
of 20 mg/ml.
3.Tulsi oil at concentrations of 4.5 and 2.25% completely inhibited
the growth of S. aureus,

10. DISCUSSION:
• This article shows biostatic activity of tulsi oil at levels of 2.25-
25µg|ml against S. auresus , E. coli but less activity against P. aeruginosa
• Result showed the cytoxicity of ectracts decreased in decreasing
conctration
• Major volatile compounds present In the tulsi camphor , eucalyptol
and eugenol
• Other than this beta – caryophyllene used for fragnance in food
addictive and cosmetics

11. A. Taygetea A. fraasii

12. Conclusion:
• completely inhibited the growth of staphylococcus aureus (including
MRSA) and Escherichia coli, while the same concentration only partly
inhibited the growth of pseudomonas aeruginosa.
• 54 comopunds identified in tulsi leaves, flower spikes, or essential oil
three are proposed to be responsible for this activity; camphor,
eucalyptol and eugenol.