Aisha Abubaker Ali Shanan, Mohammed Hossam Eldin El Mallahi And Shaimaa Eliwa Ghazy,

ABSTRACT
Oral Cancer Is A Very Aggressive Malignant Tumor Which Is Considered The Sixth Most Common Malignancy Worldwide. Chemotherapy Still The Main Treatment For Malignancy To Improve The Survival Rate And Quality Of Life For Patients. 5-fluorouracil Considered As A Standard Chemotherapy Regimen In Cases Of Recurrent Or Metastatic Head And Neck Squamous Cell Carcinoma. However, The Resistance Of Malignant Cells To Chemotherapy Remains A Major Obstacle In Cancer Treatment. Recently, Exploring Natural Products With Anticancer Properties Become A Very Growing Area Of Study To Open The Gate For New Treatment Modalities. Eucalyptus Oil Consists Of Many Chemicals That Have Anticancer Effect, Especially Alpha-pinene And Beta-pinene. Many Other Chemicals Present In Eucalyptus Oil Are Still Under Study. Aims And
Objectives: The Objective Of The Present Study Was To Evaluate The Possible Cytotoxic Effect Of Eucalyptus Oil And 5-fluorouracil On Head And Neck Squamous Cell Carcinoma Cell Line And To Compare The Effect Of Eucalyptus Oil And 5-fluorouracil On The Expression Of The Apoptotic Marker (Caspase-3) In Head And Neck Squamous Cell Carcinoma Cell Line. Methods:Human Tongue Squamous Carcinoma Cell Line (SCC-15) Was Used In This Study.Different Concentrations Of 5-fluorouracil And Eucalyptus Oil Were Prepared And Applied For 24 And 48 Hours On The Used Cell Line. The Yellow Tetrazoliumsalt (MTT) Assay Was Used For Evaluation Of Cytotoxicity Ofeach5-fluorouracil And Eucalyptus Oil.The Quantitative Sandwich Immunoassay ELISA Technique Was Used For The Assessment Of Caspase-3 Expression In The Treated Cell Line.

Results: MTT Assay Revealed That 5-fluorouracil And Eucalyptus Oil Showed A Significant Cytotoxic Effecton SCC-15cell Line. The ELISA Assessment Of Caspase-3 Expression Revealed That There Was A Statistical Increase In Caspase-3 Expression In SCC-15cell Line Treated With5-fluorouracil Than Eucalyptus Oil. Conclusion: Both 5-FU And Eucalyptus Oil Are Cytotoxic To OSCC But 5-FU Is More Effective In Activation Of Apoptotic Pathways.