Tehran University Medical Journal

Background: Aloysia citrodora belongs to the Verbenaceae family of plants, a well-known herbal medicine in Iran. The aim of the present study was to investigate the chemical composition, antioxidant, antibacterial, cytotoxic and apoptotic effect of A. citrodora extract against human colon cancer (HT29) cells by using real-time polymerase chain reaction and flow-cytometry methods.

Methods: This experimental study was carried out in Islamic Azad University, East Tehran Branch, from March to September of 2014. At first, the A. citrodora chemical constituents were analyzed by gas chromatography-mass spectrometry (GC-MS) technique. In addition, antioxidant assay, antibacterial and anti-cancer effect was performed using 1,1-diphenyl-2-picrylhydrazyl (DPPH), disk diffusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods, respectively. The half maximal inhibitory concentration (IC50) value was calculated. We extracted total RNA molecules by using RNX solution, after which cDNA was synthesized. Finally, the pro-apoptotic (Bax) and anti-apoptotic (Bcl2) gene expression was performed by real-time polymerase chain reaction and apoptotic effects were analyzed using Flow-cytometry method.

Results: GC-MS analysis of Aloysia citrodora extract was shown 37 major components and the most frequent component was belonged to Spathulenol (17.57%) and Caryophyllene oxide (15.15%) The antioxidant activity of the extract was IC50= 0.6±0.03 mg/ml. The maximum and minimum antibacterial effects of extract were belonged to gram-negative and gram-positive bacteria, respectively. Cytotoxic results revealed that the A.citrodora extract have IC50= 20.1±0.78 mg/ml against colon cancer (HT29) cell line and real-time polymerase chain reaction results showed the expression level of Bax and Bcl2 was increased and decreased respectively in colon cancer cell line (3.470±0.72 (P< 0.05), 0.43±0.35 (P< 0.05)). In addition, the flow-cytometry results indicated the 38.66% apoptosis in colon cancer cell line.

Conclusion: According to the results, it seems that A. citrodora extract has potential antioxidant, antibacterial and anticancer effects and it suggested that further studies were performed for A. citrodora pharmaceutical importance.