Mentha pulegium essential oil: chemical composition, total phenolic and its cytotoxicity on cell line HT29

Free radicals activity and their products of their oxidation can cause undesired feeling and nutritional effects such as, awful taste, destroying vitamins and destruction of essential fatty acids. These compounds which are toxic substances and damage the genetic material of cells causing heart and cardio vascular diseases and different type of cancer. Antioxidats absorb free radicals, so they can decelerate oxidation speed, then delete them to save the body from undesirable effects. Pooneh which is called scientifically Mentha pulegium belongs to lamiaceae group. The aim of this study was evaluating chemical compounds, antioxidant activity, total phenolic and cytotoxicity of Mentha pulegium essential oil (MPEO) on cell line of colon and gut cancer.

In this study, after extraction of MPEO using condensation the essential oil chemical composition were identified with gas chromatography-mass spectrometer (GC-MS). Antioxidant activity was measured with radical inhibition ability method DPPH, ABTS and also their resistance against linoleic acid oxidation and changing β-carotene color, was considered. The evaluation of total phenolic composition was carried out using folin-ciocalteu method. To do this, the concentration of 1000, 10000, 1200 and 1400 of MPEO with alcohol was prepared. One mL of each concentration was added to 2.5mL of folin-ciocalteu reagent. After 2.5 minutes, 2ml sodium carbonate was added and mixed well. The rate of sample absorbtion after one hour was 725 nm. Determination of flavonoids range was done with aluminum chloride. MPEO cytotoxicity effects (1, 3.125, 6.25, 12.5, 25, 50, 100, 200 mg/ml) on colon cancer cell line (HT29) was performed using MTT method. In this method 30 mL of MTT solution with 5 mg/mL was add to all wells and maintain for 3 hours in carbon dioxide. After removing environment, 200µl DMSO was add to each well and the rate of absorbtion in 570 nm was read usingELISA/microplate reader device. Cell aliveness curve was drawn.

The results showed that MPEO had 25 compounds, dl-limonene 28.44%, D-carvone 18.76%, Eucalyptol 8.86% and pulegone 8.65% were the top components. The rata of Mentha pulegium free radicals control with DPPH and ABTS was 51.5% and 53.43% respectively. The amount of MPEO resistance against oxidation of linoleic acids and color changing in β-carotene was 59.22%. Total phenolic was equal to 73.35 mg gallic acid/ml. The cytotoxicity effects results showed, the percent of HT29 aliveness was 100, 70.21, 61.26, 51.98, 35.12, 24.44, 18.65 and 10.92 respectively. Based on the results, increasing in MPEO concentration, caused increasing in HT29 cell line and decreasing percentage of aliveness. The most cells toxicity was in 200 mg/mL and the less was in 1 mg/mL.
According to the results, in this study MPEO had suitable antioxidant activity, so we can use Mentha pulegium as an alternative for synthesis preservatives in food industry.