Cytotoxic Effects of Imperata cylindrica Root Ethanol Extract on the Expression of PKCα, STAT3, and mTOR in A549 Lung Cancer Cell Line

Background: Imperata cylindrica or Cogon grass is a medicinal plant that has an anticancer effect. We unravel the cytotoxic effect of Imperata cylindrica root ethanol extract on the expression of PKCα, STAT3 and mTOR in A549 lung cancer cell lines. Methods: The cytotoxic effect tests were carried out on the A549 lung cancer cell line after 48 hours post-treatment using 3- [4, 5-dimethylthiazol-2-yl] -2.5 diphenyl tetrazolium bromide (MTT) assay method to discover the IC₅₀ dose, continued with apoptosis tests at doses of 150, 300, and 600 μg/mL of I.cylindrica root ethanol extract using flowcytometry, as well as measurements of PKCα, STAT3, and mTOR mRNA expressions with the RT-qPCR method and measurements of PKCα, STAT3, and mTOR protein expressions with Western blot method. Results: This study showed that the ethanol extract of I. cylindrica roots had an IC₅₀ of 541 μg/mL (weak cytotoxic) and the IC₅₀ of erlotinib was at 29 μM (moderate cytotoxic). In apoptotic test, the highest average apoptotic results were found in erlotinib group, while ethanol extract doses of 150, 300, and 600 μg/mL gave apoptotic effects on cancer cells higher than negative control group. From RT-qPCR, found that I.cylindrica significantly inhibit the expression of PKCα, STAT₃, and mTOR mRNA and from band scanning using Western Blot showed PKCα, STAT3, and mTOR protein expressions in Imperata root ethanol extract, qualitatively produced thinner bands when compared to the negative control group. Conclusion: This study demonstrated I.cylindrica root ethanol extract ability inhibiting the expression of PKCα, STAT3 and mTOR genes and proteins in the A549 lung cancer cell line, which can be taken into consideration as a complementary therapy in treatment of lung cancer.