Abstract:
Non-small-cell lung carcinoma (NSCLC) is a type of epithelial lung cancer accounting for about 85% of all lung can-
cers. In our research, a novel lupene derivative namely acetoxy-lup-5(6), 20(29)-diene (ALUP), as well as two known
triterpenes; lupeol (LUP) and betulinic acid (BA) were isolated through the chromatographic purifcation of the 95%
ethanolic extract of Thymus capitatus. Identifcation of the compounds was carried out by physicochemical properties
as well as spectral 1D and 2D NMR analysis. The anti-cancer activity of the three triterpenes was assessed on non-
small cell lung cancer cell line; A549 using MTT assay and cell cycle analysis using annexin V/propidium iodide. The
molecular mechanism underlying anti-apoptotic efects was determined by analyzing Let-7 miRNA and miRNA-21
expression, the mRNA gene expression level of Bax, CASP-8, CD95, Bcl2, KRAS, VEGF, Cyclin D1 using qRT-PCR. Our
results revealed that the three isolated compounds ALUP, LUP, and BA caused cell cycle arrest at the G2/M phase
with an increase in the apoptosis which may be attributed to their signifcant efect on raising Bax, CASP-8, and CD95
and reducing the mRNA expression levels of Bcl-2, KRAS, VEGF, and Cyclin D1 compared to control cells. RT-PCR results
showed that the ALUP, LUP, and BA signifcantly downregulated miRNA-21 expression. Meanwhile, the three com-
pounds caused signifcant overexpression of Let-7 miRNA. This is the frst report on the anti-cancer activity of acetoxy-
lup-5(6), 20(29)-diene (ALUP) in reducing the proliferation and diferentiation of the A549 cell line through inducing
apoptosis. Finally, by targeting the Let-7 miRNA/Cyclin D1/VEGF cascade, acetoxy-lup-5(6), 20(29)-diene could be
a potential therapeutic agent for lung cancer.
