Antiproliferative and apoptosis induction of cucurbitacin-type triterpenes from Ibervillea sonorae

• We examined whether triterpenes from I. sonorae have anti-proliferative and apoptosis induction capacity.
• Two cucurbitacin-type triterpenes were isolated from the root methanolic extract.
• We observed that kinoin A was able to inhibit the growth of a cancer cell lines.
• We demonstrated that kinoin A is a molecule with great apoptosis induction capacity.

Two cucurbitacin-type triterpenes kinoin A (1) and kinoin B diglucoside (2) were isolated and characterized by chromatographic and spectroscopic techniques from the root of Ibervillea sonorae. By MTT assay their antiproliferative activity was evaluated and only compound 1 was able to inhibit the growth of HeLa, M12AK.C3F6, A549 and RAW 264.7 cancer cell lines with a IC50 of 18.0, 31.4, 40.2, and 61.5 μM, respectively. L-929 cell line used as a control was more resistant to compound 1 at IC50 values greater than 100 μM. Apoptosis induction was quantified for a double staining by Annexin V/propidium iodide using flow cytometry, and it was observed that treatment of HeLa cells with compound 1 cause cell death by apoptosis.