Cucurbitacin D Inhibits the Proliferation of HepG2 Cells and Induces Apoptosis by Modulating JAK/STAT3, PI3K/Akt/mTOR and MAPK Signaling Pathways.

BACKGROUND: Cucurbitacin D (CuD) is a natural compound that can be isolated in various plant families, mainly from Ecballium elaterium (L.) A. Rich. (E. elaterium). It is a triterpenoid with a broad spectrum of biological activity, including anti-cancer properties. Hepatocellular carcinoma, the aggressive type of liver cancer, is an important public health problem worldwide. OBJECTIVE: In the present study, we investigated the anticancer effect of CuD treated at different doses on the HepG2 cell line and the underlying mechanism in vitro. METHODS: CuD was isolated from the fruit juice of E. elaterium plant, and quantitative analysis was performed using high-performance liquid chromatography. The cell viability effect of purified CuD was determined by the MTT test, and also cell apoptosis and cell cycle arrest effects were determined by flow cytometry. DNA damage was evaluated with the comet test. Proteins and genes involved in PI3K/AKT/mTOR, MAPK, and JAK2/STAT3 signaling pathways were evaluated by western blot and qRT-PCR. RESULTS: CuD showed both antiproliferative and cytotoxic effects against the HepG2 cell line in a dose and time-dependent manner. It was observed that CuD induced apoptosis and blocked the cell cycle in HepG2 cells. It was observed that the expressions of genes and some proteins that play a key role in PI3K/AKT/mTOR, MAPK, and JAK2/STAT3 cascades were dose-dependently downregulated and led to activatation of the apoptotic pathway. CONCLUSION: All these results show promise that CuD may have a therapeutic effect in hepatocellular carcinoma.

Cucurbitacin I exhibits anticancer efficacy through induction of apoptosis and modulation of JAK/STAT3, MAPK/ERK, and AKT/mTOR signaling pathways in HepG2 cell line.

Hepatocellular carcinoma is a common cancer type, especially among men. Although cucurbitacin I (CuI), widely found in plants belonging to the Ecballium elaterium (E. L) plant family, has been shown to have antitumorigenic properties in many cancer types, its anticancer effect, molecular mechanism, and apoptotic effect mediated by signal pathways on hepatocellular carcinoma have not been fully clarified. In the present study, we investigated the anticancer effect of CuI treated at different doses on the HepG2 cell line and the underlying mechanism in vitro. High-purity CuI was obtained from the E. elaterium plant with the aid of HPLC. The effects of this substance on the viability of cells were studied by the MTT assay. The effects of CuI on cell cycle progression and apoptosis were studied with flow cytometry. DNA breaks were analyzed by the Comet assay method. The proteins and genes involved in the JAK/STAT3, MAPK/ERK, and AKT/mTOR signaling pathways were investigated using Western blot and qRT-PCR, respectively. The results of this study demonstrated that CuI significantly reduced HepG2 cell growth in vitro, induced antiproliferation, and G2/M phase of the cell cycle was interrupted. PRACTICAL APPLICATIONS: CuI administration was shown to downregulate the levels of proteins in the PI3K/AKT/mTOR, MAPK, and JAK2/STAT3 cascades in HepG2 cells. CuI also reduced the expression of MAPK, STAT3, mTOR, JAK2, and Akt genes in different concentrations. DNA breaks are formed as a result of this effect. CuI, by reducing cell proliferation and promoting apoptosis, was found to have potential as a chemotherapeutic agent of hepatocellular carcinoma.