Synergistic Combination of Luteolin and Asiatic Acid on Cervical Cancer In Vitro and In Vivo

SIMPLE SUMMARY: This study was the first to demonstrate the anticancer effects of luteolin (Lut) combined with asiatic acid (AsA) on CaSki and HeLa cervical cancer cells. Lut combined with AsA effectively reduced cervical cancer cell viability by arresting the cell cycle in the sub-G1 phase and inducing caspase-mediated intrinsic apoptosis. Lut combined with AsA treatment downregulated PI3K/AKT signaling (PI3K, AKT and p70S6K), JNK/p38 MAPK signaling and FAK signaling (integrin β1, paxillin and FAK) and upregulated ERK signaling to induce apoptosis and inhibit cancer cell migration. In in vivo study, Lut combined with AsA markedly inhibited cervical cancer cell-derived xenograft tumor growth and the cytotoxic effect was minimal or nonexistent. Collectively, the present study demonstrated that Lut combined with AsA may be used as an anticancer agent in future clinical treatment to improve the prognosis of cervical cancer. ABSTRACT: Cervical cancer is an important issue globally because it is the second most common gynecological malignant tumor and conventional treatment effects have been shown to be limited. Lut and AsA are plant-derived natural flavonoid and triterpenoid products that have exhibited anticancer activities and can modulate various signaling pathways. Thus, the aim of the present study was to evaluate whether Lut combined with AsA could enhance the anticancer effect to inhibit cervical cancer cell proliferation and examine the underlying molecular mechanisms in vitro and in vivo. The results of a CCK-8 assay showed that Lut combined with AsA more effectively inhibited the proliferation of CaSki and HeLa cells than Lut or AsA treatment alone. Lut combined with AsA caused apoptosis induction and sub-G1-phase arrest in CaSki and HeLa cells, as confirmed by flow cytometry, mitoROS analysis, antioxidant activity measurement and western blot assay. In addition, Lut combined with AsA significantly inhibited the cell migration ability of CaSki and HeLa cells in a wound-healing assay. Furthermore, Lut combined with AsA induced apoptosis and inhibited migration through downregulated PI3K/AKT (PI3K, AKT and p70S6K), JNK/p38 MAPK and FAK (integrin β1, paxillin and FAK) signaling and upregulated ERK signaling. In an in vivo study, Lut combined with AsA markedly inhibited cervical cancer cell-derived xenograft tumor growth. Collectively, the present study showed that Lut combined with AsA may be used as an anticancer agent to improve the prognosis of cervical cancer. Indeed, with additional research to develop standardized dosages, Lut and AsA combination therapy could also be applied in clinical medicine.