Zanthoxylum bungeanum Seed Oil Elicits Autophagy and Apoptosis in Human Laryngeal Tumor Cells via PI3K/AKT/mTOR Signaling Pathway

Zanthoxylum bungeanum seed oil (ZBSO) is the main extract of the edible drug Zanthoxylum bungeanum seeds. Recent reports have proved that it has a significant cytotoxic effect on various cancer cells. However, systematic investigation on the role of ZBSO in laryngeal carcinoma (LC) is rare. The aim of the study was to reveal the function of ZBSO on human laryngeal squamous carcinoma cells (Hep-2) and to elucidate its underlying mechanism. In this study, the chemical composition analysis of ZBSO was done using Ultra Performance Liquid Chromatography (UPLC), and the anti-tumor effect of ZBSO on Hep-2 cells was evaluated by cell proliferation, apoptosis and cell cycle experiments. qRT-PCR, immunohistochemistry (IHC) and Western blotting were used for mechanistic investigation at the molecular level. The main compound of ZBSO was identified as polyunsaturated fatty acids. Furthermore, as compared to normal cells, significant inhibitory activities of ZBSO were observed on Hep-2 cells with dose- and timedependency, which induced apoptosis, blocked cell cycle at the S phase, and inhibited cell proliferation. In addition, IHC results showed a difference in the level of protein expression of ZBSO-induced autophagy-related markers. At last, Western blotting results indicated that ZBSO could inhibit the expression and phosphorylation levels of PI3K/AKT/mTOR protein. The anti-LC effect of ZBSO might be intimately associated with the induction of autophagy and the inhibition of the PI3K/AKT/mTOR signaling pathway. ZBSO may be a potential anti-laryngocarcinoma agent.