Cryptotanshinone inhibits oral squamous cell carcinoma through the autophagic pathway

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors with a low quality of life. Because traditional surgical treatment often causes large wounds and then affects the quality of life of patients, it is urgent to find new and efficient drugs with good safety for clinical treatment. This study aimed to identify potential anticancer drugs starting from the traditional Chinese medicine Salvia miltiorrhiza extract. Cryptotanshinone, a compound isolated from the Chinese herb Salvia miltiorrhiza, was found to significantly induce apoptosis and inhibit proliferation in OSCC. By electron microscopy, autophagosomes were found. Confocal fluorescence microscopy data showed that cryptotanshinone significantly induced autophagy in OSCC cells. Mechanistically, the western blot assay indicated that cryptotanshinone induced cell autophagy through the activation of the LC3 pathway, whereas the autophagy inhibitor 3-methyladenine attenuated these effects. Furthermore, we demonstrated that cryptotanshinone had a significant antitumor effect in a tumor xenograft model, and no damage to vital organs was observed. Our findings provide evidence that cryptotanshinone may be a novel therapeutic strategy for the treatment of OSCC.