Researchers in China have found that shikonin, a natural naphthoquinone isolated from the plant Lithospermum erythrorhizon, can suppress tumour growth in esophageal cancer.
Esophageal cancer is the eighth most common malignancy and the sixth most common cause of death worldwide. While surgery represents the primary modality of treatment, the prognosis and survival for this disease remains poor.
A study led by Dr. Yonggan Ren at the North of Si Chuan Medical University in China investigated the effects and mechanisms of shikonin against esophageal cancer. Researchers found that hypoxia inducible factor 1α (HIF1α) and pyruvate kinase M2 (PKM2) protein expression levels were higher in esophageal cancer tissues and cells than in normal esophageal tissues and cells. Shikonin reduced esophageal cancer cells viability and induced cell cycle arrest and apoptosis. Shikonin decreased EGFR, PI3K, p-AKT, HIF1α and PKM2 expression.
In vivo they found that shikonin reduced tumour burden, inducing cell arrest and apoptosis. The results from this study suggest that shikonin has a significant anti-tumour effect in the esophageal cancer by regulating HIF1α/PKM2 signal pathway.