Study on the anti-hepatocarcinoma effect and molecular mechanism of Prunella vulgaris total flavonoids

Abstract

Ethnopharmacological relevanceThe traditional use of Prunella vulgaris is for the treatment of liver cancer in a few areas of China. At present, it is used primarily for the treatment of thyroid cancer, throat cancer, and lymphosarcoma among others. However, there are few current scientific reports regarding its use for the treatment of liver cancer. In this paper, the effective treatment for liver cancer is studied to provide an experimental basis for the application of Prunella vulgaris, which is related to preparations in the treatment of liver cancer. Aim of the studyTo study the anti-hepatocarcinoma effect of Prunella vulgaris total flavonoids and explores the possible molecular mechanism. MethodsThe effects of Prunella vulgaris total flavonoids on the proliferation of SMMC-7721 cells were respected by RTCA analysis system. The tumor volume and weight were found in H22 tumor bearing mice. ELISA was used to observe the apoptosis and autophagy protein expressions in tumor tissue homogenate, along with the immune serum factor. Tumor tissue apoptosis was respected by the TUNEL method. And Bax, Bcl2, PI3K, Akt, mTOR, Beclin-1 and LC3-I/LC3-II expression were observed through Western blot. We also observed the expression of Beclin-1 and LC3-I/LC3-II through immunohistochemistry. ResultsThe total flavonoids of Prunella vulgaris inhibited the activity of SMMC-7721 cells, and reduced the tumor volume and weight in H22 tumor bearing mice. HE staining showed that the Prunella vulgaris total flavonoids inhibited liver metastasis of H22 tumor. The Prunella vulgaris total flavonoids significantly made the expressions of IL-6, TNF-α and IFN-γ immune factors increasing in the serum of tumor bearing mice, and the contents of caspase-3 and caspase-9 increase as well in tumor tissue homogenate. TUNEL showed that the mean density in the intervention group was significantly higher than that in the control group. P62 content in tumor tissue homogenate increased and ATG5 decreased after intervention. Immunohistochemistry showed Beclin-1 expression decreased and LC3-I/LC3-II increased in the tumor tissue. Western blot showed Bcl2, Beclin-1 expression decreased and Bax, PI3K, Akt, mTOR, LC3-I/LC3-II increased in the tumor tissue. ConclusionPrunella vulgaris total flavonoids have an obvious anti-hepatocarcinoma effect, and the mechanism may be linked to the inhibition of autophagy and promotion of apoptosis in liver cancer cells. The inhibition of autophagy may be related to activation of the PI3K/Akt/mTOR pathway.