Anticancer Activity of Ethyl Acetate Extract from Lethariella cladonioides in vitro and in vivo

Background: Lethariella cladonioides, also known as Red Snow Tea and Golden Silk Tea, mainly grows in Tibet, Sichuan and Yunnan of China. Its medicinal value has been gradually discovered. Objectives: This study mainly evaluated the anti‑cancer effect of AMH‑L extracted from L. cladonioides in vitro and in vivo and to explore its anticancer mechanism. Materials and Methods: MTT assay was used to determine the cytotoxicity of AMH‑L to human cancer cells A‑549 and HCT‑116 in vitro. Sarcoma S‑180 and human lung cancer NCL‑H460 cells were implanted into Kunming mice and Balb/C nude mice, respectively, anti‑cancer activity in vivo was assessed by recording body weight, organ coefficient and tumor inhibition rate. Flow cytometry and western blotting were used to preliminarily explore the anticancer mechanism. Results: AMH‑L, the active component of Red Snow Tea, had strong anticancer activity against A‑549 and HCT‑116, and IC₅₀ was 26.17 ± 3.54 and 16.21 ± 0.83. When the dosage was 50, 100 and 150 mg/ kg, the inhibition rates of S‑180 in Kunming mice were 36.04%, 43.14%, and 50.45% in turn, respectively. At the end of the experiment, the dose was 150, and the relative proliferation inhibition rate of Balb/C nude mice NCI‑H460 tumor was 50.36%. Cell cycle and apoptotic results showed that AMH‑L could block A‑549 at G2/M phase and promote apoptosis of HCT‑116 by inducing poly (ADP‑ribose) polymerase lysis. Conclusion: L. cladonioides extract AMH‑L exhibits strong anticancer activity in vivo and in vitro and can be used as a potential anticancer drug for further study.