bakuchiol and Lung-Neoplasms

Immune checkpoint therapy is an emerging frontier in cancer therapy. With the aim to develop an efficient herb derived compound to facilitate immune checkpoint therapy, here we investigate if a herb-derived compound, Bakuchiol (BAK), can be used to treat lung cancer and elucidate if BAK could serve as a PD-L1 regulator. To this end, a murine lung cancer model was established by subcutaneously inoculating murine Lewis lung carcinoma (LLC) cells. BAK of 5 to 40 mg/kg was used for treatment in vivo for 15 days. On Day 15, the population of CD4+ and CD8+ T cells, Treg cells. BAK could effectively inhibit tumor growth by starting treatment either on Day 0 or 6 after tumor inoculation at doses of 5-40 mg/kg. BAK treatment increased the population of cytotoxic immune cells (i.e., CD8+ T cells, and M1 macrophages), meanwhile decreasing pro-tumor immune cells (i.e., CD3+ T cells, Treg cells, and M2 macrophages). Anti-inflammatory cytokines, including IL1β, IL2, IFNγ, TNF-α, IL4 and IL10 were upregulated by BAK. PD-L1 expression in the tumor was also lowered by BAK. AKT and STAT3 signaling were inhibited by BAK. BAK is an efficient agent in reducing LLC tumor growth. These data support the potential of BAK as a new drug for treating lung cancer by serving as a PD-L1 inhibitor that suppresses the activation of AKT and STAT3.

Topics: Animals; B7-H1 Antigen; Cell Line, Tumor; Humans; Lung Neoplasms; Mice; Proto-Oncogene Proteins c-akt; Tumor Microenvironment

Anti-tumor activity of bakuchiol, an analogue of resveratrol, was investigated on human lung adenocarcinoma A549 cell line. MTT assay revealed that IC(50) of bakuchiol at 72h was 9.58+/-1.12 micromol/l, much lower than that of resveratrol (33.02+/-2.35 micromol/l). Bakuchiol but not resveratrol elevated intracellular reactive oxygen species. Bakuchiol reduced mitochondrial membrane potential (Psim) of cells in a concentration- and time-dependent manner, showing a more potent effect than that of resveratrol. More apoptotic cells were induced by bakuchiol, compared with resveratrol. Subsequently, S phase arrest, caspase 9/3 activaton, p53 and Bax up-regulation, as well as Bcl-2 down-regulation were observed in bakuchiol-treated A549 cells. The results point toward that S phase-related cell cycle regulation, more importantly reactive oxygen species-related apoptosis might contribute to the anticancer properties of bakuchiol, which will strongly support the further development of bakuchiol against non-small-cell lung cancer.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Apoptosis Regulatory Proteins; Cell Line; Cell Line, Tumor; Cell Survival; Cells, Cultured; Humans; Inhibitory Concentration 50; Lung Neoplasms; Membrane Potential, Mitochondrial; Mice; Osmolar Concentration; Phenols; Reactive Oxygen Species; Resveratrol; S Phase; Stilbenes; Time Factors; Tumor Suppressor Protein p53