Effect of Rosehip (Rosa canina) Extracts on Human Brain Tumor Cell Proliferation and Apoptosis.

Rosehips are blossoms from the wild rose (Rosa canina) and are commonly used as an herbal remedy. Previous reportshave shown that extracts made from rosehip plants are able to reduce cell proliferation of cancer cells. In this study, weinvestigated the efficacy of rosehip extracts in preventing cell proliferation of three human glioblastoma cell linesA-172, U-251 MG and U-1242 MG cell lines. Each of the glioblastoma cell lines treated with rosehip extracts (1mg/mL - 25 ng/mL) demonstrated a significant decrease in cell proliferation. The rosehip extract-mediated decrease incell proliferation was equal to or better than the decrease of cell proliferation observed when inhibitors of the MAPK(U0126, 10 µM) or AKT (LY294002, 20 µM) signaling pathways were utilized. Additionally, pretreatment of the thesecell lines with Rosehip extracts (1 mg/mL - 25 ng/mL) selectively decreased AKT, MAPK, and p70S6K phosphorylationsuggesting these extracts prevent glioblastoma multiforme cell proliferation by blocking both the MAPK and AKTsignaling mechanisms. Results from colorimetric cell death assays, cell cycle analysis by flow cytometry, as well aswestern blot studies demonstrate that rosehip extracts inhibit cell proliferation but do not promote apoptosis. Moreover,rosehip extracts were able to increase the efficacy of Temozolomide, a chemotherapeutic agent used to treat patientswith glioblastomas. Surprisingly, rosehip extracts demonstrated a greater inhibition of cell proliferation than in combinationwith Temozolomide (100 µM) or Temozolomide as a single agent. Taken together these data suggest that rosehipextracts are capable of decreasing glioblastoma cell proliferation without promoting apoptosis and demonstrate a greatercell proliferation inhibitory effect than Temozolomide. More importantly, rosehip extracts may serve as an alternative or compliment to current chemotherapeutic regimens for glioblastomas.