02725nas a2200253 4500008004100000245011600041210007100157260001400228300001200242490000600254520196000260653001902220653001802239653001302257653001302270653002202283653001102305100001602316700002002332700002202352700001602374700002402390856005702414 2017 eng d00aUncaria tomentosa (Willd. ex Schult.) DC (Rubiaceae) Sensitizes THP‑1 Cells to Radiation‑induced Cell Death0 aUncaria tomentosa Willd ex Schult DC Rubiaceae Sensitizes THP‑1  cJuly 2017 a221-2290 v93 a

Background: Uncaria tomentosa (Willd. ex Schult.) DC (Rubiaceae), known as Cat’s Claw or Uña de gato, is a traditionally used medicinal plant native to Peru. Some studies have shown that U. tomentosa can act as an antiapoptotic agent and enhance DNA repair in chemotherapy‑treated cells although others have shown that U. tomentosa enhanced apoptosis. Objective: To determine if treatment with U. tomentosa can significantly enhance cell death in THP‑1 cells exposed to ionizing radiation. Materials and Methods: THP‑1 monocyte‑like cells were treated with ethanolic extracts of U. tomentosa in the presence or absence of bacterial lipopolysaccharide and then exposed to ionizing radiation. Cell proliferation was assessed by MTT and clonogenic assays and the effects on cell cycle measured by flow cytometry and immunoblotting. Changes in cell signaling were determined by immunoblotting and cytokine ELISA and activation of apoptosis measured by caspase activation and DNA fragmentation analysis. Results: Treatment of THP‑1 cells with U. tomentosa had a small effect on cell proliferation. However, when the U. tomentosa‑pretreated cells were also subjected to 5–9 Gy ionizing radiation, they showed a significant decrease in cell proliferation and increased cellular apoptosis as measured by DNA fragmentation and caspase activation. Treatment with U. tomentosa also decreased the expression of Cyclin E and Cyclin B, key regulators of normal cell cycle progression, and decreased the phosphorylation of various stress‑activated, cell survival proteins including p38, ERK, and SAP/JNK kinase. Conclusions: These results suggest that U. tomentosa could be useful in enhancing cell death following anticancer therapies including ionizing radiation.

10aCell signaling10aCell survival10aCytokine10aMonocyte10aUncaria tomentosa10aX-rays1 aAllen, Lisa1 aBuckner, Alison1 aBuckner, Carly, A1 aCano, Pablo1 aLafrenie, Robert, M uhttps://phcogres.com/article/2017/9/3/104103prpr8316