Inhibition of Tumor Angiogenesis by Phloroglucinol Figure 4. Effect of phloroglucinol on tumor growth and tumor angiogenesis in LLC tumor-bearing mice. (A) Male C57BL/6 mice were injected subcutaneously with 56104 LLC cells. LLC tumor-bearing mice were treated with DMSO solvent control and phloroglucinol at 0.94 mg/kg daily for 24 days after initiation of therapy. (B) Tumor growth was measured with calipers every 3 or 4 days using the formula 3 V = height6length6depth (cm ). All data are represented as the mean tumor volume 6 SE for the 7 animals in each group.. (C) Representative photomicrographs of CD31 capillaries in tumor sections stained with rat anti-mouse CD31 (green fluorescence), a typical endothelial marker. Nuclei were counterstained with DAPI (blue). Sections were photographed at 6100 magnification using an fluorescent microscope. Bar: 500 mm, (D) Quantification of the density of CD31+ capillary neovessels. The number of CD31-stained capillaries was counted using the Image J program. Fields were chosen randomly from various section levels to ensure objective sampling (*P,0.05). doi:10.1371/journal.pone.0033618.g004 Taken together, our data provide some evidence that phloroglucinol from edible and medicinal plants might be a potential drug for cancer prevention and/or chemotherapies. Materials and Methods Ethical statement After obtaining informed consent, human umbilical cord blood was collected from healthy volunteers according to a protocol approved by the Ethics Review Board of the Hospital of the Pusan National University of YangSan, Korea. We have the list of the volunteers that university hospital can share. The Institutional Animal Care and Use Committee of the CHA University, Seoul, Korea approved all surgical interventions and post-operative animal care. The consent was written and approved. The approved protocol number is IACUC090017. Therefore, the Ethics Review Board approved this research including both the human and animal studies. PLoS ONE | www.plosone.org 6 April 2012 | Volume 7 | Issue 4 | e33618