Lycium Barbarum Polysaccharides Induce Apoptosis in Human Prostate Cancer Cells and Inhibits Prostate Cancer Growth in a Xenograft Mouse Model of Human Prostate Cancer

J Med Food. 2009 Aug;12(4):695-703. doi: 10.1089/jmf.2008.1232.

Abstract

Lycium barbarum polysaccharides (LBPs) are important functional constituents in red-colored fruits of L. barbarum (Guo Qi Zi, a well-known traditional Chinese medicinal plant commonly known as Goji berry or wolfberry). The influence of LBP on human prostate cancer cells was systematically investigated in vitro and in vivo. The in vitro effects of LBP on two cell lines (PC-3 and DU-145) were examined by using trypan blue exclusion staining, single-cell gel electrophoresis, flow cytometry, terminal dUTP nick-end labeling assay, and immunohistochemical assay (assessment of Bcl-2 and Bax expression). The in vivo effect of LBP on PC-3 cells was assessed in the nude mouse xenograft tumor model. The in vitro results showed that LBP can dose- and time-dependently inhibit the growth of both PC-3 and DU-145 cells. LBP caused the breakage of DNA strands of PC-3 and DU-145 cells; the tail frequency and tail length were significantly higher than that of control cells. LBP also markedly induced PC-3 and DU-145 cell apoptosis, with the highest apoptosis rates at 41.5% and 35.5%, respectively. The ratio of Bcl-2/Bax protein expression following LBP treatments decreased significantly with a dose-effect relationship, which suggested that LBP can regulate the expression of Bcl-2 and Bax to induce apoptosis of PC-3 and DU-145 cells. The in vivo experimental results indicate that LBP might significantly inhibit PC-3 tumor growth in nude mice. Both the tumor volume and weight of the LBP treatment group were significantly lower than those of the control group.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / pharmacology
  • Antineoplastic Agents, Phytogenic / therapeutic use*
  • Apoptosis / drug effects*
  • Cell Line, Tumor
  • DNA Damage / drug effects
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Drugs, Chinese Herbal / pharmacology
  • Drugs, Chinese Herbal / therapeutic use*
  • Fruit
  • Gene Expression
  • Genes, bcl-2
  • Humans
  • Lycium*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Phytotherapy*
  • Prostate / drug effects*
  • Prostate / pathology
  • Prostatic Neoplasms / drug therapy*
  • Prostatic Neoplasms / pathology
  • Repressor Proteins / genetics
  • Time Factors
  • Xenograft Model Antitumor Assays
  • bcl-2-Associated X Protein / genetics
  • bcl-2-Associated X Protein / metabolism

Substances

  • Antineoplastic Agents, Phytogenic
  • Bax protein, mouse
  • Bclaf1 protein, mouse
  • Drugs, Chinese Herbal
  • Repressor Proteins
  • bcl-2-Associated X Protein
  • lycium barbarum polysaccharide