Longan flower proanthocyanidins induce apoptosis in HT-29 colorectal carcinoma spheroids

J Cancer Res Ther. 2018 Jun;14(Supplement):S388-S393. doi: 10.4103/0973-1482.176170.

Abstract

Aim of study: Proanthocyanidin-rich longan flower extract (LFP) has been previously shown to inhibit the proliferation and anchorage-independent growth in soft agar of two colorectal carcinoma (CRC) cells in vitro. In this report, we further examined the effects of LFP in a CRC spheroid model.

Materials and methods: A liquid-overlay assay employing HT-29 spheroids was used to evaluate the effects of LFP on cancer cell tumorigenesis, viability, and apoptosis. Associated effects on signaling path ways (epidermal growth factor receptor [EGFR], Akt) and apoptotic regulators were measured using Western blot.

Results: Treatment with LFP up to 200 μg/ml inhibited tumor growth in a dose-dependent manner and induced prominent apoptosis as measured by annexin V staining. Cells treated with LFP showed decreased EGFR and Akt phosphorylation with decreased expression of B-cell lymphoma 2.

Conclusion: The ability of LFP to induce apoptosis in CRC spheroids warrants further investigation of its composition and identification of tumor-active components.

Keywords: Colorectal carcinoma; HT-29; longan flower proanthocyanidins; spheroid.

MeSH terms

  • Antineoplastic Agents, Phytogenic / pharmacology
  • Apoptosis / drug effects*
  • Cell Proliferation / drug effects
  • Colorectal Neoplasms / drug therapy
  • Colorectal Neoplasms / metabolism
  • Colorectal Neoplasms / pathology*
  • ErbB Receptors / metabolism
  • Flowers / chemistry*
  • Humans
  • Phosphorylation
  • Plant Extracts / pharmacology*
  • Proanthocyanidins / pharmacology*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Sapindaceae / chemistry*
  • Spheroids, Cellular / drug effects
  • Spheroids, Cellular / metabolism
  • Spheroids, Cellular / pathology*
  • Tumor Cells, Cultured

Substances

  • Antineoplastic Agents, Phytogenic
  • Plant Extracts
  • Proanthocyanidins
  • EGFR protein, human
  • ErbB Receptors
  • AKT1 protein, human
  • Proto-Oncogene Proteins c-akt