IngentaConnect Growth inhibition and induction of differentiation by panaxydol i...

Abstract:

Objectives: Panaxydol is a naturally occurring non-peptidyl small molecule isolated from the lipophilic fractions of Panax notoginseng, a well-known Chinese traditional medicine. In this study, we aimed to investigate the effects of panaxydol on growth inhibition and its mechanisms in C6 rat glioma cells.

Methods: The effects of panaxydol on cell proliferation, morphologic changes, glial fibrillary acidic protein (GFAP) expression and cell cycle regulation in rat C6 cells were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, hematoxylin and eosin (HE) staining, immunocytochemistry, flow cytometric analysis and Western blot respectively.

Results: Panaxydol markedly inhibited the proliferation of C6 cells in a dose-dependent manner with IC₅₀ of 39.5 ± 2.3 μM. In addition, the cell morphologic changes and increased expression of GFAP in C6 cells in the presence of panaxydol implied a cellular differentiation. Flow cytometric analysis revealed that panaxydol-treated cells accumulated in G₀/G₁ phase with a marked decrease in the number of C6 cells at S phase. Western blot analysis demonstrated that panaxydol resulted in an increase in the protein expression of p27 in C6 cells as early as 3 hours after treatment consistent with the differentiation response, but protein expression of p53, p21, p16 and pRb remained unchanged.

Conclusion: These findings suggest that panaxydol inhibits the proliferation of C6 cells via G₀/G₁ cell cycle arrest in association with induction of p27 expression and differentiation.

Keywords: C6 GLIOMA CELL; CELLULAR DIFFERENTIATION; GLIAL FIBRILLARY ACIDIC PROTEIN; GROWTH INHIBITION; PANAXYDOL; P27

Document Type: Research article

DOI: 10.1179/016164107X228697

Affiliations: 1: Department of Neurosurgery, Tongji Hospital, Tongji University, Shanghai, China 2: Department of Pharmacy, Shanghai Jiaotong University School of Medicine, Shanghai, China 3: Department of Cell Biology, Shanghai Jiaotong University School of Medicine, Shanghai, China

Growth inhibition and induction of differentiation by panaxydol in rat C6 glioma cells