Cytotoxic and apoptotic potential of gemini-chrysophanol nanoparticles against human colorectal cancer HCT-116 cell lines

Abstract

Background: Colorectal cancer is among the most common cancers and accounts for nearly 9% of all cancers in the world. Chrysophanol is a naturally occurring anthraquinone exerts a number of pharmacological activities such as anti-inflammation, anti-cancer, anti-bacterial, anti-viral, and anti-oxidant effects. This study aims to produce a novel gemini chrysophanol nanoparticles (Gemini-Chr NPs), and to evaluate its anti-cancer effect on the human colorectal cancer cell lines.

Methods: Gemini-Chr NPs were synthesized through nanoprecipitation method and characterized by dynamic light scattering and scanning electron microscopy, Anti-cancer activities were examined through MTT assay on HCT-116 cancer cells, apoptosis was investigated via Annexin V-FITC/PI dual stain assay. Furthermore, the expression of Bax, Bcl-2 and P53 genes were evaluated using real-time PCR and western blotting assay.  RESULTS: The average particle diameter of the synthesized Gemini-Chr NPs and zeta potential were recorded as 120 nm and 14.4 mV, respectively. In comparison to the normal cells, the cytotoxicity assay confirmed that Gemini-Chr NPs preferentially killed colorectal cancer cells via induction of apoptosis. Moreover, Gemini-Chr NPs could upregulate the expression of Bax in both cancerous and normal cells (p ≤ 0.05) and decreasing the Bcl-2 expression in only tumor cells (p ≤ 0.01), while the expression of P53 is modulated in tumor cells (p ≤ 0.05).

Conclusions: Gemini surfactants could be considered for efficient delivery and improvement of anti-cancer effect of chrysophanol. Gemini-Chr NPs might have the potential for developing novel therapeutic agent against colorectal cancer.

Keywords: Apoptosis; Bax/Bcl-2; Chrysophanol; Colorectal cancer; Gemini surfactant.

Fig. 1

The structural representation of a novel Gemini-Chr NPs

Fig. 2

Physical characterization of Gemini-Chr NPs. A Cluster size of Gemini–Chr NPs obtained from DLS measurements. B The zeta potential of Gemini–Chr NPs. C SEM imaging was used to measure mean size of nanoparticles

Fig. 3

The growth-inhibitory effect of Gemini-Chr NPs (A and B), Chrysophanol (C and D), and Gemini surfactant NPs (E) on HCT-116 and MEF cell lines using MTT-based assay. Cells were treated with Gemini-Chr NPs, chrysophanol, and Gemini surfactant NPs in a time- and dose-dependent manner. Data represent mean ± standard deviation of three independent experiments

Fig. 4

Flow cytometry analysis of mode of cell death in Gemini-Chr NPs treated colorectal cancer cells. Annexin V-FITC/propidium iodide (PI) histograms were obtained from analysis of colorectal cancer HCT-116 cells incubated with 40 and 60 µM of Gemini-Chr NPs for 24 h

Fig. 5

A Expression ratio of Bax/Bcl-2 in non-tumoral MEF and HCT-116 tumor cells. ****: p value ≤ 0.0001; B: Relative expression of Bax, Bcl-2 and P53 as apoptotic genes in both cell lines. *: p value ≤ 0.05, **: p value ≤ 0.01, ***: p value ≤ 0.001

Fig. 6

The expression of Bax, Bcl-2, and P53 in HCT-116 cells treated with 40 and 60 µM of Gemini-Chr NPs for 24 h detected by Western blot analyses. The bands show the expression of proteins in tumor cells. The relative protein expression was normalized to β-actin. Full-length blots/gels are presented in supplementary figure S1. **: p value ≤ 0.01, ***: p value ≤ 0.001, ****: p value ≤ 0.0001