Mechanism of Anti-Cancer in Breast Cancer Cells With HER2 Overexpression by Dietary Supplement of Five Edible Plants

Abstract

Edible plants are known to have many pharmacological properties, including anti-cancer. Mylife/Mylife100, a Thai dietary supplement composed of five types of edible plants (Sesamum indicum L., Psidium guajava L., Centella asiatica (L.) Urb., Glycine max (L.) Merr., and Garcinia mangostana L.) was evaluated for its anti-cancer effect on breast cancer cells with HER2 overexpression (SK-BR-3 cell line). The results demonstrated that the supplement showed cytotoxic activity against SK-BR-3 cell growth in a dose-dependent manner, with an IC₅₀ value of 116.5 ± 2.30 μg/mL. The effect of the supplement on apoptosis induction in SK-BR-3 cells was investigated. The findings revealed that the supplement induced nuclear condensation and loss of mitochondrial membrane potential, both hallmarks of apoptosis. Additionally, the supplement increased the sub-G1 population analyzed by flow cytometry and was further validated by attenuation of anti-apoptotic proteins (Bcl-xL and Mcl-1) and the induction of pro-apoptotic proteins (Bax, cleavage caspase 7 and cleavage PARP). Moreover, the supplement also inhibited the PI3K/Akt pathway and enhanced MAPK signaling pathways. These findings indicated that the Mylife/Mylife100 supplement suppresses cell growth and induces apoptosis via activation of the intrinsic pathway and regulation of the PI3K/Akt and MAPK signaling pathways against SK-BR-3 cells.

Keywords: Mylife/Mylife100 supplement; anti‐cancer; apoptosis; breast cancer cell; five edible plants.

FIGURE 1

Effects of supplement on cells proliferation inhibition in SK‐BR‐3 cells. SK‐BR‐3 cells were treated with various concentrations of supplement for 24 h and examined by using MTT assay. The percentage of cell viability was showed as mean values ± SD. p < 0.01 is considered a significant difference compared to the control.

FIGURE 2

Effects of supplement on nuclear morphological change. (A) The fluorescence images after stained with Hoechst33342 dye (20X). The red arrows present nuclear condensation and fragmentation. (B) The histogram illustrated the proportion of cells exhibiting nuclear condensation relative to the control cells. *p < 0.05 and **p < 0.01 are considered a significant difference compared to the control.

FIGURE 3

Effects of supplement on mitochondrial membrane potential (ΔΨm) using JC‐1 staining on SK‐BR‐3 cells. (A) The fluorescence images after stained with JC‐1 dye (20X). The green fluorescence signal indicates cells that loss of ΔΨm. (B) The histogram illustrated the red fluorescence intensity relative to the control cells. **p < 0.01 is considered a significant difference compared to the control.

FIGURE 4

Effect of supplement on cell cycle distribution by flow cytometry analysis on SK‐BR‐3 cells. (A) Representative histograms of cell cycle distribution depicting apoptosis in SK‐BR‐3 cells. The sub‐G1 population indicates presence of apoptotic cells. (B) The histogram illustrated the percentage of sub‐G1 population compared to the control cells. *p < 0.01 is considered a significant difference compared to the control.

FIGURE 5

Effects of supplement on apoptosis‐related proteins level in SK‐BR‐3 cells. (A) Protein expression was analyzed using western blot. (B) The relative band intensity of apoptosis‐related proteins was compared to the control cells. β‐Actin served as the internal control. *p < 0.05 and **p < 0.01 are considered a significant difference compared to the control.

FIGURE 6

Effects of supplement on PI3K/Akt signaling pathway in SK‐BR‐3 cells. (A) Protein expression was analyzed using western blot. (B) The relative band intensity of PI3K/Akt pathway proteins was compared to the control cells. β‐Actin served as the internal control. *p < 0.05 and **p < 0.01 are considered a significant difference compared to the control.

FIGURE 7

Effects of supplement on MAPK signaling pathway in SK‐BR‐3 cells. (A) Protein expression was analyzed using western blot. (B) The relative band intensity of p‐ERK1/2, ERK1/2, p‐p38 and p38 proteins was compared to the control cells. β‐Actin served as the internal control. *p < 0.05 and **p < 0.01 are considered a significant difference compared to the control.