Nanoencapsulation of pomegranate bioactive compounds for breast cancer chemoprevention

Figures & data

Figure 1 The synthesis and TEM characterization of PLGA–PEG NPs encapsulating PE.

Abbreviations: PLGA–PEG, poly(lactic-co-glycolic acid)–poly(ethylene glycol); PVA, polyvinyl alcohol; NPs, nanoparticles; PE, pomegranate extract; TEM, transmission electron microscopy.

Table 1 Characterization of NPs by DLS

NP	Particle size (nm)	PDI	Zeta potential (mV)
PE-NP	160±5	0.084±0.04	−13.0±1.53
PU-NP	216±3	0.16±0.04	−13.3±1.84
EA-NP	175±3	0.14±0.03	−6.06±0.5
Void NP	162±6	0.21±0.04	−14.1±0.55

Notes: Mean ± SD for three to four determinations is shown. For particle size, Z-average is shown.

Abbreviations: PE, pomegranate extract; PU, punicalagin; EA, ellagic acid; NP, nanoparticles; PDI, polydispersity index; DLS, dynamic light scattering; SD, standard deviation.

Figure 2 The size distribution of NPs. Representative histograms from DLS data of the size (diameter) distribution of PE-NPs (A), PU-NPs (B), and EA-NPs (C) are shown.

Abbreviations: PE, pomegranate extract; PU, punicalagin; EA, ellagic acid; NPs, nanoparticles; DLS, dynamic light scattering.

Figure 3 The intracellular uptake of NPs over a 24-hour time course.

Notes: MCF-7 cells were incubated with Alexa Fluor-488-labeled PLGA–PEG NPs for 15 minutes (A), 2 hours (B), 6 hours (C), and 24 hours (D). Confocal microscopy images were taken at 63× magnification and 5× optical zoom.

Abbreviations: NPs, nanoparticles; PLGA–PEG, poly(lactic-co-glycolic acid)–poly(ethylene glycol).

Figure 4 The effect of pomegranate nanoprototypes on MCF-7 and Hs578T breast cancer cell growth.

Notes: MCF-7 cells were treated with PE-NPs (A), PU-NPs (B), and EA-NPs (C) versus their respective free counterparts. Hs578T cells were treated with PE-NPs (D), PU-NPs (E), and EA-NPs (F) versus their respective free counterparts. Solid diamonds show pomegranate phytochemical loaded NPs, solid triangles show respective free counterparts, open circles depict void NPs and open rectangles show NaOH solvent control for EA. Cells were treated for 96 hours; n=3 experiments; error bars depict SEM.

Abbreviations: PE, pomegranate extract; PU, punicalagin; EA, ellagic acid; NPs, nanoparticles; SEM, standard error of the mean.

Table 2 IC₅₀ of pomegranate nanoprototypes and their free counterparts in MCF-7 and Hs578T cells

Treatment	IC50 (μg/mL)	IC50 (μM)	Fold change in IC50 (NP vs free compound)	P
MCF-7 cells
PE	44.34±7.81	NA	–
PE-NP	19.36±3.70	NA	2.3	<0.01
PU	44.42±8.18	40.9	–
PU-NP	8.13±3.4	7.5	5.5	<0.001
EA	35.93±5.63	119.9	–
EA-NP	15.22±1.34	50.5	2.4	<0.01
Hs578 T cells
PE	61.93±16.11	NA	–
PE-NP	29.17±7.6	NA	2.1	<0.05
PU	52.57±5.13	48.4	–
PU-NP	4.45±0.72	4.1	11.8	<0.001
EA	59.94±9.4	190.1	–
EA-NP	25.15±4.63	83.5	2.3	<0.01

Notes: Cells were treated for 96 hours. Mean ± SD for three to six experiments is shown. Fold change was calculated by dividing the IC₅₀ of a free compound by that of the respective nanoprototype. P-values show statistically significant differences between mean IC₅₀ of pomegranate nanoprototypes and their free counterparts.

Abbreviations: PE, pomegranate extract; PU, punicalagin; EA, ellagic acid; NP, nanoparticles; NA, not applicable; SD, standard deviation; IC₅₀, half maximal inhibitory concentration of cell growth.

Figure 5 Hydrolysis of PU.

Abbreviations: MW, molecular weight; PU, punicalagin.