Evaluation of the potential theranostic effects of silver nanoparticles biosynthesized with aronia extract in colon cancer cells

Aronia (Aronia melanocarpa) is one of the richest sources of antioxidants due to its polyphenolic compounds and high biological activities. Plant-mediated biosynthesis of metallic nanoparticles (NPs) occurs through biomolecules containing organic functional groups present in the plant. In the study, it was aimed to carry out the synthesis and characterization of silver nanoparticles using aronia aqueous extract and to evaluate their potential theranostic effects on HT29 colon cancer cells. The characterization of silver nanoparticles (A-AgNP) synthesized using aronia extract was evaluated by UV, FE-SEM, TEM and EDX methods. The color change from pink to brown is indicative of the synthesis of AgNPs, and a strong absorption peak at 427 nm was observed in the UV spectrum scanning. TEM and FE-SEM analyses reveal that A-AgNPs have a small size (~20 nm) and spherical structure. A-AgNPs exhibited a characteristic absorption peak at 3 keV in EDX analysis. MTT assay results showed that A-AgNPs (0-200 μg/mL) induced a dose-dependent decrease in cell viability in HT29 cells after 48 hours of incubation (IC50:5.59 μg/mL). In Western blot analyses, the p-H2AX band indicating DNA damage was clearly observed in HT29 cell lysates to which A-AgNP was applied, and it was observed that the effect of A-AgNP application on p-H2AX protein expression was approximately 55% higher than the control. The % inhibition values of DPPH free radical scavenging activity of A-AgNPs (50-4000 µg/mL) were found in the range of 23.89-69.70%. According to the oxidative stress parameters (TAS-TOS) studied in cell lysates, potent antioxidant effect of A-AgNPs was determined compared to the control (p<0.01). In the study, it has been demonstrated in vitro that green synthesis A-AgNPs can be used as a potential agent for colon cancer treatment due to their theranostic effect on HT29 cancer cells. Keywords: Aronia melanocarpa, Colon cancer, HT29 human colon cancer cell line, Silver nanoparticle, Theranostic effect