The pulverized Black rosehip seeds (100 g) were ground using a coffee grinder and heated with distilled water (400 mL) at 45
oC for 2 hours.. The mixture was filtered through Whatman filter paper and a silver nitrate solution (0.04 mM, 400 mL) was gradually added to the extract. The reaction mixture was further heated at 60
oC for 2 hours, during which the color changed from orange to dark brown. After the reaction, Rp-AgNPs were collected by repeated centrifugation at 12,000 rpm for 20 minutes and washed thoroughly with distilled water. Finally, the Rp-AgNPs were dried
via lyophilization (Fig 2).
The successful synthesis of silver nanoparticles was confirmed by UV–Vis spectroscopy, with a maximum absorption peak at 476 nm, consistent with the typical range of 400–480 nm reported in the literatüre (Fig 3),(
Sreeram et al., 2008).
The XRD analysis of Rp-AgNPs (Fig 4) revealed prominent peaks at 38
o, 44
o, 64
o and 77
o, corresponding to the fcc planes (111, 200, 220 and 311) of AgNPs (
Rahimi-Nasrabadi et al., 2014). Additional peaks likely indicate metabolites coating the nanoparticles. The calculated crystallite size was 51.93 nm (
Rahimi-Nasrabadi et al., 2014).
FTIR analysis was performed to identify functional groups in the
R. pimpinellifolia seed extract involved in the synthesis and stabilization of silver nanoparticles. The spectra of the extract and Rp-AgNPs (Fig 5) revealed peaks at 3304.33 cm
-1 and 2926.6 cm
-1 (O-H stretching), 2855.12 cm
-1 and 2111.63 cm
-1 (N-H and CºC stretching), 1743.53 cm
-1 (C=O stretching), 1637.05 cm
-1 (C=C stretching), 1548.06 cm
-1 (N-O stretching), 1450.16 cm
-1 (C-H bending), 1317.96 cm
-1 (C-F stretching and O-H bending), 1242.21 cm
-1 (C-O and C-N stretching), 1063.63 cm
-1 (S=O and C-O stretching), 969.28 cm
-1 and 896.13 cm
-1 (C=C bending) and 586.43 cm
-1 (C-I stretching).
The morphology and size distribution of nanoparticles produced through biological synthesis were examined using TEM, a robust analytical method. The TEM image reveals individual silver particles and illustrates the polydispersity of the nanoparticles. Notably, the silver nanoparticles exhibit an almost spherical shape (Fig 6).
The surface morphology and dimensions of silver nanoparticles produced under optimal conditions were assessed through SEM, as illustrated (Fig 7).
The surface morphology was also identified to possess a spherical nature, with an average size measuring 51.27 nm (Fig 8).
In the EDAX analysis, a distinct peak of silver metal was observed at 3 kV, confirming the presence of silver in the complex. Additionally, the peaks corresponding to other elements in the EDAX spectrum are illustrated (Fig 9).
Zeta potential measures the electrical potential at the solid-liquid interface, influencing nanoparticle stability. Rp-AgNPs showed a zeta potential of -18.9, indicating stability and particle repulsion (Fig 10), (
Gecer, 2021).
Differential scanning calorimetry (DSC) was used to analyze the thermal stability of Rp-AgNPs. The DSC curve showed endothermic and exothermic processes, with an exothermic peak at 92°C indicating desorption of organic components from the nanoparticle surface (Fig 11).
Surface-enhanced Raman scattering (SERS) is a highly sensitive technique for detecting and characterizing metal nanoparticles
(Bindhu et al., 2015). The Raman spectra of silver nanoparticles (AgNPs) showed vibrational modes at 238 cm
-1 (Ag-O stretching)
(Linic et al., 2015). 613 cm
-1 (C-S-C) and 1301 cm
-1 (anti-symmetric C=O stretching)
(Joshi et al., 2018) (Fig 12).
X-ray Photoelectron Spectroscopy (XPS) was used to analyze the surface composition and chemical state of Rp-AgNPs. The XPS spectrum (Fig 13) revealed Ag 3d 5/2 peaks at binding energies of 365.1 and 369.0 eV, corresponding to oxidized silver (Ag-O)
(Maiti et al., 2016).
DPPH free radical scavenging activity showed that ascorbic acid (IC
50: 11.53 μg/mL) had the highest activity, followed by Rp-AgNPs (IC
50: 30.89 μg/mL) and
R. pimpinellifolia seed extract (IC
50: 136.4 μg/mL). This is the first study on silver nanoparticles functionalized with
R. pimpinellifolia seeds. The cytotoxicity of Rp-AgNPs on H460 lung cancer cells was evaluated after 72 hours, showing significant cytotoxicity (p<0.05) at concentrations ≥25 μg/mL, with an IC
50 of 65.8 μg/mL (Table 1).
The antimicrobial activity of Rp-AgNPs synthesized using
Rosa pimpinellifolia seed extract was evaluated against various pathogenic microorganisms. The disk diffusion method and broth microdilution technique were employed to assess
in vitro activity, with results summarized in Table 2.
The increasing issue of antibiotic resistance (
Nikolich and Filippov, 2020) has driven interest in alternative antimicrobial strategies, such as nanoparticle-based approaches
(Murugaiyan et al., 2022). R. pimpinellifolia has a high polyphenol content (121.38 mg GAE/100 g fresh weight) and shows tolerance to various stresses
(Fattahi et al., 2012). Rp-AgNPs at 100 µg/mL showed inhibition zones of 10-14 mm for bacteria and 7-8 mm for
Candida strains, with MIC values of 50-100 µg/mL for bacteria and 100-200 µg/mL for
Candida. Rp-AgNPs demonstrated
in vitro antimicrobial activity against all tested pathogens, consistent with previous findings
(Fattahi et al., 2012).
Hormones are biomolecules that are involved in many physiological processes that affect the growth and development of cancer cells (
Bayraktar and Bayraktar, 2019;
Bayraktar, 2020). Plant-synthesized AgNPs have a promising potential in anticancer treatments because they can affect the development of some types of cancer by affecting the endocrine system.
Juarez-Moreno et al., (2017) demonstrated effective cytotoxicity across multiple cancer cell lines without DNA damage, suggesting potential applications in combination therapy. Studies with various plant-derived AgNPs have reported significant anticancer activity, with IC
50 values ranging from 28.125 μg/mL for lung cancer to 62.5 μg/mL for breast cancer cells
(Vijayan et al., 2018; Valsalam et al., 2019). Green-synthesized AgNPs are particularly promising due to their ability to generate ROS and penetrate cells
(Jabeen et al., 2021). Furthermore, silver nanoparticles synthesized using black rosehip seed water extract maintained their antibacterial activity for over 8 weeks when stored at 4
oC.