Discussion and conclusion
The synthesis of nanomaterials is at present one of the most active fields in the field of nanosciences. One of the nanomaterials is silver nanoparticles, which have known inhibitory and antibacterial effects. Silver ions can bind to electron donor groups such as glucose, oxygen, or nitrogen in a biological molecule (22). Silver nanoparticles break down the inhibitory components in the outer membrane of the bacterium, releasing molecularly exponential molecules such as the liposuction molecule. After penetrating the bacterial cell, nanosilver inactivates its enzymes and causes the death of the bacterium by producing hydrogen peroxide (23). Various techniques exist for synthesizing nanoparticles, but physical and chemical methods can cause environmental pollution. To mitigate this issue, green methods can be employed, where materials with minimal environmental impact are either produced or consumed as an alternative (24). Furthermore, research has demonstrated that the presence of silver ions can significantly enhance the generation of reactive oxygen species, such as superoxide anion radicals, which can induce oxidative stress at the molecular, cellular, and organ levels (25). Plants have antimicrobial and antioxidant activity due to the presence of secondary metabolites such as phenol and flavonoids which act to prevent oxidative damage to cells. Certain plants can convert Ag+ ions to Ag0, synthesizing nanoparticles with antioxidant properties through a process called bioremediation (26). It has antimicrobial and antioxidant activity and acts to prevent oxidative damage to cells. Researchers have increasingly viewed the synthesis of nanoparticles by plants and microorganisms as a biocompatible and environmentally friendly approach in recent years. The study examined the abilities of the nanoparticles that were created to act as antioxidants and antibacterials. During the study, a change in color was observed from light yellow to dark brown, which was caused by the interaction between the plant extract and silver salt solution. This color change was consistent with the findings of Rezazadeh et al. (27), Givianrad et al. (28), and Dousti et al. (29), and it served as the initial indication of the production of silver nanoparticles. Dousti et al. conducted Uv-Vis spectroscopy on the silver nanoparticles they synthesized and found that the maximum absorption occurred around 430 nm. The presence of a peak in this region is an indication of silver nanoparticle synthesis because such a peak, occurs at a wavelength of 400 - 450 nm, this phenomenon is caused by the induction of free electrons within the nanoparticles. The surface plasmon resonance observed in silver nanoparticles is linked to the induction of unbound electrons within the nanoparticles. This effect is responsible for the phenomenon. This outcome aligns with the discoveries made by Dousti et al. and other researchers (29). Also, Dousti et al. synthesized silver nanoparticles from the blue extract of the Fumaria Parviflora plant, and their XRD analysis showed peaks at 38.07°, 44.26°, 64.43°, and 77.35° with indices (311), (220), (200), and (111), respectively. These peaks correspond to the nanostructures of the silver particles and are in complete agreement with the XRD pattern of silver. The size of the silver nanoparticles’ crystallinity was determined using Debye Scherrer’s formula, which yielded a size of 30 nm for the nanoparticles. as well as the X-ray diffraction (XRD) pattern obtained from the nanoparticles created using Polygonum aviculare L. indicated that the characteristic peaks at 2θ values of 23.35°, 27.56°, 32.04°, and 46.00°, which are attributed to the spherical shape of silver nanoparticles and agreed with the XRD reference pattern of silver nanoparticles (JCPDS No. 04-0783). as well as, the size of the silver was determined to be 29nm using Debye-Scherrer’s equation, which agreed with the findings of Dousti et al.’s study (23, 30, 8, 29). Heydarzadeh and colleagues conducted a study on the eco-friendly production of silver nanoparticles using Citrus aurantium extract. The transmission electron microscope (TEM) images revealed that the silver nanoparticles had a spherical shape and appeared darker in the images. The nanoparticles obtained had a diameter ranging from 5 to 40 nm. FESEM images of silver nanoparticles synthesized with orange spring extract with different magnifications also showed the nanometer dimensions of the silver particles and indicated an almost spherical shape in all magnifications. According to the FESEM images, the cumulative size of the nanoparticles was between 10 - 60 nm . also, in this study, the FESEM image of the nanometer dimensions of silver particles shows the spherical shape at all magnifications. According to FESEM images, the cumulative size of nanoparticles varies between 40 and 70 nm , and the TEM image of silver nanoparticles synthesized from polygonum aviculare L. extract showed the silver nanoparticles were in a darker image and had a spherical shape and a size of less than 50 nm which It was in good agreement with the results of Heydarzadeh and his colleagues (40). Since it is important to find both natural and synthetic antioxidants to prevent oxidative stress and its harmful effects, the study also aimed to examine the antioxidant properties of the produced nanoparticles. The study showed that the synthesized nanoparticles were able to remove radicals the free 2 and 2-diphenyl-1-picryl is hydrazyl in such a way that by receiving an electron or free radical, hydrogen is converted into a stable molecule. Polygonum aviculare plant can transfer hydrogen to oxidants and antioxidant properties so the results showed that the antioxidant properties of synthesized nanoparticles depend on their concentration and with increasing concentration, antioxidant activity increases. The silver nanoparticles exhibited remarkable antioxidant activity, with an IC50 value of 15.63 mg/l , when compared to the standard antioxidant ascorbic acid, which had an IC50 value of 11.89 mg/l . This discovery aligns with the outcomes observed in earlier investigations (31). Abdolaziz and colleagues (32) conducted a study on the antioxidant activity of silver nanoparticles synthesized from the leaf extract of the Salmak plant using the DPPH test. The results revealed that the antioxidant effect was directly proportional to the concentration of silver nanoparticles, with an increase in concentration up to 20 mg/l resulting in a measurement of 63.45 ± 0.18 mg/l . Our research findings indicated that the inhibitory ability of nanoparticles produced using the hydroalcoholic extract of Polygonum aviculare L. plant was 41.01 at a concentration of 10 mg/l, and it increased to 93.13 at concentrations up to 100 mg/l, with statistical significance at p <0.05. This result is in line with previous studies (33, 34) and demonstrates a notable variation. When used at a concentration of 40% (%v/v) against S. aureus and E. coli, the average diameter of the growth inhibition zone was 10 mm and 12 mm, respectively. The research established that silver nanoparticles produced via the green method were more highly efficient in inhibiting the growth of gram-negative bacteria, like E. coli than gram-positive bacteria, such as S. aureus. This observation is consistent with the findings of Mobarak Ali et al. (36) and (35), who suggest that the thicker cell wall of gram-positive bacteria, such as S. aureus is the reason for this result. In contrast, gram-negative bacteria have a thinner cell wall, and their outer surface is covered by a layer of lipopolysaccharide. Due to the weak positive charge of silver nanoparticles, their interaction with bacteria is facilitated by the negative charge present on the surface of these microorganisms. This interaction is thought to result in the creation of a hole in the cell wall, which can ultimately lead to the entry of nanoparticles into the bacterial cell and the bacterium’s subsequent death. Also Vastava et al. (37) and Guzman et al. (38) reported in their milk studies that the antibacterial effectiveness of nanoparticles increases as their size decreases. Therefore, the difference in the minimum inhibitory concentration and the minimum bactericidal concentration in the synthesized nanoparticles Can also be attributed to the difference in size. This difference in the results can also be related to the type of nanoparticle shape as well as the structural and genetic differences of the strains according to the geographical location. Silver nanoparticles from common drugs can be a suitable alternative for them. The method utilized in this investigation to synthesize silver nanoparticles from the P. aviculare L. extract is regarded as an advantageous approach eco-friendly. Cost-effectiveness, avoidance of toxic solvents, waste and antimicrobial activity, and other biomedical applications allow this method to be used in large commercial comparisons.