Green synthesized silver nanoparticles (AgNPs) have been used against antibiotic-resistant bacteria and chemo-resistant cancer cells. We synthesized AgNPs from Acacia nilotica pods, evaluating their antibacterial activity against eight bacterial strains and anticancer efficiency against two colon cancer cell lines, SW620 and SW480. Expression levels of eight genes (β-catenin, APC, TP53, Beclin1, DKK3, Axin, Cyclin D1, and C-myc) were checked by a reverse transcription-polymerase chain reaction in cancer cells before and after treatment with A. nilotica extract and A. nilotica-AgNPs. Prepared nanoparticles were characterized through ultraviolet-visible (UV-vis), Zetasizer, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Fourier transform infrared spectroscopy (FTIR) was used to identify the functional group in extracts. At first, AgNPs were confirmed by a sharp peak of surface plasmon resonance at 375 nm. The Z-average size was 105.4 nm with a polydispersity index of 0.297. TEM showed particle size of 11–30 nm. The prepared AgNPs showed promising antibacterial activity against bacterial strains and cytotoxic activity against the cancer cell lines. Expression levels of all the genes were affected by extract and AgNPs treatment. Overall, this study recommended both A. nilotica pods and A. nilotica-AgNPs as attractive candidates for antibacterial and anticancer applications.

The main antioxidants present in plant extracts—quercetin, β-carotene, gallic acid, ascorbic acid, hydroxybenzoic acid, caffeic acid, catechin and scopoletin—are able to synthesize silver nanoparticles when reacting with a Ag NO3 solution. The UV-visible absorption spectrum recorded with most of the antioxidants shows the characteristic surface plasmon resonance band of silver nanoparticles. Nanoparticles synthesised with ascorbic, hydroxybenzoic, caffeic, and gallic acids and scopoletin are spherical. Nanoparticles synthesised with quercetin are grouped together to form micellar structures. Nanoparticles synthesised by β-carotene, were triangular and polyhedral forms with truncated corners. Pentagonal nanoparticles were synthesized with catechin. We used Fourier-transform infrared spectroscopy to check that the biomolecules coat the synthesised silver nanoparticles. X-ray powder diffractograms showed the presence of silver, AgO, Ag2O, Ag3O4 and Ag2O3. Rod-like structures were obtained with quercetin and gallic acid and cookie-like structures in the nanoparticles obtained with scopoletin, as a consequence of their reactivity with cyanide. This analysis explained the role played by the various agents responsible for the bio-reduction triggered by nanoparticle synthesis in their shape, size and activity. This will facilitate targeted synthesis and the application of biotechnological techniques to optimise the green synthesis of nanoparticles.

Plant-mediated silver nanoparticles are unique and are considered one of the best nanomaterials used in cancer research. We report a low-cost, eco-friendly process of green synthesis of AgNPs from Commiphora gileadensis stem extracts and evaluated their anticancer potential against colon cancer cell lines HCT-116, HT 29, and SW620. Anticancer activities were performed by an MTT assay and gene expression levels of four genes CHEK1, CHEK2, ATR, and ATM by the real-time polymerase chain reaction. Particles were initially confirmed by UV-visible spectroscopy. The morphology and stability of the particles were examined through TEM, zeta potential, and zeta sizer. GC-MS and FTIR were performed to examine the functional groups. The absorption peak was recorded at 430 nm; the average size recorded by TEM images was 13 nm, while the zeta potential and zeta sizer study showed aggregation in nanoparticles. Compared to C. gileadensis extracts, some of the FT-IR spectrum peaks were sight shifted with some new peaks in C. gileadensis AgNPs. C. gileadensis AgNPs were more toxic against HT29 followed by HTC116 and SW620. Expression levels of most of the genes in HCT116 and HT29 were increased by treatment whereas the gene expression level was least affected in SW620. C. gileadensis AgNPs have anticancer potential and need to be explored in cancer research.

The anticancer activity of silver nanoparticles (AgNPs) is well known to be synthesized using green-synthesized methods, although its mechanism of action is not understood fully. Moringa oleifera leaves were used as reducing and stabilizing agents to synthesize AgNPs. Green-synthesized AgNPs were characterized using ultraviolet-visible spectroscopy, dynamic light scattering, transmission electronic microscopy, scanning electronic microscopy, Fourier transform infrared, and energy-dispersive X-ray spectroscopy analyses. The synthesized nanoparticles were then characterized by their anticancer properties by performing a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The real-time polymerase chain reaction was used to check the expression levels of the four genes (β-catenin, adenomatous polyposis coli (APC), and lipoprotein receptor-related proteins 5 and 6 (LRP5/6)). The synthesized nanoparticles were 25 nm on average and spherical in shape and aggregated form. Noteworthy cytotoxicity is how green-synthesized M. oleifera–AgNPs were observed in comparison with the M. oleifera leaf extract against a cancerous cell line. The M. oleifera–AgNPs decreased the expression of CTNNB1 and LRP6 genes, while the LRP5 gene expression increased in both cell lines. With treatment, the APC gene expression decreased in SW480 but increased in HTC116. Our results imply that AgNPs synthesized by M. oleifera extract could be an ideal strategy to combat colon cancer.

Marine green algae are rich in various bioactive components with known anticancer activity. Some anticancer drugs present in green algae are in clinical trials nowadays. Algae-mediated silver nanoparticles (AgNPs) have been of a great interest in cancer treatment due to their unique physico-chemical properties. In this study, we evaluate the anticancer efficiency of marine alga Chaetomorpha ligustica collected from the Arabian Gulf against colon cancer cell lines HT29 and HCT116. The anticancer potential of biosynthesized AgNPs from C. ligustica extract is also reported. Fourier transform infrared (FTIR) spectroscopy and gas chromatography-mass spectrometry analyses were used to identify the phytoconstituents present in algae extract. The synthesized AgNPs were confirmed via UV-Vis spectroscopy, whereas their morphology and stability were recorded by transmission electron microscopy (TEM), zeta potential, and zetasizer. We recorded absorption peak at 420 nm; TEM images showed an average size of 8.8 nm, whereas zeta potential and zetasizer study showed aggregation of nanoparticles. FTIR spectroscopy peaks of C. ligustica AgNPs were a little different from those of the C. ligustica extract. Both extracts showed cytotoxicity against cancer cell lines in a dose-dependent manner, but nanoparticles were found to be more toxic than algae extract. HT29 was found to be more sensitive than HCT116. For the first time, species of C. ligustica have been used and reported for the synthesis of nanoparticles. C. ligustica and its biogenic nanoparticles need to be scaled up for many biomedical applications especially in cancer research.