Introduction. Biogenic silver nanoparticles (AgNPs‐GA) were successfully synthesised using Garcinia atroviridis leaf extract as a reducing agent, which has ethnopharmacological claims against various diseases including cancer. Aim of the Study. Aim of the study is to discover whether AgNPs‐GA has cytotoxic and genotoxic effects on cancerous (A549) and noncancerous (BEAS‐2B) human lung cells. Materials and Methods. The cytotoxicity profiles of AgNPs‐GA were characterized by MTT assay, intracellular reactive oxygen species (ROS) assay, and DAPI and AOPI double staining, whilst genotoxicity was assessed using Comet Assay analysis. The level of silver ions (Ag+) and cellular uptake of AgNPs‐GA were evaluated by ICP‐OES and TEM analyses, respectively. Results. A significant cytotoxic effect was observed by AgNPs‐GA on both A549 and BEAS‐2B cell lines, with IC50 values of 20–28 μg/ml and 12–35 μg/ml, respectively. The cytotoxicity profile of AgNPs‐GA was also accompanied by a pronounced increase in ROS production, DNA damage, and apoptosis. Moreover, Ag+ was also detected in cells exposed to AgNPs‐GA threefold higher compared to controls. In this study, AgNPs‐GA were endocytosed within lysosomes, which may direct to secondary toxicity effects including oxidative stress, impairment of the cell membrane, DNA fragmentation, and cell death. Conclusions. Taken together, novel toxicological‐related mechanisms by AgNPs‐GA were proposed involving the generation of ROS that causes DNA damage which led to programmed cell death in both A549 and BEAS‐2B cells. Therefore, a combination of scientific assessments is constantly needed to ensure that the quality of biosynthesized nanoparticles is controlled and their safe development is promoted.
Clinacanthus nutans is a well-known herb that has been used as an alternative and therapeutic medicine, however more selective C. nutans extracts are needed. In this study, leaves were extracted with 80% methanol and further fractionated with n-hexane, dichloromethane, chloroform, n-butanol, and aqueous residue. Subsequently, the total phenolic content (TPC), total flavonoid content (TFC), antioxidant scavenging activity, and antiproliferative effects on breast cancer (Michigan Cancer Foundation-7 [MCF7]) and normal breast (Michigan Cancer Foundation-10A [MCF 10A]) cells of the extracts were measured. Additionally, molecular docking simulation of the major compounds from C. nutans extracts was conducted. The aqueous residue had the highest TPC and TFC, whereas the crude extract had the highest scavenging activity. Among the extracts, dichloromethane extract (CN-Dcm) was selected as it had the highest selectivity index (SI) (1.48). Then, the chosen extract (CN-Dcm) was proceed for further analysis. The compounds from CN-Dcm were identified using gas chromatography–mass spectrometry (GC-MS). The major compounds from CN-Dcm were further investigated through molecular docking studies. Palmitic acid and linolenyl alcohol were the compounds found in the CN-Dcm extract that exhibited the highest binding affinities with p53-binding protein Mdm-2. These results highlight the potential of C. nutans as a source of anticancer activities.
A bottom-up approach for synthesizing silver nanoparticles (AgNPs-GA) phytomediated by Garcinia atroviridis leaf extract is described. Under optimized conditions, the AgNPs-GA were synthesized at a concentration of 0.1 M silver salt and 10% (w/v) leaf extract, 1:4 mixing ratio of reactants, pH 3, temperature 32 °C and 72 h reaction time. The AgNPs-GA were characterized by various analytical techniques and their size was determined to be 5–30 nm. FTIR spectroscopy indicates the role of phenolic functional groups in the reduction of silver ions into AgNPs-GA and in supporting their subsequent stability. The UV-Visible spectrum showed an absorption peak at 450 nm which reflects the surface plasmon resonance (SPR) of AgNPs-GA and further supports the stability of these biosynthesized nanoparticles. SEM, TEM and XRD diffractogram analyses indicate that AgNPs-GA were spherical and face-centered-cubic in shape. This study also describes the efficacy of biosynthesized AgNPs-GA as anti-proliferative agent against human breast cancer cell lines, MCF-7 and MCF-7/TAMR-1. Our findings indicate that AgNPs-GA possess significant anti-proliferative effects against both the MCF-7 and MCF-7/TAMR-1 cell lines, with inhibitory concentration at 50% (IC50 values) of 2.0 and 34.0 µg/mL, respectively, after 72 h of treatment. An induction of apoptosis was evidenced by flow cytometry using Annexin V-FITC and propidium iodide staining. Therefore, AgNPs-GA exhibited its anti-proliferative activity via apoptosis on MCF-7 and MCF-7/TAMR-1 breast cancer cells in vitro. Taken together, the leaf extract from Garcinia atroviridis was found to be highly capable of producing AgNPs-GA with favourable physicochemical and biological properties.