Antibacterial Efficacy of Green Synthesized Silver Nanoparticles Using Salvia nubicola Extract against Ralstonia solanacearum, the Causal Agent of Vascular Wilt of Tomato

Ralstonia solanacearum is a phytopathogen causing bacterial wilt diseases of tomato and affecting its productivity, which leads to prominent economic losses annually. As an alternative to conventional pesticides, green synthesized nanoparticles are believed to possess strong antibacterial activities besides being cheap and ecofriendly. Here, we present the synthesis of silver nanoparticles (Sn-AgNPs) from medicinally important aqueous plant extracts of Salvia nubicola. Characterization of biologically synthesized nanoparticles was performed through UV-vis spectrophotometry, Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), and thermogravimetric analysis. The antibacterial activity of the biosynthesized silver nanoparticles was tested against the phytopathogen R. solanacearum through in vitro experiments. Preliminary phytochemical analysis of the plant extracts revealed the presence of substantial amounts of flavonoids (57.08 mg GAE/g), phenolics (42.30 mg GAE/g), tannins, and terpenoids. The HPLC phenolic profile indicated the presence of 25 possible bioactive compounds. Results regarding green synthesized silver nanoparticles revealed the conformation of different functional groups through FTIR analysis, which could be responsible for the bioreduction and capping of Ag ions into silver NPs. TEM results revealed the spherical, crystalline shape of nanoparticles with the size in the range of 23-63 nm, which validates SEM results. Different concentrations of Sn-AgNPs (T1 (500 μg/mL) to T7 (78.1 μg/mL)) with a combination of plant extracts (PE-Sn-AgNPs) and plant extracts alone exhibited an efficient inhibition of R. solanacearum. These findings could be used as an effective alternative preparation against the bacterial wilt of tomato.

Biofabrication of nanoparticles: sources, synthesis, and biomedical applications

Nanotechnology is an emerging applied science delivering crucial human interventions. Biogenic nanoparticles produced from natural sources have received attraction in recent times due to their positive attributes in both health and the environment. It is possible to produce nanoparticles using various microorganisms, plants, and marine sources. The bioreduction mechanism is generally employed for intra/extracellular synthesis of biogenic nanoparticles. Various biogenic sources have tremendous bioreduction potential, and capping agents impart stability. The obtained nanoparticles are typically characterized by conventional physical and chemical analysis techniques. Various process parameters, such as sources, ions, and temperature incubation periods, affect the production process. Unit operations such as filtration, purification, and drying play a role in the scale-up setup. Biogenic nanoparticles have extensive biomedical and healthcare applications. In this review, we summarized various sources, synthetic processes, and biomedical applications of metal nanoparticles produced by biogenic synthesis. We highlighted some of the patented inventions and their applications. The applications range from drug delivery to biosensing in various therapeutics and diagnostics. Although biogenic nanoparticles appear to be superior to their counterparts, the molecular mechanism degradation pathways, kinetics, and biodistribution are often missing in the published literature, and scientists should focus more on these aspects to move them from the bench side to clinics.

Physicochemical Characterization of Star Anise Silver Nanoparticles Incorporated Chitosan Biomaterial for Absorb Water and Cure Wounds

Chronic wounds threaten the geriatric society worldwide irrespective of their social status. The current treatment approach to cure chronic ailments is associated with its demerits. A novel treatment approach that is coordinated is required to adsorb water from wounds and cure chronic wounds. Star anise condiment used in the Indian kitchen is shown to have the potency to cure various ailments. In this study, silver nanoparticles were prepared using the star anise extract. The biological potency of star anise extract was confirmed through Gas Chromatography Mass Spectroscopy, antioxidant assay, and anti-inflammatory study. From the DPPH assay result, it was inferred that star anise extract was able to scavenge the free radicals at the concentration of 10 μg/ml using the aqueous extract silver nanoparticles were prepared. The prepared particles were characterized by UV-visible, scanning electron microscopy, and their biological efficacy was determined for their potency against bacteria and prevention of protein aggregation. The anti-inflammatory assay suggests that nanoparticles prevent the aggregation of proteins in a dose-dependent manner. IC50 was found to be 20 μg/ml. The synthesized nanoparticle was incorporated into the chitosan biomaterial and characterized by various physicochemical parameters such as differential scanning calorimetry, scanning electron microscopy, FTIR, and thermogravimetric analysis. According to the findings, silver nanoparticles incorporated in chitosan biomaterials can be used to adsorb water from wounds and wound healing materials.

Antineoplastic activity of biogenic silver and gold nanoparticles to combat leukemia: Beginning a new era in cancer theragnostic

The American Cancer Society estimated around 61,090 new cases of leukemia were diagnosed, and around 23,660 people died from this disease in the United States alone in 2021. Due to its burden on society, there is an unmet need to explore innovative approaches to overcome leukemia. Among different strategies that have been explored, nanotechnology appears to be a promising and effective approach for therapeutics. Specifically, biogenic silver and gold nanoparticles (NPs) have attracted significant attention for their antineoplastic activity toward leukemia cancer cells due to their unique physicochemical properties. Indeed, these nanostructures have emerged as useful approaches in anti-leukemic applications, either as carriers to enhance drug bioavailability and its targeted delivery to a specific organ or as a novel therapeutic agent. This review explores recent advances in green synthesized nanomaterials and their potential use against leukemia, especially focusing on silver (Ag) and gold (Au) nanostructures. In detail, we have reviewed various eco-friendly methods of bio-synthesized NPs, their analytical properties, and toxicity effects against leukemic models. This overview confirms the satisfactory potency of biogenic NPs toward leukemic cells and desirable safety profiles against human native cells, which opens a promising door toward commercializing these types of nontherapeutic agents if challenges involve clinical validations, reproducibility, and scalability could be resolved.

Anti-human Glioma Cancer Potentials of Neobavaisoflavone as Natural Antioxidant Compound and Its Inhibition Profiles for Acetylcholinesterase and Butyrylcholinesterase Enzymes with Molecular Modeling and Spin Density Distributions Studies

In this study, the carcinogenic potential of Neobavaisoflavone as a natural antioxidant compound and the inhibitory profiles of acetylcholinesterase and butyrylcholinesterase were investigated by molecular modeling and spin density distribution studies. To evaluate the antioxidant properties of neobavaisoflavone, DPPH test was performed in the presence of butyl hydroxytoluene as a control. Neobavaisoflavone cell viability was low compared to normal human glioma cancer cell lines, namely LN-229, U-87 and A-172 cell lines, without any effect of cytotoxicity on normal cell line. Neobavaisoflavone inhibited half of DPPH at 125 μg/mL. The best effects of Neobavaisoflavone antihypertensive glioma against the above cell lines were in the LN-229 cell line. In addition, the significant anti-cancer potential of human glioma Neobavaisoflavone against the popular human glioma cancer cell lines is related in this study. IC₅₀ values were calculated by Neobavaisoflavone diagrams, 63.87 nM for AChE and 112.98 nM for BuChE, % Activity- [Inhibitor]. According to the above results, Neobavaisoflavone can be used to treat a variety of human glioma cancers in humans. In addition, molecular modeling calculations were performed to compare the biochemical activities of the Neobavaisoflavone molecule with enzymes. After molecular insertion calculations, ADME/T analysis was performed to investigate the properties of the neobavaisoflavone molecule, which will be used as a drug in the future. Then, different parameters for the antioxidant activity of the neobavaisoflavone molecule were calculated.

Novel green synthesis and characterization of a chemotherapeutic supplement by silver nanoparticles containing Berberis thunbergii leaf for the treatment of human pancreatic cancer

In recent years, silver nanoparticles have been used as modern chemotherapeutic drugs to treat several cancers such as pancreatic, breast, prostate, and blood cancers. No previous reports demonstrated the in vitro anti-human pancreatic cancer effects of the novel chemotherapeutic drug formulated by silver nanoparticles containing Berberis thunbergii leaf (AgNPs). The synthesized AgNPs were characterized using different techniques including UV-vis. and FT-IR spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), and TEM. All techniques approved the synthesized silver nanoparticles. The SEM and TEM exhibited a uniform spherical morphology and an average size of about 15 nm for the biosynthesized nanoparticles, respectively. The 4-(dimethylamino)benzaldehyde,2,2-diphenyl-1- pikrilhydrazil (DPPH) test revealed similar antioxidant potentials for B. thunbergii leaf aqueous extract, AgNPs, and butylated hydroxytoluene. AgNPs inhibited half of the DPPH molecules in the concentration of 108 μg/mL. To survey the anti-human pancreatic cancer activities of AgNO₃ , B. thunbergii leaf aqueous extract, and AgNPs, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used on common human pancreatic cancer cell lines. AgNPs had very low cell viability and anti-human pancreatic cancer effects dose-dependently against PANC-1, AsPC-1, and MIA PaCa-2. The IC50 values of the AgNPs were 259, 268, and 141 μg/mL against PANC-1, AsPC-1, and MIA PaCa-2 cell lines, respectively. It is thought that the AgNPs obtained can be used as an anticancer drug for the diagnosis of pancreatic cancer in humans after acceptance of the above findings in clinical study trials.

Doxorubicin and Trifolium pratense L. (Red clover) extract synergistically inhibits brain and lung metastases in 4T1 tumor-bearing BALB/c mice

Trifolium pratense L. (Red clover-T. pratense) commonly consumed as a healthy beverage has been demonstrated to have various biological activities including antioxidant and anticancer effects. The aim of this study was to investigate the antimetastasis effects of doxorubicin (DOX) and T. pratense extract in 4T1 tumor-bearing BALB/c mice. In this study, 56 female BALB/c mice were randomly divided into seven groups (n = 8/group) to receive DOX and T. pratense extract in three different doses (100, 200, and 400 mg/kg/day) for 35 days. On day 36 after starting treatments, serum cytokines (IL-8 and IL-6) were measured. Immunohistochemical (IHC) staining was performed for GATA-3 in the brain and lung, and for CK5/6 in tumor tissues. Metastasis-related gene (matrix metalloproteinase-2 [MMP-2] and sirtuin-1 [SIRT-1]) expressions were also measured by real-time PCR. Our results showed that cotreatment with DOX and T. pratense extract improved stereological parameters (i.e., reduction in the volume of metastatic tumors) in the lung and brain and decreased the serum levels of inflammatory cytokines (IL-8 and IL-6). DOX and T. pratense extract synergistically down-regulated MMP-2 and up-regulated SIRT-1 genes, decreased the number of CK5/6-positive cells in tumor tissues, and inhibited metastasis of GATA-3-positive cells into the lung and brain. The combination of T. pratense extract and DOX synergistically inhibited the metastasis of 4T1 xenograft cells in a dose-dependent manner.