Green Synthesis and Characterization of Carboxymethyl Cellulose Fabricated Silver-Based Nanocomposite for Various Therapeutic Applications.

PURPOSE: The current study proposed the simple, eco-friendly and cost-effective synthesis of carboxymethyl cellulose (CMC) structured silver-based nanocomposite (CMC-AgNPs) using Syzygium aromaticum buds extract. METHODS: The CMC-AgNPs were characterized by ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transmission infra-red (FTIR), energy-dispersive X-ray (EDX), and dynamic light scattering (DLS) techniques. The synthesized nanocomposites were evaluated for their bactericidal kinetics, in-vivo anti-inflammatory, anti-leishmaniasis, antioxidant and cytotoxic activities using different in-vitro and in-vivo models. RESULTS: The spherical shape nanocomposite of CMC-AgNPs was synthesized with the mean size range of 20-30 nm, and the average pore diameter is 18.2 nm while the mean zeta potential of -31.6 ± 3.64 mV. The highly significant (P < 0.005) antibacterial activity was found against six bacterial strains with the ZIs of 24.6 to 27.9 mm. More drop counts were observed in Gram-negative strains after 10 min exposure with CMC-AgNPs. Significant damage in bacterial cell membrane was also observed in atomic force microscopy (AFM) after treated with CMC-AgNPs. Nanocomposite showed highly significant anti-inflammatory activity in cotton pellet induced granuloma model (Phase I) in rats with the mean inhibitions of 43.13% and 48.68% at the doses of 0.025 and 0.05 mg/kg, respectively, when compared to control. Reduction in rat paw edema (Phase II) was also highly significant (0.025 mg/kg; 42.39%; 0.05 mg/kg, 47.82%). At dose of 0.05 mg/kg, CMC-AgNPs caused highly significant decrease in leukocyte counts (922 ± 83), levels of CRP (8.4 ± 0.73 mg/mL), IL-1 (177.4 ± 21.3 pg/mL), IL-2 (83.7 ± 11.5 pg/mL), IL-6 (83.7 ± 11.5 pg/mL) and TNF-α (18.3 ± 5.3 pg/mL) as compared to control group. CMC-AgNPs produced highly effective anti-leishmaniasis activity with the viable Leishmania major counts decreased up to 36.7% within 24 h, and the IC50 was found to be 28.41 µg/mL. The potent DPPH radical scavenging potential was also observed for CMC-AgNPs with the IC50 value of 112 µg/mL. Furthermore, the cytotoxicity was assessed using HeLa cell lines with the LC50 of 108.2 µg/mL. CONCLUSION: The current findings demonstrate positive attributes of CMC fabricated AgNPs as a promising antibacterial, anti-inflammatory, anti-leishmaniasis, and antioxidant agent with low cytotoxic potential.

A mechanistic study on the inhibition of bacterial growth and inflammation by Nerium oleander extract with comprehensive in vivo safety profile.

BACKGROUND: Nerium oleander (L.) is well known traditionally used medicinal plant with several pharmacological activities. However, the anti-bacterial, anti-inflammatory activity and in vivo toxicity potential of floral parts of this plant are not reported. Therefore the present study was designed to investigate these activities of Nerium oleander ethanolic flower extract (NOEE) in different animal models. METHODS: Antimicrobial activity of plant extract was compared with five different antibiotics using the disk diffusion method. The time-killing kinetic assay and bacterial killing mechanism of NOEE were also performed. Anti-inflammatory activity was assessed using granuloma induced by cotton-pellet, rat paw edema induced by carrageenan and levels of different inflammatory biomarkers on healthy Wistar rats. The protein and mRNA expressions of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) were also measured. Acute (14 days) and sub-acute (28 days) oral toxicity studies were also performed on healthy Sprague Dawley rats. RESULTS: NOEE produced highly significant (P < 0.005) and significant (P < 0.05) zones of inhibition at 30 mg/mL and 20 mg/mL respectively against most of the tested bacterial strains. NOEE produced a more drop in viable counts of Gram-negative isolates within 20 min. After 12 h exposure with NOEE, the SEM images of MRSA showed the destruction of cell membrane. NOEE showed highly significant (P < 0.005) anti-inflammatory activity in cotton-pellet and carrageenan inflammatory models. In addition, treatment with NOEE also decreased the production of NO, PGE2, TNF-α and IL-1ß in the rat paw after treated with carrageenan. Similarly, NOEE also suppressed the inducible nitric oxide synthase (iNOS), TNF-α, IL-1ß, and cyclooxygenase-2 (COX-2) mRNA expressions. It is also showed highly significant reduction in total leukocyte count (73.09%) and C-reactive protein levels (54.60%). NOEE also inhibited COX-1, COX-2, 5-LO and 12-LO in a highly significant manner. Moreover, acute and sub-acute toxicity studies of NOEE in rats confirm the toxicity with hepatotoxicity at higher doses (2000 mg/kg) i.e. four times greater than the therapeutic dose. CONCLUSION: It is concluded that crude flower extract of N. oleander is a potent antimicrobial and anti-inflammatory agent with no toxicity potential at therapeutic doses.

Facile, one-pot biosynthesis and characterization of iron, copper and silver nanoparticles using Syzygium cumini leaf extract: As an effective antimicrobial and aflatoxin B1 adsorption agents.

In this study, a facile, ecological and economical green method is described for the fabrication of iron (Fe), copper (Cu) and silver (Ag) nanoparticles (NPs) from the extract of Syzygium cumini leaves. The obtained metal NPs were categorized using UV/Vis, SEM, TEM, FTIR and EDX-ray spectroscopy techniques. The Fe-, Cu- and Ag-NPs were crystalline, spherical and size ranged from 40-52, 28-35 and 11-19 nm, respectively. The Ag-NPs showed excellent antimicrobial activities against methicillin- and vancomycin-resistance Staphylococcus aureus bacterial strains and Aspergillus flavus and A. parasiticus fungal species. Furthermore, the aflatoxins (AFs) production was also significantly inhibited when compared with the Fe- and Cu-NPs. In contrast, the adsorption results of NPs with aflatoxin B1 (AFB1) were observed as following order Fe->Cu->Ag-NPs. The Langmuir isotherm model well described the equilibrium data by the sorption capacity of Fe-NPs (105.3 ng mg-1), Cu-NPs (88.5 ng mg-1) and Ag-NPs (81.7 ng mg-1). The adsorption was found feasible, endothermic and follow the pseudo-second order kinetic model as revealed by the thermodynamic and kinetic studies. The present findings suggests that the green synthesis of metal NPs is a simple, sustainable, non-toxic, economical and energy-effective as compared to the others conventional approaches. In addition, synthesized metal NPs might be a promising AFs adsorbent for the detoxification of AFB1 in human and animal food/feed.

Green synthesized and characterized copper nanoparticles using various new plants extracts aggravate microbial cell membrane damage after interaction with lipopolysaccharide.

In the present study, commercially available six plants leave extracts such as Eucalyptus camaldulensis, Azadirachta indica, Murraya koenigii, Avicennia marina, Rosa rubiginosa and Datura stramonium were utilized for the production of copper nanoparticles (CuNPs). The characterization of particles was performed by UV/Vis, TEM, SEM, EDX and FTIR spectroscopy. TEM images showed the creation of CuNPs having mean size ranged from 48 to 29 nm corresponding to different plant extracts. SEM analysis showed the formation of spherical form of NPs. FTIR spectroscopy verified the availability of phytochemical components as they serves the reducing, covering and stabilizing assistant of the CuNPs. Antimicrobial ability of NPs was performed against various clinical pathogenic strains by Oxford cup method. The synthesized NPs indicated potent antibacterial activity, with relatively low values of MIC between 15 and 60 µg/mL. The antibacterial effect of each CuNPs was observed in the resulting order A. indica > D. stramonium > M. koenigii > R. rubiginosa > A. marina > E. camaldulensis. After 12 h exposure with A. indica synthesized CuNPs, the SEM images of S. typhi showed destruction of cell membrane and cell lysis was clearly observed after interaction with lipopolysaccharide. In conclusion, these obtained CuNPs could be precisely applied in treatment protocols without any covering or core-shell procedures.

Antibacterial, anticoagulant and cytotoxic evaluation of biocompatible nanocomposite of chitosan loaded green synthesized bioinspired silver nanoparticles.

Present work reports the green synthesis of chitosan functionalized silver nanoparticles (CS-AgNPs) using ethanolic buds extract of Sygyzium aromaticum. CS-AgNPs were characterized physically, evaluated for antibacterial, anticoagulant and antiplatelet activities, and toxicity profile. The physical characterization of CS-AgNPs was done by UV/vis, SEM, TEM, FTIR and EDX. The sphericity was found uniform. FTIR and EXD showed noninterfering few impurities. The antibacterial activity against VRSA (ZI, 23.2 ± 0.51 mm) and MRSA (ZI, 25.8 ± 0.32 mm) were determined. The rise in bleeding and thromboplastin was observed highly significant while increased in prothrombin and activated partial prothrombin time in significant manner at both the doses of CS-AgNPs (0.025 mg/kg and 0.05 mg/kg). Reduction in the levels of fibrinogen was also highly significant. Platelet aggregation decreased at high dose of CS-AgNPs i.e. 55.14 ± 8.25% (arachidonic acid) and 13.06 ± 2.17% (collagen). Thrombin antithrombin (TAT) complex activity was found highest for CS-AgNPs. Cytotoxicity was assessed using HeLa cell lines (LC50; 125 µg/ml) and brine shrimp lethality tests (LC50; 518 µg/ml). The work suggests that green synthesized chitosan functionalized silver nanoparticles may be utilized as an effective antibacterial agent and anticoagulant with low toxicity. The current findings will open a new window for nanomedicine development and future clinical application.