High synergistic antibacterial, antibiofilm, antidiabetic and antimetabolic activity of Withania somnifera leaf extract-assisted zinc oxide nanoparticle.

Nanotechnology is currently gaining immense attention to combat food borne bacteria, and biofilm. Diabetes is a common metabolic disease affecting majority of people. A better therapy relies on phytomediated nanoparticle synthesis. In this study, W. somnifera leaf extract-assisted ZnO NPs (Ws-ZnO NPs) was synthesized and characterized. From HR-TEM analysis, it has been found that the hexagonal wurtzite particle is 15.6 nm in size and - 12.14 mV of zeta potential. A greater antibacterial effect of Ws-ZnO NPs was noticed against E. faecalis and S. aureus at 100 µg mL-1. Also, the biofilm of E. faecalis and S. aureus was greatly inhibited at 100 µg mL-1 compared to E. coli and P. aeruginosa. The activity of α-amylase and α-glucosidase enzyme was inhibited at 100 µg mL-1 demonstrating its antidiabetic potential. The larval and pupal development was delayed at 25 µg mL-1 of Ws-ZnO NPs. A complete mortality (100%) was recorded at 25 µg mL-1. Ws-ZnO NPs showed least LC50 value (9.65 µg mL-1) compared to the uncoated ZnO NPs (38.8 µg mL-1) and leaf extract (13.06 µg mL-1). Therefore, it is concluded that Ws-ZnO NPs are promising to be used as effective antimicrobials, antidiabetic and insecticides to combat storage pests.

Biopolymer K-carrageenan wrapped ZnO nanoparticles as drug delivery vehicles for anti MRSA therapy.

Kappa-Carrageenan wrapped ZnO nanoparticles (KC-ZnO NPs) was synthesized, physico-chemically characterized and evaluated their biocompatibility and antimicrobial therapy against MRSA. XRD showed the highly crystalline and hexagonal phase structure of ZnO NPs. FETEM confirmed the spherical and hexagonal shaped particle with the mean size of 97.03 ± 9.05 nm. The synthesized KC-ZnO NPs exhibited significant antibacterial activity against MRSA. The biofilm growth of MRSA was greatly inhibited at 100 µg/ml as observed through live and dead cell assay. KC-ZnO NPs have shown invitro anti-inflammatory activity (82%) at 500 µg/ml. KC-ZnO NPs was non-toxic to NIH3T3 mouse embryonic fibroblasts cell lines. Further, no apoptotic and necrotic mediated death in NIH3T3 mouse embryonic fibroblasts cells were noticed by flow cytometric analysis. KC-ZnO NPs have good biocompatibility as recorded by the least hemolysis percentage (<3%) up to 100 µg/ml, which is much lesser than the acceptable limit. In addition, ecosafety analysis has shown that KC-ZnO NPs and kappa karrageenan (0-500 µg/ml) caused no mortality of A. salina after 48 h. However, bare zinc acetate has shown 35% mortality of A. salina after 48 h. The results conclude that KC-ZnO NPs could be a novel antibacterial therapy for the treatment of MRSA associated infectious.

Garlic clove extract assisted silver nanoparticle - Antibacterial, antibiofilm, antihelminthic, anti-inflammatory, anticancer and ecotoxicity assessment.

Facile and low cost garlic clove extract based silver nanoparticles was synthesized and its broad spectrum of therapeutic activity including antibiofilm, antiparasitic and anti-breast cancer activity was evaluated. The synthesized garlic­silver nanoparticles (G-AgNPs) were characterized by various physico-chemical techniques. G-AgNPs showed good optical property, highly crystalline nature, spherical shape and uniformly dispersed with size measuring between 10 and 50 nm. G-AgNPs have shown greater anti-bacterial and antibiofilm activity on clinically important pathogens methicillin-resistant S. aureus and P. aerigunosa at 100 µg ml-1. The efficacy of G-AgNPs against earthworm evidenced its effectiveness as anti-helminthic agent in treating intestinal parasites. The significant inhibition of BSA protein denaturation proves its anti-inflammatory property. In addition, G-AgNPs have shown remarkable anticancer effect and significantly inhibited the human breast cancer cell (MCF-7) viability at 100 µg ml-1 after 24 h. A noticeable change in the morphology of MCF-7 cells was also noticed. G-AgNPs were non-toxic to human HEK293 embryonic cells. Also, the non-toxic nature of G-AgNPs to C. cornuta and no morphological, physiological changes proved its safety to the environment. It is concluded that G-AgNPs have a broad range of biological applications and it can be used as an eco-friendly material without having negative effects in the environment.

Two potential uses for silver nanoparticles coated with Solanum nigrum unripe fruit extract: Biofilm inhibition and photodegradation of dye effluent.

Silver nanoparticle was green synthesized involving the unripe fruit extracts of Solanum nigrum (Sn-AgNPs). The synthesized Sn-AgNPs was bio-physically characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Transmission electron microscopy (TEM). UV-Vis recorded the absorbance spectra at 443 nm. XRD analysis clearly demonstrated the crystalline nature of Sn-AgNPs with Bragg's reflection peaks at 111, 200, 220 and 311 lattice planes. The FTIR spectrum of Sn-AgNPs showed strong bands at 3432, 1555, 1455, 862 and 406 cm-1 which corresponds at O-H, C-H, C-C, C-OH and C-N groups respectively. TEM exhibited the spherical shape of Sn-AgNPs with particle size between 20 and 30 nm. The antibacterial effects of Sn-AgNPs were tested on clinically important biofilm forming Gram positive (Bacillus pumulis and Enterococcus faecalis) and Gram negative (Proteus vulgaris and Vibrio parahaemolyticus) bacteria. The greater inhibition of B. pumulis and E. faecalis was observed at 100 µg mL-1 of Sn-AgNPs compared to P. vulgaris and V. parahaemolyticus. The biofilm inhibition potential of Sn-AgNPs was greater against Gram positive bacteria than that of Gram negative bacteria. Furthermore, Sn-AgNPs effectively degraded the industrial effluent methyl orange dye by photocatalysis. It is concluded that Sn-AgNPs could be used as an effective therapeutics against the biofilm of clinically important bacteria. The green synthesized Sn-AgNPs can be employed to degrade dye effluents and prevent environmental pollution as well.

A novel antimicrobial therapy for the control of Aeromonas hydrophila infection in aquaculture using marine polysaccharide coated gold nanoparticle.

In the present study, we prepared fucoidan coated Au-NPs (Fu-AuNPs), and examined its antimicrobial activity against Aeromonas hydrophila. The green synthesized Fu-AuNPs were bio-physically characterized by Ultraviolet-visible (UV-Vis) spectroscopy, X-ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Higher Transmission Electron Microscopy (HR-TEM), Zeta potential analysis and Energy Dispersive X-ray spectroscopy (EDX). Fu-AuNPs were crystalline in nature, spherical to triangular in shape, with particle size ranging within 10-100 nm. The synthesized Fu-AuNPs at 100 µg mL-1 showed inhibition zone against A. hydrophila (23.2 mm) which is much higher than that of commercial antibiotic chloramphenicol (17.3 mm). The biofilm inhibitory activity of Fu-AuNPs against Gram negative (Aeromonas hydrophila) was higher. Light and confocal laser scanning microscopic observations showed that the Fu-AuNPs at 100 µg mL-1 inhibited the biofilm of A. hydrophila. The cytotoxicity study indicated that Fu-AuNPs were effective in inhibiting the viability of human cervical cancer cells (HeLa) at 100 µg mL-1. In another experiment, the antibacterial effect of Fu-AuNPs on tilapia, Oreochromis mossambicus were evaluated in vivo. The mortality rate of O. mossambicus infected by A. hydrophila was much higher (90%), whereas, the mortality of O. mossambicus that received Fu-AuNPs followed by challenge with A. hydrophia was reduced to 30%. This study concludes that Fu-AUNPs are effective in the control of A. hydrophila infections in O. mossambicus.

Control of biofilm forming clinically important bacteria by green synthesized ZnO nanoparticles and its ecotoxicity on Ceriodaphnia cornuta.

Zinc oxide nanoparticles were synthesized using the aqueous leaf extracts of Plectranthus barbatus (Plb-ZnO NPs) and characterized by UV-visible spectroscopy, XRD, FTIR, SEM and EDS. UV-Visible spectra recorded the absorbance peak of Plb-ZnO NPs at 343 nm. SEM analyses showed the spherical shape of Plb-ZnO NPs with the particle size between 30 and 60 nm. Plb-ZnO NPs exhibited antibacterial and antibiofilm activity against Gram positive Bacillus subtilis at all tested concentrations. In contrast, Plb-ZnO NPs showed antibacterial and antibiofilm activity against Gram negative Vibrio parahaemolyticus and Proteus vulgaris only at 100 µg/ml. The Atomic absorption spectrometry (AAS) revealed that Zn2+ dissolution was 1.87 and 8.8 µg/L at 10 and 160 µg/L of Plb-ZnO NPs respectively. The body accumulation of Zn2+ was increased from 0.8 µg/g body weight to 3.5 µg/g body weight when C. cornuta exposed to 10 µg/L and 160 µg/L respectively. Plb-ZnO NPs were toxic to Ceriodaphnia cornuta neonates (LC50: 28 µg/L). Plb-ZnO NPs caused 100% mortality of C. cornuta at 160 µg/L after 24 h. However, zinc acetate does not cause any mortality of C. cornuta upto 350 µg/L. The light and confocal laser scanning microscopic images evidenced the uptake and accumulation of Plb-ZnO NPs on the internal gut regions of C. cornuta at 160 µg/L after 5, 10, 15, 20 and 24 h. Abnormalities in the swimming behaviour such as erratic swimming (ERR), migration to bottom (BOT) and migration to water surface (SUR) of C. cornuta were noticed after treatment with different concentrations of Plb-ZnO NPs.

Biological therapeutics of Pongamia pinnata coated zinc oxide nanoparticles against clinically important pathogenic bacteria, fungi and MCF-7 breast cancer cells.

The overuse of antimicrobics and drugs has led to the development of resistance in a number of pathogens and parasites, which leads to great concerns for human health and the environment. Furthermore, breast cancer is the second most common cause of cancer death in women. MCF-7 is a widely used epithelial cancer cell line, derived from breast adenocarcinoma for in vitro breast cancer studies, since the cell line has retained several ideal characteristics particular to the mammary epithelium. In this scenario, the development of novel and eco-friendly drugs are of timely importance. Green synthesis of nanoparticles is cost effective, environmental friendly and does not involve the use of toxic chemicals or elevate energy inputs. This research focused on the anticancer activity of Pongamia pinnata seed extract-fabricated zinc oxide nanoparticles (Pp-ZnO NPs) on human MCF-7 breast cancer cells, antibiofilm activity against bacteria and fungi was also investigated. Nanoparticles were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX). Pp-ZnO NPs effectively inhibited the growth of Gram positive Bacillus licheniformis (zone of inhibition: 17.3 mm) at 25 µg ml-1 followed by Gram negative Pseudomonas aeruginosa (14.2 mm) and Vibrio parahaemolyticus (12.2 mm). Pp-ZnO NPs also effectively inhibited the biofilm formation of C. albicans at 50 µg ml-1. Cytotoxicity studies revealed that a single treatment with Pp-ZnO NPs significantly reduced the cell viability of breast cancer MCF-7 cells at doses higher than 50 µg ml-1. Morphological changes in the Pp-ZnO NPs treated MCF-7 breast cancer cells were observed using phase contrast microscopy. This study concludes that the green synthesized Pp-ZnO NPs may be used as an effective antimicrobial and antibreast cancer agents.

Oreochromis mossambicus diet supplementation with Psidium guajava leaf extracts enhance growth, immune, antioxidant response and resistance to Aeromonas hydrophila.

In this research, we focused on the efficacy of aqueous and ethanol leaf extracts of Psidium guajava L. (guava) based experimental diets on the growth, immune, antioxidant and disease resistance of tilapia, Oreochromis mossambicus following challenge with Aeromonas hydrophila. The experimental diets were prepared by mixing powdered (1, 5 and 10 mg/g) aqueous and ethanol extract of guava leaf with commercial diet. The growth (FW, FCR and SGR), non-specific cellular immune (myeloperoxidase activity, reactive oxygen activity and reactive nitrogen activity) humoral immune (complement activity, antiprotease, alkaline phosphatase activity and lysozyme activity) and antioxidant enzyme responses (SOD, GPX, and CAT) were examined after 30 days of post-feeding. A significant enhancement in the biochemical and immunological parameters of fish were observed fed with experimental diets compared to control. The dietary supplementation of P. guajava leaf extract powder for 30 days significantly reduced the mortality and increased the disease resistance of O. mossambicus following challenge with A. hydrophila at 50 µl (1 × 107 cells ml-1) compared to control after post-infection. The results suggest that the guava leaf extract could be used as a promising feed additive in aquaculture.

Laurus nobilis leaf extract mediated green synthesis of ZnO nanoparticles: Characterization and biomedical applications.

The present study reports the green synthesis of zinc oxide nanoparticles using the aqueous leaf extract of Laurus nobilis (Ln-ZnO NPs) by co-precipitation method. The synthesized Ln-ZnO NPs were characterized by UV-Vis spectroscopy, FTIR, XRD, TEM, SEM and EDX. Ln-ZnO NPs were crystalline in nature, flower like and have hexagonal wurtzite structure with a mean particle size of 47.27nm. The antibacterial activity of Ln-ZnO NPs was greater against Gram positive (Staphylococcus aureus) bacteria than Gram negative (Pseudomonas aeruginosa) bacteria. The zone of inhibition against S. aureus was 11.4, 12.6 and 14.2mm at 25, 50 and 75µgmL-1. The zone of inhibition against P. aeruginosa was 9.8, 10.2 and 11.3mm at 25, 50 and 75µgmL-1. The light and confocal laser scanning microscopic images evidenced that Ln-ZnO NPs effectively inhibited the biofilm growth of S. aureus and P. aeruginosa at 75µgmL-1. The cytotoxicity studies revealed that Ln-ZnO NPs showed no effect on normal murine RAW264.7 macrophage cells. On the other hand, Ln-ZnO NPs were effective in inhibiting the viability of human A549 lung cancer cells at higher concentrations of 80µgmL-1. The morphological changes in the Ln-ZnO NPs treated A549 lung cancer cells were observed under phase contrast microscope.

Essential oils of Nigella sativa protects Artemia from the pathogenic effect of Vibrio parahaemolyticus Dahv2.

The anti-Vibrio activity of essential oils (EOs) of nine medicinal plants was tested against 28 Vibrio spp. isolated from diseased Fenneropenaeus indicus. EO of Nigella sativa exhibited anti-Vibrio activity against all Vibrio spp. and greater inhibition was noted for the isolate V2 which was identified as Vibrio parahaemolyticus Dahv2. Further, EO of N. sativa effectively inhibited V. parahaemolyticus Dahv2 with an inhibition zone of 23.9mm at 101.2µgml(-1). Moreover, EO of N. sativa revealed anti-biofilm activity at 101.2µgml(-1) against V. parahaemolyticus Dahv2 and inhibited the growth of V. parahaemolyticus Dahv2 at 100µgml(-1).In vivo experimental infection studies showed that the survival of Artemia spp. infected with V. parahaemolyticus Dahv2 at 1×10(3)cfuml(-1) was only 40%. However, the survival of Artemia spp. was significantly increased after challenge with 100µgml(-1) of EO of N. sativa. EO of N. sativa showed higher anti-oxidant potential and total phenol content than other EOs tested. The anti-oxidant activity of EO of N. sativa was highly correlated to their total phenolic contents (r=0.836, P<0.05). This observation suggests that EO of N. sativa protected the Artemia spp. after experimental infection of V. parahaemolyticus Dahv2.

Invitro acaricidal activity of ethnoveterinary plants and green synthesis of zinc oxide nanoparticles against Rhipicephalus (Boophilus) microplus.

The present study was designed to investigate the invitro acaricidal effects of seven ethnoveterinary plants, zinc acetate and green synthesized zinc oxide nanoparticles against the Southern cattle tick, Rhipicephalus (Boophilus) microplus. The selected ethnoveterinary plants were extracted using ethanol and aqueous (water) solvents at 0.02mg/ml and 0.04mg/ml concentrations. Of these seven plants, Lobelia leschenaultiana showed the highest percentage of tick mortality. The ethanol extracts of L. leschenaultiana showed 93.33% mortality at 0.04mg/ml and its LC50 was 0.05mg/ml. However, zinc acetate exhibited 70% mortality at 0.04mg/ml (LC50: 0.0192mg/ml). Further, we synthesized ZnO nanoparticle using the leaf extracts of L. leschenaultiana and zinc acetate as the precursor material to control R. (B.) microplus. The structural characterization of the synthesized ZnO nanoparticles (Ll-ZnO NPs) was performed by UV-vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microsopy (TEM). UV-vis spectra showed the absorption band at 383nm. XRD analysis clearly showed the crystalline nature of Ll-ZnO NPs with various Bragg's reflection peaks at 100, 002, 101, 102, 110, 103, 200, 201 and 202 planes. FTIR analysis showed the possible functional groups of Ll-ZnO NPs with strong band at 3420.63 and 2922.48cm(-1). SEM and TEM analysis revealed that the Ll-ZnO NPs were spherical and hexagonal in shape with particle size ranging between 20 and 65nm. The mortality of R. (B.) microplus after treatment with Ll-ZnO NPs was 35, 57.5 and 82.5% at 0.001, 0.002 and 0.004mg/ml. On the otherhand, 100% mortality of R. (B.) microplus was observed at 0.008mg/ml (LC50: 0.0017mg/ml). The results indicated that the Ll-ZnO NPs have good acaricidal properties compared to L. leschenaultiana leaf extract and zinc acetate.

Antibacterial, antibiofilm and cytotoxic effects of Nigella sativa essential oil coated gold nanoparticles.

This study reports the biological synthesis of gold nanoparticles using essential oil of Nigella sativa (NsEO-AuNPs). The synthesized NsEO-AuNPs were characterized by UV-visible spectra, X-ray diffraction (XRD), FTIR and Transmission electron microscopy (TEM). UV-vis spectra of NsEO-AuNPs showed strong absorption peak at 540 nm. The X-ray diffraction analysis revealed crystalline nature of nanoparticle with distinctive facets (111, 200, 220 and 311 planes) of NsEO-AuNPs. The FTIR spectra recorded peaks at 3388, 2842, 1685, 1607, 1391 and 1018 cm(-1). TEM studies showed the spherical shape of nanoparticles and the particle size ranges between 15.6 and 28.4 nm. The antibacterial activity of NsEO-AuNPs was greater against Gram positive Staphylococcus aureus MTCC 9542 (16 mm) than Gram negative Vibrio harveyi MTCC 7771 (5 mm) at the concentration of 10 µg ml(-1). NsEO-AuNPs effectively inhibited the biofilm formation of S. aureus and V. harveyi by decreasing the hydrophobicity index (78% and 46% respectively). The in-vitro anti-lung cancer activity confirmed by MTT assay on the cell line of A549 carcinoma cells showed IC50 values of bulk Au at 87.2 µg ml(-1), N. sativa essential oil at 64.15 µg ml(-1) and NsEO-AuNPs at 28.37 µg ml(-1). The IC50 value showed that NsEO-AuNPs was highly effective in inhibiting the A549 lung cancer cells compared to bulk Au and N. sativa essential oil.