Assessment of in vitro antimicrobial efficacy of biologically synthesized metal nanoparticles against pathogenic bacteria.

The microbial infections due to biofilm forming bacterial pathogens are very common in human subjects. The intensive application of antibiotics in integrated disease management strategy has led to increased multidrug resistance incommon pathogens. Thus, indicating need of developing an alternative method for the control of these multidrug resistant pathogens. Present study involves the Moringa oleifera aqueous extract mediated biological synthesis of silver (Ag nanoparticles (NPs)- Avg. size 82.5 nm; zeta potential = -27.9 mV), copper oxide (CuONPs- Avg. size 61 nm; zeta potential = -19.3 mV), iron oxide (FeONPs- Avg. size 83.3 nm; zeta potential = -9.37 mV) and alumina (AlONPs- Avg. size 87.3 nm; zeta potential = -10.9 mV) nanoparticles. Biological nanoparticles were detected by visual observation, spectrophotometric detection followed by zeta potential analysis, nanoparticle tracking analysis, Fourier transform infrared spectrometry and X-ray diffraction analysis. Nanoparticles were further evaluated for their in vitro antimicrobial potential, membrane damage effectiveness, biofilm inhibition activity by MTT assay. Nanoparticles were assessed against human pathogens viz. two Gram-positive (Bacillus subtilis MTCC 441 and Staphylococcus haemolyticus MTCC 3383) and two Gram-negative bacteria (Enterobacter aerogenes MTCC 111 and Salmonella enterica ser. Typhi MTCC 8767). The nanoparticles exhibited akin activity pattern against all pathogens studied i.e. AgNPs > CuONPs > AlONPs > FeONPs. Tested nanoparticles registered lower MIC values and more intensified growth inhibition against Gram-negative bacteria compared to their Gram-positive counterparts. These results pointed out that the M. oleifera mediated nanoparticles can be prospectivelyutilized in the development of alternative antimicrobials against diverse bacterial infections.

Nephroprotective effect of Bryophyllum pinnatum-mediated silver nanoparticles in ethylene glycol-induced urolithiasis in rat.

A large population is suffering from multifactorial urolithiasis worldwide with a reoccurrence rate of almost 70%-80% in males and 47%-60% in females. In the present study, the nephroprotective effect of silver nanoparticles (AgNPs) synthesised by Bryophyllum pinnatum was evaluated in ethylene glycol-induced urolithiasis in rat. B. pinnatum-mediated AgNPs which were found to be spherical and polydispersed particles with an average size of 32.65 nm determined by transmission electron microscopy analysis, and showing an absorption peak at 432 nm by the UV-Vis spectrophotometric analysis, revealing the role of hydroxyl group in the synthesis by Fourier Transformed Infrared Spectroscopy analysis, with a zeta potential value of -15.7 mV. The crystalline nature and fcc structure was demonstrated based on X-ray diffraction analysis. Animal study was performed on 36 male Wistar rats divided into six equal groups, which demonstrated significant increase in serum total protein, albumin and globulin and significant decrease in AST, ALT, creatinine, BUN, calcium and phosphorus in group V and VI when compared with group II and IV. No crystalluria was observed in rats given B. pinnatum AgNPs. Histopathological observations in group V and VI showed mild degenerative changes and restoration or maintenance of kidney parenchyma when compared with group II and IV rats. Thus, the authors conclude with the beneficial preventive and therapeutic nephroprotective effect of B. pinnatum-mediated AgNPs against ethylene glycol-induced urolithiasis in rats.

Biogenic Synthesis of Zinc Oxide Nanoparticles by Bryophyllum pinnatum and its Acute Oral Toxicity Evaluation in Wistar Rats.

The evaluation of toxic effects of nanoparticles (NPs) has become an important aspect of Nanotechnology research in the 21st century. The present investigation deals with the green synthesis of biogenic zinc oxide nanoparticles (ZnO-NPs) using Bryophyllum pinnatum leaves, their characterization and evaluation of acute oral toxicity in Wistar rats. The characterization of synthesized ZnO-NPs revealed maximum absorbance at 307 nm on UV-Vis spectrophotometric analysis, NTA showed mean size of particles and mode of the particles distribution as 128.2 nm and 12.6 nm, respectively. Zeta potential was found to be -0.369 mV. The absorbance shown by FTIR at 3469, 1644, 1355 and 887 cm-1 indicates the involvement of biomolecules that are accountable for capping and stabilization of ZnO-NPs. The XRD assessment further demonstrated the crystalline nature of the ZnO-NP. The TEM analysis of the synthesized ZnO-NPs revealed the presence of spherical NPs with the mean size of 3.7 nm. The acute oral toxicity evaluation in rat showed an approximate median lethal dose to be more than 2000 mg/kg body weight. It is thus concluded that biogenic ZnO-NPs showed absence of acute oral toxicity symptoms at the doses employed in the present study.

Biosynthesis of zinc oxide nanoparticles by petals extract of Rosa indica L., its formulation as nail paint and evaluation of antifungal activity against fungi causing onychomycosis.

Aim: The authors report the biological synthesis of zinc oxide nanoparticles (ZnO-NPs) from the petals extract of Rosa indica L. (rose). Its efficacy was evaluated against two dermatophytes: namely: Trichophyton mentagrophytes and Microsporum canis which cause onychomycosis. The activity of antibiotics against the tested dermatophytes was enhanced, when evaluated in combination with ZnO-NPs. Methods and results: The synthesised ZnO-NPs were preliminary detected by using ultraviolet UV visible spectroscopy, which showed specific absorbance. The ZnO-NPs were further characterised by nanoparticle tracking analysis (NTA), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction and Zetasizer. Moreover, nanoparticles containing nail paint (nanopaint) was formulated and its antifungal activity was also assessed against T. mentagrophytes and M. canis. ZnO-NPs and formulated nanopaint containing ZnO-NPs, both showed significant antifungal activity. The maximum activity was noted against M. canis and lesser against T. mentagrophytes. Minimum inhibitory concentration of ZnO-NPs was also determined against the dermatophytes causing onychomycosis infection. Conclusion: ZnO-NPs can be utilised as a potential antifungal agent for the treatment of onychomycosis after more experimental trials.

Development of shampoo, soap and ointment formulated by green synthesised silver nanoparticles functionalised with antimicrobial plants oils in veterinary dermatology: treatment and prevention strategies.

Many scientists have focused their research on the role of nanotechnology for the control of human pathogens, but there are also many topical pathogens present in animals, which infect animals and transfer to humans. Topical therapy is extremely important for the management of dermatological condition in animals. Therefore, the present study aims to evaluate the efficacy of biogenic silver nanoparticles (AgNPs) in combination with herbal oils against animal skin infections which may be responsible for causing infections in human beings. Here, the authors synthesised and characterised the AgNPs from Azadirachta indica. The oils were extracted from medicinal plants including Cymbopogon citratus, Cymbopogon martini, Eucalyptus globules, A. indica and Ocimum sanctum and the antifungal and antibacterial activity of plant oils along with AgNPs were evaluated. An excision wound model was used for the study of wound healing activity in rabbits. AgNPs functionalised oil has demonstrated remarkable antimicrobial activity against pathogens present on the skin of animals. The nano-functionalised antimicrobial oils were used in the formulation of shampoo, soap and ointment for veterinary dermatology. Antimicrobial products of plant origin with AgNPs are valuable, safe and have a specific role in controlling diseases. The authors believe that this approach will be a good alternative therapy to solve the continuous antibiotic resistance developed by many bacterial pathogens and will be utilised in various animal contacting areas in medicine.

Green synthesis of copper nanoparticles by Citrus medica Linn. (Idilimbu) juice and its antimicrobial activity.

We report an eco-friendly method for the synthesis of copper nanoparticles (CuNPs) using Citron juice (Citrus medica Linn.), which is nontoxic and cheap. The biogenic copper nanoparticles were characterized by UV-Vis spectrophotometer showing a typical resonance (SPR) at about 631 nm which is specific for CuNPs. Nanoparticles tracking analysis by NanoSight-LM20 showed the particles in the range of 10-60 nm with the concentration of 2.18 × 10(8) particles per ml. X-ray diffraction revealed the FCC nature of nanoparticles with an average size of 20 nm. The antimicrobial activity of CuNPs was determined by Kirby-Bauer disk diffusion method against some selected species of bacteria and plant pathogenic fungi. It was reported that the synthesized CuNPs demonstrated a significant inhibitory activity against Escherichia coli followed by Klebsiella pneumoniae, Pseudomonas aeruginosa, Propionibacterium acnes and Salmonella typhi. Among the plant pathogenic fungi tested, Fusarium culmorum was found to be most sensitive followed by F. oxysporum and F. graminearum. The novelty of this work is that for the first time citron juice was used for the synthesis of CuNPs.

Lawsonia inermis-mediated synthesis of silver nanoparticles: activity against human pathogenic fungi and bacteria with special reference to formulation of an antimicrobial nanogel.

Lawsonia inermis mediated synthesis of silver nanoparticles (Ag-NPs) and its efficacy against Candida albicans, Microsporum canis, Propioniabacterium acne and Trichophyton mentagrophytes is reported. A two-step mechanism has been proposed for bioreduction and formation of an intermediate complex leading to the synthesis of capped nanoparticles was developed. In addition, antimicrobial gel for M. canis and T. mentagrophytes was also formulated. Ag-NPs were synthesized by challenging the leaft extract of L. inermis with 1 mM AgNO3. The Ag-NPs were characterized by Ultraviolet-Visible (UV-Vis) spectrophotometer and Fourier transform infrared spectroscopy (FTIR). Transmission electron microscopy (TEM), nanoparticle tracking and analysis sytem (NTA) and zeta potential was measured to detect the size of Ag-NPs. The antimicrobial activity of Ag-NPs was evaluated by disc diffusion method against the test organisms. Thus these Ag-NPs may prove as a better candidate drug due to their biogenic nature. Moreover, Ag-NPs may be an answer to the drug-resistant microorganisms.