Antibacterial, antibiofilm and cytotoxic effects of Nigella sativa essential oil coated gold nanoparticles
Authors: Sathappan Shanthi
Sivalingam Manju
Sekar Vijayakumar
Balasubramanian Malaikozhundan
Baskaralingam Vaseeharan
Ameeramja Jaishabanu
Perumal Ekambaram
Journal: Microbial Pathogenesis (2016)
Discipline: IMMUNOLOGY
Keywords: Antibacterial; Antibiofilm; AuNPs; Cytotoxicity; Essential oil
Affiliations: Crustacean Molecular Biology and Genomics Lab, Department of Animal Health and Management, 4th Floor, Science Block, Alagappa University, Karaikudi 630 003, Tamil Nadu, India., Molecular Toxicology Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore 641 046, Tamil Nadu, India., Crustacean Molecular Biology and Genomics Lab, Department of Animal Health and Management, 4th Floor, Science Block, Alagappa University, Karaikudi 630 003, Tamil Nadu, India. Electronic address: .

Abstract:  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. 

Retracted: No

PubPeer comments:
 Figure 6: The biofilm panel showing S. aureus 20 ug ml appears to look similar to the V. harveyii 40 ug ml panel (highlighted here with red boxes). The panels appear to differ in intensity. ![file] , 
 Figure 9: The legend reads:  Fig.9. Effect of NsEO-AuNPs (50 u03bcg ml-1) on the morphology of lung cancer cells A549 in comparison with the control. (a) control with out treatment (b) cells treated with DMEM (Dulbeccou2019s modified eagle medium) showing normal morphology (c) cell treated with bulk Au showing morphological changes (d) cells treated with N. sativa essential oil showing morphological changes (e) cells treated with NsEO-AuNPs showing cell burst and membrane integrity. Arrow indicates the morphological changes in the cells. However, panels a) and b) appear to show an area of overlap, as highlighted here with pink and green boxes. ![file] , 
 Figure 9 appears to be part of a set of (at least) 4 papers by this group that all appear to show the same set of photos, but representing different treatments or cell lines. 1. Figure 9 of Sivalingam Manju et al. Microbial Pathogenesis 2016, DOI: 10.1016 j.micpath.2015.11.021 (this paper) 2. Figure 11B of S. Vijayakumar et al., Microbial Pathogenesis 2016, DOI: 10.1016 j.micpath.2016.11.029 3. Figure 10 of Sekar Vijayakumar et al., Biomedicine Pharmacotherapy 84 (2016) 1213u20131222, DOI: 10.1016 j.biopha.2016.10.038 4. Figure 8 of Balasubramanian Malaikozhundan et al., Microbial Pathogenesis 2017, DOI: 10.1016 j.micpath.2017.01.029 Here is a comparison of all 4 of these figures. ![file] , 
 #1 The bottom right figure also appears similar to the two figures boxed in red by Bik, although rotated anticlockwise by about 90 degrees. ,