Antioxidant and antibacterial activity of silver nanoparticles synthesized by Cestrum nocturnum.

BACKGROUND: Silver nanoparticles are toxic to bacteria and have widespread application in different research areas. OBJECTIVE: The aim of this study was to synthesize silver nanoparticles using an aqueous leaf extract of Cestrum nocturnum and to test its antioxidant and antibacterial activities. MATERIALS AND METHODS: The silver nanoparticles were synthesized by addition of 20 ml extract (8% w/v) with 180 ml silver nitrate solution (1 mM). The synthesis of silver nanoparticles was confirmed by UV-Vis spectrophotometer. The silver nanoparticles were characterized by X-ray diffractometer, Transmission Electron Microscope, Scanning Electron Microscope and Fourier Transform Infra-Red spectroscopy. The antioxidant property of silver nanoparticles was analyzed by the 2, 2-diphenyl-1-picrylhydrazyl, hydrogen peroxide, hydroxyl radical and superoxide radical scavenging methods. The bacteriostatic and bactericidal activity of silver nanoparticles against Escherichiacoli, Enterococcusfaecalis, and Salmonellatyphi was determined using bacterial growth inhibition method. The antibacterial sensitivity and Minimum Inhibitory Concentration (MIC) of silver nanoparticles was determined against the bacteria. RESULTS: The results confirmed that the silver nanoparticles synthesized by C.nocturnum extract were crystalline in nature, average particle size was 20 nm and were mostly spherical in shape. The antioxidant methods confirmed that the silver nanoparticles have more antioxidant activity as compared to vitamin C. The silver nanoparticles have strong antibacterial (maximum Vibrio cholerae and minimum E. faecalis) activity. The MIC value of silver nanoparticles was 16 µg/ml (Citrobacter), 4 µg/ml (E. faecalis), 16 µg/ml (S. typhi), 8 µg/ml (E. coli), 8 µg/ml (Proteusvulgaris), and 16 µg/ml (V. cholerae). CONCLUSION: Green synthesized silver nanoparticles have strong antioxidant and antibacterial activity due to the presence of bioactive molecules on the surface of silver nanoparticles.

Development of graft copolymer of carboxymethylcellulose and N-vinylcaprolactam towards strong antioxidant and antibacterial polymeric materials.

The present paper reports graft copolymerization of N-vinylcaprolactam (NVCL) onto carboxymethylcellulose (CMC) using tert-butyl hydroperoxide (TBHP) initiator in N2 atmosphere. The grafting was found to be highest when concentrations of CMC, NVCL and TBHP were 6.25×10-2gdm-3, 10×10-3moldm-3 and 20×10-5moldm-3 respectively. The graft copolymer (CMC-g-PNVCL-1) was characterized by FTIR, 1HNMR, SEM, AFM, XRD and TGA analysis. The antioxidant activity of the graft copolymer was found to be higher (3.81%) than CMC and slightly less (5.47%) than the standard one (butylated hydroxytoluene, BHT). The hydroxyl radical scavenging activity of graft copolymer was found to be slightly less (13.69%) than CMC and more (44.20%) than the BHT. The hydrogen peroxide scavenging activity of graft copolymer was observed to be less (20.42%) than CMC and 53.34% less than BHT. The superoxide scavenging activity of graft copolymer was greater than the both. Compared to CMC the graft copolymer has shown greater antibacterial activity against S. aureus, Proteus vulgaris and S. typhi bacteria and less against Klebsiellapneumonia and Salmonella typhimurium.

Prolidase-Associated Trace Elements (Mn, Zn, Co, and Ni) in the Patients with Parkinson's Disease.

Micronutrients and trace elements have been identified to play an important role in the development of Parkinson's disease (PD). In our previous study, we observed that prolidase activity is associated with oxidative stress and progression of PD. In present study, we aimed to study the association of prolidase-associated trace elements, such as Co, Mn, Ni, and Zn in the plasma of patients with PD by inductively coupled plasma spectrometry. Plasma levels of Co, Mn, and Ni were significantly increased, whereas plasma levels of Zn was significantly decreased (all P < 0.05) in the patients with PD than healthy controls. Plasma prolidase activity was not correlated to its associated trace elements in PD. A positive, linear, and significant correlation was observed between age and Co, and Mn, and Ni while negative and non-significant between age and status of Zn in the patients. Co, Mn, and Ni were continually elevated with increase in age as well as duration of disease in the patients with PD, whereas status of Zn was continually decreased. Thus, the study concluded that trace elements Co, Ni, and Mn status were increased and Zn status was decreased in the plasma of patients with PD. It is also concluded that elevated Co, Mn, and Ni has been associated with progression of Parkinson's disease.