Exploring the Effect of Operational Factors and Characterization Imperative to the Synthesis of Silver Nanoparticles

The synthesis and application of silver nanoparticles are increasingly becoming attractive. Hence, a critical examination of the various factors needed for the synthesis of silver nanoparticles as well as the characterization is imperative. In light of this, we addressed in this chapter, the nitty-gritty on the operational parameters (factors) and characterization relevant to synthesis of silver nanoparticle. The following characterization protocols were discussed in the context of silver nanoparticle synthesis. These protocols include spectroscopic techniques such as ultraviolet visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS)

Gallotannin and Annonamuricata extract inhibit polyphenol oxidase activity and mitigate browning in Malusdomestica

Background: The prevention of browning in fruits remains a great concern in the food industry.Objective: In the present study, we evaluated the anti-browning potentials of gallotannin and Annona muricata extract in red apple (Malus domestica).Materials and Methods: Apple slices were made and dipped in the different solutions; distilled water (control), 1 % gallotannin, 1 % Annona muricataextract or 1 % ascorbic acid. The treated apple slices were stored at 4 oC for 0, 7 and 14 days and used for the determination of the browning index, polyphenolic content, total protein, polyphenol oxidase and peroxidase activities. Results: The treatment with gallotannin, A. muricata and ascorbic acid reduced browning of apple for storage days 7 and 14. However, only gallotannin treatment preserved the polyphenolic content of the apple slices when compared to the control as well as the other treatment groups. Furthermore, all treatments reduced the activity of the polyphenol oxidase for days 0 and 7 storage, relative to the control. In contrast, the treatments had no effect on the peroxidase activity when compared to the control.Conclusion: Data support the anti-browning potential of gallotannin, A. muricata and ascorbic acid. Further, anti-browning potential of these naturally derived materials may be linked with their inhibitory actions against polyphenol oxidase

Detection of Hepatitis C Virus (HCV) antibodies among HIV Seropositive women attending a Rehabilitation centre.

Co-infection with human immunodeficiency Virus HIV and (HCV) is becoming a major global problem, leading to increased morbidity and mortality in both developed and developing countries. This research hence examines the risk factors and transmission of HIV and HCV co-infection. Two hundred and ninety (290) subjects were screened, with HCV global immunochromatographic test kit. Possible risk factors to co-infectious status of subject were determined using a well-structured questionnaire. Out of the 290 sera tested, 25 (8.6%) were positive for HCV antibodies. Considering Age of subjects screened, females aged 11-20 years recorded a high positivity of 3.1 %,( X2 = 2.755, P-value = 0.839; P>0.05).Marital status of subjects showed that single subjects recorded 13(4.5%), (X2 = 0.679,P-value = 0.712 ; P > 0.05)positivity compared to married subjects with 4.1%. There were no significant correlations between HCV infection with Age and Marital Status; P - values = 0.839 and 0.712 respectively (i.e P > 0.05). Significant correlation was found between HCV antibodies and educational status, (Value x2 = 7.957,P-value = 0.047; P < 0.05).However, Volunteers with secondary school level of education recorded 10(3.4%) positivity. The result obtained showed that Seroprevalence to HCV antibodies in this study was high, hence the need for its early diagnosis among HIV patients is strongly advocated to reduce the risk of further complications among these subjects

In Vivo Toxicity Studies and Phytochemical Screening of Stem Bark of Ficus Sycomorus Linn (Moraceae)

This research paper has investigated the In vivo toxicity studies and phytochemical screening of Stem bark of Ficus sycomorus Linn (Moraceae). Ethno-pharmacological relevance of Ficus sycomorus is quite obvious. It finds relevance in the treatment of Diabetes mellitus and other infectious diseases in the Northern part of Nigeria. The preliminary phytochemical screening of the extract revealed the presence of flavonoids, glycosides, reducing sugars, resins, saponins and tannins. The result of the experimental study carried out on albino rat which is close to human being indicates that stem bark extract of F. sycomorus produces toxicity at a dose of 1500 mg/kg. The outcome of this study offers support to the Ethno-medicinal uses of F. sycomorus in the treatment of various ailments. Keyword: F. sycomorus, Phytochemical, Saponins, flavonoids, glycosides, reducing sugars and Toxicit

GREEN SYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES USING Calotropis procera EXTRACT

The green synthesis of silver nanoparticles (Ag-np) using leaves extract from Calotropis Porocera has been investigated. Extract of Calotropis procera was used as both reducing and stabilizing agent instead of the general convention of the use of sodium borohydride solution. Ag-np was characterized using a combination of spectroscopic techniques: Ultraviolet-Visible (UV-VIS) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning and Transmission Electron Microscopy (SEM and TEM), and Energy Dispersive X-ray (EDX). The spectrum from UV-VIS depicted the wavelength for the formation of Ag-np at 420 nm. Both SEM and TEM depicted the morphology and size of the nanoparticles while the elemental analysis and the relative abundance of each element in the nanoparticles were revealed through the EDX. This research gives a clear efficacy and reality of the use of low cost and environmentally benign extract a main precursor in the synthesis of Ag nanoparticles

Cellular apoptosis of HFF cells by inorganic nanoparticles not susceptible to modulation by Toxoplasma gondii infection in vitro

The interaction of nanoparticles with living cells is becoming one of the urgent areas of collaborative research in materials science and biology. Previously, we showed that nanoparticles have promising anti-Toxoplasma gondii properties. Meanwhile, Toxoplasma gondii has been shown to avert apoptosis in host cells whereas nanoparticles have been implicated for apoptotic tendency. Therefore, in the present study, we assessed the in vitro apoptotic properties of inorganic nanoparticles in the absence or presence of Toxoplasma infection and/or small molecules used as metabolic modulators. Results showed that inorganic nanoparticles dose-dependently caused cellular apoptosis. However, in the presence of infection by Toxoplasma gondii, nanoparticles-induced cellular apoptosis was not mitigated. Likewise, use of several small molecules (anti-metabolites) as metabolic modulators either mildly or nearly failed to abate cellular apoptosis by nanoparticles. Taken together, our findings do not only confirm the apoptotic potential of inorganic nanoparticles but show evidence that cellular apoptosis by inorganic nanoparticles of gold and silver might not be susceptible to modulation by Toxoplasma gondii infection. The findings are new and contribute to deepen our understanding of the cellular interaction of nanoparticle

GREEN SYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES USING Calotropis procera EXTRACT

The green synthesis of silver nanoparticles (Ag-np) using leaves extract from Calotropis Porocera has been investigated. Extract of Calotropis procera was used as both reducing and stabilizing agent instead of the general convention of the use of sodium borohydride solution. Ag-np was characterized using a combination of spectroscopic techniques: Ultraviolet-Visible (UV-VIS) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning and Transmission Electron Microscopy (SEM and TEM), and Energy Dispersive X-ray (EDX). The spectrum from UV-VIS depicted the wavelength for the formation of Ag-np at 420 nm. Both SEM and TEM depicted the morphology and size of the nanoparticles while the elemental analysis and the relative abundance of each element in the nanoparticles were revealed through the EDX. This research gives a clear efficacy and reality of the use of low cost and environmentally benign extract a main precursor in the synthesis of Ag nanoparticles

Modulation of rat plasma kynurenine level by platinum nanoparticles and likely association with oxidative stres

In this study, we investigated whether oxidative stress contributes to activation of kynurenine pathway by platinum nanoparticles (PtNPs). Thirty male Wistar rats with an average weight between 126 – 130 g were randomly assigned into six groups. The negative control group was orally administered distilled water while the other treatment groups respectively received oral administration of either PtNPs (25 and 50 mg/kg bw) singly or in combination with ascorbic acid (100 mg/kg bw). Results revealed that oral administration of PtNPs did not cause lipid peroxidation in rat brain and plasma relative to negative control. In contrast, PtNPs elevated protein carbonyl levels in rat plasma relative to negative control. In the meantime, the level of reduced glutathione (GSH) in rat tissues was maintained when compared with negative control and PtNPs alone. However, plasma GSH was significantly (p<0.05) increased by PtNPs at both doses used and co-treatment with ascorbic acid. Oral exposure to PtNPs and ascorbic acid elevated kynurenine level in rat plasma. Taken together, data indicated that PtNPs given alone at the doses investigated might not have caused oxidative stress in rat tissues and plasma but co-treatment with ascorbic acid appeared to potentiate capacity to elevate oxidative stress markers. Further, elevation of kynurenine level in rat plasma by PtNPs might be connected with oxidative stress since PtNPs did elevate protein carbonyl level and co-treatment with ascorbic acid modulated the kynurenine level

The oral administration of silver nanoparticles activates the kynurenine pathway in rat brain independently of oxidative stress

In this work, we determined whether oxidative stress contributed to the activation of the kynurenine pathway by AgNPs. Male Wistar rats weighing between 130 and 146 g were randomly assigned into six groups. Animals in the negative control group were orally administered distilled water while, the other treatment groups were respectively given AgNPs (25 and 50 mg/kg bw) alone or in combination with Trolox (100 mg/kg bw). Results showed that treatments with AgNPs signi fi cantly raised protein carbonyl level in rat liver, but the co-treatment with Trolox attenuated the elevation. Conversely, AgNPs raised the level of reduced glutathione (GSH) in rat plasma and tissues compared to the negative control. Further, oral exposure to AgNPs (50 mg/kg bw) sig- ni fi cantly elevated rat plasma and brain kynurenine levels compared to the negative control. Meantime, the co- treatment with Trolox appreciably restored kynurenine level in rat plasma, but not in the rat brain. Taken together, findings indicate that the oral administration of AgNPs alone at the doses used in this study, might not have caused oxidative stress. However, the co-treatment with Trolox appears to potentiate oxidative stress in rats following exposure to AgNPs. Furthermore, data support that the activation of the kynurenine pathway in the rat brain by AgNPs might be independent of oxidative stress. The fi ndings are new and contribute to deepen our understanding of the cellular interaction by nanoparticle