The Influence of Silver Nanoparticles Against Toxic Effects of Philodryas olfersii Venom.

PURPOSE: A silver nanoparticle obtained by reducing salts with solid dispersion of curcumin (130 nm, 0.081 mg mL-1) was used to counteract against the toxic - edematogenic, myotoxic, and neurotoxic - effects of Philodryas olfersii venom. METHODS: The edematogenic effect was evaluated by plasma extravasation in rat dorsal skin after injection of 50 µg per site of venom alone or preincubated with 1, 10, and 100 µL of AgNPs; the myotoxicity was evaluated by measuring the creatine kinase released into the organ-bath before the treatment and at the end of each experiment; and neurotoxicity was evaluated in chick biventer cervicis using the conventional myographic technique, face to the exogenous acetylcholine (ACh) and potassium chloride (KCl) added into the bath before the treatment and after each experiment. Preliminarily, a concentration-response curve of AgNPs was carried out to select the concentration to be used for neutralizing assays, which consists of neutralizing the venom-induced neuromuscular paralysis and edema by preincubating AgNPs with venom for 30 min. RESULTS: The P. olfersii venom-induced edema (n=6) and a complete neuromuscular blockade (n=4) that includes the total and unrecovered block of ACh and KCl contractures. AgNPs produced a concentration-dependent decrease the venom-induced edema (n=6) from 223.3% to 134.4% and to 100.5% after 10 and 100 µL AgNPs-preincubation, respectively. The preincubation of venom with AgNPs (1 µL; n=6) was able to maintain 46.5 ± 10.9% of neuromuscular response under indirect stimuli, 39.2 ± 9.7% of extrinsic nicotinic receptors functioning in absence of electrical stimulus and 28.3 ± 8.1% of responsiveness to potassium on the sarcolemmal membrane. The CK release was not affected by any experimental protocol which was like control. CONCLUSION: AgNPs interact with constituents of P. olfersii venom responsible for the edema-forming activity and neuromuscular blockade, but not on the sarcolemma membrane-acting constituents. The protective effect of the studied AgNPs on avian preparation points out to molecular targets as intrinsic and extrinsic nicotinic receptors.

Are Silver Nanoparticles Useful for Treating Second-Degree Burns? An Experimental Study in Rats.

Purpose: In this work, the potential usefulness of silver nanoparticles (AgNPs) for treating burn wounds was examined. Methods: Second-degree burns were induced in male Wistar rats by touching the skin with a heated (70°C) metallic device for 10 s, after which the animals were randomly allocated to one of two groups: control (n=8, treated with sterile saline) and experimental (n=8, treated with AgNPs, 0.081 mg/mL; 50 µL applied to the burn surface). Seven, 14, 21 and 28 days after lesion induction two rats from each group were killed and blood samples were collected for a complete blood count and to assess oxidative stress. The livers were examined macroscopically and skin samples were collected for histological analysis. Results: Macroscopically, wound healing and skin remodeling in the experimental group were similar to the saline-treated rats. Likewise, there were no significant differences in the histological parameters between the two groups. However, treatment with AgNPs caused a persistent reduction in white blood cell (WBC) counts throughout the experiment, whereas platelet counts increased on days 7 and 28 but decreased on days 14 and 21; there was also an increase in the blood concentration of reduced glutathione on day 7 followed by a decrease on days 21 and 28. There were no significant changes in blood glutathione peroxidase (GSH-Px) and catalase (CAT) activities or in the serum concentration of thiobarbituric acid reactive substances. Conclusion: The findings of this study raise questions about the potential transitory effects of AgNPs based on the changes in WBC and platelet counts, blood glutathione concentrations and macroscopic hepatic alterations.

The emerging role of metallic nanoparticles in food.

Nanotechnology is widely used in biomedical applications, engineering sciences, and food technology. The application of nanocompounds play a pivotal role in food protection, preservation, and increasing its shelf life. The changing lifestyle, use of pesticides, and biological and/or chemical contaminants present in food directly affect its quality. Metallic nanoparticles (MNPs) are useful to develop products with antimicrobial activity and with the potential to improve shelf life of food and food products. Due to the prevention of microbial growth, MNPs have attracted the attention of researchers. Biopolymers/polymers can be easily combined with different MNPs which act as a vehicle not only for one type of particles but also as a hybrid system that allows a combination of natural compounds with metallic nanocompounds. However, there is a need for risk evaluation to use nanoparticles in food packaging. In this review, we aim to discuss how MNPs incorporated into polymers/biopolymers matrices can be used for food preservation, considering the quality and safety, which are desirable in food technology.

Determination of 17α-ethinylestradiol and toxic metals in surface waters, and estimation of daily intake.

The presence of substances such as hormones and toxic metal in aquatic ecosystem is interesting to the scientific community due to their adverse effects. We quantified 17α-ethynylestradiol (EE2) and toxic metals in the surface waters from Sorocaba and Pirajibu Rivers, in São Paulo State, and we estimated the daily intake for hormone, based on the amount of water consumed. EE2, Cd, Hg, As, Pb, and Mn were seasonally quantified in six different locations along the rivers. EE2 was evaluated by high-performance liquid chromatography. Toxic metals were determined by inductively coupled plasma mass spectrometer. Considering the entire sample year, EE2 concentrations ranged from 4.5 to 48.2 µg L-1. Comparing Sorocaba and Pirajibu rivers, the sample point in the entrance of the Pirajibu River through the city of Itu, São Paulo State, had higher amounts of EE2. Regarding metals, all results are according to the Brazilian and World Health Organization guidelines for drinking-water quality, except for Mn levels, which were higher than the limits in Autumn season in two locations. The estimated daily intake ranged from 13.45 to 40.9 µg/day/person. In conclusion, concentrations of EE2 in the Sorocaba and Pirajibu Rivers were higher than in other countries. The levels were as high as an intake of one pill for each person every day (considering an oral contraceptive has 0.03 mg of ethinylestradiol). Even though concentrations of toxic elements are in accordance with the Brazilian Regulation and World Health Organization, legislation for hormones and drugs needs to advance.

Association of Silver Nanoparticles and Curcumin Solid Dispersion: Antimicrobial and Antioxidant Properties.

The last century, more precisely after 1945, was marked by major advances in the treatment of infectious diseases which promoted a decrease in mortality and morbidity. Despite these advances, currently the development of antimicrobial resistance has been growing drastically and therefore there is a pressing need to search for new compounds. Silver nanoparticles (AgNps) have been demonstrating good antimicrobial activity against different bacteria, viruses, and fungi. Curcumin (CUR) extracted from rhizomes of Curcuma longa has a variety of applications including antiinflammatory, antioxidant, and antibacterial agent. The association between silver nanoparticles and curcumin in a formulation can be a good alternative to control infectious diseases due the antimicrobial properties of both compounds. The objective of this work was to develop a formulation composed of a thermoresponsive gel-with antimicrobial and antioxidant properties due to the association of AgNps with PVP and PVA polymers. After AgNp synthesis, these were incorporated together with the previously prepared CUR/P407 (1:2) solid dispersion (SD) into a polymer dispersion of 20% P407 (thermosensitive gel). Our results showed that the association between the AgNps with CUR SD demonstrated good antioxidant activity as compared to the standard compound. Measures of MIC showed more efficacy against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) than for Gram-positive bacteria (Staphylococcus aureus). This association enhances antimicrobial activity against E. coli and P aeruginosa and added antioxidant value in formulations.

Broadening the spectrum of small-molecule antibacterials by metallic nanoparticles to overcome microbial resistance.

Now-a-days development of microbial resistancce have become one of the most important global public health concerns. It is estimated that about 2 million people are infected in USA with multidrug resistant bacteria and out of these, about 23,000 die per year. In Europe, the number of deaths associated with infection caused by MDR bacteria is about 25,000 per year, However, the situation in Asia and other devloping countries is more critical. Considering the increasing rate of antibiotic resistance in various pathogens, it is estimated that MDR organisms can kill about 10 million people every year by 2050. The use of antibiotics in excessive and irresponsible manner is the main reason towards its ineffectiveness. However, in this context, promising application of nanotechnology in our everyday life has generated a new avenue for the development of potent antimicrobial materials and compounds (nanoantimicrobials) capable of dealing with microbial resistance. The devlopement and safe incorporation of nanoantimicrobials will bring a new revolution in health sector. In this review, we have critically focused on current worldwide situation of antibiotic resistance. In addition, the role of various nanomaterials in the management of microbial resistance and the possible mechanisms for antibacterial action of nanoparticles alone and nanoparticle-antibiotics conjuagte are also discussed.

Characterization of the Effects of the Shiitake Culinary-Medicinal Mushroom, Lentinus edodes (Agaricomycetes), on Severe Gestational Diabetes Mellitus in Rats.

This study evaluated the protective effect of Lentinus edodes in rats with streptozotocin-induced gestational diabetes mellitus (STZ-GDM) when administered orally. The rats received from the 1st to the 19th day of gestation daily doses of 100 or 200 mg/kg of lyophilized and reconstituted L. edodes; the animals in the saline control group and diabetic control group received a saline solution (DS). Gestational diabetes mellitus was induced by streptozotocin (80 mg/kg, administered intraperitoneally) on the fourth day of pregnancy; blood glucose > 180 mg/dL was considered to indicate STZ-GDM. L. edodes reduced catalase in plasma. We also observed reduced glucose in plasma, urea, triglycerides, and aspartate aminotransferase. There was a decrease in preimplantation loss when compared with the DS group. The doses of L. edodes used here had a protective effect on the preimplantation parameters in STZGDM. However, the mushroom was not able to reverse the deleterious effects caused by streptozotocin throughout the evolution of pregnancy.

Natural colorants from filamentous fungi.

In the last years, there is a trend towards the replacement of synthetic colorants by natural ones, mainly due to the increase of consumer demand for natural products. The natural colorants are used to enhance the appearance of pharmaceutical products, food, and different materials, making them preferable or attractive. This review intends to provide and describe a comprehensive overview of the history of colorants, from prehistory to modern time, of their market and their applications, as well as of the most important aspects of the fermentation process to obtain natural colorants. Focus is given to colorants produced by filamentous fungal species, aiming to demonstrate the importance of these microorganisms and biocompounds, highlighting the production performance to get high yields and the aspects of conclusion that should be taken into consideration in future studies about natural colorants.

Anticancer activities of Withania somnifera: Current research, formulations, and future perspectives.

CONTEXT: Cancer, being a cause of death for major fraction of population worldwide, is one of the most studied diseases and is being investigated for the development of new technologies and more accurate therapies. Still the currently available therapies for cancer have many lacunae which affect the patient's health severely in the form of side effects. The natural drugs obtained from the medicinal plants provide a better alternative to fight against this devastating disease. Withania somnifera L. Dunal (Solanaceae), a well-known Ayurvedic medicinal plant, has been traditionally used to cure various ailments for centuries. OBJECTIVES: Considering the immense potential of W. somnifera, this review provides a detail account of its vital phytoconstituents and summarizes the present status of the research carried out on its anticancerous activities, giving future directions. METHODS: The sources of scientific literature were accessed from various electronic databases such as PubMed, Google Scholar, Science Direct, and library search. RESULTS: Various parts of W. somnifera especially the roots with its unique contents have been proved effective against different kinds of cancers. The most active components withanolides and withaferins along with a few other metabolites including withanone (WN) and withanosides have been reported effective against different types of cancer cell lines. CONCLUSION: This herb holds an important place among various anticancer medicinal plants. It is very essential to further screen and to investigate different formulations for anticancer therapy in vitro as well as in vivo in combination with established chemotherapy.

Bacterial cellulose production by Gluconacetobacter xylinus by employing alternative culture media.

Bacterial cellulose (BC) is used in different fields as a biological material due to its unique properties. Despite there being many BC applications, there still remain many problems associated with bioprocess technology, such as increasing productivity and decreasing production cost. New technologies that use waste from the food industry as raw materials for culture media promote economic advantages because they reduce environmental pollution and stimulate new research for science sustainability. For this reason, BC production requires optimized conditions to increase its application. The main objective of this study was to evaluate BC production by Gluconacetobacter xylinus using industry waste, namely, rotten fruits and milk whey, as culture media. Furthermore, the structure of BC produced at different conditions was also determined. The culture media employed in this study were composed of rotten fruit collected from the disposal of free markets, milk whey from a local industrial disposal, and their combination, and Hestrin and Schramm media was used as standard culture media. Although all culture media studied produced BC, the highest BC yield-60 mg/mL-was achieved with the rotten fruit culture. Thus, the results showed that rotten fruit can be used for BC production. This culture media can be considered as a profitable alternative to generate high-value products. In addition, it combines environmental concern with sustainable processes that can promote also the reduction of production cost.

Current Advances in the Antimicrobial Potential of Species of Genus Ganoderma (Higher Basidiomycetes) against Human Pathogenic Microorganisms (Review).

Ganoderma spp. are very important therapeutic mushrooms and have been used traditionally for 4000 years in the treatment of various human disorders. Different species of Ganoderma possess bioactive compounds, which have already demonstrated antiviral, antibacterial, and antifungal activities. Various bioactive compounds such as triterpenoids, colossolactones, and polysaccharides, which are responsible for the antimicrobial potential of the genus, are discussed here in detail. Some Ganoderma spp. have been reported to be potential agents for the synthesis of metal nanoparticles. These nanoparticles have demonstrated antimicrobial activity and also are reviewed herein. The main aim of this review is to discuss the possible use of Ganoderma extracts and their active principles in antimicrobial therapy.

Silver nanoparticles: therapeutical uses, toxicity, and safety issues.

The promises of nanotechnology have been realized to deliver the greatest scientific and technological advances in several areas. The biocidal activity of Metal nanoparticles in general and silver nanoparticles (AgNPs) depends on several morphological and physicochemical characteristics of the particles. Many of the interactions of the AgNPs with the human body are still poorly understood; consequently, the most desirable characteristics for the AgNPs are not yet well established. Therefore, the development of nanoparticles with well-controlled morphological and physicochemical features for application in human body is still an active area of interdisciplinary research. Effects of the development of technology of nanostructured compounds seem to be so large and comprehensive that probably it will impact on all fields of science and technology. However, mechanisms of safety control in application, utilization, responsiveness, and disposal accumulation still need to be further studied in-depth to ensure that the advances provided by nanotechnology are real and liable to provide solid and consistent progress. This review aims to discuss AgNPs applied in biomedicine and as promising field for insertion and development of new compounds related to medical and pharmacy technology. The review also addresses drug delivery, toxicity issues, and the safety rules concerning biomedical applications of silver nanoparticles.

Antimicrobial effectiveness of silver nanoparticles co-stabilized by the bioactive copolymer pluronic F68.

BACKGROUND: Silver nanoparticles (AgNps) have attracted much interest in biomedical engineering, since they have excellent antimicrobial properties. Therefore, AgNps have often been considered for incorporation into medical products for skin pathologies to reduce the risk of contamination. This study aims at evaluating the antimicrobial effectiveness of AgNps stabilized by pluronic™ F68 associated with other polymers such as polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP). METHODS: AgNps antimicrobial activity was evaluated using the minimum inhibitory concentration (MIC) method. The action spectrum was evaluated for different polymers associated with pluronic™ F68 against the gram negative bacteria P. aeuroginosa and E. coli and the gram positive bacteria S. Aureus. RESULTS: AgNps stabilized with PVP or PVA and co-stabilized with pluronic™ F68 are effective against E. coli and P. aeruginosa microorganisms, with MIC values as low as 0.78% of the concentration of the original AgNps dispersion. The antimicrobial action against S. aureus is poor, with MIC values not lower than 25%. CONCLUSIONS: AgNps stabilized by different polymeric systems have shown improved antimicrobial activity against gram-negative microorganisms in comparison to unstabilized AgNps. Co-stabilization with the bioactive copolymer pluronic™ F68 has further enhanced the antimicrobial effectiveness against both microorganisms. A poor effectiveness has been found against the gram-positive S. aureus microorganism. Future assays are being delineated targeting possible therapeutic applications.

Influence of Pluronic® F68 on ceftazidime biological activity in parenteral solutions.

ß-Lactam antimicrobials are known to have a low concentration/therapeutic response. However, extending the period in which ß-lactam are free in the plasma does directly influence therapeutic outcomes. The objective of this study was to evaluate the influence of Pluronic® F68 on the antimicrobial activity of ceftazidime when admixed with aminophylline in parenteral solutions by the evaluation of its minimal inhibitory concentration (MIC) within 24 h. Ceftazidime, aminophylline, and Pluronics® F68 were evaluated using the MIC method against Escherichia coli and Pseudomonas aeruginosa, with these compounds individually and associated in the same parenteral solutions. When Pluronics® F68 was admixtured with ceftazidime alone or with ceftazidime and aminophylline, it was possible to observe lower MIC values not only at 24 h but also at 0 h for both microorganisms. This indicates that Pluronics® F68 may be able to enhance ceftazidime antimicrobial activity in the presence or absence of aminophylline. This fact suggests that Pluronics® F68 can be applied to allow the administration of ceftazidime under continuous infusion in parenteral solutions, beneficiating hospital pharmacotherapy. It may also be possible to reduce ceftazidime doses in formulations achieving the same therapeutic results.

Preliminary study on the potential utility of GFP as a biosensor for drug stability in parenteral solutions.

In the health care setting, drugs added to large volume parenteral solutions (LVPS) are routinely administered to improve therapeutic effects and provide a faster clinical response. The development of analytical techniques that permit the detection of incompatibilities between drugs and parenteral solutions is necessary to guarantee their correct association with minimum adverse effects. Green fluorescent protein (GFP) has been used as a biological indicator of sterilization and disinfection processes because it exhibits a high thermal stability and is easily detected using UV light and spectrofluorometry. The response of GFP structure and/or protonation state to physicochemical changes in the solution favors its potential use as a biosensor for drug stability in parenteral solutions. The stability of the diuretic drugs furosemide and aminophylline, individually or combined, added to parenteral solutions of 20% mannitol and 0.9% NaCl was monitored by absorbance and RP-HPLC immediately and after 20 h of storage at room temperature, with and without 1 h exposure to a strong oxidant, H2O2. Changes in GFP fluorescence intensity were evaluated under the same conditions for purified GFP added to aliquots of the drug/LVPS solutions. Results show that GFP fluorescence intensity was proportional to the loss in drug stability over time and thus may potentially be added to a lot sample of a drug/parenteral solution as an immediate on-site test for defective product.