A review on recent trends in the removal of emerging contaminants from aquatic environment using low-cost adsorbents

Emerging contaminants (ECs), a class of contaminants with low concentrations but significant harm, have received a lot of attention in recent times. ECs comprises of various chemicals that enter the environment every day. In today's modern lifestyle, we use many chemical-based products. These persist in wastewater and ultimately enter the water bodies, causing serious problems to the human and aquatic ecosystem. This is because the conventional wastewater treatment methods are inefficient in identifying and removing such contaminants. Aiming for a long-term, effective solution to this issue, Adsorption was proposed. Although several adsorbents are already present in the market, which have proved beneficial in removing such ECs, not all are affordable. This article reviews replacing costly adsorbents with agriculture-based biomass that are abundant, inexpensive, and biodegradable and possess excellent adsorption capacity. The objectives of this article is to look at adsorption as a viable treatment option for emerging pollutants, as well as sophisticated and cost-effective emerging contaminants treatment options.

Sulfidation of silver nanoparticle reduces its toxicity in zebrafish

Chemical transformations of metal nanoparticles can be an important way to mitigate nanoparticle toxicity. Sulfidation of silver nanoparticle (AgNPs) is a natural process shown to occur in environment. Very few studies, employing microbes and embryonic stages of zebrafish, have shown reduction in AgNPs toxicity as a direct result of sulfidation. However the feasibility of reducing nanoparticle toxicity by sulfidation of AgNPs has never been studied in adult vertebrates. In this study, we have used adult zebrafish as a model to study the efficacy of sulfidation of AgNPs in reducing nanoparticle toxicity by employing a battery of biomarkers in liver and brain. While AgNPs enhanced liver oxidative stress, altered detoxification enzymes and affected brain acetylcholinesterase activity, sulfidation of AgNPs resulted in significant alleviation of changes in these parameters. Histopathological analyses of liver and sulphydryl levels also support the significance of sulfidated AgNPs in controlling the toxicity of AgNPs. Our study provides the first biochemical data on the importance of sulfidation of AgNPs in reducing biological toxicity in adult vertebrates.

Sulfidation modulates the toxicity of biogenic copper nanoparticles

First report to show sulfidation reduces CuNP toxicity in vivo. Sulfidation lowered oxidative stress and liver pathology, protected biochemical components, prevented micronucleus formation – strategy for reducing environmental impact of nanoparticles.

Vitamin K1 alleviates streptozotocin-induced type 1 diabetes by mitigating free radical stress, as well as inhibiting NF-κB activation and iNOS expression in rat pancreas

OBJECTIVE

The aim of this study was to understand the mechanism of action of vitamin K1 against streptozotocin (STZ)-induced diabetes.

METHODS

Male Wistar rats were administered 35 mg/kg STZ and after 3 d were treated with vitamin K1 (5 mg/kg, twice a week) for 3 months. Blood glucose was monitored twice a month. At the end of the study, animals were sacrificed and pancreas dissected out and analyzed for free radicals, antioxidants, metabolic enzymes related to glucose, membrane ATPases, histopathological evaluation, and expression of nuclear factor (NF)-κB and inducible nitric oxide synthase (iNOS). Glycated hemoglobin, plasma insulin, and islet area were determined at the end of the study.

RESULTS

Treatment of STZ-induced type 1 diabetic rats with vitamin K1 reduced oxidative stress, enhanced antioxidants, and inhibited aldose reductase in pancreas. Vitamin K1 administration rescued endocrine pancreas from STZ-induced cell death, resulting in enhanced insulin secretion and normal blood glucose and glycosylated hemoglobin levels. Histologic analyses also showed the antidiabetic potential of vitamin K1. Measure of pancreatic islet area showed an increase in the islet area upon vitamin K1 treatment when compared with the STZ-administered group, suggesting the possibility of regeneration. To understand the mechanism involved in vitamin K1 mediated changes, we performed immunohistochemical analyses for NF-κB and iNOS enzyme. Vitamin K1 was shown to suppress NF-κB activation and iNOS expression in the islets upon administration of STZ.

CONCLUSION

This work shows, to our knowledge for the first time, the mechanism of action of vitamin K1 against type 1 diabetes and the possible therapeutic use of this vitamin in stimulating islet cell proliferation/regeneration.

Enamel renal syndrome: a rare case report

Enamel renal syndrome is a very rare disorder associating amelogenesis imperfecta with nephrocalcinosis. It is known by various synonyms such as amelogenesis imperfecta nephrocalcinosis syndrome, MacGibbon syndrome, Lubinsky syndrome, and Lubinsky-MacGibbon syndrome. It is characterized by enamel agenesis and medullary nephrocalcinosis. This paper describes enamel renal syndrome in a female patient born in a consanguineous family.

Production of bioactive cyclotides in somatic embryos of Viola odorata

Viola odorata L. (Violaceae), an Indian medicinal plant, contains a plethora of cyclotides, which are a class of cyclic peptides derived from plants, possessing several applications. Somatic embryo culture of V. odorata was developed, via indirect somatic embryogenesis, to serve as an alternative to natural plant biomass for sustainable and continuous production of its bioactive ingredients, such as cyclotides. Among the various combinations of phytohormones tested, Murashige and Skoog medium supplemented with 1 mg/l thidiazuron gave rise to the maximum frequency of induction (86.7%) and a high number of somatic embryos (3) from an embryogenic callus. Identification and characterization of cyclotides in the somatic embryos were carried out using a Fourier transform mass spectrometer coupled with liquid chromatography (LC-FTMS). Among the cyclotides identified in the study, few were found to be exclusively present in the somatic embryo culture. Furthermore, the relative abundance of the cyclotides was higher in somatic embryo extract than in the natural plant extract. The biological activities (cytotoxic, haemolytic and antimicrobial) of the somatic embryos and the parent plant were compared. Unlike the natural plants, the somatic embryo extracts demonstrated specificity i.e. they were found to be potent against cancerous cells but not against non-cancerous cell line or red blood cells. In contrast to the plant extract, the somatic embryos extracts were found to be potent against Escherichia coli and Staphylococcus aureus. These results suggest that somatic embryos of V. odorata (rich in cyclotides) can be used as an alternative to plant biomass for its therapeutic applications and germplasm conservation.

Vitamin K1 prevents diabetic cataract by inhibiting lens aldose reductase 2 (ALR2) activity

This study investigated the potential of vitamin K1 as a novel lens aldose reductase inhibitor in a streptozotocin-induced diabetic cataract model. A single, intraperitoneal injection of streptozotocin (STZ) (35 mg/kg) resulted in hyperglycemia, activation of lens aldose reductase 2 (ALR2) and accumulation of sorbitol in eye lens which could have contributed to diabetic cataract formation. However, when diabetic rats were treated with vitamin K1 (5 mg/kg, sc, twice a week) it resulted in lowering of blood glucose and inhibition of lens aldose reductase activity because of which there was a corresponding decrease in lens sorbitol accumulation. These results suggest that vitamin K1 is a potent inhibitor of lens aldose reductase enzyme and we made an attempt to understand the nature of this inhibition using crude lens homogenate as well as recombinant human aldose reductase enzyme. Our results from protein docking and spectrofluorimetric analyses clearly show that vitamin K1 is a potent inhibitor of ALR2 and this inhibition is primarily mediated by the blockage of DL-glyceraldehyde binding to ALR2. At the same time docking also suggests that vitamin K1 overlaps at the NADPH binding site of ALR2, which probably shows that vitamin K1 could possibly bind both these sites in the enzyme. Another deduction that we can derive from the experiments performed with pure protein is that ALR2 has three levels of affinity, first for NADPH, second for vitamin K1 and third for the substrate DL-glyceraldehyde. This was evident based on the dose-dependency experiments performed with both NADPH and DL-glyceraldehyde. Overall, our study shows the potential of vitamin K1 as an ALR2 inhibitor which primarily blocks enzyme activity by inhibiting substrate interaction of the enzyme. Further structural studies are needed to fully comprehend the exact nature of binding and inhibition of ALR2 by vitamin K1 that could open up possibilities of its therapeutic application.

ATR-FTIR and LC-Q-ToF-MS analysis of indoor dust from different micro-environments located in a tropical metropolitan area

Indoor dust is an important matrix that exposes humans to a broad spectrum of chemicals. The information on the occurrence of contaminants of emerging concern (CECs), their metabolites, and re-emerging contaminants in indoor dust is rather limited. As the indoor environment is exposed to various chemicals from personal care products, furniture, building materials, machineries and cooking/cleaning products, there is a high chance of the presence of hazardous contaminants in indoor dust. In the present study, dust samples were collected from four different micro indoor environments (photocopying centres, residential houses, classrooms, and ATM cabins) located in an urban environment located in India's southwestern part. The collected samples were subjected to ATR - FTIR and LC-Q-ToF-MS analyses. The ATR - FTIR analysis indicated the presence of aldehydes, anhydrides, carboxylic acids, esters, sulphonic acids, and asbestos - a re-emerging contaminant. A total of 19 compounds were identified from the LC-Q-ToF-MS analysis. These compounds belonged to various classes such as plasticisers, plasticiser metabolites, photoinitiators, personal care products, pharmaceutical intermediates, surfactants, and pesticides. To the best of our knowledge, this is the first report regarding the presence of CECs in indoor environments in Kerala and also the suspected occurrence of pesticides (metaldehyde and ethofumesate) in classroom dust in India. Another important highlight of this work is the demonstration of ATR-FTIR as a complementary technique for LC-Q-ToF-MS in the analysis of indoor pollution while dealing with totally unknown pollutants. These results further highlight the occurrence of probable chemically modified metabolites in the tropical climatic conditions in a microenvironment.

Electrodeionization: Principle, techniques and factors influencing its performance

Ecosystems are becoming more and more polluted, hence sustainable techniques of pollution removal are needed. In the recent times, exceedingly pure water has become ideal for several industries. Modern industry needs ultra-pure water, which is highly processed water that is devoid of colloidal particles and has a conductivity of less than 0.06 μS. A very effective method for removing ionic chemicals from polluted waters emerged recently called electrodeionization. Continuous electrodeionization (CEDI) is a technique for producing high-purity water. Besides rendering purified water, the technique has got promising wastewater treatment technologies - by facilitating the eradication of ionizable compounds, hazardous chemicals, radioactive pollutants, heavy metals and other potential contaminants. Innovative materials have been developed in order to advance and improve this technique, which would result in enormous ecological and financial benefit on a worldwide scale. In this review article, several factors that affect the performance of CEDI has been comprehended, with the impact of Ion-exchange resins and membranes as the focal point.