A review on heavy metal pollution, toxicity and remedial measures: Current trends and future perspectives

An extensive review on the consequences of chemical pesticides on human health and environment

The scientific community is exploiting the use of silver nanoparticles (AgNPs) in nanomedicine and other AgNPs combination like with biomaterials to reduce microbial contamination. In the field of nanomedicine and biomaterials, AgNPs are used as an antimicrobial agent. One of the most effective approaches for the production of AgNPs is green synthesis. Lysiloma acapulcensis (L. acapulcensis) is a perennial tree used in traditional medicine in Mexico. This tree contains abundant antimicrobial compounds. In the context of antimicrobial activity, the use of L. acapulcensis extracts can reduce silver to AgNPs and enhance its antimicrobial activity. In this work, we demonstrate such antimicrobial activity effect employing green synthesized AgNPs with L. acapulcensis. The FTIR and LC–MS results showed the presence of chemical groups that could act as either (i) reducing agents stabilizing the AgNPs or (ii) antimicrobial capping agents enhancing antimicrobial properties of AgNPs. The synthesized AgNPs with L. acapulcensis were crystalline with a spherical and quasi-spherical shape with diameters from 1.2 to 62 nm with an average size diameter of 5 nm. The disk diffusion method shows the magnitude of the susceptibility over four pathogenic microorganisms of clinical interest. The antimicrobial potency obtained was as follows: E. coli ≥ S. aureus ≥ P. aeruginosa > C. albicans. The results showed that green synthesized (biogenic) AgNPs possess higher antimicrobial potency than chemically produced AgNPs. The obtained results confirm a more significant antimicrobial effect of the biogenic AgNPs maintaining low-cytotoxicity than the AgNPs produced chemically.

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Green synthesis of silver nanoparticles using Lysiloma acapulcensis exhibit high-antimicrobial activity.

Synthesis of metal nanoparticles using plant extracts is one of the most simple, convenient, economical, and environmentally friendly methods that mitigate the involvement of toxic chemicals. Hence, in recent years, several eco-friendly processes for the rapid synthesis of silver nanoparticles have been reported using aqueous extracts of plant parts such as the leaf, bark, roots, etc. This review summarizes and elaborates the new findings in this research domain of the green synthesis of silver nanoparticles (AgNPs) using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015. While highlighting the recently used different plants for the synthesis of highly efficient antimicrobial green AgNPs, we aim to provide a systematic in-depth discussion on the possible influence of the phytochemicals and their concentrations in the plants extracts, extraction solvent, and extraction temperature, as well as reaction temperature, pH, reaction time, and concentration of precursor on the size, shape and stability of the produced AgNPs. Exhaustive details of the plausible mechanism of the interaction of AgNPs with the cell wall of microbes, leading to cell death, and high antimicrobial activities have also been elaborated. The shape and size-dependent antimicrobial activities of the biogenic AgNPs and the enhanced antimicrobial activities by synergetic interaction of AgNPs with known commercial antibiotic drugs have also been comprehensively detailed.

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Green synthesis of silver nanoparticles using plant extracts and their antimicrobial activities: a review of recent literature

https://www.hal.inserm.fr/inserm-01947474/document

Dormant, quiescent, tolerant and persister cells: Four synonyms for the same target in cancer.

The Malwa region of Punjab, India, is facing an unprecedented crisis of environmental health linked to indiscriminate, excessive, and unsafe use of pesticides, fertilizers, and poor groundwater quality. The region has been described as India's “cancer capital” due to abnormally high number of cancer cases, which have increased 3-fold in the last 10 years. Studies of this region have also highlighted a sharp increase in many other pesticide-related diseases, such as mental retardation and reproductive disorders. The most affected individuals are the agricultural workers who are directly exposed to pesticides. The Malwa region of Punjab, India, is less than 15% of the total area of Punjab (only 0.5% of the total geographical area of India), but it consumes nearly 75% of the total pesticides used in Punjab. The high use of pesticides, along with environmental and social factors, is responsible for the high concentration of pesticide residues in the food chain of this region. Moreover, many banned an...

Effects of Environmental Pesticides on the Health of Rural Communities in the Malwa Region of Punjab, India: A Review

Fruit waste (peel) as bio-reductant to synthesize silver nanoparticles with antimicrobial, antioxidant and cytotoxic activities

This work aimed to synthesize silver nanoparticles via an environmentally benign route, using the aqueous extract of Punica granatum as a precursor as well as a stabilizing and reducing agent. The as-synthesized silver nanoparticles were confirmed using UV-visible spectroscopy with an absorbance peak at 450 nm and were thereafter further confirmed using dynamic light scattering (DLS), High Resolution Transmission Electron Microscopy (HR-TEM) and X-Ray Diffraction (XRD). TEM analysis revealed 6–45 nm and spherically dispersed nanoparticles and XRD showed the crystalline nature of the nanoparticles. The free radical scavenging activity of the nanoparticles for DPPH and intracellular reactive oxidative species (ROS) production were observed using dihydroethidium (DHE) non-fluorescent stain and a CellROX® Deep Red fluorescent probe. Antibacterial assays against the most common Gram negative (Escherichia coli) and Gram positive (Staphylococcus aureus) bacteria showed a higher zone of inhibition against S. aureus. Furthermore, the anti-cancerous activity of the biologically synthesized silver nanoparticles was revealed by the inhibited cell growth of lung cancer A549 cells and no cytotoxicity was observed. This may be due to their ability to arrest the cell cycle at G1 phase. Thus, this work provides a gateway to explore more about the anticancer properties of biogenically synthesized silver nanoparticles and these biologically prepared silver nanoparticles have the potential to be utilized in biomedical science.

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Evaluation of the antioxidant, antibacterial and anticancer (lung cancer cell line A549) activity of Punica granatum mediated silver nanoparticles.

The cells of malignant cancers result in the evolution of cells with stem-like characteristics, commonly known as cancer stem cells (CSCs). Progress of anticancer therapies is severely hampered because of disease relapse mostly in a more aggressive form due to CSCs. These CSCs are more or less like embryonic or tissue stem cells, known for their capacity of self-renewal, exactly recapitulate of the original tumor. Deregulation of key stem cell pathways like Wnt, Hedgehog (Hh), and Notch is attributed towards the rise of CSCs. Recent breakthroughs offer better insights into CSC signaling. Scientists have developed several combinatorial therapies like targeting one/multiple of these CSC pathways. The article summarized various markers used to identify CSCs and discuss major signaling pathways in them. The futuristic probabilities to use CSC therapeutics in clinical development have been discussed. Our views have been highlighted on the future directions for targeting advances in the clinical development.

Eradicating Cancer Stem Cells: Concepts, Issues, and Challenges

In the present scenario of increased accumulation of pesticides in the environment, it is important to understand its impact on human health. The focus is on gene–environment interaction, highlighting the consequences and factors that may halt the biotransformation of some pesticides and change their actual dose response curve due to mixed exposure to pesticides. The paraoxonase and cytochrome P450 gene families are involved in the metabolism of oxon derivate (toxic than its parent compound) of organophosphate pesticides, thus, mutations in these genes may impact the metabolic outcome of pesticides and subsequent health hazards. The complex multi gene–environment interaction and one gene – one risk factor are two different aspects to understand the potential health effect related to environmental exposure studies. The genetic polymorphisms are associated with varying levels of risk within the population, as gene products of varied genotype alter the biotransformation of exogenous/endogenous substrates. This paper is aimed to review the impact of endogenous and exogenous factors on a mechanistic pathway of organophosphate pesticide biotransformation and various risk associated with it among the human population. Understanding the genetic polymorphism of genes involved in pesticide metabolism and highlighting the gene isoform dependent interindividual differences to metabolize particular pesticides may help us to unravel the reasons behind differential toxicity for pesticides exposure than expected.

Gurpreet Kaur

Papers

Effects of Environmental Pesticides on the Health of Rural Communities in the Malwa Region of Punjab, India: A Review

Fruit waste (peel) as bio-reductant to synthesize silver nanoparticles with antimicrobial, antioxidant and cytotoxic activities

Evaluation of the antioxidant, antibacterial and anticancer (lung cancer cell line A549) activity of Punica granatum mediated silver nanoparticles.

Eradicating Cancer Stem Cells: Concepts, Issues, and Challenges

CYP / PON genetic variations as determinant of organophosphate pesticides toxicity