Chlorpyrifos degradation by combined solar photo-Fenton and bacterial metabolism and simultaneous toxicity analysis in zebrafish (Danio rerio)

Chlorpyrifos (CP) is a widely used insecticide that has been used extensively, contributing towards a negative impact on public health concerns and associated ecosystems. Bioremediation is one of the key biological methods used for reducing these environmental toxicants. The present study examined the effectiveness of a combined process including solar photo-Fenton process followed by bacterial degradation using Ochrobactrum sp. CPD-03 for effective CP degradation in wastewater. Results showed that solar photo-Fenton treatment had CP degradation efficiency of ~42% in 4 h with a final degradation efficiency of ~92% in 96 h upon combined bacterial degradation. Simultaneous survivability of zebrafish (Danio rerio) was also studied during CP degradation. Compared to control, adult zebrafishes showed increased survivability following the addition of CPD-03 in water resulting a reduced CP concentration. CP toxicity in wastewater had caused acetylcholinesterase inhibition in zebrafish; however, this inhibition is due to absence of CP degrading bacteria. Therefore, a combined approach would influence for regulating CP degradation in wastewater along with simultaneous survival of Danio rerio.

Structure Elucidation and Toxicity Analysis of the Byproducts Formed after Biodegradation of Aflatoxins B1 and B2 Using Extracts of Mentha arvensis

The aqueous extracts of leaves and shoots of Mentha arvensis were checked for their potential to biodegrade aflatoxin B1 and B2 (AFB1; 100 µg/L and AFB2; 50 µg/L) through in vitro assays. Overall, the results showed that leaf extract degrades aflatoxins more efficiently than the shoot extract. First, the pH, temperature and incubation time were optimized for maximum degradation by observing this activity at different temperatures between 25 and 60 °C, pH between 2 and 10 and incubation time from 3 to 72 h. In general, an increase in all these parameters significantly increased the percentage of biodegradation. In vitro trials on mature maize stock were performed under optimized conditions, i.e., pH 8, temperature 30 °C and an incubation period of 72 h. The leaf extract resulted in 75% and 80% biodegradation of AFB1 and AFB2, respectively. Whereas the shoot extract degraded both toxins up to 40–48%. The structural elucidation of degraded toxin products by LCMS/MS analysis showed seven degraded products of AFB1 and three of AFB2. MS/MS spectra showed that most of the products were formed by the loss of the methoxy group from the side chain of the benzene ring, the removal of the double bond in the terminal furan ring and the modification of the lactone group, indicating less toxicity compared to the parent compounds. The degraded products showed low toxicity against brine shrimps, confirming that M. arvensis leaf extract has significant potential to biodegrade aflatoxins.

Proteome wide screening for identification of putative drug target gene in Nautella italica and structure-based ligand screening for therapeutic candidates

In silico based subtractive genomic approaches were employed to identify the key drug targets for an opportunistic pathogen Nautella italica, a member of the marine Roseobacter clade that causes bleaching disease in the temperate-marine red macro algae, Delisea pulchra. The aim of this study is to propose new active ligands against bleaching disease seen in algae. Using comparative and subtractive genomic approach, a set of 21 proteins were identified as the therapeutic drug target proteins for algal bleaching. This core set of drug targets has been analyzed for network topology using string network analysis and major hub gene identified by CytoHubba was rpoB (DNA directed RNA Polymerase subunit beta). The three-dimensional structure of rpoB was built by comparative modelling and used to perform a virtual screening of Zinc database by DOCK Blaster server. The 50 top scored compounds were screened for toxicity analysis by OSIRIS Data Warrior and ECOSAR tool. Further refinement by autodock program revealed two compounds ZINC49821385 and ZINC97218938 with the best binding energy of -7.07 and -6.79 respectively. These results indicated that 5-(4- isopropylphenyl)furan-2-carboxamide (ZINC ID 49821385) could be one of the potential ligand to treat bleaching disease in algae.

Label-free prediction of Cell Painting from brightfield images

Cell Painting is a high-content image-based assay which can reveal rich cellular morphology and is applied in drug discovery to predict bioactivity, assess toxicity and understand diverse mechanisms of action of chemical and genetic perturbations. In this study, we investigate label-free Cell Painting by predicting the five fluorescent Cell Painting channels from paired brightfield z-stacks using deep learning models. We train and validate the models with a dataset representing 1000s of pan-assay interference compounds sampled from 17 unique batches. The model predictions are evaluated using a test set from two additional batches, treated with compounds comprised from a publicly available phenotypic set. In addition to pixel-level evaluation, we process the label-free Cell Painting images with a segmentation-based feature-extraction pipeline to understand whether the generated images are useful in downstream analysis. The mean Pearson correlation coefficient (PCC) of the images across all five channels is 0.84. Without actually incorporating these features into the model training we achieved a mean correlation of 0.45 from the features extracted from the images. Additionally we identified 30 features which correlated greater than 0.8 to the ground truth. Toxicity analysis on the label-free Cell Painting resulted a sensitivity of 62.5% and specificity of 99.3% on images from unseen batches. Additionally, we provide a breakdown of the feature profiles by channel and feature type to understand the potential and limitation of the approach in morphological profiling. Our findings demonstrate that label-free Cell Painting has potential above the improved visualization of cellular components, and it can be used for downstream analysis. The findings also suggest that label-free Cell Painting could allow for repurposing the imaging channels for other non-generic fluorescent stains of more targeted biological interest, thus increasing the information content of the assay.

Isopropyl Ricinoleate, A Potential Alternative to Isopropyl Myristate: Experimental and Computational evaluation

Background: Due to growing environmental concerns, eco-friendly and sustainable materials have become one of the key interests of cosmetics research. Isopropyl myristate is being used as a major cosmetic ingredient, like in many other cosmetic items, as an emollient for a long time. Methods: An emollient ester, isopropyl ricinoleate, is derived from non-edible oil, castor oil. The synthesized isopropyl ricinoleate using greener enzyme catalysed methodology was further tested for sensory evaluation and transepidermal water loss (TEWL) studies. Results: An ester, isopropyl ricinoleate, imparted better gloss and shine to the skin as compared to isopropyl myristate due to its higher refractive index. Both esters, isopropyl ricinoleate and isopropyl myristate, showed minimum tackiness and residue after spreading. Moreover, in-silico toxicity analysis of ester, isopropyl ricinoleate, supported previously reported in-vitro toxicity data. Conclusion: Thus, the current study provides better insights on the replacement of emollient ester isopropyl myristate by isopropyl ricinoleate.