Biology subjects

Singh, A. S.

Publications and source records attributed to Singh, A. S..

6 recordsLinked to original sources

bioRxiv2026

Bio-Templated Zinc Oxide Nanotherapeutics from Flemingia macrophylla kuntze Ex Merr: In Vivo Anti-Diabetic and Anti-Inflammatory Efficacy in Drosophila melanogaster

Nanotechnology has a major impact on the creation of novel and effective therapies for the treatment of several diseases, including diabetes and cancer. The current work is a report on the use of the aqueous extract from the leaves of the Flemingia macrophylla plant as a capping and reducing agent in the green synthesis of zinc oxide nanoparticles (ZnO-NPs).The synthesized ZnO-NPs were subjected to characterization through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) scanning electron microscopy (SEM), and ultraviolet-visible spectroscopy (UV-Vis). Dose-dependent in vivo effects were investigated using Drosophila melanogaster subjected to a high-sugar diet (HSD) to induce a diabetic-like model. In vitro anti-oxidant, anti-diabetic, anti-inflammatory assay, survival, locomotor function, neuroanatomical integrity, ovary and testis morphology, egg-laying capacity, and male fertility were evaluated. The most prominent UV-visible peak was detected at around 370 nm. Structural and morphological analysis via XRD and electron microscopy confirmed the hexagonal phase of the ZnO-NPs, indicating an average calcined particle size of around 47 nm at 500 degree C. The manuscript reports significant anti-diabetic and anti-inflammatory effects in vitro and in the in vivo Drosophila model, together with antioxidant activity. The in vivo results indicate that green-synthesized ZnO-NPs mitigate adverse phenotypes triggered by a high-sugar diet and also potential as an anti-diabetic intervention and warrant further mechanistic and preclinical investigation. Keywords: Flemingia macrophylla; Green ZnO-NPs; Drosophila melanogaster; high-sugar diet; nanobiotechnology

pharmacology and toxicology↗

bioRxiv2026

Metagenome-assembled genomes (MAGs) revealed a functionally stratified microbiome in Jeevamrit, enabling co-operative nutrient cycling and rhizospheric growth promotion in the natural farming practices

Jeevamrit, a fermented liquid microbial bioinoculant, is increasingly recognized as a soil and plant growth enhancer in sustainable agricultural practices such as zero-budget natural farming; however, the genetic pool attributed to the functionality by microbial constituents remained poorly resolved. In this study, we reconstructed 16 high-quality metagenome-assembled genomes (MAGs) from Jeevamrit under two critical mixing regimes to elucidate the contributions of key taxa affiliated with Pseudomonadota, Bacillota, and Bacteroidota to nutrient cycling and plant growth promotion. Functional annotation revealed a stratified (upper-middle-lower) metabolic organization with interdependent interactions driving combinatorial functionality. Upper-layer MAGs, including Klebsiella and Pseudaeromonas exhibited organic polymer degradation, glycolytic and oxidative carbon metabolism, respiratory versatility with nutrient acquisition traits such as nitrogen fixation and phosphate/iron solubilization. In middle and lower-layer, Trichococcus, Clostridium, and Veillonella displayed fermentative and reductive metabolisms that facilitate the turnover of partially degraded organic matter and production of organic acids, nitrogen transformations, and metabolic cross-feeding under fluctuating redox conditions. Phylogenetic and taxono-genomic analyses support the designation of eight MAGs as novel species (sp. nov.), for which new names are proposed. A consensus genetic map deciphered traits linked to phytohormone biosynthesis (IAA, cytokinins), quorum-sensing-mediated rhizosphere colonization, and abiotic stress tolerance. Ultimately, this culture-independent metagenome study underpins field-relevant mechanistic insights into an indigenous microbial inoculant, highlighting its potential as a locally adapted solution for sustainable agriculture. ImportanceMicrobial bioinoculants such as Jeevamrit are increasingly used in sustainable agriculture, yet their functional basis remains insufficiently understood due to the limited genome-level resolution of constituent microbiota. This study addresses this gap by applying genome-resolved metagenomics to connect microbial diversity with agriculture-associated ecological functions in a complex fermented local formulation. By integrating metabolic reconstruction with plant-associated functional traits, this study advances understanding of how microbial consortia contribute to nutrient mobilization, rhizosphere competence, and environmental adaptability. This highlights the contribution of yet-to-be-cultivated but metabolically versatile taxa, which are important to the functions of agricultural ecosystems. By uncovering the roles of key microbes and their cooperative metabolic interactions, this work provides a scientific basis for improving Jeevamrit formulations through informed selection or enrichment of functionally important microbes to enhance nutrient delivery and plant growth performance.

microbiology↗

bioRxiv2024

Neuroinflammation underlies the development of social stress induced cognitive deficit in sickle cell disease.

Cognitive deficit is a debilitating complication of SCD with multifactorial pathobiology. Here we show that neuroinflammation and dysregulation in lipidomics and transcriptomics profiles are major underlying mechanisms of social stress-induced cognitive deficit in SCD. Townes sickle cell (SS) mice and controls (AA) were exposed to social stress using the repeat social defeat (RSD) paradigm concurrently with or without treatment with minocycline. Mice were tested for cognitive deficit using novel object recognition (NOR) and fear conditioning (FC) tests. SS mice exposed to RSD without treatment had worse performance on cognitive tests compared to SS mice exposed to RSD with treatment or to AA controls, irrespective of their RSD or treatment disposition. Additionally, compared to SS mice exposed to RSD with treatment, SS mice exposed to RSD without treatment had significantly more cellular evidence of neuroinflammation coupled with a significant shift in the differentiation of neural progenitor cells towards astrogliogenesis. Additionally, brain tissue from SS mice exposed to RSD was significantly enriched for genes associated with blood-brain barrier dysfunction, neuron excitotoxicity, inflammation, and significant dysregulation in sphingolipids important to neuronal cell processes. We demonstrate in this study that neuroinflammation and lipid dysregulation are potential underlying mechanisms of social stress-related cognitive deficit in SS mice. Key PointsO_LINeuroinflammation and lipid dysfunction are potential underlying mechanisms of social stress-related cognitive deficit in SCD patients. C_LIO_LIMitigating or ameliorating the impact of cognitive deficits in SCD needs to consider the biological changes already created by exposure to social stress. C_LI Novelty of our FindingsWe show for the first time, that neuroinflammation along with changes in the brain lipidome and transcriptome, are underlying biological mechanism contributing to the development and potentially progression of cognitive impairment among sickle cell patients. These findings also provide for the first time, a mechanistic basis for an earlier reported observation of a higher likelihood of having lower intelligence quotient scores among children with sickle cell disease exposed to social stress in the form of low parental socioeconomic status.

neuroscience↗

bioRxiv2022

Potential role of immediate early genes Egr-1, Hr-38 and Kakusei in the foraging behavior and learning of in honeybees

The foraging behavior of honeybees is one of the most systematically composed behaviors among social insects which are admirable to watch. The main purpose of honeybee foraging is to collect food for their colony and since ancient days honeybee products have been used for various medicinal purposes (Singh and Takhellambam 2021). During foraging, honeybees gather information and transmit to their colony members regarding the location, distance, and profitability of forage sites with the help of unique movements called waggle dance. The capacities of honeybees time memory enable the foragers to return to a good food source in anticipation of the time of day. This highly intellectual, dynamic, and well-coordinated behavior of honeybees makes them to be one of the best choices of behavioral model to study various aspects of dynamic behaviors. As a result, vast knowledge in honeybee behavior has been accumulated and several recent studies immerge towards finding the underpinning regulatory biology of honeybee foraging behaviors. Immediate early genes (IE) genes are well documented neural markers and their promising roles in honeybee foraging have been demonstrated. Two of our recent studies showed three IE genes Egr-1, Hr38 and Kakusei involvement during the daily foraging of honeybees. This finding has provided an avenue to further explore and identify the regulatory genes/proteins and neurons that underlie a specific behavior such as learning, memory, communication, and interaction etc. In this study we further analyze our previous published data to examine interaction of the three genes during the daily foraging of honeybees.

neuroscience↗

bioRxiv2021

A method to study honeybee foraging regulatory molecules at different times during foraging

The foraging of honey bees is one of the most well organized and admirable behaviors that exist among social insects. In behavioral studies, these beautiful insects have been extensively used for understanding time-space learning, landmark use and concept of learning etc. Highly organized behaviors such as social interaction and communication are systematically well organized behavioral components of honeybee foraging. Over the last two decades, understanding the regulatory mechanisms underlying honey bee foraging at the cellular and molecular levels has been increasingly interested to several researchers. Upon the search of regulatory genes of brain and behavior, immediate early (IE) genes are considered as tool to begin the investigation. Our two recent studies, have demonstrated three IE genes namely Egr-1, Hr38 and kakusei having a role in the daily foraging of bees and their association with learning and memory during the foraging. These studies further evidence that IE genes can be used as a tool in finding the specific molecular/cellular players of foraging in honey bees and its behavioral components such as learning, memory, social interaction, social communication etc. In this article we provide the details of the method of sample collection at different times during foraging to investigate the foraging regulatory molecules.

neuroscience↗

bioRxiv2019

Immediate early gene kakusei plays a role in the daily foraging and learning of honey bees

kakusei is a non-coding RNA that is overexpressed in foraging bee brain. This study describes a fundamental role of the IEG kakusei during the daily foraging of honey bees. kakusei was found to be transiently upregulated within two hours during rewarded foraging. Interestingly, during unrewarded foraging the gene was also found to be up-regulated, but immediately lowered as food was not rewarded. Moreover, the kakusei overexpression was diminished within a very short time when the time schedule of feeding was changed. This indicates the potential role of kakusei on the motivation of learned reward foraging, reflecting associative learning memory. These results provide evidence for a dynamic role of kakusei during foraging of bees, and eventually its possible involvement in learning and memory. Thus the kakusei gene could be used as key search tool in finding distinct molecular pathways that mediate diverse behavioral components of foraging.

neuroscience↗