Chloroform extract of Carica papaya seeds induces long-term reversible azoospermia in langur monkey

AIM

To evaluate the antifertility activity of the chloroform extract of Carica papaya seeds by oral administration in langur monkey, Presbytis entellus entellus.

METHODS

The chloroform extract of Carica papaya seeds, 50 mg/kg/day, was administered orally for 360 days to adult male langur monkeys. The sperm characteristics by light and electron microscopy, the sperm functional tests, the semen biochemistry, the serum testosterone level, the Leydig cell function, and the histology and ultrastructure of testis were determined to evaluate the antifertility activity and the blood biochemistry and hematology, to evaluate the toxicology.

RESULTS

The extract gradually decreased the sperm concentration since days 30-60 of treatment with a total inhibition of sperm motility, a decrease in sperm viability and increase in sperm abnormality. Azoospermia was observed after day 90 of treatment and continued during the whole treatment period. Treatment withdrawal resulted in a gradual recovery in these parameters and 150 days later they reverted to nearly the pretreatment values. Morphological observation of the ejaculated sperm by light and scanning electron microscopy showed deleterious changes, particularly on the mid-piece. Sperm functional tests, viz., sperm mitochondrial activity index, acrosome intactness test and hypo-osmotic swelling test scored in the infertile range during treatment and returned to the fertile values 150 days after drug withdrawal. Histology of the testis revealed shrunken tubules, germ cell atrophy and normal Leydig cells. Ultrastructure of the testis showed vacuolization in the cytoplasm of Sertoli cells and germ cells. Loss of cytoplasmic organelles were evident in the spermatocytes and spermatids. Round spermatids showed loss of Golgi bodies, peripheral mitochondria and vacuolated cytoplasm, indicating maturational arrest. Leydig cell functional test indicated a mild inhibition of steroidogenic function. Haematology and serum biochemistry study disclosed no significant toxicological effect and the serum testosterone level was not affected.

CONCLUSION

Carica papaya seed extract may selectively act on the developing germ cells, possibly mediated via Sertoli cells, leading to azoospermia.

Microcystin-LR in drinking water: An emerging role of mitochondrial-induced epigenetic modifications and possible mitigation strategies

Algal blooms are a serious menace to freshwater bodies all over the world. These blooms typically comprise cyanobacterial outgrowths that produce a heptapeptide toxin, Microcystin-LR (MC-LR). Chronic MC-LR exposure impairs mitochondrial-nuclear crosstalk, ROS generation, activation of DNA damage repair pathways, apoptosis, and calcium homeostasis by interfering with PC/MAPK/RTK/PI3K signaling. The discovery of the toxin's biosynthesis pathways paved the way for the development of molecular techniques for the early detection of microcystin. Phosphatase inhibition-based bioassays, high-performance liquid chromatography, and enzyme-linked immunosorbent tests have recently been employed to identify MC-LR in aquatic ecosystems. Biosensors are an exciting alternative for effective on-site analysis and field-based characterization. Here, we present a synthesis of evidence supporting MC-LR as a mitotoxicant, examine various detection methods, and propose a novel theory for the relevance of MC-LR-induced breakdown of mitochondrial machinery and its myriad biological ramifications in human health and disease.

Air pollution-linked epigenetic modifications in placental DNA: Prognostic potential for identifying future foetal anomalies

Prenatal exposure to air pollution is a significant risk factor for the mother and the developing foetus. The accumulation of pollutants in the placenta can cause a self-cascade loop of pro-inflammatory cytokine responses and DNA double-strand breaks. Previous research has shown that airborne particulate matter can damage the epigenome and disturb mitochondrial machinery, ultimately impairing placental function. Mitochondria are essential for preserving cellular homeostasis, energy metabolism, redox equilibrium, and epigenetic reprogramming. As these organelles are subtle targets of environmental exposures, any disruption in the signaling pathways can result in epigenomic instability, which can impact gene expression and mitochondrial function. This, in turn, can lead to changes in DNA methylation, post-translational histone modifications, and aberrant expression of microRNAs in proliferating trophoblast cells. The placenta has two distinct layers, cytotrophoblasts, and syncytiotrophoblasts, each with its mitochondria, which play important roles in preeclampsia, gestational diabetes, and overall health. Foetal nucleic acids enter maternal circulation during placental development because of necrotic, apoptotic, and inflammatory mechanisms. These nucleic acids reflect normal or abnormal ongoing cellular changes during prenatal foetal development. Detecting cell-free DNA in the bloodstream can be a biomarker for predicting negative pregnancy-related outcomes and recognizing abnormalities in foetal growth. Hence, a thorough understanding of how air pollution induces epigenetic variations within the placenta could offer crucial insights into underlying mechanisms and prolonged repercussions on foetal development and susceptibility in later stages of life.

Modulatory Effects of Vitamin D: A Possible Approach to Mitigate Air Pollution Related Pregnancy Complications

Approximately 99% of people on the planet breathe air that exceeds the World Health Organization's permitted threshold for pollution. South Asia is home to the world's most polluted cities. Population-based studies have suggested that women's reproductive health outcomes are worsening due to air pollution. Preeclampsia, miscarriage, gestational diabetes, high blood pressure, and unfavorable birth outcomes, including preterm birth, low birth weight, or even stillbirth are all linked to exposure to air pollution during pregnancy. It is estimated that 0.61 million deaths in India alone were related to indoor air pollution. Females frequently cook in the household using solid fuel as a primary combustion source. Women in the regions with the highest population density are disproportionately affected by high levels of poor-quality indoor air. Recently, it has been proposed that air pollution has a distinct role in the onset of vitamin D deficiency. Numerous studies have explored associations between low vitamin D level and various female reproductive health conditions since the discovery of the vitamin D receptor. It is worthy to note that some of these reproductive health conditions positively correlate with the severity of air pollution. In this study, the evidence has been synthesized on vitamin D's protective properties and dietary and pharmaceutical interventions have been discussed to show their beneficial effects in decreasing the long-term negative impacts of air pollution on women's health.

The enigma of mitochondrial epigenetic alterations in air pollution-induced neurodegenerative diseases

The incidence of neurodegenerative diseases is a growing concern worldwide, affecting individuals from diverse backgrounds. Although these pathologies are primarily associated with aging and genetic susceptibility, their severity varies among the affected population. Numerous studies have indicated air pollution as a significant contributor to the increasing prevalence of neurodegeneration. Cohort studies have provided compelling evidence of the association between prolonged exposure to different air toxicants and cognitive decline, behavioural deficits, memory impairment, and overall neuronal health deterioration. Furthermore, molecular research has revealed that air pollutants can disrupt the body's protective mechanisms, participate in neuroinflammatory pathways, and cause neuronal epigenetic modifications. The mitochondrial epigenome is particularly interesting to the scientific community due to its potential to significantly impact our understanding of neurodegenerative diseases' pathogenesis and their release in the peripheral circulation. While protein hallmarks have been extensively studied, the possibility of using circulating epigenetic signatures, such as methylated DNA fragments, miRNAs, and genome-associated factors, as diagnostic tools and therapeutic targets requires further groundwork. The utilization of circulating epigenetic signatures holds promise for developing novel prognostic strategies, creating paramount point-of-care devices for disease diagnosis, identifying therapeutic targets, and developing clinical data-based disease models utilizing multi-omics technologies and artificial intelligence, ultimately mitigating the threat and prevalence of neurodegeneration.

Nanophotonic waveguide-based sensing of circulating cell-free mitochondrial DNA: implications for personalized medicine

Circulating cell-free mitochondrial DNA (ccf-mtDNA) has emerged as a promising biomarker, with potential implications for disease diagnosis. Changes in mtDNA, such as deletions, mutations or variations in the number of copies, have been associated with mitochondrial disorders, heart diseases, cancer and age-related non-communicable diseases. Previous methods, such as polymerase chain reaction-based approaches, next-generation sequencing and imaging-based techniques, have shown improved accuracy in identifying rare mtDNA variants or mutations, but they have limitations. This article explains the basic principles and benefits of using planar optical waveguide-based detection devices, which represent an advanced approach in the field of sensing.

Genetic variants and type 2 diabetes in India: a systematic review and meta-analysis of associated polymorphisms in case-control studies

BACKGROUND

India, with the largest population and second-highest type 2 diabetes mellitus (T2DM) prevalence, presents a unique genetic landscape. This study explores the genetic profiling of T2DM, aiming to bridge gaps in existing research and provide insights for further explorations.

METHODS

We conducted a systematic review and meta-analysis of literature published up to September 2024 using databases like PubMed, Web of Science, Scopus, and Google Scholar to identify SNPs associated with T2DM in case-control studies within the Indian population. Data extraction followed a rigorously designed checklist independently verified by two reviewers. The quality of the studies assessed by utilizing Newcastle Ottawa scale, and heterogeneity through Cochran's Q, τ2, H2 and I 2 statistics. Fixed effect and random effect model was employed for meta-analysis based on heterogeneity, and publication bias was assessed by funnel plot analysis, Egger's and Begg's statistical test. In SNPs with adequate studies meta-regression was used to assess source of heterogeneity. Statistical analyses were performed using Stata 18.0 software.

FINDINGS

Our search identified 1309 articles, with 67 included in the systematic review and 35 in the meta-analysis. These 67 case-control studies, involving 33,407 cases and 30,762 controls, analyzed 167 SNPs across 61 genes. Of these, 89 SNPs mapped to 46 genes showed significant associations with T2DM risk (P < 0.05), including 67 linked to increased risk and 16 with protective effects. Geographical analysis highlighted inter- and intra-regional variations. Meta-analysis of 25 SNPs revealed 12 SNPs with high T2DM risk compatibility. TCF7L2 gene exhibited a strong compatibility with an overall OR of 1.44 (95% CI 1.36-1.52) and S-value 112.41, while TCF7L2 variants rs7903146 and rs12255372, with OR 1.56 (95% CI 1.43-1.66) and S-value 89.036, OR of 1.36 (95% CI 1.17-1.35) with an S-value of 15.45 respectively.

INTERPRETATION

Our study highlights the importance of considering the diverse ethnic groups of India for development of targeted and effective T2DM management strategies.

FUNDING

Department of Biotechnology (DBT) and Indian Council of Medical Research (ICMR), Government of India.

Smart carbon-based sensors for the detection of non-coding RNAs associated with exposure to micro(nano)plastics: an artificial intelligence perspective

Micro(nano)plastics (MNPs) are pervasive environmental pollutants that individuals eventually consume. Despite this, little is known about MNP's impact on public health. In this article, we assess the evidence for potentially harmful consequences of MNPs in the human body, concentrating on molecular toxicity and exposure routes. Since MNPs are present in various consumer products, foodstuffs, and the air we breathe, exposure can occur through ingestion, inhalation, and skin contact. MNPs exposure can cause mitochondrial oxidative stress, inflammatory lesions, and epigenetic modifications, releasing specific non-coding RNAs in circulation, which can be detected to diagnose non-communicable diseases. This article examines the most fascinating smart carbon-based nanobiosensors for detecting circulating non-coding RNAs (lncRNAs and microRNAs). Carbon-based smart nanomaterials offer many advantages over traditional methods, such as ease of use, sensitivity, specificity, and efficiency, for capturing non-coding RNAs. In particular, the synthetic methods, conjugation chemistries, doping, and in silico approach for the characterization of synthesized carbon nanodots and their adaptability to identify and measure non-coding RNAs associated with MNPs exposure is discussed. Furthermore, the article provides insights into the use of artificial intelligence tools for designing smart carbon nanomaterials.

Gut-resident regulatory T cells (GTregs) play a pivotal role in maintaining bone health under postmenopausal osteoporotic conditions

Osteoporosis is a skeletal condition characterized by the deterioration of bone tissue. The immune system plays a crucial role in maintaining bone homeostasis and combating the development of osteoporosis. Immunoporosis is the term used to describe the recent convergence of research on the immune system's role in osteoporosis. The gut harbors the largest component of the immune system, and there is growing evidence that intestinal immunity plays a vital role in regulating bone health. Gut-resident regulatory T cells are essential in inhibiting immune responses and preventing various inflammatory manifestations. Our findings show that gut-resident regulatory T cells are pivotal in the pathophysiology of postmenopausal osteoporosis. We investigated the potential of gut-resident regulatory T cells in regulating the development of bone cells in vitro. We observed that gut-resident regulatory T cells significantly enhance osteoblastogenesis with concomitant inhibition of osteoclastogenesis in a cell ratio-dependent manner. We further report that the deficiency of short-chain fatty acids in osteoporotic conditions substantially disrupts the composition of gut-resident regulatory T cells, leading to a loss of peripherally derived regulatory T cells and an expansion of thymus-derived regulatory T cells. Moreover, the administration of probiotics Lactobacillus rhamnosus (UBLR-58) and Bifidobacterium longum (UBBL-64) modulated the gut-resident regulatory T cells compartment in a short-chain fatty acid-dependent manner to mitigate inflammatory bone loss in postmenopausal osteoporosis. Notably, short-chain fatty acid-primed gut-resident regulatory T cells were found to be significantly more effective in inhibiting osteoclastogenesis compared with unprimed gut-resident regulatory T cells. Altogether our results, for the first time, highlight the crucial role of gut-resident regulatory T cells in the pathophysiology of postmenopausal osteoporosis, with potential clinical implications.

Protocol for detection of pathogenic enteric RNA viruses by regular monitoring of environmental samples from wastewater treatment plants using droplet digital PCR

BACKGROUND

The present comprehensive protocol is focused on the detection of pathogenic enteric RNA viruses, explicitly focusing on norovirus genogroup Ⅱ (GⅡ), astrovirus, rotavirus, Aichi virus, sapovirus, hepatitis A and E viruses in wastewater treatment plants through droplet digital PCR (ddPCR). Enteric viruses are of significant public health concern, as they are the leading cause of diseases like gastroenteritis. Regular monitoring of environmental samples, particularly from wastewater treatment plants, is crucial for early detection and control of these viruses. This research aims to improve the understanding of the prevalence and dynamics of enteric viruses in urban India and will serve as a model for similar studies in other regions. Our protocol's objective is to establish a novel ddPCR-based methodology for the detection and molecular characterization of enteric viruses present in wastewater samples sourced from Bhopal, India. Our assay is capable of accurately quantifying virus concentrations without standard curves, minimizing extensive optimization, and enhancing sensitivity and precision, especially for low-abundance targets.

METHODS

The study involves fortnightly collecting and analyzing samples from nine wastewater treatment plants over two years, ensuring comprehensive coverage and consistent data. Our study innovatively applies ddPCR to simultaneously detect and quantify enteric viruses in wastewater, a more advanced technique. Additionally, we will employ next-generation sequencing for detailed viral genome identification in samples tested positive for pathogenic viruses.

CONCLUSION

This study will aid in understanding these viruses' genetic diversity and mutation rates, which is crucial for developing tailored intervention strategies. The findings will be instrumental in shaping public health responses and improving epidemiological surveillance, especially in localities heaving sewage networks.

A pragmatic & translational approach of human biomonitoring to methyl isocyanate exposure in Bhopal

Human biomonitoring has evolved beyond margins to ascertain exposure-response relationship in environmental associated human diseases. As occupational ailments continue to dominate global concerns, biomonitoring strategies have evolved better in terms of evaluating health risks associated with systemic uptake from chronic (long-term) environment exposures. Even though contributions of acute toxic exposures (short-term) towards initiation of disease processes have been gradually recognized, a comprehensive approach delineating mechanistic insights of such an implication remains elusive. Molecular biomonitoring in a strictly selected defined surviving cohort of the infamous Bhopal gas tragedy "as a model", could provide an unparallel opportunity to discern the long standing implications of acute exposures. Besides comprehending clinical significance of isocyanate toxicity, the results might provide a framework for understanding the molecular repercussions pertaining to a host of other such acute environmental exposures. The investigative strategy might also be helpful in identification of biomarkers with potential for translational research.

Human sperm immobilization effect of Carica papaya seed extracts: an in vitro study

AIM

To examine if the seed extracts of Carica papaya, which showed antispermatogenic/sperm immobilization properties in animal models, could cause human sperm immobilization in vitro.

METHODS

Chloroform extract, benzene chromatographic fraction of the chloroform extract, its methanol and ethyl acetate sub-fractions and the isolated compounds from the sub-fractions i.e., ECP 1 & 2 and MCP 1 &2, of the seeds of Carica papaya were used at concentrations of 0.1%, 0.5%, 1% and 2%. Sperm motility was assessed immediately after addition of extracts and every 5 minutes thereafter for 30 minutes.

RESULTS

There were dose-dependent spermicidal effects showing an instant fall in the sperm motility to less than 20% at 2% concentration. Isolated compounds ECP 1 & 2 were more effective inducing a motility of less than 10%. Many of the spermatozoa became vibratory on the spot. Total inhibition of motility was observed within 20-25 min at all concentrations of all products. Scanning and transmission electron microscopy revealed deleterious changes in the plasma membrane of the head and mid-piece of spermatozoa. Sperm viability test and the number of abnormal spermatozoa after completion of incubation suggested that the spermatozoa were infertile. The effects were spermicidal but not spermiostatic as revealed by the sperm revival test.

CONCLUSION

The results reveal spermicidal activity in vitro of the seed extracts of Carica papaya.