Pinostrobin alleviates testicular and spermatological damage induced by polystyrene microplastics in adult albino rats

Reproductive toxicity and related mechanisms of micro(nano)plastics in terrestrial mammals: Review of current evidence

Micro(nano)plastics (MNPs) have been detected in various ecological environments and are widely used due to their stable properties, raising widespread concern about their potential human reproductive toxicity. Currently, infertility affects approximately 10-30% of couples of reproductive age globally. MNPs, as environmental pollutants, have been shown to exhibit reproductive toxicity through intrinsic mechanisms or as carriers of other hazardous substances. Numerous studies have established that MNPs of varying sizes and types can penetrate biological barriers, and enter tissues and even organelles of organisms through four main routes: dietary ingestion, inhalation, dermal contact, and medical interventions. However, historical research on the toxic effects of MNPs on reproduction mainly focused on lower and aquatic species. We conducted an inclusive review of studies involving terrestrial mammals, revealing that MNPs can induce reproductive toxicity via various mechanisms such as oxidative stress, inflammation, fibrosis, apoptosis, autophagy, disruption of intestinal flora, endocrine disruption, endoplasmic reticulum stress, and DNA damage. In terrestrial mammals, reproductive toxicity predominantly manifests as disruption in the blood-testis barrier (BTB), impaired spermatogenesis, sperm malformation, sperm DNA damage, reduced sperm fertilizing capacity, compromised oocyte maturation, impaired follicular growth, granulosa cell apoptosis, diminished ovarian reserve function, uterine and ovarian fibrosis, and endocrine disruption, among other effects. Furthermore, MNPs can traverse the maternal-fetal interface, potentially impacting offspring reproductive health. To gain a comprehensive understanding of the potential reproductive toxicity and underlying mechanisms of MNPs with different sizes, polymer types, shapes, and carried toxins, as well as to explore effective protective interventions for mitigating reproductive damage, further in-depth animal studies, clinical trials, and large-scale epidemiological studies are urgently required.

Adverse effects and potential mechanisms of polystyrene microplastics (PS-MPs) on the blood-testis barrier

Microplastics (MPs) are defined as plastic particles or fragments with a diameter of less than 5 mm. These particles have been identified as causing male reproductive toxicity, although the precise mechanism behind this association is yet to be fully understood. Recent research has found that exposure to polystyrene microplastics (PS-MPs) can disrupt spermatogenesis by impacting the integrity of the blood-testis barrier (BTB), a formidable barrier within mammalian blood tissues. The BTB safeguards germ cells from harmful substances and infiltration by immune cells. However, the disruption of the BTB leads to the entry of environmental pollutants and immune cells into the seminiferous tubules, resulting in adverse reproductive effects. Additionally, PS-MPs induce reproductive damage by generating oxidative stress, inflammation, autophagy, and alterations in the composition of intestinal flora. Despite these findings, the precise mechanism by which PS-MPs disrupt the BTB remains inconclusive, necessitating further investigation into the underlying processes. This review aims to enhance our understanding of the pernicious effects of PS-MP exposure on the BTB and explore potential mechanisms to offer novel perspectives on BTB damage caused by PS-MPs.

Prevalence and implications of microplastic contaminants in general human seminal fluid: A Raman spectroscopic study

Microplastics are ubiquitous environmental contaminants that have been detected in human semen from polluted areas, yet their prevalence and effects in the general population remain largely unexplored. To examine microplastic presence, abundance, polymer types, and associations with semen quality parameters in individuals without occupational exposures, this study was conducted by collecting semen samples from 40 participants undergoing premarital health assessments in Jinan, China. Raman microspectroscopy was employed to identify, quantify, and categorize microplastic polymers, sperm motility was assessed via computer-assisted analysis, and morphology was evaluated through Diff-Quik staining. Correlations between demographics, semen parameters, and microplastic content were examined by statistical analysis. We found that microplastics were detected in all semen samples, with 2 particles per sample (ranging from 0.72 to 7.02 μm). Eight distinct polymers were identified, with polystyrene (31 %) being most prevalent. Semen exposed to polystyrene demonstrated higher sperm progressive motility as compared to polyvinyl chloride exposure group (43.52 ± 14.21 % vs 19.04 ± 13.46 %). Sperm morphological abnormalities were observed but not significantly associated with specific plastic types. In conclusion, this study reveals microplastic contamination in semen from individuals without occupational exposure, with PS, PE, and PVC being the most prevalent and exhibiting differential correlations with sperm progressive motility, and highlight the need for further research into the potential reproductive impacts of microplastic exposure.

Polystyrene microplastics disturb maternal glucose homeostasis and induce adverse pregnancy outcomes

Pregnant women are a special group that is sensitive to adverse external stimuli, causing metabolic abnormalities and adverse pregnancy outcomes. Microplastics (MPs), an environmental pollutant widely used in various fields, can induce a variety of toxic responses in mammals. Recent studies verified an association between MPs and metabolic disorders. Our research built a gestational mouse model in which polystyrene microplastics (PS-MPs) of 1 μm size were consumed at concentrations of 0.1, 1, and 10 mg/L during pregnancy. Results indicated that PS-MPs induced placental malfunction and fetal growth retardation. Significant glucose disorders, decreased liver function, hepatic inflammation, and oxidative stress were also observed after PS-MPs exposure. The hepatic SIRT1/IRS1/PI3K pathway was inhibited in the 10 mg/L PS-MPs exposure group. Our study found that PS-MPs activated inflammatory response and oxidative stress by increasing hepatic lipopolysaccharide (LPS) that inhibited the hepatic SIRT1/IRS1/PI3K pathway, ultimately leading to insulin resistance, glucose metabolism disorders, and adverse pregnancy outcomes. This study provides a basis for preventing environment-related gestational diabetes and concomitant adverse pregnancy outcomes.

Di (2-ethylhexyl) phthalate and polystyrene microplastics co-exposure caused oxidative stress to activate NF-κB/NLRP3 pathway aggravated pyroptosis and inflammation in mouse kidney

Polystyrene microplastic (PS-MPs) contamination has become a worldwide hotspot of concern, and its entry into organisms can cause oxidative stress resulting in multi-organ damage. The plasticizer di (2-ethylhexyl) phthalate (DEHP) is a common endocrine disruptor, these two environmental toxins often occur together, but their combined toxicity to the kidney and its mechanism of toxicity are unknown. Therefore, in this study, we established PS-MPS and/or DEHP-exposed mouse models. The results showed that alone exposure to both PS-MPs and DEHP caused inflammatory cell infiltration, cell membrane rupture, and content spillage in kidney tissues. There were also down-regulation of antioxidant enzyme levels, increased ROS content, activated of the NF-κB pathway, stimulated the levels of heat shock proteins (HSPs), pyroptosis, and inflammatory associated factors. Notably, the co-exposure group showed greater toxicity to kidney tissues, the cellular assay further validated these results. The introduction of the antioxidant n-acetylcysteine (NAC) and the NLRP3 inhibitor (MCC950) could mitigate the changes in the above measures. In summary, co-exposure of PS-MPs and DEHP induced oxidative stress that activated the NF-κB/NLRP3 pathway and aggravated kidney pyroptosis and inflammation, as well as that HSPs are also involved in this pathologic injury process. This study not only enriched the nephrotoxicity of plasticizers and microplastics, but also provided new insights into the toxicity mechanisms of multicomponent co-pollution in environmental.

Apigetrin ameliorates doxorubicin prompted testicular damage: biochemical, spermatological and histological based study

Doxorubicin (DOX) is a highly effective, commonly prescribed, potent anti-neoplastic drug that damages the testicular tissues and leads to infertility. Apigetrin (APG) is an important flavonoid that shows diverse biological activities. The present research was designed to evaluate the alleviative role of APG against DOX-induced testicular damages in rats. Forty-eight adult male albino rats were randomly distributed into 4 groups, control, DOX administered (3 mgkg-1), DOX + APG co-administered (3 mgkg-1 of DOX; 15 mgkg-1 of APG), and APG administered group (15 mgkg-1). Results of the current study indicated that DOX treatment significantly reduced the activities of superoxide dismutase (SOD), glutathione reductase (GSR), catalase (CAT) and glutathione peroxidase (GPx), while increasing the levels of malondialdehyde (MDA) and reactive oxygen species (ROS). DOX treatment also reduced the sperm count, viability, and motility. Moreover, DOX significantly increased the sperm morphological anomalies and reduced the levels of plasma testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The administration of DOX significantly increased the expressions of Bax and Caspase-3, as well as the levels of inflammatory markers. Additionally, DOX treatment significantly downregulated the expressions of steroidogenic enzymes (StAR, 3β-HSD and 17β-HSD) and Bcl-2. Furthermore, DOX administration provoked significant histopathological abnormalities in the testicular tissues. However, APG supplementation significantly reversed all the testicular damages due to its androgenic, anti-apoptotic, anti-oxidant and anti-inflammatory nature. Therefore, it is concluded that APG may prove a promising therapeutic agent to treat DOX-induced testicular damages.

The beneficial effect of Allium Cepa bulb extract on reproduction of rats; A two-generation study on fecundity and sex hormones

Allium Cepa Linn. (Onions) has extensively been used in traditional medicine, is one of the important Allium species regularly used in our daily diet, and has been the source of robust phenolic compounds. The current study is intended to evaluate the fecundity-enhancing effect of A. Cepa on the reproductive performance of two successive generations of rats; F0 and F1. A. Cepa extract was initially tested for in vitro antioxidant assay via DPPH and ROS, followed by in vivo toxicity testing. In the fecundity assessment, eighteen pairs of male and female rats (n = 36, 1:1, F0 generation) were divided into three groups and dosed with 75mg/kg and 150 mg/kg daily of A. Cepa extract and saline respectively, up to pre-cohabitation, cohabitation, gestation and lactation period. The reproductive performance, including body weight, live birth index, fertility index, and litter size, was assessed. Various parameters like Hematological, Hormonal (FSH, LH, Testosterone, estradiol), antioxidant markers (SOD, Glutathione peroxidase) and lipid profile of F0 and F1 generations were assessed with evaluation of histopathology of male and female organs. Ethanolic extract of A. Cepa showed the greatest antioxidant potential in DPPH and ROS methods. The continued exposure of the F0 and F1 generations to A. Cepa extract did not affect body weight, fertility index, litter size, and survival index. However, semen pH, sperm motility, sperm count, sperm viability, and semen volume were significantly improved in both generations. We have found pronounced fecundity outcomes in both genders of F0 and F1 generations with A. Cepa 150mg/kg/day extract as compared to control. Results showed that A. Cepa significantly increased (P < 0.05) hemoglobin, follicular stimulating hormone (FSH), luteinizing hormone (LH), plasma testosterone and glutathione peroxidase activities, while total lipid, LDL, and cholesterol were significantly decreased (P < 0.05) in both generations. Histology of both generations of animals reveals enhanced spermatogenesis and enhanced folliculogenesis with improved architecture. Altogether, the present results suggest that A. Cepa extract improved fecundity in both male and female rats by improving hormonal activities and oxidative stress.

Unveiling the impact of environmental microplastics on mussel spermatozoa: First evidence of prothymosin-α detection in invertebrate's male gametes

Mytilus galloprovincialis mussels, like many other marine invertebrates, employ external fertilization as a mating strategy, exposing their gametes to various contaminants upon release into seawater. Environmental microplastics (EMP) are prevalent marine pollutants that pose a significant threat to aquatic biota. In this regard, our study aimed to investigate the potential effects of exposing mussels' male gametes to increasing concentrations of EMP (1, 10, 50, and 100 μg/l) collected from a Mediterranean sandy beach. We focused on assessing gamete quality by analysing physiological parameters such as viability, mitochondrial membrane potential, oxidative status, and motility. Additionally, we evaluated DNA integrity and activation of apoptosis. Furthermore, our study aimed to detect the presence of the prothymosin-α (PTMA) protein, which has never been previously investigated in invertebrate spermatozoa. Our data revealed that exposure of mussel spermatozoa to EMPs altered their oxidative status and mitochondrial membrane potential, induced a decrease in motility, DNA integrity, and an increased apoptotic occurrence, leading to a decline in overall viability. The localization of PTMA into the head and flagellum of spermatozoa further supported its presence and susceptibility to the effects of microplastics. These findings raise concerns about the reproductive capacity of mussels under environmental microplastic pollution and highlight potential long-term threats to population sustainability.

Fucoidan from Cladosiphon okamuranus enhances antioxidant activity and prevents reproductive dysfunction in polystyrene microplastic-induced male rats

Plastic pollution, including microplastic, has emerged as a severe environmental and public health problem. The health risks, especially in the case of reproductive damage caused by polystyrene microplastic (PS-MP) exposure, are emerging problems that need to be solved. This study aimed to investigate the effects of fucoidan extracted from Cladosiphon okamuranus on the polystyrene microplastic-induced oxidative stress of the Leydig (LC540) cells and reproductive damage in male rats. The oxidative stress of the LC540 cells and reproductive damage in the rats were induced by PS-MP. The fucoidan treatment reduces nitric oxide (NO) and reactive oxygen species generation in the LC540 cells. In the animal study, fucoidan treatment enhanced enzymatic antioxidant activities (glutathione peroxidase, superoxide dismutase, glucose-6-phosphate dehydrogenase, and glutathione reductase) and reduced malondialdehyde and nitric oxide production. Fucoidan supplementation also downregulates tumor necrosis factor-alpha, interleukin-6, and caspase-3 expression. Additionally, fucoidan upregulates testosterone levels, prevents the reduction of epithelium thickness, and reduces the area of the seminiferous tubule lumen. According to these conditions, fucoidan from Cladosiphon okamuranus prevents reproductive damage by downregulating oxidative stress and pro-inflammatory cytokines. Therefore, fucoidan can be used as a source of food supplements or functional food ingredients for reproductive or testicular damage management.

Discrimination of different feed additives and poly-herbal formulations based on their untargeted phytochemical profiles

INTRODUCTION

Feed additives represents a valid tool in animal nutrition to improve animal performance and livestock productivity under a sustainable perspective; however, there is a paucity of information about their comprehensive metabolomic and bioactive profiles.

OBJECTIVE

In this study, we tested the ability of an untargeted metabolomics approach to discriminate nine commercial feed additives and unique blends of botanical extracts used in both ruminant and non-ruminant nutrition, according to their phytochemical profiles and different in vitro bioactive properties.

METHODS

An ultra-high-performance liquid chromatography coupled with Orbitrap mass spectrometry and multivariate statistics were combined to search for potential markers, in order to better discriminate the different commercial samples.

RESULTS

Several phytochemicals were identified, namely alkaloids, phenolics, organosulfurs, and terpenoids. The polyherbal formulation Zigbir was the best source of phytochemicals, accounting for a cumulative total content of phytochemicals equal to 3.03 mg Eq./g, being particularly abundant in terpenoids, stilbenes, phenolic acids, and small-molecular-weight phenolics. Multivariate statistics allowed to group the different products in 2 bioactive subclusters. The diterpenoid andrographolide recorded the highest abundance in Zigbir and Sangrovit. The most predictive biomarkers were: piperine, isoquercitrin, 6-methylthiohexyldesulfoglucosinolate, 6-methylumbelliferone, benzoic acid, (+)-(1R,2R)-1,2-diphenylethane-1,2-diol, and piperitenone. Flavonoids were highly correlated with both in vitro antioxidant and enzyme inhibition assays.

CONCLUSIONS

Our findings provide new insights into the comprehensive phytochemical composition of commercial feed additives and blend of botanical extracts used for both ruminant and non-ruminant nutrition. A great importance of polyphenols in relation to the biological activities was detected.

Adverse effects of microplastics and nanoplastics on the reproductive system: A comprehensive review of fertility and potential harmful interactions

In recent years, microplastics (MPs) and nanoplastics (NPs) have caused ubiquitous environmental pollution and raised widespread concern about their potential toxicity to human health, especially in the reproductive system. Moreover, infertility affects >15 % of couples worldwide, and the birth rate is decreasing. Environmental factors are some of the most important causes of infertility. However, little is known about the effects of MPs and NPs on the testes and ovaries. These particles can enter the body primarily via ingestion, inhalation, and skin contact, target the reproductive system in a size-dependent manner and disturb germ cell and other somatic cell development. Our study systematically reviewed the adverse effects of plastic particles on reproductive function and offers valuable insights into the different stages of germ cells and the potential mechanisms. Moreover, the synergistic reproductive toxicity of these particles and carried contaminants was summarized. Given the limited research scale, a shift toward innovative technologies and the adoption of multiple omics are recommended for advancing related studies. Further study is needed to explore the reproductive toxicity of MPs and NPs based on their size, polymer type, shape, and carried toxins, establish effective protective measures, and develop precision medicine for targeted reproductive damage.

Jabbar A, Abdel Aziz Ibrahim I, Almaimani G, AbdulMonam Zainel M, Bamagous GA, Almaimani RA, Almasmoum HA, Ghaith MM, Farrash WF, Almutawif YA. Pinostrobin attenuates azoxymethane-induced colorectal cytotoxicity in rats through augmentation of apoptotic Bax/Bcl-2 proteins and antioxidants

OBJECTIVES

Pinostrobin (5-hydroxy-7-methoxyflavanone; PN) is a natural active ingredient with numerous biological activities extensively utilized in tumour chemotherapy. The present study investigates the chemo-preventive potentials of PN on azoxymethane-mediated colonic aberrant crypt foci in rats.

METHODS

Sprague Dawley rats clustered into five groups, normal control (A) and cancer controls were subcutaneously injected with normal saline and 15 mg/kg azoxymethane, respectively, and nourished on 10% tween 20 and fed on 10% tween 20; reference control (C), injected with 15 mg/kg azoxymethane and injected (intraperitoneal) with 35 mg/kg 5-fluorouracil (5-FU); D and E rat groups received a subcutaneous injection of 15 mg/kg azoxymethane and nourished on 30 and 60 mg/kg of PN, respectively.

RESULTS

The acute toxicity trial showed a lack of any abnormal signs or mortality in rats ingested with 250 and 500 mg/kg of PN. The gross morphology of colon tissues revealed significantly lower total colonic aberrant crypt foci incidence in PN-treated rats than that of cancer controls. Histological examination of colon tissues showed increased aberrant crypt foci availability with bizarrely elongated nuclei, stratified cells and higher depletion of the submucosal glands in cancer controls. PN treatment caused positive modulation of apoptotic (Bax and Bcl-2) proteins and inflammatory cytokines (TNF-α, IL-6 and IL-10). Moreover, rats fed on PN had significantly higher antioxidants (superoxide dismutase) and lower malondialdehyde concentrations in their colon tissue homogenates.

CONCLUSION

The chemoprotective efficiency of PN against azoxymethane-induced aberrant crypt foci is shown by lower aberrant crypt foci values and higher aberrant crypt foci inhibition percentage, possibly through augmentation of genes responsible for apoptotic cascade and inflammations originating from azoxymethane oxidative stress insults.

Carvacrol showed a curative effect on reproductive toxicity caused by Bisphenol AF via antioxidant, anti-inflammatory and anti-apoptotic properties

Bisphenol AF (BPAF) is an endocrine disruptor, and human exposure to these chemicals is growing in industrialized nations. BPAF has been demonstrated in studies to have toxic effects on reproductive health. This study examined the effects of oral exposure to BPAF on the reproductive system and the protective effects of carvacrol in rats. From 32 Wistar albino rats, four separate groups were set up for this purpose. Carvacrol 75 mg/kg and BPAF 200 mg/kg were administered by oral gavage method. Rat sperm parameters and serum testosterone levels were measured after 28 days of administration. The study looked at the MDA in the testis tissues, as well as CAT, GPx, and GSH as antioxidants parameters, NF-κB and TNF-α as inflammatory markers, caspase-3 and Bcl-2 as apoptosis parameters, and PCNA as cell proliferation markers. In addition, testis tissues underwent histological evaluation. As a result, in rats exposed to only BPAF, sperm counts declined, testosterone levels reduced, oxidative stress, inflammation, and apoptosis increased, and cell proliferation decreased. Furthermore, severe disruptions in tissue architecture and decreased spermatogenesis were reported. In contrast, sperm parameters improved, testosterone levels increased, oxidative stress and inflammation decreased, and apoptosis was prevented in the carvacrol-treated group compared to the BPAF-only group. It was also found that spermatogenesis was maintained, and structural abnormalities in testicular tissue were mostly avoided with an increase in PCNA expression. According to the findings, despite BPAF-induced testicular and reproductive toxicity, carvacrol had therapeutic potential due to its anti-inflammatory, antioxidant, cell proliferation-increasing, and anti-apoptotic activities.

Evaluation of possible attenuative role of chrysoeriol against polyethylene microplastics instigated testicular damage: A biochemical, spermatogenic and histological study

The current study was designed to evaluate the protective role of chrysoeriol against polyethylene microplastics (PE-MP) induced testicular damage. Forty eight male rats were distributed into 4 equal groups: vehicle control, PE-MP administrated, PE-MP + chrysoeriol co-administrated and only chrysoeriol supplemented group. The administration of PE-MP significantly reduced the activities of anti-oxidant enzymes, i.e., glutathione peroxidase, catalase, glutathione reductase and superoxide dismutase, whereas the levels of reactive oxygen species and malondialdehyde were increased. PE-MP exposure increased the levels of inflammatory markers (TNF-α, 1L-1β, NF-κβ, IL-6 & COX-2). Additionally, a considerable increase was observed in dead sperms number, abnormality of sperms (tail, midpiece and head), while a potential decrease was noticed in sperm motility in PE-MP treated rats. The expressions of steroidogenic enzymes were also decreased in PE-MP administrated group. The levels of plasma testosterone, luteinizing & follicle stimulating hormone were decreased in PE-MP treated group. Moreover, Bax and Caspase-3 expressions were increased, whereas Bcl-2 expressions were reduced. Furthermore, histopathological analysis showed that PE-MP exposure considerably damaged the testicular tissues. However, chrysoeriol supplementation potentially decreased all the adverse effects induced by PE-MP. Taken together, our findings indicate that chrysoeriol holds significant potential to avert PE-MP-induced testicular damage due to its androgenic, anti-apoptotic, anti-oxidant and anti-inflammatory nature.

Probiotics improve polystyrene microplastics-induced male reproductive toxicity in mice by alleviating inflammatory response

As a new type of environmental pollutant, microplastics have been garnered increasing attention, especially in regard to their effects on the reproductive system. However, researchers have yet to report whether prevention and treatment measures exist for reproductive injury caused by microplastics. The aim of this study was therefore to explore the mechanism of spermatogenic injury induced by polystyrene microplastics (PS-MPs) and the intervention effect of probiotics based on the gut microbiota-testis axis. Mice were orally exposed for 35 days to 5 µm of PS-MPs with a gavage dose was 0.1 mg/day, and the intervention group was given probiotics (Lactobacillus, Bifidobacterium longum, and Enterococcus) orally. Fecal samples were then subjected to 16 S rRNA sequencing analysis, and sperm motion was analyzed by a Hamilton-Thorne Sperm analyzer. The results showed that PS-MPs exposed mice had significant spermatogenic dysfunction and testicular inflammation. In addition, the intestinal microbial structure of exposed mice changed significantly; the abundance of Lactobacillus decreased, and the abundance of Prevotella increased. Furthermore, with fecal microbiota transplantation, the recipient mice showed a significant decrease in sperm quality. However, probiotics supplementation helped inhibit the activation of IL-17A signaling driven by gut microbes, thereby alleviating the inflammatory response and improving sperm quality decline caused by PS-MPs. These results may provide a scientific basis for further understanding of the mechanism of male reproductive damage caused by environmental pollutants such as microplastics and for novel reproductive damage intervention measures.

Attenuative effect of astilbin on polystyrene microplastics induced testicular damage: Biochemical, spermatological and histopathological-based evidences

Polystyrene microplastics (PS-MPs) are the potential environmental pollutants that possess the ability to induce testicular damage. Astilbin (ASB) is a dihydroflavonol, abundantly reported in multiple plants that has various pharmacological properties. This research elucidated the mitigative potential of ASB against PS-MPs-instigated testicular toxicity. 48 adult male rats (200 ± 10 g) were distributed into 4 groups (n = 12): control, PS-MPs received (0.01 mg/kg), PS-MPs + ASB received (0.01 mg/kg + 20 mg/kg) and ASB supplemented group (20 mg/kg). After 56th day of the trial, animals were sacrificed and testes were harvested for the estimation of biochemical, hormonal, spermatogenic, steroidogenic, apoptotic and histological profiles. PS-MPs intoxication significantly (P < 0.05) lowered glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione reductase (GSR) as well as catalase (CAT) activities, whereas elevated MDA as well as ROS levels. Besides, the levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), nuclear factor kappa-B (NF-κB) along with cyclooxygenase-2 (COX-2) activity were raised. PS-MPs treatment reduced luteinizing hormone (LH), plasma testosterone and follicle-stimulating hormone (FSH) level besides decreased epididymal sperm number, viability, motility as well as the count of HOS coil-tailed spermatozoa and increased sperm morphological irregularities. PS-MPs exposure lowered steroidogenic enzymes (17β-HSD, 3β-HSD and StAR protein along with Bcl-2 expression, besides increasing Caspase-3 and Bax expressions and histopathological alterations in testicular tissues. However, ASB treatment significantly reversed PS-MPs mediated damage. In conclusion, ASB administration is protective against PS-MPs-instigated testicular damage owing to its anti-inflammatory, anti-apoptotic, antioxidant and androgenic nature.

The need for environmentally realistic studies on the health effects of terrestrial microplastics

Plastic pollution is now so widespread that microplastics are regularly detected in biological samples surveyed for their presence. Despite their pervasiveness, very little is known about the effects of microplastics on the health of terrestrial vertebrates. While emerging studies are showing that microplastics represent a potentially serious threat to animal health, data have been limited to in vivo studies on laboratory rodents that were force fed plastics. The extent to which these studies are representative of the conditions that animals and humans might actually experience in the real world is largely unknown. Here, we review 114 papers from the peer-reviewed literature in order to understand how the concentrations and types of microplastics being administered to rodents in lab studies compare to those found in terrestrial soils. From 73 in vivo lab studies, and 41 soil studies, we found that lab studies have heretofore fed rodents microplastics at concentrations that were hundreds of thousands of times greater than they would be exposed to in nature. Furthermore, health effects have been studied for only 20% of the microplastic polymers that are known to occur in soils. Plastic pollution is arguably one of the most pressing ecological and public health issues of our time, yet existing lab-based research on the health effects of terrestrial microplastics does not reflect the conditions that free-ranging vertebrates are actually experiencing. Going forward, performing more true-to-life research will be of the utmost importance to fully understand the impacts of microplastics and maintain the public's faith in the scientific process.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s43591-023-00059-1.