Table 1 Effects of microplastics on the animal reproductive system
Organism | Sample size | Type of MPs | Particle size | Dose | Exposure duration | Exposure method | Employed experimental methods | Influenced pathway | Outcomes | Reference |
|---|---|---|---|---|---|---|---|---|---|---|
A) Rat and mice experimental models | ||||||||||
Wistar rat | 32 | PS-MPs | 0.5 μm | 0, 0.015, 0.15 and 1.5 mg/kg/d | 90 days | Drinking deionized water with microplastics | - TEM observation - Hematoxylin-eosin (HE) staining - Protein extraction - Immunohistochemistry - ELISA - Fluorescence microscopy - TUNEL staining - Flow cytometry - Western blot assays | NLRP3/Caspase-1 signaling pathway, Oxidative stress | Involvement in apoptosis and pyroptosis of granulosa cells in the ovary through the NLRP3/Caspase-1 signaling pathway; decrease in the levels of SOD, CAT, and GSH-Px, AMH, and increase in the levels of MDA, IL-1β, and IL-18 | [46] |
Wistar rat | 32 | PS-MPs | 0.5 μm | 0, 0.015, 0.15 and 1.5 mg/kg/d | 90 days | Direct drinking deionized water with microplastics | - Hematoxylin-eosin (HE) staining - TEM observation - ELISA - Flow cytometry - Immunohistochemistry - Masson’s trichrome and Sirius red staining - Enzyme assay - Western blot assays | Wnt/β-Catenin signaling pathway, Oxidative stress | Ovarian fibrosis and pyroptosis through the Wnt/β-Catenin signaling pathway, apoptosis in granulosa cells, decrease in ovarian reserve capacity and AMH levels, reduction growing follicles number, and upregulation of TGF-β, fibronectin, Wnt, β-catenin, p-β catenin, and α-SMA | [21] |
Wistar rat | 30 | PS-MPs | 876 nm | 2.5, 5, and 10 mg/kg/d | 45 days | Gavage | - ELISA - Folin phenol method - Enzyme assay - Compound microscopy | Inflammation, oxidative stress, metabolic and endocrine disruption | Increase the serum level of NF-κB and IL-6, decrease the catalase and SOD activity in the ovary, increase oxidative stress in the ovary, alteration of lipid profile, and increase the levels of FSH, T, and E2 | [50] |
Wistar rats Rattus norvegicus | 21 | PS-MPs | 5 μm | 0, 0.1 mg/d | within 24–26 days (four estrus cycles) | Oral gavage | - RNA extraction - Hematoxylin-eosin (HE) staining - Optical microscopy - Immunofluorescence - Enzyme assay - Estradiol assay - RT-PCR | Oxidative stress and disturbance of cytoskeleton | Change in the folliculogenesis and estrous cycle duration, decrease in ovarian weight, decrease in the levels of serum E2, increase in the levels of MDA and CAT and Sod, decrease in the levels of PSH in the ovary, and a significant decrease in DAAM-1 and α-tubulin expression in ovary | [51] |
Time-pregnant Sprague Dawley rats | 21 | PS-NPs | 21.86 nm ± 0.026 | 2.64 × 1014 particles in 300 µl | Only once before the experimental operation | Intratracheal instillation | - Fluorescent Optical Imaging - Fluorescence spectroscopy - Hematoxylin-eosin (HE) staining | Reproductive and developmental health | A significant decrease in placental and fetal weight, particle accumulation in the placenta, maternal heart, lung, and spleen, and maternal lung-to-fetal tissue nanoparticle translocation | [29] |
C57BL/6 mice | 40 | PS-MPs | 5.0–5.9 μm | Saline and 0.1 mg/d | 30 or 44 days | Gavage | - ELISA - SEM microscopy - Fluorescence microscopy - Fluorescence spectroscopy - Hematoxylin-eosin (HE) staining | Oxidative stress, Reproductive and developmental health | PS-MP accumulation and oxidative stress in the ovary, reduction in the size of ovary and number of follicles, decreased the rate of pregnancy and produced fewer embryos, increase in the levels of LH, T, and FSH, decrease in the levels of E2 | [24] |
C57BL/6 mice | 32 | PS-MPs and Pb | 100 nm | 0.1 to 2 g/day | 28 to 35 days | Gavage | - Hematoxylin-eosin (HE) staining - Optical microscopy - RT-qPCR - Fluorescent microscopy - Immunofluorescence (IF) assay - Immunohistochemistry (IHC) assay - Sex hormone analysis and oxidative stress analysis | Oxidative stress, PERK/eIF2α signaling pathway | Histopathological damage in the uterus and ovaries, increase in serum MDA levels, and decrease in sex hormone levels and serum SOD, increase ER stress in the ovary by activating the PERK/eIF2α signaling pathway, which leads to apoptosis, induced oxidative stress, and decreased the quality of the oocyte | [52] |
SPF C57BL mice | 30 | PS-NPs and PS-MPs | 100Â nm and 1000Â nm | 10Â mg/mL solution | 1 to 17 gestational days | Intragastric gavage | - Fluorescence imaging - Fluorescence microscope - Immunofluorescent staining - TUNEL assay - RNA-sequencing - Optical microscopy - Hematoxylin-eosin (HE) staining - RNA extraction - qPCR - TEM microscopy - ELISA - Enzyme assay - Cell culture - Western blotting - Flow cytometry - Bioinformatic analysis | Reproductive and developmental health | Accumulation of particles in the uterus, brain, alimentary tract, and placenta in maternal mice | [53] |
C57BL/6-mated BALB/c mice | 18 | PS-MPs | 10 μm | 250 µg/ 200 µL saline | 11 days | intraperitoneally injection | - RNA extraction - Flow cytometry - Hematoxylin-eosin (HE) staining - qRT-PCR | Immune disturbance | Spontaneous abortion | [33] |
Balb/C nude mice with human EOC cell line HEY | 16 | PS-NPs | 100Â nm | 10Â mg/L/d | 27 days | Drinking water with PS-NPs | - Hematoxylin-eosin (HE) staining - Cell culture - Confocal microscopy - Cell wound healing analysis - Transcriptional assay - RNA extraction - RNA sequencing - RT-qPCR - Bioinformatics analysis | Alteration in tumor growth microenvironment | Increased EOC tumor growth, reduction in the relative viability of EOC cells via changing the microenvironment of tumor growth, increase in mitotic counts in EOC tumor tissues, immune-related responses, and the tumor microenvironment pathway | [54] |
ICR mice | 60 | PS-NPs | 50Â nm | 0, 5, 25Â mg/kg/d | 8 weeks | Intragastric administration (Gavage) | - Hematoxylin-eosin (HE) staining - Fluorescence microscopy - Enzyme assay - Cell viability assay - ELISA - Flow cytometry - Immunofluorescence staining - Western blotting - TUNEL assay | Nrf2 signaling pathway, Oxidative stress | Increase in oxidative stress and apoptosis levels, decrease in the quantity of offspring, cell viability, and the occurrence of cell cycle arrest, decrease in the ovarian reserve capacity, increase in a higher ratio of metestrus and diestrus phases, and decrease in proportion of the estrous phase | [55] |
ICR Mice | 20 | PE-MPs (modified to contain acid and hydroxy groups) | 40–48 μm | 0, 3.75, 15, or 60 mg/kg body weight-day | 123 days | Gavage | - Hematoxylin-eosin (HE) staining - TEM observation - Flow cytometry | Reproductive and developmental health | Increase in the number of abnormal neonates, dilation of the abdominal aorta and fallopian tubes in parent mice, decrease in the number of live births, alteration in body weight and sex ratio of the pups, and increase in the proportion of neutrophils in the blood | [56] |
ICR Mice | Conducted in triplicates using 20 fertilized embryos for each one replica and for control | PS-MPs | 0.7918 ± 0.00273 and 0.7939 ± 0.00282 μm | 30 mg/kg body weight-d | 35 days | Oral gavage | - Fluorescence spectroscopy - ELISA - Fluorescence microscopy - Light microscopy - Laser scanning confocal microscope - Parthenogenic activation -MMP and ATP assay - qRT-PCR | Inflammation and oxidative stress | Increase in the IL-6 level, decrease in MDA levels in the ovary, GSH and MMP and [Ca2+] ER reduction, increase in ROS levels, and reduced the first polar body extrusion rate and the survival rate of superovulated oocytes | [57] |
Kunming mice | 60 | PE-MPs | 10–150 μm | 0.4, 4, and 40 mg/kg/d | 30 days | Daily oral doses | - Immunofluorescence (IF) staining - Breeding assay - Fluorescence microscope - Enzyme assay - Apoptosis assay | Oxidative stress, DNA damage, Reproductive and developmental health | A decrease in the oocyte maturation and the rate of fertilization, development of embryo, and fertility, increased the level of ROS in oocytes and embryos, resulting in oxidative stress, dysfunction of mitochondrial, and apoptosis, causing the damage of DNA in oocytes | [58] |
Mice | 12 | PS-MPs | 5–10 μm | 0.01 mg to 1 g | 42 days | Drinking | - Optical microscopy - Immunohistochemistry - Fluorescence microscopy - Western blotting - Intracellular ROS assay - Real-time quantitative PCR analysis | TLR4/NOX2 signaling pathway, Oxidative stress, Notch and TGF-β signaling pathway | Endometrial thinning and severe collagen fiber deposition, increased the expression of HMGB1 and acetyl-HMGB1, activating the TLR4/NOX2 signaling pathway and increase cause oxidative stress, activation of Notch and TGF-β signaling pathway, and increase in the levels of fibrotic proteins and collagen, | [22] |
B) Other species | ||||||||||
Drosophila melanogaster | Continued exposure of 5 generations | PS-NPs | 100 nm | 1, 10, 50, and 100 mg L−1 | 5 days | PS-NPs solution mixed with the standard cornmeal fly feed | - Fluorescence microscopy - RNA extraction and transcriptome sequencing - qRT-PCR - Transcriptome analysis | Reproductive and developmental health | PS-NPs accumulation in the crop, gut, and ovaries, decrease in the number of egg production and eclosion rate, and delay in development | [59] |
Caenorhabditis elegans | - | PS-MPs | 0.01 to 2 μm | 0.1 to 100 µg/L | 28 days | Environmental exposure | - SEM microscopy - XPS - FTIR - Fluorescence microscopy - RT-qPCR | DNA damage, Apoptosis, Reproductive and developmental health | Increased the number of HUS-1::GFP foci and the gene expression essential for DNA damage, including egl-1, and cep-1, clk-2, proposing DNA damage induction, the number of cell corpses and apoptosis-related gene expression (e.g., ced-9, ced-4, and ced-3) were changed, suggesting the apoptosis induction | [60] |
Folsomia candida | 20 | PE-MPs | < 500 μm | ≥ 0.1% w/w in dry soil | 28 days | Artificial soil contaminated with MPs | - Counting - DNA extraction - PCR - Sequencing | Reproductive health | Reduction in reproduction by 70.2% | [61] |
Oysters | 240 | PS microsphere (Micro-PS) | 2 and 6 μm | 0.023 mg/L | 2 months | Particles were supplied continuously to the tanks by peristaltic pumps from a concentrated micro-PS solution, maintained in a glass flask on a magnetic stirrer | - Electronic particle counting - Flow Cytometry - Gamete Quality Analyses - Inverted microscopy - Protein Extraction and Proteomic Analysis - RNA Extraction, Amplification, Labeling, and Microarray Hybridization - Preprocessing and Microarray Data Analysis | Reproductive health, feeding modifications | Substantial reductions in oocyte number (-38%) and diameter (-5%), Alterations in feeding behavior, and reproduction impairment in oysters with outstanding influences on offspring, revealed molecular signatures of endocrine disruption | [62] |
Zebrafish | 12 | PS-MPs + MT | 5 μm | 0 or 50 ng L-1 MT, 0.5 mg∙L-1 PS-MPs, or 50 ng∙L-1 MT + 0.5 mg∙L-1 PS-MPs | 7, 14, and 21 days | adding an equal concentration of MT and PS-MPs to the aquatic environment in which they are placed | - Hematoxylin-eosin (HE) staining - Light microscopy - RNA extraction and cDNA synthesis - qRT-PCR - ELISA - Stereomicroscopy | Disruption of gene expression and hormone levels, reproductive health | Increase in the ratio of mature oocytes, a decrease in the levels of E2, LH, and FSH in the (after 14 d of exposure), reduction in cyp11a mRNA expression in all groups after 7 days but an increase in StAR and cyp19a1a mRNA expression in MT + PS-MPs group after 14 days | [63] |
Zebrafish (Danio rerio) | 3 | PS-MPs | 1 μm | 10, 100, and 1000 µg/L | 21 days | The exposure was performed in a flow through system | - µ-FT-IR - Infrared Microscopy - Fluorescence microscopy - TUNEL assay - ROS levels analysis - Hematoxylin-eosin (HE) staining - qPCR | histological alterations, Reproductive and developmental health | ROS levels significantly enhanced in gonads and liver (At concentrations above 100 µg/L), Alteration in histological and molecular response in gonads of fish | [64] |
Carp | 30 | PE-MPs | 8 μm | 1000 ng/L | 21 days | - | - Hematoxylin-eosin (HE) staining - TUNEL assay - Fluorescence microscopy - Enzyme assay - RT-PCR - UV spectrophotometry - Western blotting - ELISA | TRAF6/NF-kB signaling pathway, Oxidative stress, inflammation | Inflamed ovarian tissues and impaired oocyte development, elevated apoptosis in ovarian cells, reduced miR-132 expression alongside increased CAPN expression, heightened calcium ion concentration in tissues leading to increased CAPN enzyme activity, raised expression of genes associated with mitochondrial damage, and lowered expression of genes that inhibit apoptosis. Changes in the levels of bcl-2, caspase-3, Bax, AIF, and bcl-xl, activation of the p65 factor via the TRAF6/NF-kB pathway leading to increased production of pro-inflammatory factors IL-1β, IL-6, and TNF-α, which contribute to the development of ovarian inflammation | [65] |
Marine medaka (Oryzias melastigma) | 20 | PS-MPs | 10 μm | 0, 2, 20, and 200 µg/L | 60 days | A semistatic system with daily seawater replenishment | - Light microscopy - Oxidative stress analysis - Hematoxylin-eosin (HE) staining - qPCR | Oxidative stress, HPG axis alteration | Histological changes, oxidative stress, disruption of HPG axis, imbalance in sex hormone, delayed development of reproductive glands and decreased fecundity (2, 20, and 200 µg/L), downregulation of the genes involved in the steroidogenesis pathway, decrease in E2 and T | [66] |
Daphnia magna | 200 individuals/pe treatment | PE-MPs | 34.43 ± 13.09 μm and 17.23 ± 3.43 μm | 5 mg/L | 7 days | particles with a latex bead-like shape in the aquatic environment in which they are placed | - Fluorescence microscopy | Reproductive and developmental health | Reduced reproductive output was noted in particles of smaller sizes, resulting in a decrease in the number of offspring | [67] |
Daphnia magna | - | nano-PS beads | 70Â nm | 0.22 and 103Â mg nanoPS/L | 21 days | Through the aquatic environment in which they are placed | - Microscopy - Spectrophotometry | Reproductive and developmental health | Reduced population growth, malformation changes, reduced body size and reproduction | [68] |
Daphnia magna | 20 | Pristine polymer microspheres | 1–5 μm | 0.1 mg/L | 21 days | Exposure to powder | - Fluorescence microscopy | Growth, reproductive and developmental health | Parental mortality, reduced growth, decreased reproduction, and decline in population growth rate ultimately led to the extinction of the model population exposed to microplastics in the F1-F3 generations. It takes a minimum of three generations to mitigate the reproductive and developmental abnormalities caused by this exposure | [69] |
Poecilia reticulata | 60 | PS-NPs | 23.03 ± 0.266 nm | 50 µg/L | 30 days | Semi-static exposure system | - ELISA | Reproductive health | A decrease in the pregnancy rate, fewer offspring being produced, the transfer of these nanomaterials from mother to offspring, and physiological impacts on the offspring | [70] |
Oryzias melastigma | 5 replicates in F and NF groups each including 30 larvaes | PS microspheres | 10–11 μm | 1 × 105 particles/L | 120 days | Stock PS suspension in artificial seawater in which animals are placed | - Microscopy - MPs content analysis - Fluorescence microscopy | Reproductive and developmental health | Decreased rate of egg production, reduced reproduction, and slowed growth, accompanied by elevated mortality | [71] |
Japanese medaka (Oryzias latipes) | Three replicate tanks (n = 60) were randomly assigned to each treatment group | PS-MPs | 10 μm | 500, 1000, or 2000 µg/g | 10 weeks | mixed with ultrapure water and then put in a glass tube | - SEM microscopy - ATR-FTIR spectroscopy - Gel permeation chromatography - X-ray photoelectron spectroscopy (XPS) - EPR spectroscopy | Oxidative stress | Reduced egg number in a dose- dependent way | [72] |
Tigriopus japonicus | 200 | PE-MPs and polyamide-nylon 6 (PA 6) | 10–30 μm and 5–20 μm | 12.5 mg/L | 24 h | In artificial seawater in which animals are placed | - SEM microscopy - Fluorescence microscopy | Reproductive and developmental health | Detrimental effects on feeding, egestion, reproduction, survival in a dose-dependent manner, and damage to reproductive organs | [73] |
Tigriopus japonicus | 10 | PS-MPs | 0.05, 0.5, and 6 μm | 1.25–25 µg/mL | 24 h | In artificial seawater in which animals are placed | - Fluorescence microscopy - Oxidative stress analysis - Acute and chronic toxicity tests | Oxidative stress, Reproductive and developmental health | Decrease in fecundity at all concentrations, and caused the mortality in the F0 generation at a concentration greater than 12.5 µg/mL | [74] |
Calanus helgolandicus | 60 | PS-MPs beads | 20 μm | 75 beads/mL | 9 days | glass bottles were filled with either control or microplastic enriched stock solution | - Dissecting microscopy - Analysis of carbon - Ingestion rate, respiration rate, survival rate, egg production rate and egg size determination | Reproductive and developmental health | Decrease in reproductive output, reduced reproductive fertility, eggs with smaller size, and reduced percentage of eggs that successfully hatch | [75] |