Hemato-immunologic impact of subchronic exposure to melamine and/or formaldehyde in mice

Erythrocyte membrane biomimetic EGCG nanoparticles attenuate renal injury induced by diquat through the NF-κB/NLRP3 inflammasome pathway

Diquat (DQ) poisoning can cause multiple organ damage, and the kidney is considered to be the main target organ. Increasing evidence shows that alleviating oxidative stress and inflammatory response has promising application prospects. Epigallocatechin gallate (EGCG) has potent antioxidant and anti-inflammatory effects. In this study, red blood cell membrane (RBCm)-camouflaged polylactic-co-glycolic acid (PLGA) nanoparticles (NPs) were synthesized to deliver EGCG (EGCG-RBCm/NPs) for renal injury induced by DQ. Human renal tubular epithelial cells (HK-2 cells) were stimulated with 600 μM DQ for 12 h and mice were intraperitoneally injected with 50 mg/kg b.w. DQ, followed by 20 mg/kg b.w./day EGCG or EGCG-RBCM/NPs for 3 days. The assessment of cellular vitality was carried out using the CCK-8 assay, while the quantification of reactive oxygen species (ROS) was performed through ROS specific probes. Apoptosis analysis was conducted by both flow cytometry and TUNEL staining methods. Pathological changes in renal tissue were observed. The expressions of NLRP3, IL-1β, IL-18, NFκB and Caspase1 were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunohistochemistry, immunofluorescence, and Western blot. The results showed that the DQ group had increased ROS expression, increased the level of oxidative stress, and increased apoptosis rate compared with the control group. Histopathological analysis of mice in the DQ group showed renal tubular injury and elevated levels of blood urea nitrogen (BUN), serum creatinine (SCr), kidney injury molecule-1 (KIM-1), and cystatin C (Cys C). Furthermore, the DQ group exhibited heightened expression of NLRP3, p-NFκB p65, Caspase1 p20, IL-1β, and IL-18. However, EGCG-RBCm/NPs treatment mitigated DQ-induced increases in ROS, apoptosis, and oxidative stress, as well as renal toxicity and decreases in renal biomarker levels. Meanwhile, the expression of the above proteins were significantly decreased, and the survival rate of mice was ultimately improved, with an effect better than that of the EGCG treatment group. In conclusion, EGCG-RBCm/NPs can improve oxidative stress, inflammation, and apoptosis induced by DQ. This effect is related to the NF-κB/NLRP3 inflammasome pathway. Overall, this study provides a new approach for treating renal injury induced by DQ.

Exposure to melamine and its derivatives in Chinese adults: The cumulative risk assessment and the effect on routine blood parameters

Melamine (MEL) and its derivatives, ammeline (AMN), ammelide (AMD), cyanuric acid (CYA) are widely existed in environmental media. Animal studies have reported the cumulative risk assessment (CRA) of simultaneous exposure to MEL and its derivatives and explored the associations between exposure and routine blood parameters. Such information is largely unknown in human studies. In this study, we detected the urinary concentrations of MEL and its derivatives in 239 Chinese adults to conduct the CRA by evaluating their hazard quotients (HQ) and hazard Index (HI), and also explored the possible associations between exposure and measured routine blood parameters in study population. The detectable frequencies of MEL, AMN, AMD and CYA were 96.65%, 41.00%, 97.91% and 97.07%, respectively. The median values of creatinine (Cr)-adjusted MEL, AMN, AMD, CYA and the total concentrations of MEL and its derivatives (∑MEL) were 11.41 μg/g Cr, not detected (ND), 2.64 μg/g Cr, 15.30 μg/g Cr, 35.02 μg/g Cr, respectively. There were 9 (3.77%) participants with estimated daily intakes (EDIs) of CYA exceeding the tolerable daily intake (TDI) of 2500 ng/kg bw/day, and 12 (5.02%) participants with HI of ∑MEL exposure exceeding 1 based on the strictest TDI value. Urinary concentrations of MEL and its derivatives were positively associated with specific routine blood parameters, including hematocrit, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, white blood cell, neutrophil count (P < 0.05). Meanwhile, exposure to MEL and its derivatives increased the risk of red blood cell abnormality (P < 0.05). Our study is the first study to provide evidence-based data on the CRA of exposure to MEL and its derivatives in Chinese adults, and to propose a possible association between such exposure and routine blood parameters in human.

Prevention of melamine-induced hepatorenal impairment by an ethanolic extract of Moringa oleifera: Changes in KIM-1, TIMP-1, oxidative stress, apoptosis, and inflammation-related genes

BACKGROUND/AIMS

Melamine (ML) is a common food adulterant and contaminant. Moringa oleifera is a well-known medicinal plant with many beneficial biological properties. This study investigated the possible prophylactic and therapeutic activity of an ethanolic extract of M. oleifera (MEE) against ML-induced hepatorenal damage.

METHOD

Fifty male Sprague Dawley rats were orally administered distilled water, MEE (800 mg/kg bw), ML (700 mg/kg bw), MEE/ML (prophylactically) or MEE+ML (therapeutically). Hepatic aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphate (ALP) in serum were measured. Serum total bilirubin, direct bilirubin, indirect bilirubin, protein, albumin, and globulin contents were also assayed, and urea and creatinine levels were determined. Moreover, antioxidant enzyme activity of glutathione peroxidase (GPx) and catalase (CAT) in serum levels were quantified. Complementary histological and histochemical evaluation of renal and hepatic tissues was conducted, and expression of oxidative stress (GPx and CAT) and apoptosis-related genes, p53 and Bcl-2, in hepatic tissue were assessed. In parallel, transcriptional expression of inflammation and renal injury-related genes, including kidney injury molecule 1 (KIM-1), metallopeptidase inhibitor 1 (TIMP1), and tumor necrosis factor alpha (TNF-α) in the kidney tissue were determined.

RESULTS

ML caused significant increases in serum levels of ALT, AST, ALP, total bilirubin, direct bilirubin, indirect bilirubin, urea, and creatinine. Further, ML treated rats showed significant reductions in serum levels of protein, albumin, globulin, GPx, and CAT. Distinct histopathological damage and disturbances in glycogen and DNA content in hepatic and renal tissues of ML treated rats were observed. KIM-1, TIMP-1, and TNF-α gene expression was significantly upregulated in kidney tissue. Also, GPx, CAT, and Bcl-2 genes were significantly downregulated, and p53 was significantly upregulated in liver tissue after ML treatment. MEE significantly counteracted the ML-induced hepatorenal damage primarily for co-exposed rats.

CONCLUSION

MEE could be an effective therapeutic supplement for treatment of ML-induced hepato-renal damage, probably via modulating oxidative stress, apoptosis, and inflammation.

Does melamine exposure during infancy cause rhabdomyolysis?

We investigated the possible toxic effects of melamine on muscle tissue in rats using biochemical, hematological and histopathological methods. We used three groups of female albino Wistar rats. The first group was given 0.1 ml saline. The second and third groups were given 50 and 75 mg/kg melamine dissolved in 0.1 ml saline, respectively, daily for 21 days. On day 45, all rats were sacrificed, and whole blood and plasma were analyzed for hematologic and biochemical characteristics. Muscle samples were stained with hematoxylin and eosin for histopathological investigation. Other sections were immunostained for matrix metalloproteinase-9 (MMP-9) and type IV collagen. We found a significant increase in the lymphocytosis-compliant leukocyte number in the 75 mg/kg melamine group compared to the other groups. We also found significant decreases in the hemoglobin levels and hematocrit values in the 75 mg/kg compared to the other groups. We found that the 75 mg/kg melamine group exhibited a significant increase in plasma aspartate aminotransferase (AST) activity compared to the other groups. Changes in plasma creatine kinase and lactate dehydrogenase activity were not statistically significant. Plasma AST activity and mean corpuscular hemoglobin levels were correlated with the lymphocyte:neutrophil ratio. We found mononuclear cell infiltration at the periphery of muscle bundles and in the connective tissue bundles in the melamine treated group. We found MMP-9 expression in muscle cell membranes and type IV collagen expression in degenerative connective tissue fibers. Whole blood, plasma and muscle tissue analysis indicated that the 75 mg/kg melamine group exhibited rhabdomyolysis that was associated with lymphocytosis and anemia. The underlying mechanisms by which melamine causes rhabdomyolytic effects remain unclear.

Involvement of tumor necrosis factor-α, interferon gamma-γ, and interleukins 1β, 6, and 10 in immunosuppression due to long-term exposure to five common food preservatives in rats

BACKGROUND/AIMS

Food preservatives are abundant in many products in the human environment. However, little is known about the impact of many food preservatives on the immune system and the immune related genes. Hence, this study aimed to evaluate the effects of five widespread food preservatives, including butylated hydroxyanisole (BHA), potassium sorbate (PS), sodium benzoate (SB), boric acid (BA), and calcium propionate (CP), on haemato-immune functions.

METHOD

Sixty Sprague-Dawley rats were assigned to groups orally administered water (control), BHA (0.09 mg/kg), PS (4.5 mg/kg), SB (0.9 mg/kg), BA (0.16 mg/kg) or CP (0.18 mg/kg) for 90 consecutive days. Leukogram and erythrogram profiles were assessed. Nitric oxide and immunoglobulin levels together with phagocytic and lysozyme activities were estimated. Histologic examinations and histomorphometric analysis of splenic tissues were performed. Variations in the mRNA expression levels of tumour necrosis factor alpha (TNF-α), interferon gamma (IFNγ), interleukin (IL)-1β, IL-6, and IL-10 were assessed.

RESULTS

Anemic conditions, thrombocytopenia, leucocytopaenia simultaneous with lymphocytopaenia, monocytopenia, and esinopenia have been obvious following long term exposure to the tested food additives. Prominent exhaustion was noted in immunoglobulin and NO levels and in lysozyme and phagocytic activities. IFNγ, TNF-α, IL-1β, IL-6, and IL-10 were obviously upregulated in the groups exposed to food preservatives.

CONCLUSION

These results confirmed that continued exposure to high levels of BHA, PS, SB, BA, and CP has haematotoxic and immunotoxic effects. Furthermore, these adverse effects are mediated by cytokine production.

Presence of melamine in human milk and the evaluation of the effects on mother–infant pairs in a cohort study

Melamine contamination is a recent public health problem emerging globally. Present study aimed to detect the rate of melamine presence in human milk in a cohort study and to evaluate any possible differences in maternal–infant pair characteristics such as breastfeeding status, crying and sleep problems of infants, maternal postpartum depression, maternal–infant bonding, infant and maternal anthropometry, and maternal complete blood count caused by the melamine exposure. Mothers of infants born in Şanlıurfa were invited to participate in ‘Urfa Child Cohort Survey’. Overall, two breast milk samples were taken between 5 days and 15 days postpartum and between 4 weeks and 10 weeks. Randox Food’s InfiniPlex array was used to analyse the presence of melamine. Melamine was detected in 32.2% and 24.4% of the first and the second milk samples; 16.7% of mothers had two positive samples. z Scores for birth weight and z scores for height for age were detected to be significantly lower in cases with two positive samples compared to cases with negative samples. Mean maternal white blood cells counts were found to be lower in cases with repeated melamine contact. Melamine might have a detrimental effect on birth weight, infant height and maternal blood count. Further studies should be done to detect environmental contamination in different regions and countries.

Derivation of safe exposure levels for potential migration of formaldehyde into food

Polyoxymethylene (POM) is a polymer of formaldehyde used inter alia for kitchenware and food processing machines. By migration into food, consumers may be exposed to small additional amounts of formaldehyde in food. In order to address such potential exposures, Specific Migration Limits are derived using all studies with oral exposure in mammals and birds. The assessment is not only based on local irritation observed in a 2-year rat study that has previously served to calculate acceptable exposure levels, but also on systemic effects, namely on effects on the kidney in adult rats and testes in birds before sexual maturity. At the relatively high oral exposure levels (up to 2000 ppm in drinking water) long-term effects caused by formic acid, the first step metabolite of formaldehyde, such as acidosis, cannot be excluded. The lowest Specific Migration Limit of 2.74 mg/dm², corresponding to 16.5 mg formaldehyde/kg food, is based upon kidney effects in rats, leading to potential exposures that range between 2900 and 4400 times below the endogenous turnover of formaldehyde. Lastly, a recent migration study with POM showed that migration of formaldehyde into food simulants is over an order of magnitude below the lowest Specific Migration Limit derived herein.

Involvement of the anti-inflammatory, anti-apoptotic, and anti-secretory activity of bee venom in its therapeutic effects on acetylsalicylic acid-induced gastric ulceration in rats

Acetylsalicylic acid (ASA) is the most highly consumed pharmaceutical product worldwide. Importantly, gastrointestinal ulceration due to ASA is a major complication. Hence, the present work aimed to examine, for the first time, the healing properties of bee venom (BV) in acute gastric ulceration induced by ASA. Forty adult male Sprague-Dawley rats were divided into four groups that received distilled water only, ASA (500 mg/kg BW) twice daily for 3 days, ASA for 3 days followed by BV (2 mg/kg BW) for 7 days, or ASA for 3 days followed by ranitidine hydrochloride (50 mg/kg BW) for 7 days. Haematological analysis, haemostatic evaluation, and inflammatory marker estimation were performed. Rat stomachs were collected for ulcer scoring, gene expression analysis, oxidative stress assays, histopathological and immunohistochemical examinations, and tissue eosinophil scoring. The results revealed that BV markedly decreased the ulcer index, pro-inflammatory cytokine levels, malondialdehyde levels, BAX distribution, caspase-3 expression, and tissue eosinophil levels. Additionally, significant increases in antioxidant enzymes and heat shock protein 70 localization in gastric tissue were evident following BV treatment after ASA exposure. Also, BV has been found to attenuate the haematological, haemostatic, and histopathological alterations induced by ASA. Our findings collectively indicate that the gastroprotective effect of BV against ASA-induced ulceration in rats is mediated by its antioxidant, anti-inflammatory, anti-apoptotic, and anti-secretory properties.

Imidacloprid Impacts on Neurobehavioral Performance, Oxidative Stress, and Apoptotic Events in the Brain of Adolescent and Adult Rats

Currently, imidacloprid (IMI) is the first insecticide and the second agrochemical highly applied all over the world. Here, we report on the impacts of IMI on neurobehavioral performance, oxidative stress, and apoptotic changes in the brain in either adult or adolescent rats. Forty male rats (adult and adolescent) were allocated to four groups. IMI groups were orally given 1 mg IMI/kg b.wt. dissolved in corn oil, whereas the controls were orally administered corn oil daily for 60 days. The obtained results demonstrated that IMI exposure resulted in less exploratory activity, deficit sensorimotor functions, and high depression. Levels of neurotransmitter including serotonin, gamma-aminobutyric acid, and dopamine were significantly reduced. Oxidative damage of brain tissues was evident following IMI exposure represented by the high levels of protein carbonyl, 8-hydroxyguanosine, and malondialdehyde, but total antioxidant capacity was reduced. Histopathological investigations of the brain tissues of IMI treated group revealed varying degrees of degeneration of the neuron. The immunohistochemical evaluation revealed a strong presence of glial fibrillary acidic protein (GFAP) and Bax positive cells, but a low expression of Bcl-2. These injurious impacts of IMI were very prominent in the adult rats than in the adolescent rats. Conclusively, exposure to IMI even at very low concentration could induce multiple neurobehavioral aberrations and neurotoxic impacts, especially in adults.

Effects of the food additives sodium acid pyrophosphate, sodium acetate, and citric acid on hemato-immunological pathological biomarkers in rats: Relation to PPAR-α, PPAR-γ and tnfα signaling pathway

The food additives sodium acid pyrophosphate (SAPP), sodium acetate (SA), and citric acid (CA) were evaluated for their hemato-immunotoxic effects. Forty adult Sprague-Dawley rats were distributed into four groups and were orally administered water, SAPP (12.6 mg/kg), CA (180 mg/kg), or SA (13.5 mg /kg) daily for 90 days. Erythrogram and leukogram profiles were evaluated. The levels of lysozyme, nitric oxide, immunoglobulin, and phagocytic activity were measured. Histologic and immunohistochemical evaluations of splenic tissues were performed. Changes in the mRNA expression levels of peroxisome proliferator-activated receptor α and γ (PPAR-α and PPAR-γ), and tumor necrosis factor α (TNF-α) genes were assessed. A significant leukopenic condition was observed with SAPP, while CA induced marked leukocytosis, and SA showed a lymphocytosis condition. Both the innate and humoral parameters were significantly depressed. Various pathological lesions were observed, including diffuse hyperplasia of the red pulp, depletion of the white pulp, and capsular and parenchymal fibrosis. A marked decrease in CD3 T-lymphocyte and CD20 B-lymphocyte immunolabeling in rats treated with SAPP and SA was evident. Marked downregulation of PPAR-α and PPAR-γ together with upregulation of TNF-α was recorded. These results indicate that high doses of SAPP, SA and CA exert hematotoxic and immunotoxic effects with long-term exposure.

Palliative effects of Moringa olifera ethanolic extract on hemato-immunologic impacts of melamine in rats

Melamine (MEL) is a widespread food contaminant and adulterant. Moringa olifera is a widely known medicinal plant with various pharmacological properties. Herein, this study aimed to investigate, for the first time, the probable protective or therapeutic role of M. olifera ethanolic extract (MOE) against MEL induced hemato-immune toxic hazards. Fifty Sprague Dawely male rats were orally treated with distilled water, MOE (800 mg/kg bw), MEL (700 mg/kg bw), MOE/MEl or MOE + MEl. Erythrogram and leukogram profiling were evaluated to assess hematological status. Innate immune functions were evaluated via measuring lysozyme levels, nitric oxide concentration, and bactericidal activity of phagocytes. Serum immunoglobulin levels were estimated as indicators of humoral immunity. Histologic and immunohistochemical evaluations of splenic tissues were also performed. The results indicated that MEL caused a significant decline in RBC, Hb, PCV, total WBC, neutrophil, lymphocyte, phagocytes bactericidal activity, lysozyme activity, nitric oxide, total IgM and IgG levels. Also, MEL induced various pathologic lesions in the spleen with strong expression of CD4 and CD8 positive cells. MOE significantly counteracted the former anaemic, leucopenic, innate and humoral depressant effects of MEL particularly at co-exposure. In conclusion, these findings revealed that MOE could be candidate therapy against MEL hemato-immunotoxic impacts.

Melamine, beyond the kidney: A ubiquitous endocrine disruptor and neurotoxicant?

Melamine is commonly used in a variety of consumer products such as furniture, dining ware, and food utensils. The chemical infamously gained worldwide attention by its illegal addition to a variety of foodstuffs in order to falsify protein content, which led to serious, sometimes fatal, health impacts in children and pets. This resulted in a large amount of published primary studies and reviews of the impacts of melamine exposure on kidney function. However, a growing body of literature suggests that melamine may have impacts beyond renal dysfunction. We conducted a scoping review of this literature which yielded more than 40 studies with human, animal, and in vitro findings. Neurological impacts, reproductive function, and anthropometric outcomes were identified as possible candidates for systematic review based on evidence stream and replication of endpoints. The results of this analysis provide a basis for prioritizing future research on health impacts associated with melamine exposure.

Pulmonary apoptotic and oxidative damaging effects of Triclosan alone or in combination with Fluoride in Sprague Dawley rats

This study aimed to assess the potential apoptotic and oxidative damaging impacts of Triclosan (TCS) and Sodium Fluoride (NaF) administered separately or in combination, in rats for thirty days. For this purpose, forty immature female Sprague-Dawley rats were equally allocated into five groups. TCS group administered 185mg TCS/kg Bw dissolved in distilled water (DW), while its control group received only DW. NaF group was given 50mg/kg NaF in corn oil BW and its respective control had corn oil alone. The co-treated group was administered TCS and NaF. The oxidative stress biomarkers were evaluated in lung tissue homogenate and apoptotic proteins (BcL-2 and Caspase-3) expression were quantified in lung tissues. The results of TCS or NaF treated groups revealed a prominent depletion of super oxide dismutase (SOD), Catalase (CAT) and Glutathione (GSH) in lung tissue homogenate. On contrary, a marked increase in the tissue levels of Malondialdehyde (MDA) and lactate dehydrogenase (LDH) enzymatic assay levels. The co-exposed group evoked less severity in the oxidative stress biomarkers concentration than individually exposed groups. The apoptotic genes protein expression was significantly higher in TCS or NaF treated rats when compared to the control with intense to moderate immunolabeling of the bronchiolar lining epithelium and surrounding mononuclear inflammatory cells. On the contrary, no significant differences were detected in the expression of the investigated apoptotic biomarkers between the control and the combined exposed group. We concluded that the exposure to either TCS or NaF resulted in significant perturbations in lung tissue after short term oral administration at variable instances but the co-exposure resulted in less severe toxicological consequences.

Effects of hesperidin on formaldehyde-induced toxicity in pregnant rats

This experimental study aimed to investigate the protective effect of a bioflavonoid, hesperidin (HP), on formaldehyde (FA)-related pathophysiological and behavioral outcomes in pregnant rats and developmental aspects in their offspring. Female Wistar rats were subjected to perigestational exposure to FA (2 mg/kg/day per os) with a concomitant treatment with HP (50 mg/kg/day per os). Pregnant rats were weighed throughout gestation and tested in two behavioral paradigms (elevated plus-maze and open field) at gestational days (GD) 1, 10 and 19 to evaluate the anxiety-like behavior and locomotive alterations. Another subset of rats was decapitated at GD19 to determine the hematological profile along with cortisol, 17β-estradiol, and progesterone plasma levels. Reproductive and fetal measures and observations were also performed to check for developmental deformities. Significant body weight loss, hemato-immune decline, hormonal changes, anxiety and lethargy signs, locomotor disabilities, reproductive failure and fetal weight decrease were observed in FA-exposed rats. Treatment with HP alleviated the reproductive and fetal weight defects. Its behavioral benefits were only seen at GD1 and 10. This flavanone ameliorated some hematological parameters, decreased cortisol levels and increased 17β-estradiol rates. A potential preventive impact of HP was found against FA toxicity in pregnant rats.