Neuroprotective effect of dietary black seed flour on key enzymes linked with neuronal signaling molecules in rats exposed to mixture of environmental metals

Neurotoxic effects of low dose ranges of environmental metal mixture in a rat model: The benchmark approach

Metals exert detrimental effects on various systems within the body, including the nervous system. Nevertheless, the dose-response relationship concerning the administration of low doses of metal mixtures remains inadequately explored. The assessment of neurotoxic effects of lead, cadmium, mercury, and arsenic mixture (MIX) administered at low dose ranges, was conducted using an in vivo approach. A subacute study was conducted on a rat model consisting of a control and five treatment groups subjected to oral exposure with gradually increasing doses (from MIX 1 to MIX 5). The results indicated that behavioural patterns in an already developed nervous system displayed a reduced susceptibility to the metal mixture exposure with tendency of higher doses to alter short term memory. However, the vulnerability of the mature brain to even minimal amounts of the investigated metal mixture was evident, particularly in the context of oxidative stress. Moreover, the study highlights superoxide dismutase's sensitivity as an early-stage neurotoxicity marker, as indicated by dose-dependent induction of oxidative stress in the brain revealed through Benchmark analysis. The narrowest Benchmark Dose Interval (BMDI) for superoxide dismutase (SOD) activity (1e-06 - 3.18e-05 mg As/kg b.w./day) indicates that arsenic may dictate the alterations in SOD activity when co-exposed with the other examined metals. The predicted Benchmark doses for oxidative stress parameters were very low, supporting "no-threshold" concept. Histopathological alterations were most severe in the groups treated with higher doses of metal mixture. Similarly, the brain acetylcholinesterase (AChE) activity demonstrated a dose-dependent decrease significant in higher doses, while BMDI suggested Cd as the main contributor in the examined metal mixture. These findings imply varying susceptibility of neurotoxic endpoints to different doses of environmentally relevant metal mixtures, advocating for risk assessment and regulatory measures to address metal pollution and enhance remediation strategies.

The First Evidence on the Occurrence of Bisphenol Analogues in the Aqueous Humor of Patients Undergoing Cataract Surgery

Human exposure to BPs is inevitable mostly due to contaminated food. In this preliminary study, for the first time, the presence of bisphenols (BPs) in aqueous humor (AH) collected from 44 patients undergoing cataract surgery was investigated. The measurements were performed using a sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC−MS/MS). Chromatographic separation was achieved using a reverse-phase column and a gradient elution mode. Multiple reaction monitoring (MRM) was used. The method was validated for bisphenol A (BPA) and bisphenol F (BPF). The limits of quantification (LOQs) of both investigated analytes were 0.25 ng mL−1. The method was linear in the range of 0.25−20.0 ng mL−1 with correlation coefficients (R2) higher than 0.98. Recovery of analytes was in the range of 99.9 to 104.3% and intra-assay and inter-assay precision expressed by relative standard deviations (RSD%) were less than 5%. BPA was detected in 12 AH samples with mean concentrations of 1.41 ng mL−1. BPF was not detected at all. Furthermore, two structural isomers termed BPA-1, and BPA-2 were identified, for the first time, in 40.9% of the AH samples, with almost twice higher mean concentrations of 2.15 ng mL−1, and 2.25 ng mL−1, respectively. The total content of BPs were higher in patients with coexisting ocular pathologies such as glaucoma, age-related macular degeneration (AMD), and diabetes in comparison to cataracts alone. However, the difference between these groups did not reach statistical significance (p > 0.05). Performed investigations indicate the need for further research on a larger population with the aim of knowing the consequences of BPs’ accumulation in AH for visual function.

Meta-inhibition of ocular and gastrointestinal dysfunctions by phenolic-rich fraction of Croton zambsicus leaves in a rat model exposed to chronic mixed metals

PURPOSE

This study was aimed at investigating the protective effect of antioxidant-rich fraction of Croton zambsicus (C-ZAMB) leaves on ocular-gastrointestinal dysfunction in rats exposed to environmental mixed-metal (EOMABRSL).

MATERIALS AND METHODS

The rats were divided into five (n = 10) groups. Group I designates the control which received 0.5 mL of distilled water. Group II and III received 0.5 mL of EOMABRSL for 98 days (non-withdrawal) and 70 days (withdrawal for 28 days), respectively. Group IV received 0.5 mL EOMABRSL for 70 days and 400 mg/kg C-ZAMB fraction for 28 days. Group V received 400 mg/kg C-ZAMB only for 28 days via oral route.

RESULTS

Exposure of the animals to EOMARBSL for 98 days and 70 days significantly up-regulated the activities of ocular-gastrointestinal aldolase-reductase, α-amylase, α-glucosidase and eco-5¹-nucleotidase with corresponding depletion of lactate dehydrogenase activity. Furthermore, exposure to EOMABRSL significantly altered the antioxidant proteins with up-production of MDA content. Apparently, management with 400 mg/kg C-ZAMB fraction significantly inhibited the key markers linked with ocular-gastrointestinal disorders.

CONCLUSION

Hence, this study underscores the biochemical mechanisms for managing ocular-gastrointestinal lesions by 400 mg/kg C-ZAMB fraction on exposure to mixture of environmental metals.

Lycopene suppresses palmitic acid-induced brain oxidative stress, hyperactivity of some neuro-signalling enzymes, and inflammation in female Wistar rat

Neuroinflammation can be triggered by certain high caloric nutrients such as palmitic acid (PA). The effect of lycopene against PA-induced neuroinflammation in female rats has not been as explored. In the present study, thirty rats (weighing 150–200) g were randomly allotted into six groups (n = 5) comprising normal control, PA control, PA + lycopene (0.24 mg/kg), PA + lycopene (0.48 mg/kg), lycopene (0.24 mg/kg), and lycopene (0.48 mg/kg), respectively. After seven weeks of PA challenge (5 mM) including two weeks of lycopene treatment, the brain was excised for analyses. Palmitic acid overload caused significant (p < 0.05) increases in adenosine deaminase, monoamine oxidase-A, nucleotides tri-phosphatase, 5′-nucleotidase, acetylcholine esterase, and myeloperoxidase activities, and malondialdehyde (MDA) levels which were reduced significantly in the lycopene-treated groups. Conversely, catalase and glutathione peroxidase activities, and reduced glutathione levels concentration decreased by 43%, 34%, and 12%, respectively in the PA control groups compared with the Control. Also, PA triggered a decrease in the brain phospholipids (11.43%) and cholesterol (11.11%), but increased triacylglycerol level (50%). Furthermore, upregulated expressions of Interleukin-1β, Interleukin-6, and NF-ĸB-p65 in the PA control were attenuated, while decreased Interleukine-10 expression was upregulated due to lycopene treatment. Severe brain vacuolation observed in the histology of the PA control rats was normalized by lycopene. This study concludes that lycopene ameliorated PA-induced neuroinflammation, probably via attenuation of oxidative stress, and downregulation of TLR4/ NF-κB -p65 axis.

Modulation of Cardiopulmonary Toxicity and Oxidative Stress by Phenolic-Rich Fraction of Croton zambiscus Leaves in Rat Exposed to Chronic Mixture of Environmental Toxicants

Chronic mixed toxicant exposure has been implicated in the aetiology of lung and heart failure through prolonged free radical generations. This study was carried out to assess the protective effect of naturally occurring phenolic components from Croton zambesicus (400 mg/kg C-ZAMB) leaves against cardiopulmonary toxicity induced by chronic mixed toxicant (0.5 mL EOMABRSL) in rats. Chronic cardiopulmonary injury via oral administration of 0.5 ml EOMABRSL for 98 days (non-withdrawal) and 70 days (withdrawal) caused unhealthy alteration in the levels of oxidative stress biomarkers [malondialdehyde (MDA), reduced glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD) and catalase]. Similarly, both withdrawal and non-withdrawal approaches of EOMABRSL-exposed animals exhibited increase in the activity of eco-51-nucleotidase (51ENT) with corresponding diminution in the activity of lactate dehydrogenase (LDH), i.e. the metabolic fuel for cardiopulmonary wellness. Ultimately, histology examination confirmed hyperplastic, bronchopneumonia and cloudy swelling of cardiovascular cells followed by the accumulation of cellular exudates and haemorrhage in the alveoli and bronchioles. The active antioxidants of 400 mg/kg C-ZAMB leaves were responsible for the biological protection of cardiopulmonary toxicity by modulating the activities of 51ENT and LDH. The oxidative stress was also reversed by 400 mg/kg phenolic C-ZAMB leaves in the heart and lungs. Hence, 400 mg/kg phenolic C-ZAMB leaves may be a natural therapy for the treatment of cardiovascular disorder associated with pulmonary dysfunction in rats.

Naringin attenuates Bisphenol-A mediated neurotoxicity in hypertensive rats by abrogation of cerebral nucleotide depletion, oxidative damage and neuroinflammation

We examined whether active fruit naringin can reduce the risk of BPA-mediated neurotoxicity in L-NAME induced hypertensive rats and whether the modulation could be linked to improvement of brain NO signaling. Male albino rats were randomly distributed into eight (n = 7) groups. Group I was control animals, Group II was orally-treated with L-NAME, Group III was orally treated with 100 mg/kg BPA, Group IV was orally-treated with L-NAME +100 mg/kg BPA. Group V was orally-administered with L-NAME +80 mg/kg NAR. Group VI was orally-administered with 100 mg/kg BPA +80 mg/kg NAR. Group VII was orally-administered with L-NAME+100 mg/kg BPA +80 mg/kg NAR. Lastly, group VIII was orally-treated with 80 mg/kg NAR. The treatment lasted for 14 days. Sub-acute exposure to L-NAME and BPA induced hypertension and mediated-neuroinflammation at CA-2 and CA-4 of hippocampus cells. It was evident by increase in PDE-5¹ and enzymes of ATP hydrolysis (ATPase, ADPase and AMPase) with corresponding upsurge in cholinergic (AChE and BuChE), dopaminergic (MAO-A) and adenosinergic (ADA) enzymes as well as movement disorder. The hypertensive-mediated neurotoxicity was related to alteration of NO signaling and higher release of pro-inflammatory cytokines (TNF-α and IL-1β), apoptotic proteins (P53 and caspace-9) and facilitated entry of T-lymphocytes (CD43⁺) into CNS through blood brain barrier potentiated by antigen presenting cells. Hence, these features of BPA-mediated neurotoxicity in L-NAME induced hypertensive rats were prohibited by co-administration of NAR through production of neuro-inflammatory mediators, stabilizing neurotransmitter enzymes, normalizing NO signaling and improving brain histology.

Naringin protects against Bisphenol-A induced oculopathy as implication of cataract in hypertensive rat model

People who have experienced high blood pressure are at greater risk of susceptibility to other health problems including oculopathy. The patients with these experiences do not have adequate treatment and those who do; spend much funds on the drug purchase. The study examines the protective effect of naringin (NRG) against ocular impairment in _L-NAME induced hypertensive rat on exposure to a cellular disruptor. Fifty-six adult male albino rats were randomly distributed into eight (n = 7) groups. Group I: control animals, Group II was treated with Nω-nitro-L-arginine methyl ester hydrochloride (_L-NAME), Group III was treated with 50 mg/kg Bisphenol-A, Group IV was treated with _L-NAME +50 mg/kg Bisphenol-A. Group V was administered with _L-NAME +80 mg/kg NRG. Group VI was administered with 50 Mg/kg BPA + 80 mg/kg NRG. Group VII was administered with _L-NAME+50 mg/kg Bisphenol-A +80 mg/kg NRG. Lastly, group VIII was treated with 80 mg/kg NRG alone for 14 days. Naringin prevented hypertension and ocular dysfunction by depleting the activities of angiotensin-converting enzymes, arginase, aldose-reductase and phosphodiesterase-5¹ (PDE-5¹) with corresponding down-regulation of inflammatory markers including TNF-α and IL-B. Moreover, ocular impairment was remarkably reduced by NRG as manifested by the decreased activities of AChE, BuChE, MAO-A and enzymes of ATP hydrolysis (ATPase, ADPase, AMPase) and adenosine deaminase with resultant increased NO level. Also, ocular expression of CD43 transcript, caspaace-9 and tumor suppressor P53 proteins were suppressed on treatment with NRG. This study corroborates the view that NRG may be a useful therapy in alleviating inflammatory markers, apoptosis and metabolic nucleotides disorders via the NOS/cGMP/PKG signaling pathways in hypertensive rat model on exposure to a cellular disruptor.

Rat liver and kidney post-mitochondrial dysfunction by addition of chronic mixed metal intoxication and hepatorenal wellness mediated by phenolic components from Croton zambiscus leaves

Chronic exposure of mixed-metal intoxication has been associated with prolonged oxidative stress and severe hepatorenal damage. This present study demonstrates the hepatoprotective and renoprotective activity of Croton zambesicus (C-ZAMB) leaves, naturally occurring phenolic compounds against chronic mixed-metal (EOMABRSL) induced toxicity. 0.5 ml of EOMABRSL via oral route induced chronic hepatoxicity and nephrotoxicity on exposure for 98 days (non-withdrawal) and 70 days (withdrawal) by abnormal alteration in the levels of endogenous antioxidants. Moreover, EOMABRSL induced hepatorenal damage by increasing the markers of liver toxicity (ALT, AST, ALP, GGT and bilirubin) and kidney failure (creatinine, urea, uric acid, and renal electrolytes-Na⁺ and K⁺). Both non-withdrawal and withdrawal approaches of EOMABRSL-exposed animals exhibited hepatorenal dysfunctions by increasing the activity of eco-5¹-nucleotidase (5¹ENT) followed by the decreased in the activity of lactate dehydrogenase (LDH)-index of cellular ATP. These results were further supported by the histopathological examination of nephritic cells, hepatocytes and splenocytes, manifested by hepatocellular necrosis, swelling or degeneration of tubular kidney epithelial cells as well as coalescing splenic periarteriolar lymphoid sheaths (PALSs) and lymphoid haemosiderin. The chronic EOMABRSL intoxication was ameliorated by administration of phenolic antioxidants from C-ZAMB leaves. Therefore, our study supports the view that phenolic C-ZAMB leaves may mediate hepatorenal wellness on chronic exposure to mixed-metal intoxication.

Metabolic treatment of syndrome linked with Parkinson's disease and hypothalamus pituitary gonadal hormones by turmeric curcumin in Bisphenol-A induced neuro-testicular dysfunction of wistar rat

The metabolic shift in cholinesterase activity and inhibitor of hypothalamus pituitary gonadal hormones were hypothesized as resultant effect of Parkinson's disease (PD) which is clinically characterized by a movement disorder. This study therefore examined the effect of turmeric curcumin (CUR) on index of PD, acetylcholine esterase activity and disorder of hypothalamus pituitary gonadal hormone (HPGH) in Bisphenol-A induced injury using animal model. Forty adult male albino rats were randomly distributed into five (n = 8) groups. Group I: vehicle control (olive oil 0.5 ml), Group II was given 50 mg/kg of BPA only, Group III was given 50 mg/kg BPA + 50 mg/kg curcumin, Group IV was given 50 mg/kg BPA + 100 mg/kg curcumin and Group V was administered 50 mg/kg of curcumin only for 14 days. The study examined the effect of curcumin on acetylcholineesterase (AChE) activity, nitric oxide radical (NO•) production, HPGH (LH, FSH and testosterone), MDA level, antioxidant enzymes (SOD and CAT), in BPA induced male rat. Sperm parameters were similarly examined. The animals induced with BPA exhibited impairment to striatum, leydig cells and sertoli cells by depleting LH, FSH, testosterone and spermatozoa with reduced AChE activity and significant (p < 0.05) alteration in cerebral enzymatic antioxidants. Locomotive activity was impeded followed by the increase of brain NO• level (marker of pro-inflammation). Therapeutically, CUR promoted hypothalamus-pituitary-testicular hormones via modulation of AChE and locomotive activities, reduction of intracellular NO• level, prevention of striatum-endocrine injury as well as oxidative damage. Hence, CUR abolished HPGH dysfunction linked with PD mediated by BPA in rat.