Prosopis africana exerts neuroprotective activity against quaternary metal mixture-induced memory impairment mediated by oxido-inflammatory response via Nrf2 pathway.

The beneficial effects of Prosopis africana (PA) on human health have been demonstrated; however, its protective effects against heavy metals (HM) are not yet understood. This study evaluated the potential neuroprotective effects of PA in the cerebral cortex and cerebellum. To accomplish this, we divided 35 albino Sprague Dawley rats into five groups. Group I did not receive either heavy metal mixture (HMM) or PA. Group II received a HMM of PbCl2 (20 mg/kg), CdCl2 (1.61 mg/kg), HgCl2 (0.40 mg/kg), and NaAsO3 (10 mg/kg) orally for a period of two months. Groups III, IV, and V received HMM along with PA at doses of 500, 1000, and 1500 mg/kg, respectively. PA caused decreased levels of HM accumulation in the cerebral cortex and cerebellum and improved performance in the Barnes maze and rotarod tests. PA significantly reduced levels of IL-6 and TNF-α. PA increased concentrations of SOD, CAT, GSH, and Hmox-1 and decreased the activities of AChE and Nrf2. In addition, levels of MDA and NO decreased in groups III, IV, and V, along with an increase in the number of live neurons. In conclusion, PA demonstrates a complex neuroprotective effect with the potential to alleviate various aspects of HM-induced neurotoxicity.

Selenium and zinc protect against heavy metal mixture-induced, olfactory bulb and hippocampal damage by augmenting antioxidant capacity and activation of Nrf2-Hmox-1 signaling in male rats.

PURPOSE/AIM OF THE STUDY: Heavy metals and metalloids have been implicated in neurodenerative diseases. Present study has evaluated the potential protective effects of Se and Zn on heavy metals and metalloids mixture-induced (Cd, Pb, Hg and As) toxicity in the hippocampus and olfactory bulb in male rats. MATERIALS AND METHODS: Five groups of Wistar rats were randomly divided in to: controls, toxic metals mixture (TMM) exposed rats (PbCl2, 20 mg·kg-1; CdCl2, 1.61 mg·kg-1; HgCl2, 0.40 mg·kg-1 and NaAsO3, 10 mg·kg-1)), TMM + Zn, TMM + Se and TMM-+Zn + Se groups and were orally treated for 60 days. RESULTS: We found that in hippocampus and olfactory bulb, TMM generated increased lipid peroxidation and diminished antioxidant capacity. These adverse effects induced by TMM were alleviated by Zn and Se co-treatment; moreover, essential trace elements (Zn and Se) decreased activity of acetylcholinesterase, reduced Cd, Pb, Hg and As bioaccumulation in hippocampus and olfactory bulb and decreased levels of TNF-α in the hippocampus. TMM treated rats had lower levels of Hmox-1 (hippocampus), higher levels of Nrf2 (olfactory bulb and hippocampus) and NF-kB (olfactory bulb). TMM treated rats showed significantly highest time in locating the escape hole. Histopathological examination revealed hypertrophied granule cells in OB of TMM exposed rats. CONCLUSION: Zn and Se supplementation can reverse quaternary mixture-induced (Cd, Pb, Hg and As) toxicity in hippocampus and OB in male albino rats.

Polycyclic Aromatic Hydrocarbons in Soil and Vegetation of Niger Delta, Nigeria: Ecological Risk Assessment.

The Niger Delta, Nigeria, is noted for crude oil exploration. Whereas there seems to be a handful of data on soil polycyclic aromatic hydrocarbon (PAH) levels in this area, there is a paucity of studies that have evaluated soil and vegetation PAHs simultaneously. The present study has addressed this information gap. Fresh Panicum maximum (Jacq) (guinea grass), Pennisetum purpureum Schumach (elephant grass), Zea mays (L.) (maize), and soil samples were collected in triplicate from Choba, Khana, Trans-Amadi, Eleme, Uyo, and Yenagoa. PAHs determination was carried out using GC-MS. The percentage composition of the molecular weight distribution of PAHs, the molecular ratio of selected PAHs for identification of possible sources, and the isomeric ratio and total index of soil were evaluated. Pennisetum purpureum Schumach (elephant grass) from Uyo has the highest (10.0 mg·kg-1) PAH while Panicum maximum (Jacq) (guinea grass) has the highest PAH (32.5 mg·kg-1 from Khana. Zea mays (L.) (maize) from Uyo (46.04%), Pennisetum purpureum Schumach (elephant grass) from Trans-Amadi (47.7%), guinea grass from Eleme (49.2%), and elephant grass from Choba (39.9%) contained the highest percentage of high molecular weight (HMW) PAHs. Soil samples from Yenagoa (53.5%) and Khana (55.3%) showed the highest percentage of HMW PAHs. The total index ranged 0.27-12.4 in Uyo, 0.29-8.69 in Choba, 0.02-10.1 in Khana, 0.01-5.53 in Yenagoa, 0.21-9.52 in Eleme, and 0.13-8.96 in Trans-Amadi. The presence of HMW PAHs and molecular diagnostic ratios suggest PAH pollution from pyrogenic and petrogenic sources. Some soils in the Niger Delta show RQ(NCs) values higher than 800 and require remediation to forestall ecohealth consequences.

Essential Trace Elements Prevent the Impairment in the Retention Memory, Cerebral Cortex, and Cerebellum Damage in Male Rats Exposed to Quaternary Metal Mixture by Up-regulation, of Heme Oxygynase-1 and Down-regulation of Nuclear Factor Erythroid 2-related Factor 2-NOs Signaling Pathways.

In the present study, we examined adverse effects of metals and metalloids in the Cerebral cortex (CC) and Cerebellum (CE). Group 1 comprised from the controls while other four groups of male Wistar rats were treated with following pattern: Group II (Heavy Metal Mixture HMM only: PbCl2, 20 mg·kg-1; CdCl2, 1.61 mg·kg-1; HgCl2, 0.40 mg·kg-1, and NaAsO3,10 mg·kg-1), Groups III (HMM + ZnCl2); Group IV (HMM + Na2SeO3) and Group V (HMM + ZnCl2 + Na2SeO3) for 60 days per os. HMM promoted oxidative stress in the CC and CE of treated rats compared to controls; moreover, exposure to HMM led to increased activity of the AChE and pro-inflammatory cytokines; also, HMM promoted accumulation of caspase 3 and other transcriptional factors such as Nrf2 and decreased levels of Hmox-1. Essential metals reduced increased bioaccumulation of Pb, Cd, As and Hg in CC and CE caused by HMM exposure. Also, all mentioned adverse effects were diminished by essential metals treatment (Se and Zn). HMM exposed rats had considerably less escape dormancy than controls. Histopathological analysis revealed moderate cell loss at the intermediate (Purkinje cell) and granular layer. Zinc and selenium supplementations could reverse adverse effects of heavy metals at various cellular levels in neurons.

Arsenic and toxic metals in meat and fish consumed in Niger delta, Nigeria: Employing the margin of exposure approach in human health risk assessment.

This study provides information on the health risk of As, Cd, Hg, Pb and V exposure from Nigerian foods consumption (fish, cow, goat and chicken meat) in different age-groups (children, adolescent, adult, senior) and six areas of Niger Delta, Nigeria (Choba, Khana, Eleme, TransAmadi, Uyo, and Yenogoa). The health risk assessment was performed by estimating the weekly or monthly intake of metals from foods and Margin of Exposure (MOE) approach by using established benchmark dose levels (BMDLs). Regarding As, cow and chicken meat products contributed to As exposure intake especially in children resulting in values higher than BMDL0.1 for cancer risk in TransAmadi and Uyo areas. Cadmium exposure was due to cow, chicken and goat meat ingestion mostly in adolescent above the tolerable monthly intake limit in TransAmadi and Uyo areas. Concerning Hg and V, the exposure from Nigerian food did not constitute a potential health hazard. Lead exposure in children were above or close to BMDL0.1 for developmental neurotoxicity by ingestion of cow and goat meat in all the Nigerian areas. In adult and senior the Pb dietary exposure were above the BMDL10 providing a low to negligible risk for kidney effects. The potential concern for health effects in Niger Delta population needs further efforts to decrease As, Cd and Pb dietary exposure especially for children and adolescent, who are more vulnerable to adverse life events.

Concentrations of polycyclic aromatic hydrocarbons in samples of soil, feed and food collected in the Niger Delta region, Nigeria: A probabilistic human health risk assessment.

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed compounds with two or more fused aromatic ring, being some of them classified as carcinogenic. In the present study, the concentrations of 16 PAHs and the sum of them (∑PAHs) were determined in samples of food, feed, plant and soil collected in six different heavily polluted areas (Choba, Khana, Trans Amadi, Eleme, Uyo and Yenagoa) of the Niger Delta Region (Nigeria). Principal component analysis (PCA) was then used to identify groups of variables (PAHs) and groups of samples that were the best in rendering the environmental pollution in that Region of Nigeria. In addition, PAHs food consumption and the derived carcinogenic risks were assessed in a probabilistic way. The highest ∑PAHs (mg/kg) were: 16.7 in cow meat, 8.06 in goat meat, 25.4 in chicken meat, 7.72 in fish, 28.70 in fish feed, 15.3 in chicken feed, 8.42 in plant, and 8.80 in soil. In most of the Nigerian areas, cooked cow meat, chicken and chicken feed presented the highest impact regarding PAHs contamination. The highest intake of PAHs was through meat consumption, with a very high and unassumable carcinogenic risk, which is quite above 10-5 for some PAHs, including benzo [a]pyrene. The results of the present survey highlight the importance of reducing PAHs content in food, specially in meat, in the Niger Delta region.

Multi-organ protective effect of Costus afer on low concentration toxic metal mixture in albino rats.

Heavy metal mixture can induce multiple organ damage through oxidative stress and inflammatory processes. Dietary intervention using natural antidotes in resource poor countries where classical metal chelators are either not affordable or available can be explored as an alternative means of management of public health effects of chronic heavy metal exposure. The search for natural antidote against the deleterious effects of heavy metals gives the thrust for this study. Thus, the study investigated the effect of aqueous leaf extract of Costus afer on liver, kidney, brain and testis induced by low dose heavy metal mixture (LDHMM) of PbCl2, CdCl2 and HgCl2 of concentrations of 20 mg/kg, 1.61 mg/kg and 0.40 mg/kg, respectively. Five groups of seven rats each (weight-matched) were used. First and second groups received deionized water and heavy metal mixture and served as normal and toxic controls, respectively. Groups 3, 4 and 5 received through oral gavage 750, 1500, 2250 mg/kg of the Costus afer extract respectively, with the metal mixture concurrently. All treatments were four times a week for 90 days (4/week/90 days). Hepatorenal, hormonal, oxidative stress markers, cytokines (interleukin-6 and interleukin-10), and heavy metals (Pb, Cd and Hg) concentrations were assayed. The one-way analysis of variance, agglomerative hierarchical clustering, parallel coordinates plot, principal component analysis and Bray Curtis dissimilarity were used to statistically analyze the data. LDHMM caused significant changes in these organs and however, the plant extract provided a protective effect against these pathological changes. The statistical analysis revealed that the kidney was the most affected organ, followed by the liver, then brain and testis, respectively. Costus afer may be an important nutraceutical in multi-organ deleterious effects of LDHMM following its regulation of oxidative stress markers, inflammatory cytokines and biometal chelation.

Metal pollution of soil, plants, feed and food in the Niger Delta, Nigeria: Health risk assessment through meat and fish consumption.

This study was aimed at determining mainly the concentrations of As and other metals (Cd, Cu, Hg, Pb, V and Zn) in samples of feed, soil, plants and foods (fish, chicken, goat and cow meat) grown and consumed in six areas of Niger Delta, Nigeria (Choba, Khana, Trans Amadi, Eleme, Uyo and Yenagoa). Principal Component Analysis (PCA) models were used for identifying groups of variables (i.e., elements) based on the loadings and groups of samples (i.e., plants, soil, fish, meet, feed) according to the scores that contributed most to the environmental pollution in each Nigerian area. In Choba and Khana sites, the results showed a cluster of elements like As, Pb, V and Zn, mostly associated with samples of goat and cow meat, as well as soils, and separated from another cluster of metals composed by Cu and Hg with different origin. In Trans Amadi area, a clustering of As, Cd and V was found associated to different types of meat (chicken, goat, and cow) located in the opposite side of Cu and Hg, which correlated to plants and soil. In Eleme, the strongest loadings were obtained for V and Zn associated with soil and meat (goat and cow) samples and separated from As and Cd. Finally, in Uyo and Yenagoa, dominant elements were As, Cu, Pb and Zn, with proximity to cow and goat liver samples, while Cd and V corresponded to a different pollution pattern. Lead intake trough meat and fish consumption for adults and children were much higher than the tolerable limits set by international organizations. The results of this study should allow a better understanding of the complex phenomenon of metal pollution in the feed-to-food chain and human health in Nigeria, which should help to manage a pollution reduction strategy and give priorities of research and monitoring.

Protective Effect of Costus afer Aqueous Leaf Extract (CALE) on Low-Dose Heavy Metal Mixture-Induced Alterations in Serum Lipid Profile and Hematological Parameters of Male Wistar Albino Rats.

The present work investigated the protective effects of Costus afer Ker Gawl. aqueous leaf extract (CALE) on lipid profile and hematological changes induced by exposure to low-dose heavy metal mixture in male albino rats. The experimental animals were divided into six weight matched groups. The normal (group 1) and toxic (group 2) controls received deionized water and metal mixture (20 mg/kg PbCl2, 1.61 mg/kg CdCl2, and 0.40 mg/kg HgCl2), respectively. Test rats in groups 3, 4, and 5 were treated with metal mixture and CALE (750, 1500, and 2250 mg/kg, respectively), and group 6 received metal mixture and ZnCl2. All treatments were administered through oral gavage for 12 weeks. LDHMM caused a marked increase (p < 0.05) in cholesterol, triglyceride, low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) levels and a decrease in high-density lipoprotein (HDL), percentage body weight gain, and feed and fluid intake. Also, a significant decrease in RBC, Hb, and PCV, a significant increase in WBC, and no significant increase in platelet PLT were observed in the metal mixture-treated group. But in CALE treated groups, their levels were found to attain almost normal values as found in normal control which is also similar to the zinc-treated group. Costus afer may hold a promise in improving lipid profile and hemodynamic picture in cardiovascular diseases.

Neuroprotective effect of Costus afer on low dose heavy metal mixture (lead, cadmium and mercury) induced neurotoxicity via antioxidant, anti-inflammatory activities.

Humans are constantly exposed to heavy metals due to their ubiquity in the environment. Hence, this study investigated the possible protective effect of Costus afer aqueous leaf extract (CALE) against low dose heavy metal mixture (LDHMM)-induced neurotoxicity. Male albino rats were divided into 6 equal groups. Group 1 served as the normal control receiving only deionized water. Group 2 served as the toxic control receiving on metal mixture (20 mg/kg PbCl2, 1.61 mg/kg CdCl2 and 0.40 mg/kg HgCl2), groups 3, 4 and 5 were co-treated with metal mixture and CALE (750, 1500 and 2250 mg/kg body weight, respectively) and group 6 was treated with metal mixture and ZnCl2. All treatments were administered through oral gavage for 90days. Oxidative stress biomarkers [malondialdehyde (MDA), superoxide dismutase (SOD), glutathione content (GSH) and catalase (CAT)], inflammatory cytokines [interlukin-6 (IL-6) and interlukin-10 (IL-10)], histopathological changes and heavy metal concentration were determined in brain of rats. Results indicated that LDHMM significantly increased (p < 0.05) the lipid peroxidation marker (MDA) and the pro-inflammatory cytokine (IL-6), while lowered levels of the oxidative biomarkers (SOD, CAT and GSH) and anti-inflammatory cytokine (IL-10). Also, LDHMM caused some histopathological changes such as reactive gliosis and glia cell proliferation. LDHMM elevated the lead, cadmium and mercury concentrations in the brain. Severity of the distorted cortical parameters were ameliorated by CALE administration. The CALE induced significant protective effect on LDHMM-mediated neurotoxicity in a dose-dependent manner which may be a result of its antioxidant anti-inflammatory and metal chelation mechanisms.

Low-dose heavy metal mixture (lead, cadmium and mercury)-induced testicular injury and protective effect of zinc and Costus afer in wistar albino rats.

The study evaluated the protective effect of Costus afer on low-dose heavy metal mixture (LDHMM)-mediated effects in the testis of albino rats. The weight-matched animals were divided into six groups: normal control, metal mixture of (PbCl2  + CdCl2 + HgCl2 ), combination of metal mixture + Costus afer at 750 mg/kg, combination of metal mixture + Costus afer at 1,500 mg/kg, combination of metal mixture + Costus afer at 2,250 mg/kg and combination of metal mixture + (ZnCl2 ). LDHMM reduced (p < .05) the antioxidant biomarkers (superoxide dismutase, SOD; catalase, CAT; and glutathione, GSH) and increased (p < .05) the lipid peroxidation marker (malondialdehyde, MDA) and lead, cadmium and mercury concentrations in the testis. Treatment with LDHMM increased (p < .05) abnormal sperm morphology and plasma prolactin (PRL) level and decreased epididymal sperm count, viability, follicle-stimulating hormone (FSH), luteinising hormone (LH) and testosterone. LDHMM exposure caused deleterious changes in the testis. Treatment of rats with Costus afer (750, 1,500 and 2,250 mg/kg) dose-dependently reduced (p < .05) the LDHMM-mediated toxicity. Treatment with Costus afer also reversed the testicular weight and LDHMM decrease in antioxidant biomarkers. Costus afer may be a defensive modulator of LDHMM-mediated testicular lesions.