Airway inflammation and related respiratory complaints are common symptoms among waste management workers (WMWs). This study investigated the relationship between exposure to municipal solid waste (MSW) and the levels of inflammatory markers and oxidative stress among WMW of Ogun State, South West Nigeria. A total of 280 subjects consisting of 180 WMW and 100 controls were recruited. Ten millilitres of blood were collected from antecubital vein of the subjects for analysis. Results reveal that exposure to MSW is associated with systemic inflammation and oxidative stress. Significant (p < 0.001) elevation of ceruloplasmin (Cp) and C-reactive protein was associated with marked decreases in superoxide dismutase (p < 0.01), catalase (p < 0.001), and glutathione (p < 0.05) and significant (p < 0.001) increases in malondialdehyde (MDA) and uric acid when compared with control. Haematological disorders include significant (p < 0.05) decreases in haemoglobin, packed cell volume, and mean corpuscular volume and significant (p < 0.01) increase in total leucocyte count. Apart from decreased albumin (p < 0.05) and elevated aspartate aminotransferase (p < 0.05) activity observed in WMW, other markers of hepatic (alanine aminotransferase, alkaline phosphatase, total cholesterol and triglycerides) and renal (urea and creatinine) functions did not change significantly (p > 0.05) when compared with the control. A positive correlation between leucocytes (r = 0.195, p < 0.01), Cp (r = 0.210, p < 0.01) and job duration and between Cp and MDA (r = 0.200, p < 0.01) and Cp and leucocytes (r = 0.260, p < 0.001) were observed in WMW. Overall, exposure to MSW predisposes to systemic inflammation and oxidative stress and Cp may be a useful biomarker for monitoring health status of Nigerian WMWs.

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Cyclooxygenase-2 (COX-2) expression and prostaglandin production are suggested to play important, complex roles in the pathogenesis of various liver diseases. Studies on the effects of COX-2 inhibitors on the progression of liver fibrosis present controversial results, and the proposed therapeutic potential of these agents in chronic liver disease is predicated largely on their effectiveness in modulating hepatic stellate cell activation in vitro. This study investigated the modulatory effect of celecoxib, a selective COX-2 inhibitor, in CCl(4)-mediated hepatotoxicity in rats. Thirty Wistar albino rats, weighing 120-180 g, were assigned into five groups of 6 rats/group. Groups 1 and 2 received saline (10 mL/kg) and CCl(4) (80 mg/kg), respectively. Group 3 was given celecoxib (5.7 mg/kg), whereas groups 4 and 5 were pretreated with 2.9 and 5.7 mg/kg/day of celecoxib, respectively, 1 hour before CCl(4) treatment. Plasma aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities increased significantly by 118.5, 150.0, and 51.3%, respectively, with an accompanying decrease (P < 0.05) in total protein and albumin after CCl(4) treatment. Hepatotoxicity was associated with a significant increase in plasma cholesterol, hepatic lipid peroxidation (LPO), and severe hepatic necrosis with marked fatty and cellular (i.e., mononuclear cells) infiltration. Although celecoxib neither reduced CCl(4)-induced increases in marker enzymes of hepatotoxicity nor significantly attenuated hepatic necrosis, it, however, was effective in reducing elevated cholesterol by 16.5 and 20.8% and LPO by 12.9 and 35.5% at 2.9 and 5.7 mg/kg, respectively. Data suggest that COX-2 inhibitors may be effective in controlling hypercholesterolemia and peroxidative changes associated with liver injury.

The renin-angiotensin system (RAS) subserves vital physiological functions and also implicated in certain pathological states. Modulation of this system has been proposed in recent studies to be a promising strategy in treating liver fibrosis. We investigated the effect of the pharmacologic inhibition of RAS with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in CCl4-induced liver injury with a view to ascertaining the chemopreventive benefit. Fifty-six Wistar albino rats were divided into eight experimental groups of seven rats/group. Groups 1–4 received normal saline (10 ml/kg), enalapril (0.6 mg/kg), losartan (1.4 mg/kg) and CCl4 (80 mg/kg), respectively. Groups 5–8 were pretreated with enalapril (0.3 mg/kg), enalapril (0.6 mg/kg), losartan (0.7 mg/kg) and losartan (1.4 mg/kg) 1 hour before CCl4 administration. Experiment lasted 11 days and dosing was via oral route. Rats were killed 24 hours after the last treatment. Serum activities of alkaline phosphatase, aspartate and alanine aminotransferases increased significantly ( p < 0.05) by 46.0%, 90.6% and 122.3%, respectively, with severe hepatic centrilobular necrosis, fatty infiltration and increase in liver weight ( p < 0.05) in the CCl4-treated rats. Enalapril (0.6 mg/kg) and losartan (1.4 mg/kg) significantly ( p < 0.05) increased aspartate aminotransferase activity by 37.0% and 94.7% and produced mild centrilobular and periportal hepatic necrosis, respectively, with enalapril significantly ( p < 0.05) increasing liver weight. Serum total cholesterol, triglyceride, albumin and total protein did not change significantly in these rats. Also, glutathione, malondialdehyde and uric acid levels were not significantly altered. Enalapril and losartan failed to attenuate liver injury associated with CCl4 treatment. Although both drugs did not significantly alter serum biochemistry in the CCl4-treated rats, they however produced slight elevations in biomarkers of liver function and appear to worsen liver histopathology. Overall, the chemopreventive benefits of RAS inhibitors in liver disease remain doubtful and should be used with caution during hepatic dysfunction.

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Waste management workers (WMWs) around the world are at risk of work-related health disorders. The influence of employment duration on individuals occupationally exposed to solid waste was investigated in this study. The study comprised (n = 280) 180 WMWs and 100 controls. Employment duration was obtained from questionnaire survey and categorized into three groups: group I (0.5-2 years), group II (>2-4 years) and group III (>4-6 years). Blood sample (10 ml) was collected from the antecubital vein of subjects for analysis. WMWs exhibited significantly (p < 0.001) elevated inflammatory markers (erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and ceruloplasmin (Cp)) relative to control. While Cp increased, ESR and CRP decreased with increasing WMWs' employment duration. Alteration in oxidant/antioxidant markers was characterized by significant (p < 0.001) decrease in ferric-reducing ability of plasma (FRAP) and catalase activity together with marked (p < 0.01) elevation of thiobarbituric acid reactive substances (TBARS) and uric acid (UA). TBARS, UA and FRAP increased while catalase decreased with WMWs' employment duration. In addition, WMWs exhibited significantly (p < 0.01) elevated immunoglobulin A (IgA) and IgG, which also increased and decreased, respectively, with job duration. The significantly (p < 0.01) decreased haemoglobin and haematocrit levels as well as the significantly (p < 0.001) elevated total leukocytes in WMWs increased with employment duration. Alanine aminotransferase increased and albumin decreased significantly (p < 0.05) in WMWs, and these changes also increased and decreased, respectively, with job duration. Data suggest that levels of alteration of important systemic markers of health/disease are related to WMWs' employment or exposure duration.

BackgroundThe global increase in acceptance and use of herbal remedies in recent times is still accompanied with poor knowledge of their potential adverse effects and the toxicological implications of their use are underestimated.MethodsBon-santé Cleanser® (BSC), a polyherbal containing Anogeissus leiocarpus, Terminalia ivorensis, Massularia acuminate and Macuna pruriens, is an “energizer and hormone booster”. We assessed the effect of BSC on reproductive function after administration for 60 days in male Wistar rats. Rats (150–300 g) were assigned into four groups of 8/group. Control received distilled water (10 ml/kg) while other groups received BSC 250, 500 and 1000 mg/kg/day p.o. respectively. Animals were euthanized by cervical dislocation and samples collected for analysis.ResultsBSC (250 mg/kg) elevated (p < 0.05) follicle stimulating hormone and luteinizing hormone levels respectively. BSC decreased sperm motility and the live-dead ratio at 1000 mg/kg and reduced reproductive hormone at 500 mg/kg and 1000 mg/kg respectively. BSC at 500 mg/kg increased (p < 0.05, F = 3.18–13.21) testicular reduced glutathione level (50.3%) and catalase (43.7%) but not activities of superoxide dismutase, glutathione S-transferase, and malondialdehyde level. Further, BSC influenced Mg, Zn, Cu, P, Mn, Ni and Fe levels (p < 0.05). BSC (1000 mg/kg) decreased testis weight (p < 0.05) and induced mild inflammation characterized by atrophic tubules.ConclusionOverall, our data suggest BSC at low doses may increase reproductive hormones regulated by FSH and LH as observed in this study. However, BSC administration should be done with caution as it may induce reproductive toxicity in large doses.

Recent studies have indicated an increased incidence of toxic neuropathies among waste management workers (WMW) possibly linked to increased detection of heavy metals in municipal solid wastes. The present study evaluated serum levels of some heavy and essential trace metals in relation to oxidant/antioxidant status of WMW. One hundred and twenty-six WMW and 84 non-WMW (control) were recruited. Metal/element concentration was measured by atomic absorption spectrophotometry and oxidant/antioxidant markers were determined using standard procedures. The WMW exhibited significantly ( p < 0.001) decreased ferric reducing ability of plasma (FRAP) and higher levels of ceruloplasmin (Cp) and malondialdehyde. Iron (Fe) and copper (Cu) levels were significantly lower ( p < 0.05) and higher ( p < 0.001), respectively in WMW when compared with control while levels of other trace elements were not significantly different between these groups. Lead (Pb) and chromium levels were significantly higher ( p < 0.001 and p < 0.05, respectively) in WMW while mercury levels were comparable with those of control subjects. In WMW, Cp ( r = -0.182; p > 0.05) and FRAP ( r = 0.277; p < 0.05) negatively and positively correlated with Pb, respectively, while a positive correlation was observed between zinc ( r = 0.230; p < 0.05) and Pb and between Cu ( r = 0.541; p > 0.001) and Fe. Overall, the decreased antioxidant capacity and increased oxidative stress observed in WMW in this study may be related to their blood levels of heavy and essential trace metals. Conscious efforts are required, therefore, to reduce risk and protect WMW from toxic neuropathies and other adverse health consequences of occupational exposure.