The Protective Role of Procyanidins and Lycopene Against Mercuric Chloride Renal Damage in Rats

Objective This study aims to investigate the protection of procyanidins and lycopene from the renal damage induced by mercuric chloride.Methods Rats were treated with either procyanidins or lycopene 2h before HgCl 2 subcutaneously injection,once daily treatment for 2 successive days.Results In comparison with HgCl 2 group,markers of renal function such as blood urea nitrogen in serum and urinary protein were decreased to （18.45±11.63） mmol/L and （15.93±9.36） mmol/L,（4.54±0.78） g/（g Cr） and （4.40±1.12） g/（g Cr）.N‐acetyl‐beta‐D‐glucosaminidase,lactate dehydrogenase,alkaline phosphatase in urine were depressed to （125.49±11.68） U/（g Cr）,（103.73±21.79） U/（g Cr）,（101.99±12.28） U/（g Cr）,and （113.19±23.74） U/（g Cr）,（71.14±21.80） U/（g Cr）,（73.64±21.51） U/（g Cr） in procyanidins and lycopene groups.Indicators of oxidative stress,for example,Glutathion was reduced to （45.58±9.89） μmol/（g pro） and （45.33±5.90） μmol/（g pro）,and antioxidant enzymes such as superoxide dismutase,glutathione‐peroxidase were enhanced to （43.07±10.97） U/（mg pro） and （39.94±6.04） U/（mg pro）,（83.85±18.48） U/（mg pro）,and （85.62±12.68） U/（mg pro）.Malondialdehyde was lowered to （0.95±0.12） （μmol/g pro） and （1.03±0.12） μmol/（g pro） in procyanidins and lycopene groups.ROS generation was decreased by 27.63% and 16.40% and apoptosis was also decreased in procyanidins and lycopene groups respectively.Pathological changes were much better as well.Conclusion Procyanidins and Lycopene play some protective role against mercury kidney damage.

Effect of Short-Term Exposure to Mercuric Chloride on the Air-Breathing Catfish,Heteropneustes fossilis──Ⅱ.Scanning Electron Microscopic Study of the Gill

Alterations in the respiratory epithelium of gills of a catfish, Heteropneustes fossilis by the sublethal and lethal concentrations of HgCl2 have been observcd using scanning electron microscope. Fish exposed to 0.1 ppm shows a thin coat ot mucus, but the continuous layer of mucus is not retained in 0.3 ppm after 24 h of exposure. Epithelial cells of the gill filament are hyperplastic. Other changcs in the respiratory epithelium are contraction of epithelium, formation of interlamellar bridge and diminishing number of microridges. Massive destruction of the respiratory epithelium by deep lesions and sloughing of epithelial layer in 0.5 and 1.0 ppm solutions after 6-12 h of exposure apparently causes death to the fish. SEM observations are well in conformity with the findings made at light microscopic level

Effect of mercuric chloride on membrane-bound enzymes in rat testis

Aim: To study the effect of mercuric chloride on the membrane-bound enzymes. Methods: The effect of mercuric chloride at two different doses, 1 mg/kg (low dose) and 2 mg/kg (high dose), orally for 30 days, was observed on the membrane-bound enzymes in the testis of adult albino rats. Results: Mercuric chloride significantly decreased the body weight and testis weight in the high dose group (P<0.05), but not in the low dose group. The activities of 5' nucleotidase and adenosine triphosphatases were markedly decreased (P<0.01) in the testis of both groups. Alkaline phosphatase and γ-glutamyl transferase activities were significantly increased (P<0.01) in both groups. However, the effect was more pronounced in the high than in the low dose groups. Conclusion: The dose dependent effect of mercuric chloride on these enzymes may affect the membrane characteristics and thereby the fertility of the animal. (Asian J Androl 2002 Dec; 4:309-311)

Drought stress,mercuric chloride,andβ-mercaptoethanol effects on hydraulic characteristics of three cultivars of wolfberry(Lycium chinense)

In order to further understand the effects of drought stress on hydraulic characteristics and the relationship between hydraulic conductivity and aquaporins or water channels of root systems of three wolfberry cultivars(Lycium chinense Mill.),hydraulic conductivity of 2-yearold pot-grown seedlings was measured under drought stress,rewatering,and treatment with exogenous mercuric chloride andβ-mercaptoethanol.Under moderate and severe drought stress levels,the most significant decrease of hydraulic conductivity was 37.3%and 24.0%,respectively,in the‘Ningqi 5’cultivar compared with the nonstressed control.After rewatering,the rate of recovery in specific conductivity was most rapid in the‘Mengqi 1’cultivar,at 0.058 and 0.072 kg MPa^-1 m^-2 s^-1 h^-1 under moderate and severe drought stress levels,respectively.The‘Mengqi 1’cultivar had the highest recovery degree of hydraulic conductivity under two concentrations ofβ-ME(500 or 1000 lmol L^-1),reaching 82.4%and 88.5%,respectively,of the initial conductivity.The adaptive capacity of hydraulic conductivity in the‘Ningqi 5’cultivar was weaker than in the‘Ningqi 1’and‘Mengqi 1’cultivars under drought stress.The recovery capacity of hydraulic conductivity in‘Mengqi 1’cultivar was stronger than the‘Ningqi 1’and‘Ningqi 5’cultivars after rewatering.Aquaporins of the‘Ningqi 1’cultivar root systems had the highest binding affinity with mercuric chloride,which was the most likely cause in the decrease in hydraulic conductivity,whereas aquaporins of‘Mengqi 1’root systems had the weakest binding affinity.The inhibitory effect of mercuric chloride was readily eliminated byβ-mercaptoethanol in the‘Mengqi 1’cultivar.The hydraulic characteristics of this cultivar were more sensitive to drought,mercuric chloride andβ-mercaptoethanol than the other cultivars.

PROTECTIVE EFFECTS OF CALCIUM ANTAGONIST ON VASCULAR SYSTEM AGAINST TOXICITY INDUCED BY MERCURIC CHLORIDE

Objective To explore the toxic effects of mercuric chloride (HgCl 2) on vascular smooth muscle as well as its relationship to calcium antagonist. Methods By using isolated vascular tension methods, we studied the effect of HgCl 2 on isolated rabbit aortic rings. Results HgCl 2 (1-100 μmol·L -1) caused a concentration-dependent contraction of rabbit aortic rings, which did not change with phentolamin or without endothelium. In KH solution with Ca 2+ , the maximum contraction amplitude reduced by(61.2±3.3)%. Nifedipine produced a concentration-dependent decrease of the maximum contraction amplitude. Conclusion Calcium antagonist has protective effects on vascular smooth muscle against damage induced by HgCl 2.

Effect of Short-Term Exposure to Mercuric Chloride on the Air-Breathing Catfish,Heteropneustes fossilis──Ⅰ.Light Microscopic Study of the Gill

Histopathological effects of sublethal (0.1, 0.2, 0.3 ppm) and lethal (0.5, 1.0 ppm)solutions of mercuric chloride (HgCl2) have been studied on the gills of the air breathing catfish, Heteropneustes fossilis at the intervals ranging from 6h to 15 days. Thickening of the epithelium, swelling and hyperplasia of the mucous cells, fusion of secondary lamellae, formation of interlamellar bridge and deposition of mucous over the entire surface are some noteworthy features of mercury poisoning in sublethal concentrations. Acute pathological manifestations are formation of subepithelial space, sloughing of the epithelial layer, hemorrhage and hypertrophy of the mucous cells. Causes and impact of these cellular alterations affecting survival of the fish have been discussed

Acute Toxic Effects of Mercuric Chloride on the Mucocytes of the Epithelial Lining of the Accessory Respiratory Organ and Skin of the Air Breathing Catfish Heteropneustes fossilis（Bloch）^1

Acute toxicity of 0.3 ppm mercuric chloride on the mucocytes of the branchial diverticulum and skin of Heteropneustes fossilis results in cyclic increases followed by decreases in the density, area occupancy and volume at different intervals of exposure. The alterations in the two tissues do not follow the same path perhaps due to different modes of action of the mercury salt: The skin comes under direct contact effects, while the branchial diverticulum may be affected by hormonal imbalance caused by a stress effect.

Histopathological Changes in the Epidermis of the Air Breathing Catfish Heteropneustes fossilis Exposed to Sublethal Concentration of Mercuric Chloride

Histopathological alterations induced by the sublethal concentration of (0.03 ppm) mercuric chloride solution on the epidermis of the fresh-water catfish Heteropneuates fossilis have been studied. It induces slow but significant histopathological changes in the various cellular components of the epidermis. It induces vacuolization, necrosis and pycnosis of the nuclei of the epithelial cells which subsequently shed. Loosening of epithelial cells of the outermost and middle layers following degeneration of the intercellular material and widened intercellular spaces is another important alteration. Prolonged mercury treatment also causes a gradual decrease in staining intensity for sulphated glycosaminoglycans in the outer border of the most superficial layer epithelial cells. The glandular elements (club cells and mucocytes) also get affected, showing cyclic degeneration followed by regeneration.

Effect of Mercuric Chloride and Cadmium Chloride on Gonadal Function and Its Regulation in SexuallyMature Common Carp Cyprinus carpio

Gonadal function in fish, CJprinus carpio was significantly affected by sublethal doses of mercuric chloride (HgCl2 ) and cadmium chloride (CdCl2 ) in chronic (45 days ) exposure.Parameters investigated were nonesterified (NE) and esterified (E) cholestcrol of ovary,liver and serum and ovarian 3β-Hydroxysteroid and 17β-Hydroxysteroid dehyrogenaseenzyme activity and serum and pituitary gonadotropin (GtH) levels. Both the pollutantswere able to reduce the hypothalamic extract (HE) or gonadotropin releasing hormone(GnRH) induced pituitary GtH release in vitro. Short term (96h) exposure of the fish tothe pollutants had no significant effect on the gonadal function. ln addition to thedeleterious effect of pollutants on the gonadal steroidogenesis and pituitary gonadotropin release, using [4-14C] cholesterol as a tracer it was found that for 45 days expeure, HgCl2'had an adverse effect on the transport of cholesterol from circulation to ovary.

Red onion extract(Allium cepa L.)supplementation improves redox balance in oxidatively stressed rats

Onions,consumed worldwide,are a good source of dietary phytochemicals with proven antioxidant properties.Catechin and quercetin are the most common and widely consumed flavonoids.The present study aimed to investigate the possible protective effect of onion extract as well as flavonoids(catechin and quercetin)on rats subjected to oxidative stress by mercuric chloride(HgCl2)treatment.Experiments were conducted on rat erythrocytes,which are a good model system to study oxidative stress.Results show that the oxidative stress induced by HgCl2 in Wistar rats resulted in substantially increased erythrocyte lipid peroxidation and higher activity of red cell plasma membrane redox system(PMRS)along with corresponding decrease in the intracellular reduced glutathione and antioxidant activity.Onion extract supplementation significantly(P<0.05)attenuated these adverse effects of HgCl2.Flavonoid supplementation resulted in a slightly higher antioxidant response compared to onion extract.We conclude that supplementation of these flavonoids results in normalization of erythrocyte PMRS activity which provides onion(rich in quercetin),a novel mechanism to exert its antioxidant effect against HgCl2-induced oxidative stress in rat erythrocytes in vivo.©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Surface chemical characterization of deactivated low-level mercury catalysts for acetylene hydrochlorination

Mercury-containing catalysts are widely used for acetylene hydrochlorination in China. Surface chemical characteristics of the fresh low-level mercury catalysts and spent low-level mercury catalysts were compared using multiple characterization methods. Pore blockage and active site coverage caused by chlorine-containing organics are responsible for catalyst deactivation. The reactions of chloroethylene and acetylene with chlorine free radical can generate chlorine-containing organic species. SiO_2 and functional groups on activated carbon contribute to the generation of carbon deposition. No significant reduction in the total content of mercury was observed after catalyst deactivation, while there was mercury loss locally. The irreversible loss of HgCl_2 caused by volatilization, reduction and poisoning of elements S and P also can lead to catalyst deactivation. Si, Al, Ca and Fe oxides are scattered on the activated carbon. Active components are still uniformly absorbed on activated carbon after catalyst deactivation.

Combined Effects of Cd and Hg on Liver and Kidney Histology and Function in Wistar Rats

The present study was performed in order to discern the effects of combined exposure to cadmium and mercury on liver function and histopathological alterations in male adult Wistar rats. In the present investigation, cadmium (100 mg/l) and mercury (25 mg/l) were administered orally for 10 weeks separately or in combination. The rational for studying cadmium and mercury is that both of these metals are encountered frequently in the same contaminated areas. In liver, the activities of serum alanine aminotransferase (ALT) and aspartate amino tranferase (AST) increased significantly in the cadmium (Cd) and mercury (Hg) alone or in combination (Cd + Hg) compared to the control suggesting that both cadmium and mercury cause hepatotoxicity spatially when co-administrated. We noted an increase in serum lactate dehydrogenase (LDH) activity in Cd and combined Cd + Hg treated groups while it decreased in Hg treated group. There was no statistically significant change in the level of total bilirubilin. Serum urea concentration showed a significant increase in the Cd and Hg groups compared to the control group. However an increase in serum creatinine concentration was noted only in the combined treated rats showing that renal insufficiency is more serious in the co-exposed group. Light microscopic examination indicated severe histological changes in the two organs under Cd and mercury influence. Results of the present investigation clearly showed that mercury has profound effects of hepatic handling of cadmium (synergistic effect) as shown by histological and biochemical results. Moreover, we observed a antagonist effect between these two toxic metals on kidney markers such as urea.

Mercurous Chloride Catalyzed Mannich Condensation of Terminal Alkynes with Secondary Amines and Aldehydes

Mercurous chloride catalyzed Mannich condensation of terminal alkynes with secondary amines and aldehydes has been developed. The reaction generated β-aminoalkynes in good yields.

Improvement of the stability of Hg/AC catalysts by CsCl for the high-temperature hydrochlorination of acetylene

Activated carbon-supported mercuric chloride（HgCl2） is used as an industrial catalyst for acetylene hydrochlorination. However, the characteristic of easy sublimation of HgCl2 leads to the deactivation o the catalyst. Here, we showed that the thermal stability of the Hg/AC catalyst can be evidently improved when Cs Cl is added into the Hg/AC catalyst. Compared with the pure Hg/AC catalyst, the sublimation rate of HgCl2 from the Hg–Cs/AC catalyst decreased significantly and the Hg–Cs/AC catalyst showed bette catalytic activity and stability in the reaction. This promoting effect is related to the existence of cesium mercuric chlorides（CsxHgyCl（x＋2y）） highlighted by XRD, HR-TEM and EDX analyses. Thus, reacting HgCl2 with alkali chlorides to form alkali-mercuric chlorides may be a key to design highly efficient and thermally stable mercuric chloride catalyst for hydrochlorination reactions.

Fuzheng Huayu Formula(扶正化瘀方) Prevents Rat Renal Interstitial Fibrosis Induced by HgCl2 via Antioxidative Stress and Down-regulation of Nuclear Factor-Kappa B Activity

Objective：To investigate the mechanism of action of Fuzheng Huayu Formula（扶正化瘀方,FZHY）against renal interstitial fibrosis（RIF）relating to oxidative injury and nuclear factor-kappa B（NF-κB）activity.Methods：Thirty-two Sprague-Dawley rats were randomly divided into 3 groups：normal group,model group and FZHY treatment group.The RIF model was induced by oral administration of HgC l2 at a dose of 8 mg/kg body weight once a day for 9 weeks.Meanwhile,rats in FZHY treatment group orally took FZHY at a dose of4.0 g/kg rat weight for 9 weeks.The content of hydroxyproline（Hyp）and collagen deposition in kidney were observed.The activities of superoxide dismutase（SOD）and glutathione peroxidase（GSH-Px）,the content of glutathione（GSH）and malondialdehyde（MDA）of kidney were tested.The expressions of inhibitor-κappa B（IκB）,phospho-IκB（p-IκB）,tumor necrosis factor-α（TNF-α）,matrix metalloproteinase-2（MMP-2）andα-smooth muscle actin（α-SMA）were analyzed by Western blot.α-SMA expression was also observed by immunofluorescent staining.MMP-2 activity was measured by gelatin zymography.NF-κB activation was determined by electrophoretic mobility shift assay.Results：Renal interstitial fibrosis was induced by Hg Cl2,demonstrated by remarkably increased Hyp contents and excessive collagen deposition in kidney（P〈0.01）.FZHY significantly inhibited renal interstitial collagen deposition and reduced Hyp content of the Hg Cl2-treated rats（P〈0.01）.GSH content decreased obviously,and MDA content increased significantly in HgC l2-treated rats compared with that of normal rats（P〈0.01）.FZHY significantly increased GSH content and decreased MDA content in the model rats（P〈0.01）.The expressionα-SMA was increased in model rats compared with that of normal rats,FZHY significantly decreased its expression（P〈0.01）.The expressions of p-IκB and TNF-αand MMP-2,MMP-2 activity,and NF-κB activation were increased in model group compared with that in normal group（P〈0.01）,FZHY significantly decreased NF-κB activation,MMP-2 activity and p-IκB and TNF-αexpressions（P〈0.01）.Conclusions：FZHY could protect kidney from oxidative injury intoxicated by Hg Cl2,and antagonized oxidative stress-stimulated NF-κB activity through inhibition of IκB phosphorylation in the interstitial fibrotic kidney,these effects importantly contributed to FZHY action mechanism against renal interstitial fibrosis.

100 years of high GEM concentration in the Central Italian Herbarium and Tropical Herbarium Studies Centre(Florence,Italy)

Up to 1980 s,the most used preservative for herbaria specimens was HgCl2,sublimating at ambient air conditions;ionic Hg then reduces to Hg0(gaseous elemental mercury,GEM)and diffuses throughout poor ventilated environments.High GEM levels may indeed persist for decades,representing a health hazard.In this study,we present new GEM data from the Central Italian Herbarium and Tropical Herbarium Studies Centre of the University of Florence(Italy).These herbaria host one of the largest collection of plants in the world.Here,HgCl2 was documented as plant preservative up to the 1920 s.GEM surveys were conducted in July 2013 and July and December 2017,to account for temporal and seasonal variations.Herbaria show GEM concentrations well above those of external locations,with peak levels within specimen storage cabinets,exceeding 50,000 ng/m3.GEM concentrations up to^7800 ng/m3 were observed where the most ancient collections are stored and no ventilation systems were active.On the contrary,lower GEM concentrations were observed at the first floor.Here,lower and more homogeneously distributed GEM concentrations were measured in 2017 than in 2013 since the air-conditioning system was updated in early2017.GEM concentrations were similar to other herbaria worldwide and lower than Italian permissible exposure limit of 20,000 ng/m3(8-hr working day).Our results indicate that after a century from the latest HgCl2 treatment GEM concentrations are still high,i.e.,the treatment itself is almost irreversible.Air conditioning and renewing is probably the less expensive and more effective method for GEM lowering.

Hepatic endogenous defense potential of propolis after mercury intoxication

Exposure to mercuric chloride(HgCl2;5 mg kg–1 body weight;i.p.)induced oxidative stress in mice and substantially increased lipid peroxidation(LPO)and oxidized glutathione(GSSG)levels,decreased the level of reduced glu-tathione(GSH)and various antioxidant enzymes in liver and also increased the activities of liver marker enzymes in serum.Therapy with propolis extract,a resinous wax-like beehive product(200 mg kg–1 orally,after mercury administration),for 3 days inhibited LPO and the formation of GSSG and increased the level of GSH in the liver.Release of serum transaminases,alkaline phosphatase,lactate dehydrogenase and-glutamyl transpeptidase were significantly restored after propolis treatment.The activities of antioxidant enzymes,that is,superoxide dismutase,catalase,glutathione-S-transferase and glucose-6-phosphate dehydrogenase,were also concomitantly restored towards normal levels after propolis administration.These observations clearly demonstrate that propolis treatment augments antioxidant defense against mercury-induced toxicity and provide evidence that propolis has therapeutic potential as a hepatoprotective agent.