Exposition to tannery wastewater did not alter behavioral and biochemical parameters in Wistar rats

Valorization of treated wastewater from the soaking of baby alpaca skin fur

Baby alpaca fur industry generates considerable wastewater during the soaking process, which contains high levels of total suspended solids (TSSs), proteins, and salts, among other components. The valorization of wastewater after precipitation, coagulation-flocculation, and aeration treatments was evaluated for use in irrigation water, fertigation, groundwater recharge, concrete construction, and disposal. The precipitation treatment sludge and the coagulation-flocculation treatment were evaluated as a protein source, soil quality improvement, and disposal. The treatment system included evaluations of nine pH levels, seven coagulant doses, and seven aeration times. The contents of TSSs, chemical oxygen demand (COD), total Kjeldalh nitrogen (TKN), ammonia nitrogen (N-NH3), and oils and fats (O&G), among other parameters, were determined in the treated and untreated wastewater. Before entering the treatment system, the physicochemical characterization of the wastewater showed a high concentration of parameters related to organic matter and dust, such as O&G, five-day biological oxygen demand (BOD5), COD, TSSs, TKN, and N-NH3. The optimal removal parameters were pH 12 for the chemical precipitation of proteins, a dose of 480 mg/L FeCl3 as a coagulant for TSSs removal, and 150 min of aeration; removal efficiencies of 99.02 %, 77.49 %, 79.93 %, and 64.62 % for TSSs, Cod, TKN, and N-NH3, respectively, were obtained. The wastewater after treatment can be used for groundwater recharge and concrete construction, and the wastewater with 2 % dilution can be used for irrigation water and fertigation. The sludge after precipitation is rich in protein and can be used as a protein source or soil quality improver.

An insight on the plausible biological and non-biological detoxification of heavy metals in tannery waste: A comprehensive review

A key challenge for the tannery industries is the volume of tannery waste water (TWW) generated during the processing of leather, releasing various forms of toxic heavy metals resulting in uncontrolled discharge of tannery waste (TW) into the environment leading to pollution. The pollutants in TW includes heavy metals such as chromium (Cr), cadmium (Cd), lead (Pb) etc, when discharged above the permissible limit causes ill effects on humans. Therefore, several researchers have reported the application of biological and non-biological methods for the removal of pollutants in TW. This review provides insights on the global scenario of tannery industries and the harmful effects of heavy metal generated by tannery industry on micro and macroorganisms of the various ecological niches. It also provides information on the process, advantages and disadvantages of non-biological methods such as electrochemical oxidation, advanced oxidation processes, photon assisted catalytic remediation, adsorption and membrane technology. The various biological methods emphasised includes strategies such as constructed wetland, vermitechnology, phytoremediation, bioaugmentation, quorum sensing and biofilm in the remediation of heavy metals from tannery wastewater (TWW) with special emphasize on chromium.

Management of tannery waste effluents towards the reclamation of clean water using an integrated membrane system: A state-of-the-art review

Tanning and other leather processing methods utilize a large amount of freshwater, dyes, chemicals, and salts and produce toxic waste, raising questions regarding their environmental sensitivity and eco-friendly nature. Total suspended solids, total dissolved solids, chemical oxygen demand, and ions such as chromium, sulfate, and chloride turn tannery wastewater exceedingly toxic for any living species. Therefore, it is imperative to treat tannery effluent, and existing plants must be examined and upgraded to keep up with recent technological developments. Different conventional techniques to treat tannery wastewater have been reported based on their pollutant removal efficiencies, advantages, and disadvantages. Research on photo-assisted catalyst-enhanced deterioration has inferred that both homogeneous and heterogeneous catalysis can be established as green initiatives, the latter being more efficient at degrading organic pollutants. However, the scientific community experiences significant problems developing a feasible treatment technique owing to the long degradation times and low removal efficiency. Hence, there is a chance for an improved solution to the problem of treating tannery wastewater through the development of a hybrid technology that uses flocculation as the primary treatment, a unique integrated photo-catalyst in a precision-designed reactor as the secondary method, and finally, membrane-based tertiary treatment to recover the spent catalyst and reclaimable water. This review gives an understanding of the progressive advancement of a cutting-edge membrane-based system for the management of tanning industrial waste effluents towards the reclamation of clean water. Adaptable routes toward sludge disposal and the reviews on techno-economic assessments have been shown in detail, strengthening the scale-up confidence for implementing such innovative hybrid systems.

Occurrence of Textile Dyes and Metals in Tunisian Textile Dyeing Effluent: Effects on Oxidative Stress Status and Histological Changes in Balb/c Mice

Although it is known that textile wastewater contains highly toxic contaminants whose effects in humans represent public health problems in several countries, studies involving mammal species are scarce. This study was aimed to evaluate the toxicity profile of 90-days oral administration of textile dyeing effluent (TDE) on oxidative stress status and histological changes of male mice. The TDE was collected from the textile plant of Monastir, Tunisia and evaluated for the metals, aromatic amines, and textile dyes using analytical approaches. Metal analysis by ICP-MS showed that the tested TDE exhibited very high levels of Cr, As, and Sr, which exceeded the wastewater emission limits prescribed by WHO and Tunisian authority. The screening of TDE through UPLC-MS/MS confirmed the presence of two textile dyes: a triphenylmethane dye (Crystal violet) and a disperse azo dye (Disperse yellow 3). Exposure to TDE significantly altered the malondialdehyde (MDA), Conjugated dienes (CDs), Sulfhydryl proteins (SHP) and catalase levels in the hepatic and renal tissues. Furthermore, histopathology observation showed that hepatocellular and renal lesions were induced by TDE exposure. The present study concluded that TDE may involve induction of oxidative stress which ensues in pathological lesions in several vital organs suggesting its high toxicity. Metals and textile dyes may be associated with the observed toxicological effects of the TDE. These pollutants, which may have seeped into surrounding rivers in Monastir city, can cause severe health malaise in wildlife and humans.

In vivo toxicities of the hospital effluent in Mahdia Tunisia

Hospital effluent (HE) is one of the most important sources of pharmaceuticals released into the environment. This kind of pollution is a recognized problem for both human health and aquatic life. Consequently, in the present study, we assessed the effects of untreated hospital effluent on mice via biochemical and histopathological determinations. Female mice were given free access to water bottles containing untreated HE at different dilutions for 21 days. Then clinical biochemistry and histopathology evaluation were conducted. Serum biochemistry analysis showed the presence of significant increase in cholesterol, triglycerides, glycaemia and total bilirubin. However, phosphatase alkaline and urea activities have been significantly decreased compared to the control group. No significant variation was observed for the rest of the studied parameters (high-density lipoproteins; low-density lipoproteins and uric acid). Additionally, multiple alterations, including cellular necrosis, leucocyte infiltration and congestion, were observed in different tissues of mice exposed to the tested HE.

Evaluating the reproductive toxicology of tannery effluent in male SWISS mice

The transformation of skin in-natura into leather in tannery industries generates large volumes of organic matter that attract small mammals. i.e., rodents living close to these facilities. Animals foraging in the backyards of such industries get exposed to the effluent produced by them; however, attention has not been given to the impacts of such exposure on the reproductive biology of these animals. Thus, our study assessed whether the direct exposure to this effluent for periods longer than 90 days leads to reproductive loss in male Swiss mice. We assessed animals' sexual behavior at the end of the experimental period and analyzed their testicular histology, as well as semen quality and volume, besides measuring pro-inflammatory markers and assessing the reproductive performance of the exposed animals. Based on the herein collected data, mice exposed to the gross effluent collected in the backyard of a tannery industry, as well as to the effluent diluted in 5% of water, presented behavioral and histological changes in the testes, disorganized germinal cells in the seminiferous tubules and inflammatory process in intertubular spaces. The inflammatory process resulted from increased proinflammatory cytokine (IFN-gamma and CCL2) concentrations in the testes, fact that explained the larger number of sperm abnormalities and the reduced number of produced sperms. These factors, along with the previously reported changes, may have led to the low reproductive performance of animals exposed to the tested pollutant, which was assessed through the lethal dominant test. This pioneering article addressed the reproductive impact caused by the direct exposure of small rodents to tannery effluents. The research helped better understanding how these pollutants can influence natural ecosystems.

Precopulatory sexual behavior of male mice is changed by the exposure to tannery effluent

Although the toxic potential of tannery effluents (TE) is acknowledged, the impacts these residues have on mammals who intake water contaminated with this pollutant are not completely known. Thus, in order to broaden the knowledge about how these contaminants affect the biota, the aim of the current study is to assess different behavioral categories (e.g.: sexual odor preference, opposite-sex attraction, and sexual discrimination) related to the sexual motivation and pre-copulation of male Swiss mice subjected to TE intake for 30 days, at concentrations 0.8% and 22%. The animals were subjected to locomotor performance evaluation through the Basso Mouse Scale (BMS), as well as to the open field (OF), odor preference (OPT), sexual orientation (SOT) and to scent marking tests (SMT) one week before the experiment ended. Our results evidenced that the treatments did not affect the animals' locomotor activity (in OF and BMS) or caused changes compatible to anxiogenic or anxiolytic behavior (in OF). However, mice exposed to TE (at both concentrations) presented discriminatory capacity deficit in the OPT test at the time to distinguish conspecific odors from the same sex, and from the opposite sex. They randomly explored (without preference) males and females, did not responded to stimuli in the SOT test, as well as did not appear capable of detecting female odor (in estrus phase) during the SMT. Thus, the current study was pioneer in evidencing that TE can influence the reproduction and the population dynamics of small rodents who intake water contaminated with the pollutant.

Effects of tannery wastewater exposure on adult Drosophila melanogaster

Our aim was to evaluate the effects of exposure to tannery wastewater on mortality and/or antioxidant enzyme system in adult wild-type Canton-S Drosophila melanogaster. Exposure to tannery wastewater induced a concentration-dependent lethality in adult Canton-S flies. Tannery wastewater was able to alter antioxidant enzyme activities, specifically glutathione peroxidase-like and glutathione S-transferase, in adult Canton-S D. melanogaster. We conclude that D. melanogaster is a reliable model to evaluate the toxicity induced by tannery wastewater.

Short-term social memory deficits in adult female mice exposed to tannery effluent and possible mechanism of action

The accumulated organic residues in tannery-plant courtyards are an eating attraction to small rodents; however, the contact of these animals with these residues may change their social behavior. Thus, the aim of the present study is to investigate whether the exposure to tannery effluent (TE) can damage the social recognition memory of female Swiss mice, as well as to assess whether vitamin C supplementation could provide information about how TE constituents can damage these animals' memory. We have observed that resident females exposed to TE (without vitamin supplementation) did not explore the anogenital region, their body or chased intruding females for shorter time or with lower frequency during the retest session of the social recognition test, fact that indicates social recognition memory deficit in these animals. Such finding is reinforced by the confirmation that there was no change in the animals' olfactory function during the buried food test, or locomotor changes in females exposed to the pollutant. Since no behavioral change was observed in the females exposed to TE and treated with vitamin C (before or after the exposure), it is possible saying that these social cognitive impairments seem to be directly related to the imbalance between the cellular production of reactive oxygen species and the counteracting antioxidant mechanisms (oxidative stress) in female mice exposed to the pollutant (without vitamin supplementation). Therefore, the present study evidences that the direct contact with tannery effluent, even for a short period-of-time, may cause short-term social memory deficits in adult female Swiss mice.

Mice exposure to tannery effluents changes their olfactory capacity, and their response to predators and to the inhibitory avoidance test

The current study has assessed whether the oral and/or dermal exposure of C57Bl/6 J mice to tannery effluent (a complex pollutant consisting of xenobiotic mixtures) could damage their olfactory functions, as well as whether it changes their aversive behavior in the inhibitory avoidance test. Accordingly, the animals were distributed in groups which were exposed or not to this xenobiotic through two different routes (oral and dermal), for 15 days. The effluent group subjected to oral exposure received drinking water containing 5% tannery effluent, whereas the animals in the dermal group were exposed to raw tannery effluent for 1 h/day. The animals dermally exposed to the tannery effluent (males and females) have shown the highest latency to find palatable food in the buried food test. The shortest time spent by the animals (orally or dermally) exposed to tannery effluent in the safety zone of the apparatus used in the predator exposure test, as well as the longest time spent by them in the aversive zone, have shown failures in their perception to the risk represented by the presence of the predator (cat). The passive avoidance test results have shown that the dermal exposure to tannery effluent led to partial memory deficit in male and female mice; therefore, the present study has confirmed the tannery effluent toxicity to mammals. Moreover, the present study was pioneer in demonstrating that the dermal exposure to this xenobiotic, even for a short period-of-time, can change the olfactory and cognitive functions of animals, as well as lead to harmful consequences to their health.

Protective effect of vitamin C in female Swiss mice dermally-exposed to the tannery effluent

Previous studies involving the oral exposure of mice to tannery effluents have found neurotoxic effects. However, studies about the effects the dermal exposure to pollutant have on the cognitive function of females have not been found in the literature. Thus, the aim of the current study is to investigate whether the dermal exposure of female Swiss mice to tannery effluents (2 h/day for 20 days) can cause cognitive impairment, as it was already evidenced in male Swiss mice. Furthermore, based on the administration of vitamin C (before or after the exposure to the xenobiotic), the current study also aims to assess the protective effect of vitamin C in female Swiss mice dermally-exposed to the tannery effluent. Female Swiss mice exposed to the tannery effluent (without vitamin supplementation) have shown lower novel object recognition index during the test session of the novel object recognition task, and they have descended significantly faster from the inhibitory avoidance platform when they were compared to mice belonging to the other groups, therefore evidencing memory deficit. However, the test performance of females receiving vitamin C was similar to that of control animals. Thus, the current study confirms the initial hypothesis that the dermal exposure to the pollutant, even for a short period, causes cognitive deficit in female Swiss mice. The herein presented findings also provide evidence that the mechanisms of action of the tannery effluent in these animals are related to oxidative damages in specific brain regions directed to the formation of short memory to perform aversive and object recognition tasks.

Effect of tannery effluent on oxidative status of brain structures and liver of rodents

Oxidative stress has been considered as a central mechanism of toxicity induced by xenobiotics. Previously, it was demonstrated that mice exposed to tannery effluent showed an anxiety-like behavior, without any comparable behavioral effects in rats. The aim of the present study was to investigate the impact of tannery wastewater on oxidative status in in vitro and in vivo assays with two mammal species, mice and rats. Specifically, homogenates of two brain areas and the liver were incubated with tannery wastewater; reactive species and lipid peroxidation levels and antioxidant enzyme activities were detected. In addition, the effects of in vivo exposure of mice to tannery effluents on and lipid peroxidation levels and the total reactive antioxidant capacity in brain areas and liver. Brain areas, the hippocampus and frontal cortex, and the liver of mice exposed to tannery wastewater showed oxidative stress. Our data suggest that divergent species-dependent hepatic enzymes adaptations, such as glutathione peroxidase and glutathione S-transferase activities, induced by tannery effluent could explain previous behavioral findings.

Inbred mice strain shows neurobehavioral changes when exposed to tannery effluent

The bovine leather processing (tanning industries) stands as a generating activity of potentially toxic waste. The emission of untreated effluents into the environment may cause serious harm to human and environmental health. Nevertheless, few studies have investigated the possible effects of intake of these effluents in experimental mammalian models. Thus, this study aimed to evaluate the neurobehavioral effects of chronic intake of different tannery effluent concentrations diluted with water (0.1, 1, and 5%) in male C57BL/6J mice. After 120 days of exposure, the animals were subjected to different behavioral tests, predictive of anxiety (elevated plus maze (EPM), open-field (OF), and neophobia test), depression (forced swim), and memory deficits (object recognition test). From the EPM test, it was observed that the mice exposed to 0.1, 1, and 5% of tannery effluents showed higher anxiety scores compared to the animals in the control group. However, the results of this study revealed no differences among the experimental groups in the proportion (percentage) of locomotion in the central quarters/total locomotion calculated (by OF), considered an indirect measure for anxiety. At neophobia test, all the animals exposed to chronic intake of tannery effluents showed higher latency time to start eating, which corresponds to an anxiogenic behavior. Regarding the forced swim test, it was observed that the animals exposed to tannery effluents had longer time in immobility behavior, suggesting a predictive behavior to depression. Finally, the object recognition test showed that the treatments did not cause damage to the animals' memory. The recognition rate of the new object did not differ among the experimental groups. Thus, it is concluded that male C57BL/6J mice (inbred strain) exposed to tannery effluents have predictive neurobehavioral changes of anxiety and depression, without memory deficit.

Anxiety and memory deficits induced by tannery effluent in C57BL/6J female mice

This study aimed to evaluate the behavior of female C57Bl/6J mice exposed to tannery effluents diluted in drinking water. Female mice were divided into a control group, in which the animals received only drinking water, and experimental groups, which received raw tannery effluent in 7.5 and 15 % concentrations diluted in water (period of 60 days). In the last experimental week, the mice (in diestrus phase) were subjected to different behavioral tests: elevated plus-maze, open-field test, forced swim test, and object recognition test. Our data demonstrated that exposure to tannery effluent increased the anxiety index of animals and decreased the locomotion ratio in the central quadrants/total, indicating an increase in anxiety-like behavior. Regarding the forced swim test, we did not observe changes in the evaluated behaviors. There were no statistically significant differences in the recognition index of the novel and familiar object in the groups exposed to tannery effluent compared with the control group, indicating a possible influence of the constituents of tannery effluent on cognition. Thus, our findings support the hypothesis that effluents, containing neurotoxic substances, could cause behavioral disruptions in female C57Bl/6J mice.

The C57BL/6J mice offspring originated from a parental generation exposed to tannery effluents shows object recognition deficits

The main aim of the present paper is to assess whether the parental generation exposure to such discharges could cause object recognition deficits in their offspring. Male and female C57Bl/6J mice were put to mate after they were exposed to 7.5% and 15% tannery effluents or water (control group), for 60 days. The male mice were withdrawn from the boxes after 15 days and the female mice remained exposed to the treatment during the gestation and lactation periods. The offspring were subjected to the object recognition test after weaning in order to assess possible cognition losses. The results of the analysis of the novel object recognition index found in the testing session (performed 1 h after the training session) applied to offspring from different experimental groups appeared to be statistically different. The novel object recognition index of the offspring from female mice exposed to tannery effluents (7.5% and 15% groups) was lower than that of the control group, and it demonstrated object recognition deficit in the studied offspring. The present study is the first to report evidences that parental exposure to effluent of tannery (father and mother) can cause object recognition deficit in the offspring, which is related to problems in the central nervous system.

An evaluation of aversive memory and hippocampal oxidative status in streptozotocin-induced diabetic rats treated with resveratrol

The present study evaluated the effects of streptozotocin (STZ)-induced diabetes on aversive memory, free radical content and enzymatic antioxidant activity in the hippocampus of adult Wistar rats submitted to oral treatment with resveratrol. Animals were divided into eight groups: non-diabetic rats treated with saline (ND SAL), non-diabetic rats treated with resveratrol at a dose 5mg/kg (ND RSV 5), non-diabetic rats treated with resveratrol at a dose 10mg/kg (ND RSV 10), non-diabetic rats treated with resveratrol at a dose 20mg/kg (ND RSV 20), diabetic rats treated with saline (D SAL), diabetic rats treated with resveratrol at a dose 5mg/kg (D RSV 5), diabetic rats treated with resveratrol at a dose 10mg/kg (D RSV 10) and diabetic rats treated with resveratrol at a dose 20mg/kg (D RSV 20). The animals received oral gavage for 35days. The contextual fear conditioning task was performed to evaluate aversive-based learning and memory. The oxidative status was evaluated in the hippocampus, by measuring the free radical content - using a 2',7'-dichlorofluorescein diacetate probe - and enzymatic antioxidant activities, such as superoxide dismutase and glutathione peroxidase. Our main behavioral results demonstrated that rats from the D RSV 10 and D RSV 20 groups showed an increase in freezing behavior when compared, respectively, to the ND RSV 10 (p<0.01) and ND RSV 20 (p<0.05). Oxidative stress parameters remained unchanged in the hippocampus of all the experimental groups. In contrast to previous experimental findings, our study was unable to detect either cognitive impairments or oxidative stress in the hippocampus of the diabetic rats. We suggest additional long-term investigations be conducted into the temporal pattern of STZ-induced diabetic disruption in memory and hippocampal oxidative status, as well as the effects of resveratrol on these parameters, in a time and dose-dependent manner.

Dermal exposure to tannery effluent causes neurobehavioral changes in C57Bl/6J and Swiss mice

Tannery effluents constitute highly polluting residues, which can cause negative impacts to people's health and the environment. However, studies that have investigated the effects of the exposure to these xenobiotics on the central nervous system of mammal experimental models are rare, the few that have been published focusing on the exposure via oral intake (ingestion of water containing tannery effluent concentrations). In this sense, and with the objective of expanding the knowledge beyond the neurotoxic effects observed when water contaminated by these xenobiotics is ingested, the neurobehavioral effects of dermal exposure of male C57Bl/6J and Swiss mice were analyzed. The animals were exposed to raw (wet blue-type) tannery effluent for two hours during five days, totalizing 15 days of exposure. Afterwards, the animals underwent the elevated plus-maze (predictive of anxiety) and the object recognition tests (identification of memory deficit). Our data show that the dermal exposure to the tannery effluent caused an anxiogenic behavior in these animals, when compared those that did not have direct contact with these xenobiotics. It was also observed that the animals exposed to the tannery effluent obtained lower novel object recognition indices, thus evidencing memory deficit and indicating a possible influence of the tannery effluent constituents in animal cognition. The present study attests the hypothesis that dermal exposure to tannery effluents containing neurotoxic substances causes behavioral disorders in C57Bl/6J and Swiss mice.

Antiepileptogenic, antioxidant and genotoxic evaluation of rosmarinic acid and its metabolite caffeic acid in mice

AIMS

Antioxidant compounds have been extensively investigated as a pharmacological alternatives to prevent epileptogenesis. Rosmarinic acid (RA) and caffeic acid (CA) are compounds with antioxidant properties, and RA has been shown to inhibit GABA transaminase activity (in vitro). Our aim was to evaluate the effect of RA and CA on seizures induced by pentylenotetrazole (PTZ) using the kindling model in mice.

MAIN METHODS

Male CF-1 mice were treated once every three days during 16days with RA (1, 2 or 4mg/kg; i.p.), or CA (1, 4 or 8mg/kg; i.p.), or positive controls diazepam (1mg/kg; i.p.) or vigabatrin (600mg/kg; p.o.), 30min before PTZ administration (50mg/kg; s.c.). After the last treatment, animals were sacrificed and the cortex was collected to evaluate free radicals (determined by 2',7'-dichlorofluorescein diacetate probe), superoxide dismutase (SOD) and genotoxic activity (Alkaline Comet Assay).

KEY FINDINGS

Rosmarinic acid 2mg/kg increased latency and decreased percentage of seizures, only on the 4th day of observation. The other tested doses of RA and CA did not show any effect. Rosmarinic acid 1mg/kg, CA 4mg/kg and CA 8mg/kg decreased free radicals, but no dose altered the levels of enzyme SOD. In the comet assay, RA 4mg/kg and CA 4mg/kg reduced the DNA damage index.

SIGNIFICANCE

Some doses of rosmarinic acid and CA tested showed neuroprotective action against oxidative and DNA damage produced in the kindling epilepsy model, although they did not produce antiepileptogenic effect in vivo.