HgCl2 Research Articles

Establishment of In Vitro Cultures and Genetic Fidelity Analysis in Valeriana jatamansi -a High Value Endangered Medicinal Herb

The present study was conducted in the Department of Biotechnology, College of Horticulture and Forestry, Neri, Hamirpur, Himachal Pradesh, India during 2018–2020 for 18 months to develop an efficient, rapid and reproducible protocol for in vitro establishment along with analysing antioxidant activity. In the present study, surface sterilization protocol was standardized using Sodium hypochlorite and mercuric chloride as sterilant. Maximum direct shoot induction frequency from nodal explant was achieved on Murashige and Skoog medium enriched with BAP (5.0 mg l-l), TDZ (3.0 mg l-l) and NAA (1.0 mg l-l) for 18 days. Microshoots inoculated on MS media supplemented with 4.0 mg l-l BAP, 2.0 mg l-l TDZ, 1.0 mg l-l NAA and 0.5 mg l-l GA3) showed maximum frequency of shoot multiplication with average shoot length (4.36±0.08 cm) and average shoot number (14.00±0.57). A 75.00±1.15% rooting with significantly high mean root number (8.00±0.57) and root length was achieved in full strength MS medium, supplemented with same concentration i.e. 4.0 mg l-l BAP, 2.0 mg l-l TDZ, 1.0 mg l-l NAA and 0.5 mg l-l GA3) combination. Maximum plantlets survive after 1 year of acclimatization. RAPD and ISSR markers were used to confirmed genetic stability of in vitro raised plants by showing 100% monomorphism. High multiplication rate associated with genetic stability ensure the efficacy of the present in vitro clonal propagation protocol of this important medicinal plant.

Establishment of An in Vitro Mass Propagation System for Dendrocalamus asper.

Dendrocalamus asper is a species of bamboo that has high commercial value and is the bamboo of choice for large scale agro-forestry plantations in the tropical regions of the world. Micropropagation using tissue culture is essential to generate uniform clones that are amenable to establishment in industrial agro-forestry projects for bamboo biomass, habitat restoration or in carbon sequestration. This paper reports on the establishment of D. asper invitro using commercially available seeds. The seeds were surface sterilized using three different chemical agents which were Sodium Hypochlorite (20%), Mercuric Chloride (0.1%) and Ethanol (70%) followed by shoot initiation on Murashige and Skoog (MS) medium supplemented with 6-Benzylaminopurine (BAP) with a concentration ranging from 1.0 - 5.0 mg/L. Propagules were multiplied on MS media supplemented with different concentration of IBA Indole-3-Butyric Acid (IBA) and Naphthalene Acetic Acid (NAA), and finally rooted and hardened in peat moss. The findings of our study indicate that the sterilization protocol eliminated all the plant pathogens, resulting in an axenic culture. Full strength MS medium supplemented with 5 mg/L BAP yielded the highest number of shoots (11.46 per explant) after four weeks of inoculation. The highest multiplication rate (3.95 shoots per explant) was obtained on MS medium supplemented with 3 mg/L BAP. The time required from initiation to hardening was 70 to 90 days, following which the plantlets were ready for field trials. The findings of this study will facilitate the establishment of plant tissue culture programmes dedicated to the production of D. asper locally, thus eliminating the need for imports and the possible entry of plant pathogens that can be detrimental to the local agro-forestry industry.

First report of Colletotrichum siamense causing Fruit Drop in Kinnow mandarin (Citrus nobilis x Citrus deliciosa) in Punjab, India

Kinnow, a hybrid developed by crossing two cultivars of mandarin i.e. King (Citrus nobilis) x Willow leaf (Citrus deliciosa) accounts for its high economic productivity and possess high processing quality along with great aromatic flavour. Kinnow mandarin cultivation occupies 4,73,000 ha of land in India with an annual production of 62,65,000 MT (Anonymous, 2021) and Punjab is the leading Kinnow producing state in India. Fruit drop is a major problem in Kinnow mandarin causing serious damage in the quality and yield of the fruit. During 2020–21, the symptoms of fruit drop were observed in Kinnow orchards of Punjab as; drying of twigs from the tip downwards, brown discoloured circular areas on stem-end of the fruit, rotting, and dropping of the fruit. To identify the casual agent, the infected fruit tissue bits (2 mm) was surface sterilized with 1% mercuric chloride solution for 30–40 s and given three washings of distilled water and placed on whatman filter paper-1 to soak all the excessive moisture. The bits was placed on Potato Dextrose Agar (PDA) plates and incubated at 25 ± 1 °C. The colony colour ranged from creamy white to light gray with orange conidial mass in the centre. Based on various morphological characteristics i.e., conidial shape, size, spore production, presence or absence of fruiting body and size of fruiting body the fungus was identified as Colletotrichum siamense. For molecular confirmation ITS region, actin (ACT) and beta-tubulin2 (TUB2) genes were amplified using primers ITS-6/ITS-4, ACT-512F/ACT-783R and T1/Bt2b, respectively. PCR amplicons for three loci (ITS, ACT and TUB2) were sequenced and sequences were deposited in GenBank as accession numbers OQ857285, OQ983464 and OQ983465 for isolate no. C-4 and OQ888798, OQ983466 and OQ983467 for isolate no. C-19, respectively. The BLAST analysis and multigene phylogenetic analysis showed that the isolates collected in present study were phylogenetically similar to the C. siamense. Thus, based on morphological, phylogenetic analysis and pathogenicity assays, the causal agent was identified as Colletotrichum siamense. This is the first report of C. siamense causing fruit drop of kinnow mandarin in Punjab, India.

The Behavior of Terbuthylazine, Tebuconazole, and Alachlor during Denitrification Process.

Pesticide compounds can influence denitrification processes in groundwater in many ways. This study observed behavior of three selected pesticides under denitrifying conditions. Alachlor, terbuthylazine, and tebuconazole, in a concentration of 0.1 mL L-1, were examined using two laboratory denitrifications assays: a "short" 7-day and a "long" 28-day test. During these tests, removal of pesticides via adsorption and biotic decomposition, as well as the efficiency of nitrate removal in the presence of the pesticides, were measured. No considerable inhibition of the denitrification process was observed for any of the pesticides. On the contrary, significant stimulation was observed after 21 days for alachlor (49%) and after seven days for terbuthylazine (40%) and tebuconazole (36%). Adsorption was in progress only during the first seven days in the case of all tested pesticides and increased only negligibly afterwards. Immediate adsorption of terbuthylazine was probably influenced by the mercuric chloride inhibitor. A biotic loss of 4% was measured only in the case of alachlor.

Impact of Water Pollution on Fish Physiology - A Study

The freshwater air-breathing teleost, Channa punctatus were exposed to mercuric chloride (0.15 ppm) and cadmium chloride (35.5 ppm) for 1, 2, 7, 15 and 30 days so as to determine short and long-term effects of sub-lethal doses of these industrial pollutants on different haematological parameters. The selection of pollutants and their concentrations was based on the real data, in relation to the degree of water pollution of Damodar River. Blood samples were collected from the fishes exposed to various exposure periods for each pollutant and the blood glucose, haemoglobin content, cholesterol, HDL-cholesterol, LDL- cholesterol, VLDL- cholesterol, triglycerides, total RBC and WBC counts were measured. The blood glucose, haemoglobin content, total RBC and WBC counts progressively decreased. Blood cholesterol, HDL-cholesterol, LDL- cholesterol, VLDL-cholesterol and triglycerides were also depleted. Linear regression analysis with appreciable values of R2 and tratios revealed that the values of different blood parameters were reduced radically with the progress of days, except haemoglobin, signifying negative impact of pollutant of HgCl2. Strong correlation between different blood parameters calls for that adverse variations. Histopathological changes in the hepatopancreas induced by the heavy metals like mercuric chloride and cadmium chloride include degeneration of hepatic cells, clumping of cytoplasmic materials, displacement of nucleus towards the periphery, derangement of the pancreatic acini and coagulation of blood in the sinusoids. Analysis of experimental data suggests the depletion of energy resources and disturbance of the metabolic pathway as indicated by the adverse effects on haematological parameters and histopathological lesions in the haepatopancreas.

Crystal growth and characterization of piperazinium mercuric chloride (PMC) single crystal for nonlinear optical (NLO) application

A single organic NLO crystal of piperazinium mercuric chloride (abbreviated as PMC) was grown from water solvent by the conventional solution growth method. The synthesised PMC crystal was purified by repetitive recrystallization. The PMC structure was confirmed by single-crystal X-ray diffraction analysis. Various other characterizations were carried out for the grown PMC single crystal, such as Powder X-ray diffraction analysis, UV–Visible-NIR, High resolution X-ray diffraction, Fourier Transform Infrared analysis, Nuclear magnetic resonance, Photoluminescence, Photoconductivity, Chemical etching, Dielectric analysis, Vickers microhardness, and Third harmonic generation (Z-Scan) analysis. The above-mentioned analyses revealed the various planes (h, k, and l) of crystal structure, optical analysis, crystalline perfection, structural analysis, etch pit density, mechanical stability, electrical analysis, and NLO properties of the grown crystal.

Preparation and quality control of in‐house reference materials for marine dissolved inorganic carbon and total alkalinity measurements

AbstractAccurate measurements of seawater carbonate chemistry are crucial for marine carbon cycle research. Certified reference materials (CRMs) are typically analyzed alongside samples to correct measurements for calibration drift. However, the COVID‐19 pandemic led to a limited access to CRMs. In response to this shortage, we prepared and monitored in‐house reference materials (IHRMs) for total alkalinity (TA) and dissolved inorganic carbon (DIC), over 12 and 15 months, respectively. Overall, TA was stable, but a slight increase in DIC of about 2 μmol kg−1 occurred over 15 months. The increase could potentially be attributed to bacterial growth, despite mercuric chloride fixation and repeated UV exposure. It is noted that this small increase was most likely within our instrument and measurements uncertainties. Our repeated measurements also identified a few bottles that had TA or DIC concentrations 4–5 μmol kg−1 higher than the rest, indicating issues during cleaning, fixation, or storage of individual bottles. This study emphasizes the importance of careful and continuous monitoring if self‐prepared IHRMs are used. Given that the amount of work required is very high, IHRM preparation is only recommended when CRMs are not available.

Optimizing Surface Sterilization for Micropropagation of Gerbera jamesonii: A Study on Explant Survival and Contamination Control

In the commercial production of gerberas, micropropagation enables the large-scale production of plants in a limited space, as well as the obtaining of disease and pest-free uniform plants. This technique also ensures precision in production schedules and product quality, regarding plant homogeneity and vigour. Nevertheless, the occurrence of contamination in an in vitro culture is frequent, and might result in high damage. Plant materials have different kind of microbes i.e., exogenous and endogenous in nature which is the main reason for contamination in tissue culture. Pre-treatments to explants with fungicides and bactericides can be effectively used to eliminate the surface contamination. Surface sterilizing agents, their levels and duration of exposure are known to impact the in vitro culture establishment. In the present experiment, pre-treatment of explants was carried out with Teepol BleachTM solution (0.1%) and BavistinTM (0.1%) for 15 and 20 minutes respectively for effective control of fungal contaminations in all the cultures. For the control of bacterial contamination antibiotics were added in culture medium. Surface sterilization of explants with 0.1% mercuric chloride (HgCl2) for five minutes gave the maximum survival of the growing cultures.

Toxicity Evaluation, Oxidative, and Immune Responses of Mercury on Nile Tilapia: Modulatory Role of Dietary Nannochloropsis oculata.

The current study evaluated the potential ameliorative effect of a dietary immune modulator, Nannochloropsis oculata microalga, on the mercuric chloride (HgCl2)-induced toxicity of Nile tilapia. Nile tilapia (45-50g) were fed a control diet or exposed to ¼ LC50 of HgCl2 (0.3mg/L) and fed on a medicated feed supplemented with N. oculata (5% and 10% (50 or 100g/kg dry feed)) for 21days. Growth and somatic indices, Hg2+ bioaccumulation in muscles, and serum acetylcholinesterase (AChE) activity were investigated. Antioxidant and stress-related gene expression analyses were carried out in gills and intestines. Histopathological examinations of gills and intestines were performed to monitor the traits associated with Hg2+ toxicity or refer to detoxification. Hg2+ toxicity led to significant musculature bioaccumulation, inhibited AChE activity, downregulated genes related to antioxidants and stress, and elicited histopathological changes in the gills and intestine. Supplementation with N. oculata at 10% was able to upregulate the anti-oxidative-related genes while downregulated the stress apoptotic genes in gills and intestines compared to the unexposed group. In addition, minor to no histopathological traits were detected in the gills and intestines of the N. oculata-supplemented diets. Our data showed the benefit of dietary N. oculata in suppressing Hg2+ toxicity, which might support its efficacy as therapeutic/preventive agent to overcome environmental heavy metal pollution in aquatic habitats.

Anandamide modulates WNT-5A/BCL-2, IP3/NFATc1, and HMGB1/NF-κB trajectories to protect against mercuric chloride-induced acute kidney injury.

Endocannabinoid anandamide (AEA) has a physiological role in regulating renal blood flow, whereas its analogs ameliorated renal ischemia/reperfusion injury. Nonetheless, the role of AEA against mercuric chloride (HgCl2)-induced renal toxicity has not been unraveled. Rats were allocated into control, HgCl2, and HgCl2/AEA treated groups. The administration of AEA quelled the HgCl2-mediated increase in inositol trisphosphate (IP3) and nuclear factor of activated T-cells cytoplasmic 1 (NFATc1). The endocannabinoid also signified its anti-inflammatory potential by turning off the inflammatory cascade evidenced by the suppression of high mobility group box protein-1 (HMGB1), receptor of glycated end products (RAGE), nuclear factor-κB p65 (NF-κB), and unexpectedly PPAR-γ. Additionally, the aptitude of AEA to inhibit malondialdehyde and boost glutathione points to its antioxidant capacity. Moreover, AEA by enhancing the depleted renal WNT-5A and reducing cystatin-C and KIM-1 (two kidney function parameters) partly verified its anti-apoptotic capacity, confirmed by inhibiting caspase-3 and increasing B-cell lymphoma-2 (BCL-2). The beneficial effect of AEA was mirrored by the improved architecture and kidney function evidenced by the reduction in cystatin-C, KIM-1, creatinine, BUN, and caspase1-induced activated IL-18. In conclusion, our results verify the reno-protective potential of AEA against HgCl2-induced kidney injury by its anti-inflammatory, antioxidant, and anti-apoptotic capacities by modulating WNT-5A/BCL-2, IP3/NFATC1, HMGB-1/RAGE/NF-κB, caspase-1/IL-18, and caspase-3/BCL-2 cues.

First Report of Colletotrichum siamense Causing Anthracnose on Eriobotrya japonica in China.

Eriobotrya japonica (Thunb.) Lindl. is a subtropical evergreen tree with economic and medicinal value. In 2021-2022, leaf-spot symptoms were observed on the leaves of E. japonica in Nanchang city, Jiangxi Province, China (28°68'N, 115°95'E). The disease incidence was 30% (20 diseased plants/60 surveyed plants). Symptoms included brown spots that gradually turned dark brown. The lesions were ca. 3-8 mm, and coalescing into irregular or round large lesions. Black acervuli were observed within the lesions. The margin of the diseased tissues was cut and surface sterilized in 75% ethanol for 10 s and 0.1% (v/v) mercuric chloride for 1 min, followed by three rinses in sterile water. Thirteen single spore isolates were purified and deposited in the Mycological Herbarium of Jiangxi Agricultural University. After 7 days, the colonies were grey-white with dense aerial mycelium. Conidia were uni-celled, hyaline and cylindrical. The sizes of the conidia were 12.6 to 17.5 × 4.2 to 6.5 μm. Appressoria were oval to irregular in shape and dark brown in color. These characteristics were consistent with descriptions of Colletotrichum siamense Prihastuti, L. Cai & K.D. Hyde (Weir et al. 2012; Rodríguez-Palafox et al. 2021). The internal transcribed spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), calmodulin (CAL), and actin (ACT) genes were amplified and sequenced (Diao et al. 2017). The sequences were submitted to GenBank with accession numbers ON631874, ON642546, ON642547 and ON642548, respectively. BLASTn searches confirmed high identity (>99%) with the type-strain of C. siamense (MH863513, KC297007, JX009702, JX009549). The concatenated sequences were used to construct a phylogenetic tree. The present isolate JXCS1 formed a single clade with the C. siamense. For pathogenicity, the leaves of two-year-old seedlings (cv. Dawuxing) were inoculated with 10 µL of spore suspension (1×106 conidia/mL). Leaves inoculated with sterile distilled water served as controls. Each treatment was replicated three times. Five days post-inoculation, water-soaked lesions appeared on the leaves, lesions gradually expanded into large round necrotic spots. No symptoms were observed on the control plants. C. siamense was reisolated from all inoculated samples, fulfilling Koch's postulates. To our knowledge, this is the first report of C. siamense causing anthracnose on E. japonica in China. The results further expand the range of plants that can be infected by C. siamense. This disease may decrease the value of plants and proper management strategies should be applied.

Mercuric chloride induced brain toxicity in mice: The protective effects of puerarin-loaded PLGA nanoparticles.

Mercury is a toxic, environmentally heavy metal that can cause severe damage to all organs, including the nervous system. The functions of puerarin include antioxidant, anti-inflammatory, nerve cell repair, regulation of autophagy, and so forth. But because of the limited oral absorption of puerarin, it affects the protective effect on brain tissue. The nano-encapsulation of Pue can improve its limitation. Therefore, this study investigated the protective effect of Pue drug-loaded PLGA nanoparticles (Pue-PLGA-nps) on brain injury induced by mercuric chloride (HgCl2 ) in mice. The mice were divided into normal saline (NS) group, HgCl2 (4 mg/kg) group, Pue-PLGA-nps (50 mg/kg) group, HgCl2 + Pue (4 mg/kg + 30 mg/kg) group, and HgCl2 + Pue-PLGA-nps (4 mg/kg + 50 mg/kg) group. After 28 days of treatment, the mice were observed for behavioral changes, antioxidant capacity, autophagy and inflammatory response, and mercury levels in the brain, blood, and urine were measured. The results showed that HgCl2 toxicity caused learning and memory dysfunction in mice, increased mercury content in brain and blood, and increased serum levels of interleukin(IL-6), IL-1β, and tumor necrosis factor-α in the mice. HgCl2 exposure decreased the activity of T-AOC, superoxide dismutase, and glutathione peroxidase, and increased the expression of malondialdehydein the brain of mice. Moreover, the expression levels of TRIM32, toll-like receptor 4(TLR4), and LC3 proteins were upregulated. Both Pue and Pue-PLGA-nps interventions mitigated the changes caused by HgCl2 exposure, and Pue-PLGA-nps further enhanced this effect. Our results suggest that Pue-PLGA-nps can ameliorate HgCl2 -induced brain injury and reduce Hg accumulation, which is associated with inhibition of oxidative stress, inflammatory response, and TLR4/TRIM32/LC3 signaling pathway.

Toxicological manifestations in gills, liver, kidney and muscles of Channa punctatus exposed to mercuric chloride

Aquatic regimes are exposed to a variety of pollutants that are mainly released by anthropogenic activities. Mercuric chloride (HgCl2) pose serious hazards to freshwater fish resource for its toxicity and long persistence. It is also a threat to humans who consume fish as a food resource. This study aimed to determine the consequences of acute exposure to HgCl2 in the freshwater food fish Channa punctatus (Bloch, 1973). The acute study of 96 hours was composed of three groups (in triplicates), having ten fish in each group which includes group I (control), group II (0.112 mg/l of HgCl2) and group III (0.224 mg/l of HgCl2). Results showed induction in reactive oxygen species (ROS) level in erythrocytes of group III (22159 ± 258.036). The biomarkers of oxidative stress, glutathione reduced (GSH) and lipid peroxidase (LPO) showed significant (p < 0.05) decrement and increment in their activity, respectively, in gills, liver, kidney and muscle tissues of the fish treated with HgCl2. Further, micronuclei (MN) and nuclear abnormalities (NAs) were formed in the erythrocytes of the fish of groups II and III, revealing DNA damage, hence showing genotoxicity. Histopathological studies in sample tissues of HgCl2 treated group demonstrated irreversible tissue injuries and anomalies. Thus, the findings from the study demonstrate that biological stress is induced in fish because of acute exposure to HgCl2, leading to health impairment

Improvement of Safflower (Carthamus tinctorius L.) for Salinity Tolerance under in vitro Condition

Aim: The primary aim of the present study was to screen the salt tolerant calli and optimization of in-vitro regeneration protocol from selected screen calli.
 Methodology: The cotyledonary leaf explants was sterilized by using 1% Bavistin, 0.1% Mercuric chloride and 70% ethanol followed by washing with distilled water. Sterilized explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentration of NaCl (i.e. 0, 50mM, 100mM, 200mM, 300 mM and 400 mM) to check the salinity tolerance ability of PKV pink genotype. In vitro screening of callus was studied by morphological characters like colour and texture of callus, callus growth percentage, relative water contained, cell survivility and proline content from saline stress and unstress calli to confirm the saline tolerance pressure to regenerate the PKV Pink safflower genotype.
 Results: MS medium supplemented with 150 mM NaCl showed 50% survival of calli, whereas no growth was obtained in high concentration of NaCl. Moreover, biochemical assay like proline estimation was done for its confirmation from different NaCl stress and unstress calli. The proline accumulation found to be highest callus grown on MS media supplemented with 150 mM NaCl as compared to control. Also studied the morphological observation i.e. colour and texture of calli, callus growth percentage, relative water content and cell viability under different NaCl stress to select the saline tolerance pressure to regenerate the tolerance line in PKV Pink. The saline tolerance shoots failed to produce in vitro rooting on the standardized rooting medium. So, the different approach like higher auxin shock and grafting experiment were attempted to overcome the rooting problem. Higher auxin shock experiment failed but grafting approach found satisfactory to overcome the rooting in saline tolerance shoot and for development of saline tolerance line in PKV Pink safflower genotype.
 Conclusion: The development of abiotic stress tolerance plants found the better understanding of physiological and biochemical changes in plants under in vitro stress conditions.

Morphological, serological, molecular detection, and phylogenetic analysis of Trypanosoma evansi in horses of different regions in Iran.

Trypanosoma evansi, the causative agent of "surra" is enzootic in Iran. The current study aimed to detect T. evansi in horses from different regions of Iran using morphological, serological, and molecular methods. In 2021, 400 blood samples were collected from horses in eight regions. Eighty horses showed clinical signs such as cachexia (n = 64), fever (n = 36), foot edema (n = 40), and abdominal edema (n = 32), and 320 horses appeared healthy. All samples from the studied regions were evaluated for the presence of trypanosomes using direct analysis of blood smears, mercuric chloride, and PCR-based tests. In total, 12% (95% CI: ± 3.1%), 21% (95% CI: ± 3.9%), and 21% (84) of animals were positive for Trypanosoma in microscopic, serologic, and molecular analyses, respectively. All animals positive for SSU rDNA PCR were from Qom, Semnan, and Golestan regions. Further molecular analyses on 84 PCR-positive horses revealed that 29 horses scored positive in PCR using primers of trypanozoon species and 5 scored positive in PCR using primers of Trypanosoma evansi type A. All samples (n = 5) were from Qom region. The 205-bp fragments of T. evansi RoTat 1.2VSG (accession numbers: ON017789-93) analyzed and compared to other isolates sequence from GenBank BLAST search. It has close similarities with isolates from Pakistan, Egypt, Malaysia, Kenya, and India. Data herein demonstrated that horses from Iran were at high risk of T. evansi infection. Comprehensive control programs, such as those based on the application of repellants and traps, and also, compliance with quarantine standards are recommended for minimizing the risk of the infection.

Mercuric Chloride Induced Nephrotoxicity: Ameliorative Effect of Carica papaya Leaves Confirmed by Histopathology, Immunohistochemistry, and Gene Expression Studies.

The present study analyzes the efficacy of the ethanolic extract of C. papaya leaves (ECP) against HgCl2-induced nephrotoxicity. The effects on the biochemical and percentage of body and organ weight against HgCl2-induced nephrotoxicity in female Wistar rats were studied. Wistar rats were divided into five groups with six animals in each group: control, HgCl2 (2.5 mg/kg b.w.), N-acetylcysteine (NAC 180 mg/kg) + HgCl2, ECP (300 mg/kg b.w.) + HgCl2, and ECP (600 mg/kg) + HgCl2 groups. After 28 days of study, animals were sacrificed on the 29th day to harvest the blood and kidneys for further analysis. The effect ECP was analyzed by immunohistochemistry (NGAL) and real-time PCR (KIM-1 and NGAL mRNA) in HgCl2-induced nephrotoxicity. The results revealed that the HgCl2 group showed prominent damage in the proximal tubules and glomerulus of nephrons and enormous expression of NGAL in immunohistochemistry and KIM-1 and NGAL in real-time PCR compared to the control group. The simultaneous pretreatment with NAC (180 mg/kg) and ECP (600 and 300 mg/kg) reduced renal damage and expression of NGAL in immunohistochemistry and KIM-1 and NGAL gene in real-time PCR. This study attests to the nephroprotective effect of ECP against HgCl2-induced toxicity.

In-vivo Ameliorative Potential Effect of N-Acetylcysteine and Gallic Acid against Hepatotoxicity Induced by Mercuric Chloride in Wistar Rats

Mercury is a highly toxic metal induces oxidative stress in the body and results in a variety of adverse health effects including liver damage. In the present experimental study was to investigate the hepatoprotective effect of some phytochemical on Mercury intoxicated rats. During treatment periods, a sub-lethal dose of mercuric chloride (1.29 mg/kg body weight) treated rat liver tissue shows hepatic injury is mainly associated with distortion of the metabolic function of the liver in rats, it is Hepatic damage can be evaluated by biochemical analysis of the serum tests, includes levels of serum Alanine and Aspartate aminotransferases, alkaline phosphatase, lactic dehydrogenase of liver marker enzymes. In the present experimental study, drastically altered in the level of Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Alkaline phosphatase (ALP), Lactic dehyrogenase (LDH) and Bilirubin levels were observed in the blood serum of mercuric chloride intoxicated Wistar rats. The activity of liver marker enzymes such as ALT AST, ALP and LDH were significantly increased. In addition, lipid peroxidation (LPO) were significantly increased while the activities of the levels of non enzymatic antioxidants (reduced glutathione (GSH)) and enzymatic antioxidants (glutathione peroxidase (GPx) superoxide dismutase (SOD) and catalase (CAT)) were significantly decreased in liver tissues and the toxicity with mercury is associated with oxidative stress in which mercury induces the formation of free radicals including ROS. It alters the antioxidant capacity of the cells to promote cellular damages. During the recovery period, the hepatic marker enzymes, enzymatic antioxidant and non-enzymatic antioxidant are restored to near normal level in liver tissues. Our experimental studies indicate that treatment for N-Acetylcysteine and Gallic acid exhibited the strong hepatoprotective activity against mercuric chloride induced liver damage in Wistar rat.

Assessing Kidney Injury Induced by Mercuric Chloride in Guinea Pigs with In Vivo and In Vitro Experiments.

Acute kidney injury, which is associated with high levels of morbidity and mortality, affects a significant number of individuals, and can be triggered by multiple factors, such as medications, exposure to toxic chemicals or other substances, disease, and trauma. Because the kidney is a critical organ, understanding and identifying early cellular or gene-level changes can provide a foundation for designing medical interventions. In our earlier work, we identified gene modules anchored to histopathology phenotypes associated with toxicant-induced liver and kidney injuries. Here, using in vivo and in vitro experiments, we assessed and validated these kidney injury-associated modules by analyzing gene expression data from the kidneys of male Hartley guinea pigs exposed to mercuric chloride. Using plasma creatinine levels and cell-viability assays as measures of the extent of renal dysfunction under in vivo and in vitro conditions, we performed an initial range-finding study to identify the appropriate doses and exposure times associated with mild and severe kidney injuries. We then monitored changes in kidney gene expression at the selected doses and time points post-toxicant exposure to characterize the mechanisms of kidney injury. Our injury module-based analysis revealed a dose-dependent activation of several phenotypic cellular processes associated with dilatation, necrosis, and fibrogenesis that were common across the experimental platforms and indicative of processes that initiate kidney damage. Furthermore, a comparison of activated injury modules between guinea pigs and rats indicated a strong correlation between the modules, highlighting their potential for cross-species translational studies.

Mercury remediation potential of mercury-resistant strain Rheinheimera metallidurans sp. nov. isolated from a municipal waste dumping site

A novel mercury-resistant bacterium, designated strain DCL_24T, was isolated from the legacy waste at the Daddu Majra dumping site in Chandigarh, India. It showed resistance up to 300 µM of inorganic mercury (mercuric chloride). The isolate was found to be a Gram-negative, facultative anaerobic, motile, and rod-shaped bacterium that can grow at 4 – 30 °C (optimum 25 °C), pH 6.0 – 12.0 (optimum 7.0), and 0 – 4.0 % (w/v) NaCl (optimum 0.5 – 2.0 %). The 16 S rRNA gene-based phylogenetic analysis showed that DCL_ 24 T shared a 97.53 % similarity with itsºlosest type strain Rheinheimera muenzenbergensis E-49T. Insilico DNA-DNA hybridization and average nucleotide identity values were found to be 18.60 % and 73.77 %, respectively, between the genomes of DCL_24T and R. muenzenbergensis E-49T. The strain DCL_24T has 44.33 DNA G+C content (mol %). Based on the phenotypic, chemotaxonomic, and genotypic data, the strain DCL_24T represents a novel species within the genus Rheinheimera, for which the name Rheinheimera metallidurans sp. nov is proposed. The type strain is DCL_24T (MTCC13203T = NBRC115780T = JCM 35551 T). The isolate was found to volatilize and remove mercury efficiently, as demonstrated by X-ray film and dithizone-based colorimetric methods. Around 92 % of mercury removal was observed within 48 h. The mercury-resistant determinant mer operon consisting of merA, encoding the mercuric reductase enzyme, and transport and regulatory genes (merT, merP, merD, and merR) were found in the isolate. Relative expression analysis of merA at increasing concentrations of HgCl2 was confirmed by quantitative real-time PCR. These data indicate the merA-mediated reduction of toxic Hg2+ into a non-toxic volatile Hg0. The phytotoxicity assay performed using Arabidopsis thaliana seeds further demonstrated the mercury toxicity reduction potential of DCL_24T. The study shows that this novel isolate, DCL_24T, is an interesting candidate for mercury bioremediation. However, further studies are required to assess the bioremediation efficacy of the strain under the harsh environmental conditions prevailing in polluted sites.

N‐Aroyl‐N′‐(1‐Naphthyl)‐N′′‐aryl guanidines as a New Entry to Urease Inhibitors: Synthesis, Kinetic Mechanism, Molecular Docking and MD Simulation Studies

AbstractA series of novel guanidines (6 a–j) was synthesized from corresponding thioureas using catalytic mercuric chloride in DMF. The synthesized compounds were characterized by spectroscopic techniques and appraised for Jack Bean Urease (JBU) inhibition. All compounds (6 a–j) exhibited strong potential against JBU whilst compound 6 b (IC50=0.0155±0.00087 μM) and 6 e (IC50=0.0091±0.00036 μM) displayed excellent urease inhibition compared to thiourea (IC50=18.27 μM) used as reference. The kinetic mechanism analyzed by Lineweaver‐Burk plots revealed that 6 b is a mixed‐type inhibitor while 6 e is a non‐competitive inhibitor. Thus, compounds 6 e and 6 b can serve as a structural model for the designing of super‐effective urease inhibitors. Binding affinity and interaction of N‐aryl guanidine analogs were evaluated through molecular docking studies. To evaluate the residual flexibility of receptor through MD simulation, RMSD and RMSF graphs were evaluated to determine the protein structural behavior. It is implied that compound 6 e can serve as a novel molecular template to medicinal chemists for designing more potent urease inhibitors.