Allium sativum Essential Oil Supplementation Reverses the Hepatic Inflammation, Genotoxicity and Apoptotic Effects in Swiss Albino Mice Intoxicated with the Lead Nitrate

Prolonged lead (Pb) exposure impairs human health due to its interference with physiological and biochemical processes. Therefore, it is necessary to investigate natural therapeutics to alleviate Pb-induced intoxication. In the current investigation, essential oil extracted from the fresh bulbs of Allium sativum was considered as a natural remedy. Initially, in vitro antioxidant and anti-inflammatory activity of A. sativum essential oil (ASEO) were explored. The results reported that ASEO exhibits potent antioxidant and anti-inflammatory potential. Additionally, an in vivo study was conducted to elucidate its preventive role against Lead-nitrate (LN)-induced hepatic damage in Swiss albino mice. The experimental mice were allocated into six groups: Control, LN-intoxicated group (50 mg/kg), LN + ASEO (50 mg/kg), LN + ASEO (80 mg/kg), LN + Silymarin (25 mg/kg), and LN + vehicle oil control group. The entire duration of the study was of 30 days. From the results, it was determined that LN exposure elevated the Pb content in hepatic tissues which subsequently increased the serum biomarkers, inflammatory cytokines (NF-kB, TNF-α, IL-6) as well as apoptotic factors (caspase-3, BAX), all of which contribute to DNA damage. Meanwhile, it reduced anti-inflammatory (IFN-γ and IL-10) and anti-apoptotic factors (Bcl-2). Furthermore, Pb accumulation in hepatic tissues changed the histological architecture, which was linked to necrosis, central vein dilation, inflammatory cell infiltration and Kupffer cell activation. In contrast to this, ASEO administration decreased the Pb content, which in turn reduced the level of serum biomarkers, inflammatory and apoptotic factors. At the same time, it increased the anti-inflammatory and anti-apoptotic factors, thereby reduced DNA damage and restored the hepatic histology. In conclusion, exhaustive research is of the utmost demand to elucidate the precise defense mechanisms of ASEO against LN-induced hepatotoxicity.

Comparative effects of caffeine and lead nitrate on the bio-physiological and yield associated traits of lentil (Lens culinaris Medik.)

Lentil belonging to the fabaceae family is a proteinaceous cool-season legume consumed across the world. However, lentil is low yielding with a narrow genetic base compared to other grain legumes such as chickpea, faba bean, and cowpea. In the present study, we intended to investigate the effect of two different mutagens viz., caffeine and lead nitrate on the bio-physiological and agronomical traits of lentil. Unlike other mutagens like ethyl methanesulphonate, sodium azide, and hydrazine hydrates very little is known about the mutagenic potency of caffeine and lead nitrate. The results revealed contrasting effects as lower doses of caffeine-induced a substantial increase in mean values of physiological and agronomical traits whereas both lower and higher doses of lead nitrate negatively impacted the agronomical traits of lentil. Among the mutagen doses, 0.1% caffeine was most efficient in inducing a substantial increase in mean values of bio-physiological and quantitative traits. The present study also revealed the successful conduct of induced mutagenesis in lentil and present a protocol that could be followed in future breeding programs aimed at increasing the yielding potential of legumes.

Morinda lucida stem bark reversed the pattern and extent of lead nitrate-induced liver injury in Wistar rats

Lead toxicity remains one of the most important occupational and environmental health problems with characteristic features that are incompatible with life. Considering the foregoing, we investigated the ameliorative potentials of Morinda lucida stem bark (MLSB) extract on lead nitrate-induced hepatic injury with particular emphasis on its effects on the pattern and extent of lead nitrate toxicity. Thirty-six adult Wistar rats were randomly assigned into six groups (n=6). Normal control group received 2.2mL/kg distilled water only for 4 weeks while hepatic injury was induced by 2-week oral administration of 30mg/kg lead nitrate to experimental rats in the remaining five groups. Following induction, test groups were treated with MLSB for another 2 weeks at 100, 250, and 500mg/kg concentrations respectively while silymarin was administered orally for 2 weeks to positive control group. At the end of the study, serum activities of liver function enzymes and tissue levels of malondialdehyde were determined. Patterns and extent of injury were determined in hematoxylin and eosin-stained section. The result revealed a significant reduction in sera levels of liver function enzymes and tissue level of malondialdehyde (MDA) in extract treated groups. Lead nitrate-induced necrotic changes and other deranged features observed in histological sections were multifocal and they span through multiple zones of hepatic acini (panacinar), MLSB at 250mg/kg concentration reversed by some of these effects. The study concluded that ameliorative property of MLSB could be due to the antioxidant and membrane stabilizing properties of its phenolic compounds.

Toxicopathological impact of sub-lethal concentrations of lead nitrate on the gill of the catfish Heteropneustes fossilis

In recent studies, fish are heavily used as biomarkers of aquatic pollution, and heavy metals are among the main contributors to water pollution. In the present study, we investigated histopathological changes along with alterations in localization and activity of enzymes alkaline phosphatase (ALP), acid phosphatase (ACP), catalase (CAT), peroxidase (PER) and Na⁺/K⁺-ATPase in the gill tissues of Indian stinging catfish Heteropneustes fossilis exposed to two different concentrations (0.4 and 4 mg/L) of lead nitrate for 15 days. Histopathological examination of gill tissues revealed hypertrophy and swelling of epithelial cells, the fusion of epithelium of gill filaments and secondary lamellae, and alteration of secondary lamellae structure. Biochemical assays and histochemical localization show a pronounced effect on enzyme alkaline phosphatase activity and acid phosphatase in the gills of both groups of treated groups. In contrast, a significant decrease was noticed in the enzymatic response including catalase and peroxidase activity. Being a vital organ gill reflects the fish's physiological condition and the severity of the contamination in the surrounding environment. Gill is also the prime organ of osmoregulation in teleosts. Decreased activity of Na⁺/K⁺-ATPase suggests lead as a potent inhibitor of Na⁺/K⁺-ATPase that causes sodium hyperregulation. Alteration in the activity of metabolic enzymes reflects the level of tissue damage and metabolic disruption. At the same time, the increased activity of antioxidant enzymes states the condition of oxidative stress. Haematological parameters also altered with the lead nitrate exposure, reflecting metal toxicity and immune response against it. Meanwhile, this study also provides a potential use of H. fossilis as a biomarker for aquatic pollution.

Impact of salicylic acid on the growth and physiological activities of parsley plants under lead toxicity

Impact of spraying 50 µM salicylic acid (SA), lead nitrate soil treatments [1 and 2 mM Pb (NO₃)₂] and their combinations on parsley leaves (Petroselinum crispum L.) for 3 weeks was studied to evaluate leaf symptoms, photosynthetic pigments, anthocyanin, ultrastructure, malondialdehyde (MDA), soluble proteins, phenolic compounds, and guaiacol peroxidase activity (GPOX). Under Pb effect, parsley leaves showed chlorosis and decline in the content of photosynthetic pigments chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoid (Car) with increasing Pb treatments compared to the control. SA spraying helped to reduce chlorosis and increase photosynthetic pigments of Pb-treated plants compared to that of Pb treatment alone. Leaf anthocyanin content of SA-sprayed plants significantly increased compared to the control. On contrast, the anthocyanin content of Pb-treated plants with or without SA treatment decreased compared to the control. Parsley leaf chloroplasts were characterized by many and large starch grains. Deformations of chloroplast shape, increasing formation of plastoglobules and degeneration of chloroplast grana thylakoids were observed in Pb-treated plants. MDA and total phenolic compound contents increased in Pb-treated plants compared to the control. In contrast, soluble protein content decreased in Pb-treated plants. The decrease in leaf photosynthetic pigments and increase MDA contents was Pb-concentration dependent. The results as indicated by increasing lipid peroxidation confirmed Pb treatments generated reactive oxygen species (ROS) which caused oxidative stress. In contrast, SA application declined the extent of detrimental and harmful influence of Pb toxicity as indicated by the decrease MDA content, and increase in photosynthetic pigments, anthocyanin and phenolic compound contents of parsley leaves.

Immune status of Oreochromis niloticus subjected to long-term lead nitrate exposure and a Arthrospira platensis treatment trial

In this study, the impacts of lead toxicity on Oreochromisniloticus were investigated. Additionally, the potential ameliorative effects of the Spirulina algae Arthrospira platensis were evaluated. The median lethal concentration (LC₅₀) of PbNO₃ was determined to be 143.3 mg/l for O. niloticus weighing 42 ± 2.5 g. O. niloticus were exposed to 10 % of the estimated PbNO₃ LC₅₀ for 12 weeks. The cumulative mortality rate (CMR) increased with exposure time. The results of assays for red blood cells (RBCs), haemoglobin (Hb), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC) indicated that the exposed O. niloticus suffered from anaemia. The levels of liver enzymes, namely, aspartate transaminase (AST) and alanine transaminase (ALT), as well as metallothionein)MT(revealed deterioration of hepatic tissue. The activity of the antioxidant enzymes glutathione peroxidase (GPx) as well as catalase (CAT) was stimulated in the hepatic tissue of O. niloticus exposed to PbNO₃ and in those treated with A. platensis. Based on the results of serum bactericidal activity (SBA) and oxidative burst activity (OBA) assays as well as challenge tests with Aeromonas hydrophila, it was clear that supplementation with 5 or 10 g/kg A. platensis significantly enhanced the fish immune status and decreased the mortality rate (MR). However, these effects were reduced by PbNO₃ exposure with no differences in MR percentage. Therefore, it was clear that O. niloticus reared in lead nitrate-polluted water were immunosuppressed, while diet supplementation with A. platensis could ameliorate such impacts.

Ameliorative effect of Spirulina platensis against lead nitrate-induced cytotoxicity and genotoxicity in catfish Clarias gariepinus

The present study was designed to investigate the protective role of dietary supplementation of Spirulina platensis (SP) against cytotoxic and genotoxic effects of lead nitrate in Clarias gariepinus. Four groups of fishes were used: first group as control which fed on basal diet, second group fed on basal diet and exposed to (1 mg/L of lead nitrate), third group fed on diet containing 0.25% SP and exposed to (1 mg/L of lead nitrate), and fourth group fed on diet containing 0.5%SP and exposed to (1 mg/L of lead nitrate). Fish samples were taken at 2nd and 4th week of exposure. The hematological indices of lead nitrate-exposed group were decreased significantly compared to the control group at 2nd and 4th week of exposure. Lead nitrate caused a significant increase in the percentage of poikilocytosis, micronuclei, and apoptotic cells as well as comet tail length and olive tail moment compared with the control group at 2nd and 4th week of exposure. The highest level of damage was found on 4th week of exposure with all parameters. Dietary inclusion of SP ameliorated these cytotoxic and genetic changes, as well as this amelioration was concentration and time dependent. Consequently, the present study proposed that the addition of SP to the fish diet can be used as a promising protective agent to oppose cytotoxic and genotoxic effects of lead nitrate in aquaculture. Graphical abstract.

Protective effects of a novel pyrazolecarboxamide derivative against lead nitrate induced oxidative stress and DNA damage in Clarias gariepinus

Pyrazole derivatives display diverse biological and pharmacological activities. The aim of this study is to investigate the antioxidant properties of a novel pyrazolecarboxamide derivative (4-amino-N-[(4-chlorophenyl)]-3-methyl-1-phenyl-1H-thieno [2, 3-c] pyrazole-5-carboxamide) in African catfish, Clarias gariepinus, exposed to 1 mg/L PbNO₃. Fish were intramuscularly injected with pyrazole-5-carboxamidederivative according to the following groupings: Group 1 (control), Group 2 (1 mg/L lead nitrate), Group 3 (1 mg/L lead nitrate + 5 mg pyrazole derivative/kg body weight), and Group 4 (1 mg/L lead nitrate + 10 mg pyrazole derivative/kg body weight) for two weeks and four weeks. Lead nitrate (1 mg/L) caused significant elevation of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, uric acid, cholesterol, and glucose-6-phosphate dehydrogenase (G6PDH) compared to the control group after two and four weeks of exposure, while serum total lipids, alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) were significantly reduced compared to the control group. Furthermore, levels of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) and total antioxidant capacity (TAC) were reduced in group 2 compared to the control group. However, in group 2, hepatic lipid peroxidation (LPO) and DNA fragmentation percentage were significantly increased compared to the control group. Histopathological changes in the liver of lead-exposed groups included marked disturbance of hepatic tissue organization, degeneration of hepatocytes, dilation of blood sinusoids and the central vein as well as necrosis. Injection of pyrazole derivative for two weeks and four weeks reversed alterations in biochemical parameters, antioxidant biomarkers, lipid peroxidation, hepatic DNA damage, and histopathological changes in liver tissue induced by 1 mg/L lead nitrate. This amelioration was higher in response to high-dose pyrazole derivative (10 mg) at the fourth week of exposure, showing concentration-and time-dependency. Overall, the sensitized derivative pyrazolecarboxamide is likely a useful tool to minimize the effects of lead toxicity due to its potent antioxidant activity.

Platelet-rich plasma as a potential therapeutic approach against lead nitrate- and/or gamma radiation-induced hepatotoxicity

Because of the potential regenerative and cytoprotective effects of its content of numerous bioactive growth factors and cytokines, platelet-rich plasma (PRP) became an attractive biomaterial for therapeutic purposes. Therefore, the current study was designed to investigate the potential therapeutic effect of PRP against lead nitrate- and/or γ-radiation-induced hepatotoxicity. To do so, hepatotoxicity was induced in rats by intraperitoneal administration of lead nitrate (7.5 mg/kg) thrice weekly for two consecutive weeks and/or a whole-body γ-irradiation at a single dose of 6 Gy. Activated PRP (0.5 ml/kg) was injected subcutaneously 24 h after the last dose of lead nitrate and/or γ-irradiation and continued twice weekly for three successive weeks. Lead nitrate intoxication and/or γ-irradiation resulted in a significant elevation of serum alanine transaminase and aspartate transaminase activities accompanied with a significant decrease in serum levels of total protein and albumin. Further, a significant increase in malondialdehyde level and nitric oxide content accompanied with a significant decrease in the reduced glutathione content and the enzyme activities of glutathione-S-transferase, superoxide dismutase, and catalase were observed. Additionally, hepatic extracellular signal-regulated kinase (ERK) and Akt signaling pathways were stimulated. PRP treatment notably ameliorated the induced cell injury, reduced the intracellular oxidative and interestingly increased the upregulation of phosphorylated ERK1/2 and Akt. Moreover, PRP treatment relieved lead nitrate and/or γ-radiation-induced hepatic histological damages. In conclusion, this study sheds the light on a probable therapeutic role of PRP against lead nitrate- and/or γ-radiation-induced hepatotoxicity which might attribute to its ability to activate ERK and Akt signaling pathways.

Eco-toxicological effects of two kinds of lead compounds on forest tree seed in alkaline soil

In order to compare the different eco-toxicological effects of lead nitrate and lead acetate on forest tree seed, a biological incubation experiment was conducted to testify the inhibition effects of two lead compounds on rates of seed germination, root and stem elongation, and seedling fresh weight for six plants (Amaorpha fruticosa L., Robinia psedoacacia L., Pinus tabuliformis Carr., Platycladus orientalis L., Koelreuteria paniculata Laxm., Hippophae rhamnoides L.) in soil. The results indicate that the inhibition effects of the two lead compounds on the rates of root elongation of plants were greater than other indices; root elongation can possibly be used as indices to investigate the relationship between lead toxicity and plant response. The response of trees to lead toxicity varied significantly, and the order of tolerance to lead pollution was as follows: Amaorpha fruticosa L. > Platycladus orientalis L. > Koelreuteria paniculata Laxm. > Robinia psedoacacia L. > Pinus tabuliformis Carr. > Hippophae rhamnoides L. Therefore, we suggest that Amaorpha fruticosa L. and Platycladus orientalis L. be used as tolerant plants for soil phytoremediation and Hippophae rhamnoides L. as an indicative plant to diagnose the toxicity of lead pollution on soil quality. Lead nitrate and lead acetate differentially restrain seeds, with seeds being more sensitive to lead nitrate than lead acetate in the soil. Thus, the characteristics of lead compounds should be taken into full consideration to appraise its impact on the environment.

Subacute effects of low dose lead nitrate and mercury chloride exposure on kidney of rats

Lead nitrate and mercury chloride are the most common heavy metal pollutants. In the present study, the effects of lead and mercury induced nephrotoxicity were studied in Wistar rats. Lead nitrate (LN, 45 mg/kg b.w/day) and mercury chloride (MC, 0.02 mg/kg b.w/day) and their combination were administered orally for 28 days. Four groups of rats were used in the study: control, LN, MC and LN plus MC groups. Serum biochemical parameters, lipid peroxidation, antioxidant enzymes and histopathological changes in kidney tissues were investigated in all treatment groups. LN and MC caused severe histopathological changes. It was shown that LN, MC and also co-treatment with LN and MC exposure induced significant increase in serum urea, uric acid and creatinine levels. There were also statistically significant changes in antioxidant enzyme activities (SOD, CAT, GPx and GST) and lipid peroxidation (MDA) in all groups except control group. In this study, we showed that MC caused more harmful effects than LN in rats.