Oxidative stress and histopathological effect of zinc oxide nanoparticles on the garden snail Helix aspersa

Zingiber officinale Ameliorates Acute Toxoplasmosis-Induced Pathology in Mice

BACKGROUND

Toxoplasma gondii (T. gondii) infects one third of the world's population with significant illness, mainly among immunocompromised individuals and pregnant women. Treatment options for toxoplasmosis are limited which signifies the need for novel, potent, and safe therapeutic options. The goal of this study was to assess the effectiveness of the ethanolic extract of Zingiber officinale (Z. officinale) in treating mice infected with the RH T. gondii strain.

MATERIALS AND METHODS

Gas Chromatography/Mass Spectrometry (GC/MS) was used to identify components of ethanolic extract of Z. officinale. A total of 80 mice were randomly allocated into four experimental groups that contained 20 mice each. The first group was left uninfected (uninfected control), while three groups were infected with T. gondii RH virulent strain tachyzoites at 2500 tachyzoites/mouse. One infected group was left untreated (infected, untreated), whereas the other two groups were treated orally with either spiramycin (positive control) or Z. officinale ethanolic extract at doses of 200 mg/kg and 500 mg/kg, respectively for 5 days, starting the day of infection. Ten mice from each group were used to assess mice survival in different groups, whereas the other ten mice in each group were sacrificed on the 5th day post-infectin (dpi) to estimate the treatment efficacy by quantifying liver parasite load, liver function, nitric oxide (NO) production, and levels of antioxidant enzymes. Additionally, histopathological studies were performed to evaluate the therapeutic effect of Z. officinale treatment on toxoplasmosis-induced pathological alterations in liver, brain, and spleen.

RESULTS

Treatment with Z. officinale ethanolic extract extended the survival of mice till 9th dpi compared to 7th dpi in infected untreated mice. Higher percentage of mice survived in Z. officinale-treated group compared to spiramycin-treatment group at different time points. Liver parasite loads were significantly lower in Z. officinale extract-treated mice and spiramycin-treated mice compared to infected untreated mice which correlated with significantly lower levels of serum liver enzymes (ALT, AST) and nitric oxide (NO), as well as significantly higher catalase (CAT) antioxidant enzyme activity. Scanning electron microscopy (SEM) examination of tachyzoites from the peritoneal fluid revealed marked damage in tachyzoites from Z. officinale-treated group compared to that from infected untreated mice. Moreover, treatment with Z. officinale ethanolic extract alleviated infection-induced pathological alterations and restored normal tissue morphology of liver, brain, and spleen.

CONCLUSION

Our results demonstrated that Z. officinale treatment reduced parasite burden and reversed histopathological and biochemical alterations in acute murine toxoplasmosis. These findings support the potential utility of Z. officinale as a future effective natural therapeutic for toxoplasmosis. Further studies are needed to determine the effective active ingredient in Z. officinale extract that can be further optimized for treatment of toxoplasmosis.

Hassan A, Mohamed K, Alfaifi MS, Elshazly H, Alamri ZZ, Wakid MH, Gattan HS, Altwaim SA, Al-Megrin WAI, Younis S. Zinc oxide nanoparticles produced by Zingiber officinale ameliorates acute toxoplasmosis-induced pathological and biochemical alterations and reduced parasite burden in mice model

BACKGROUND

Although, approximately 30% of the world's population is estimated to be infected with Toxoplasma gondii (T. gondii) with serious manifestations in immunocompromised patients and pregnant females, the available treatment options for toxoplasmosis are limited with serious side effects. Therefore, it is of great importance to identify novel potent, well tolerated candidates for treatment of toxoplasmosis. The present study aimed to evaluate the effect of Zinc oxide nanoparticles (ZnO NPs) synthesized using Zingiber officinale against acute toxoplasmosis in experimentally infected mice.

METHODS

The ethanolic extract of ginger was used to prepare ZnO NPs. The produced ZnO NPs were characterized in terms of structure and morphology using Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), UV- spectroscopy and scanning electron microscopy (SEM). The prepared formula was used in treatment of T. gondii RH virulent strain. Forty animals were divided into four groups, with ten mice per group. The first group was the uninfected, control group. The second group was infected but untreated. The third and the fourth groups received ZnO NPs and Spiramycin orally in a dose of 10 mg/kg and 200 mg/kg/day respectively. The effect of the used formulas on the animals survival rate, parasite burden, liver enzymes -including Alanine transaminase (ALT) and aspartate transaminase (AST)-, nitric oxide (NO) and Catalase antioxidant enzyme (CAT) activity was measured. Moreover, the effect of treatment on histopathological alterations associated with toxoplasmosis was examined.

RESULTS

Mice treated with ZnO NPs showed the longest survival time with significant reduction in the parasite load in the livers and peritoneal fluids of the same group. Moreover, ZnO NPs treatment was associated with a significant reduction in the level of liver enzymes (ALT, AST) and NO and a significant increase in the antioxidant activity of CAT enzyme. SEM examination of tachyzoites from the peritoneal fluid showed marked distortion of T. gondii tachyzoites isolated from mice treated with ZnO NPs in comparison to untreated group. T. gondii induced histopathological alterations in the liver and brain were reversed by ZnO NPs treatment with restoration of normal tissue morphology.

CONCLUSION

The produced formula showed a good therapeutic potential in treatment of murine toxoplasmosis as demonstrated by prolonged survival rate, reduced parasite burden, improved T. gondii associated liver injury and histopathological alterations. Thus, we assume that the protective effect observed in the current research is attributed to the antioxidant capability of NPs. Based on the results obtained from the current work, we suggest greenly produced ZnO NPs as a chemotherapeutic agent with good therapeutic potential and high levels of safety in the treatment of toxoplasmosis.

Potential toxic effects of titanium oxide (TiO2) nanoparticles on the biological, biochemical, and histological aspects of the land snail Helix aspersa

Nanotechnology has come a long way in our lives. However, it maintains some negative effects on the environment. This study aims to use the land snail Helix aspersa as a bioindicator. Titanium dioxide nanoparticles (TiO₂NPs) had been used at 70 and 140 µg/L for two weeks by the spraying method. The oxidative biomarkers, condition index (CI), DNA damage, hemocyte count, and phagocytic activity were estimated. The toxicity of TiO₂NPs was determined (LC₅₀ = 544 µg/L). The exposure to TiO₂NPs caused a significant reduction of the activities of superoxide dismutase (SOD) and catalase (CAT) in the digestive gland of Helix aspersa (the activity of CAT was 3.4 ± 0.1 (P = 0.001), SOD was 11 ± 1 (P = 0.0002) at concentration 140 µg/L after two weeks). The activity of glutathione peroxidase (GPX) was (1.13 ± 0.01 µ/mg protein at 140 µg/L compared with controls (5.47 ± 0.01 µ/mg protein). The treatment caused DNA damage in the hemocytes (tail DNA % = 8.66 ± 0.02 and tail moment = 52.99 ± 0 at140 µg/L (P = 0.002)). In the digestive gland, both tail DNA % and tail moment increased (tail moment = 78.38 ± 0.08 compared with control = 2.29 ± 0.09 (P = 0.0001)). The total count of hemocytes significantly decreased after two weeks (the average number was 71 ± 1.5 compared with controls 79 ± 1.1 at 140 µg/L). Furthermore, TiO₂NPs caused histological alterations in the digestive gland of Helix aspersa. It can be concluded that the Helix aspersa can be used as environmental pollution bioindicator. A comprehensive evaluation of toxic effects induced by TiO₂NPs in vivo assays must be investigated.

Chronic and transgenerational effects of silver nanoparticles in freshwater gastropod Lymnaea stagnalis

Traditional ecotoxicological studies prove to be focused mainly on single-generation, multigenerational research in ecotoxicological testing is needed to improve the predictive approaches in ecological risk assessment. Silver nanoparticles (AgNPs) have been increasingly detected in aquatic environments due to their extensive use in consumer products. We investigated the transgenerational effects of AgNPs on the life traits of freshwater model gastropods Lymnaea stagnalis for two generations. The reversibility of the effects of using recovery experiments was also performed. Results showed that AgNPs induced high Ag bioaccumulation in the whole soft tissues of parental L. stagnalis after 21 days of exposure. The increased ROS production and reduced condition index and fecundity were found after exposure to AgNPs at 500 μg/L. These results highlight that under AgNPs exposure, adult gastropods might allocate more resources to resist oxidative stress rather than to growth or reproduction. Furthermore, the Ag accumulation and ROS production of egg clutches were significantly related to parental exposure duration and concentrations. On the other hand, isolated eggs exposure demonstrated biological effects were persistent in terms of the next generation. For example, after transfer to a clean medium, similar Ag bioaccumulation and ROS production were observed from eggs which parents were pre-exposed to 50 and 500 μg/L AgNPs. Current explicit consideration of offspring performance adds value to existing toxicity testing protocols. Parental exposure duration has important implications for offspring effects, and parental exposure can cause transgenerational changes in resistance that have significant implications for toxicity testing and adaptive responses. These effects across generations point out the need for multigenerational tests to assess the environmental risk of MNPs in aquatic organisms.

Crosstalk Between the Mitochondrial Dynamics and Oxidative Stress in Zinc-induced Cytotoxicity

Zinc is an essential trace element, which plays an important role in multiple biological activities. However, excessive exposure to zinc can cause toxic damage to living organism. Here, we investigated the relationship between oxidative stress and mitochondrial dynamics in the zinc-induced cytotoxicity. Results showed that excess exposure to zinc could significantly reduce cell viability and induce cell vacuolation in PK-15 cells. Additionally, zinc exposure caused mitochondrial dynamics disorder, manifested as mitochondrial fission, and the elevated mRNA level of Drp1 and downregulated mRNA levels of OPA1, Mfn1, and Mfn2. Meanwhile, zinc could induce oxidative damage, evidenced by the increasing levels of hydrogen peroxide, malondialdehyde, lipid peroxidation, oxidized form of nicotinamide adenine dinucleotide phosphate/nicotinamide adenine dinucleotide phosphate, oxidized glutathione/glutathione, superoxide dismutase activity, and the mRNA expression of SOD-1 and NOQ1, and decreasing levels of catalase activity, glutathione peroxidase activity, glutathione reductase activity, and the mRNA expression of CAT, and GPX1. Interestingly, N-acetyl-L-cysteine, an inhibitor for oxidative stress, could reduce the mitochondrial fission under zinc treatment. Besides, Mdivi-1, a mitochondrial fission inhibitor, could relieve oxidative stress caused by excess zinc. In general, these results suggested that mitochondrial fission and oxidative stress induced by zinc were interrelated in PK-15 cells, which is conducive to explore the new mechanism of zinc toxicity and proposes a theoretical foundation for selecting effective drugs to alleviate the toxic effects caused by zinc.

Molluscicidal and biochemical effects of green-synthesized F-doped ZnO nanoparticles against land snail Monacha cartusiana under laboratory and field conditions

The glass clover snail, Monacha cartusiana (M. cartusiana) is one of the most seriously impacting economic animal pests spreading across Egypt which inflicts severe damages to the agriculture. A green route is developed by deploying an abundant Rosemary plant leaves aqueous extract to synthesize ZnO and F-doped ZnO (F-ZnO) nanoparticles (NPs) that display high molluscicidal activities against the M. cartusiana land snails via leaf dipping and contact techniques. The effect of lethal concentrations, that kills 50% of exposed snails (LC50) value of the treatments, is examined on the activity of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), enzymes, total protein (TP), total lipids (TL) and cholesterol level of snails, including the histopathological evaluation of the digestive gland and foot of M. Cartusiana. Their molluscicidal activity as poisonous baits under field conditions is also evaluated and compared to the recommended molluscicide, Neomyl. The results show that F^- doping dramatically improves the snail control capability of ZnO NPs, and promotes a considerable increase in both ALT and AST enzymes with an enhancement of TL and Cholesterol levels, but a significant decrease in TP content and ALP activity in treated snails compared to the control group. The LC₅₀ values are found to be 1381.55 and 2197.59 ppm using the leaf dipping for F-ZnO and ZnO, while 237.51 and 245.90 ppm can be achieved using the contact technique, respectively. The greenly synthesized F-ZnO and ZnO NPs induce severe histological alterations in the digestive gland and foot of M. cartusiana, including a complete destruction of the digestive tubules. The histological evaluation of the foot of M. cartusiana exposed to ZnO, shows a rupture of the epithelial layer of the foot sole, while F- ZnO NPs causes the folds of the foot becoming deeper and the rupture of epithelial layer. Our field experiments further demonstrate that F-ZnO achieves 60.08% reduction, while ZnO attains 56.39% diminution in snail population compared to the commercial, Neomyl (69.55%), exhibiting great potentials in controlling the harmful land snail populations.

Metabolic response of earthworms (Pheretima guillemi) to silver nanoparticles in sludge-amended soil

Silver nanoparticles (AgNPs) can enter soils via the application of sludge and pose risks to soil invertebrates. However, current knowledge regarding the toxicity of AgNPs at environmentally relevant concentration is insufficient, especially at the molecular level. Therefore, we examined the effects of low-level AgNPs (7.2 mg kg^-1, dry weight) on the bioaccumulation, pathology and metabolism of earthworms (Pheretima guillemi). After exposure for 28 d, earthworms were dissected into digestive system and the rest of the body to explore the response of different body parts to AgNPs. Ag concentration in the digestive system of exposed group (2.5 mg kg^-1, dry weight) was significantly higher than that of the control group (0.5 mg kg^-1, dry weight). AgNPs exposure had no significant effects on the survival and growth, but induced intestinal damage and metabolic interference to earthworms relative to the control. Metabolomics analysis showed that AgNPs exposure disturbed the glycerophospholipid metabolism, glutathione metabolism and energy metabolism in the digestive system and the energy metabolism in the rest of the body. AgNPs exposure also induced lipid peroxidation in the digestive system. The different metabolic responses between two body parts highlighted the importance of the uptake routes of Ag. These results provide a biochemical insight for the risk assessment of low-level AgNPs in terrestrial environment.