Antileishmanial activity and cytotoxicity of ZnO-based nano-formulations

Souza AB, Levita DP, Mello CC, da Silva AFM, dos Santos TC, Ronconi CM. Innovating Leishmaniasis Treatment: A Critical Chemist's Review of Inorganic Nanomaterials

Leishmaniasis, a critical Neglected Tropical Disease caused by Leishmania protozoa, represents a significant global health risk, particularly in resource-limited regions. Conventional treatments are effective but suffer from serious limitations, such as toxicity, prolonged treatment courses, and rising drug resistance. Herein, we highlight the potential of inorganic nanomaterials as an innovative approach to enhance Leishmaniasis therapy, aligning with the One Health concept by considering these treatments' environmental, veterinary, and public health impacts. By leveraging the adjustable properties of these nanomaterials─including size, shape, and surface charge, tailored treatments for various diseases can be developed that are less harmful to the environment and nontarget species. We review recent advances in metal-, oxide-, and carbon-based nanomaterials for combating Leishmaniasis, examining their mechanisms of action and their dual use as standalone treatments or drug delivery systems. Our analysis highlights a promising yet underexplored frontier in employing these materials for more holistic and effective disease management.

Green synthesis of zinc oxide/Allium sativum nano-composite and its efficacy against murine cryptosporidiosis

Cryptosporidiosis is a global health problem threats life of immunocompromised patients. Allium sativum (A. sativum) is one of the therapeutic options for cryptosporidiosis. This study develops green synthesized ZnO-NPs based on A. sativum extract, and assesses its therapeutic application in treating experimental cryptosporidiosis in immunosuppressed mice. FTIR, scanning electron microscopy, and zeta analyzer were used for characterization of bio ZnO-NPs. The morphology of prepared materials appeared as sponge with many pores on the whole surface that allows the feasibility of bio ZnO-NPs for different biological activities. Its structural analysis was highly stabilized with negative charge surface which indicated for well distribution into the parasite matrix. Twenty-five immunosuppressed Cryptosporidium parvum infected mice, classified into 5 groups were sacrificed at 21th day after infection with evaluation of parasitological, histopathological, oxidative, and proinflammatory biomarkers. Treated mice groups with 50 and 100 mg/kg of AS/ZnO-NPs showed a highly significant decline (79.9% and 83.23%, respectively) in the total number of expelled oocysts. Both doses revealed actual amelioration of the intestinal, hepatic, and pulmonary histopathological lesions. They also significantly produced an increase in GSH values and improved the changes in NO and MDA levels, and showed high anti-inflammatory properties. This study is the first to report green synthesis of ZnO/A. sativum nano-composite as an effective therapy in treating cryptosporidiosis which gave better results than using A. sativum alone. It provides an economical and environment-friendly approach towards novel delivery synthesis for antiparasitic applications. RESEARCH HIGHLIGHTS: Green synthesis of ZnO-NPs was developed using A. sativum extract. The morphology of prepared ZnO-NPs appeared as sponge with many pores on SEM The study evaluates its therapeutic efficacy against murine cryptosporidiosis The green synthesized ZnO-NPs significantly reduced percent of oocyst shedding, improved the pathological changes, and showed high antioxidant and anti-inflammatory potentials.

Biomedical Applications of Green Synthesized Zinc Oxide and Magnesium-Doped Zinc Oxide Nanoparticles Using Aqueous Extract of Ziziphus Oxyphylla Leaves

Zinc oxide (ZnO) and magnesium-doped zinc oxide (Mg-doped ZnO) nanoparticles (NPs) were synthesized using Ziziphus oxyphylla 's aqueous leaf extract as reducing agent. UV-Vis absorption peaks at 324 nm and 335 nm were indicative of ZnO and Mg-doped ZnO, respectively. FTIR absorption bands observed at 3238, 1043, 1400, 1401, 2186 and 2320 cm -1 suggested the presence of phenols, alcohols, saturated hydrocarbons, and possibly alkynes. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy revealed pure, spherical and agglomerated NPs with average size of 35.9 nm (ZnO) and 56.8 nm (Mg-doped ZnO). Both NPs remained active against all bacterial strains with the highest inhibition zones observed against Proteus vulgaris (21.16±1.25 mm for ZnO and 24.1±0.76 mm for Mg-doped ZnO. EtBr fluorescence (cartwheel assay) indicated efflux pump blockage, suggesting its facilitation in the bacterial growth inhibition. Antioxidant potential, determined via DPPH radical scavenging assay, revealed stronger antioxidant potential for Mg-doped ZnO (IC [Formula: see text]/mL) than pure ZnO (IC [Formula: see text]/mL). Furthermore, both NPs showed antileishmanial activity against Leishmania tropica promastigotes (IC [Formula: see text]/mL for Mg-doped ZnO and 64.34±6.56 for ZnO), while neither NP exhibited significant hemolysis, indicating biocompatibility and further assessment for their drugability.

Tuning Biocompatibility and Bactericidal Efficacy as a Function of Doping of Gold in ZnO Nanocrystals

Doping nanoparticles represents a strategy for modulating the energy levels and surface states of nanocrystals (NCs), thereby enhancing their efficiency and mitigating toxicity. Thus, we herein focus on the successful synthesis of pure and gold (Au)-doped zinc oxide (ZnO) nanocrystals (NCs), investigating their physical-chemical properties and evaluating their applicability and toxicity through in vitro and in vivo assessments. The optical, structural, and photocatalytic characteristics of these NCs were scrutinized by using optical absorption (OA), X-ray diffraction (XRD), and methylene blue degradation, respectively. The formation and doping of the NCs were corroborated by the XRD and OA results. While the introduction of Au as a dopant did induce changes in the phase and size of ZnO, a high concentration of Au ions in ZnO led to a reduction in their photocatalytic activity. This demonstrated a restricted antibacterial efficacy against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Remarkably, Au-doped counterparts exhibited enhanced biocompatibility in comparison to ZnO, as evidenced in both in vitro (murine macrophage cells) and in vivo (Drosophila melanogaster) studies. Furthermore, confocal microscopy images showed a high luminescence of Au-doped ZnO NCs in vivo. Thus, this study underscores the potential of Au doping of ZnO NCs as a promising technique to enhance material properties and increase biocompatibility.

Metallic nanoparticles and treatment of cutaneous leishmaniasis: A systematic review

BACKGROUND

Cutaneous leishmaniasis (LC) is an infectious vector-borne disease caused by parasites belonging to the genus Leishmania. Metallic nanoparticles (MNPs) have been investigated as alternatives for the treatment of LC owing to their small size and high surface area. Here, we aimed to evaluate the effect of MNPs in the treatment of LC through experimental, in vitro and in vivo investigations.

METHODS

The databases used were MEDLINE/ PubMed, Scopus, Web of Science, Embase, and Science Direct. Manual searches of the reference lists of the included studies and grey literature were also performed. English language and experimental in vitro and in vivo studies using different Leishmania species, both related to MNP treatment, were included. This study was registered in PROSPERO (CRD42021248245).

RESULTS

A total of 93 articles were included. Silver nanoparticles are the most studied MNPs, and L. tropica is the most studied species. Among the mechanisms of action of MNPs in vitro, we highlight the production of reactive oxygen species, direct contact of MNPs with the biomolecules of the parasite, and release of metal ions.

CONCLUSION

MNPs may be considered a promising alternative for the treatment of LC, but further studies are needed to define their efficacy and safety.

Anthelmintic and Hepatoprotective Activities of the Green-Synthesized Zinc Oxide Nanoparticles Against Parascaris equorum Infection in Rats

MAIN CONCLUSIONS

Green-synthesized zinc oxide nanoparticle is a promising treatment modality against parasitic infection through its powerful anthelmintic, antioxidant, healing promotion, and anti-inflammation effects.

BACKGROUND

Nanoparticles have many properties, depending on their size, shape, and morphology, allowing them to interact with microorganisms, plants, and animals.

OBJECTIVES

Investigation of the therapeutic effects of green-synthesized zinc oxide nanoparticles (ZnO NPs) on Parascaris equorum infection in rats.

METHODS

Thirty-six rats were divided into two divisions: the first division is noninfected groups were allocated into three groups. Group 1: Control, group 2: ZnO NPs (30 mg/kg), and group 3: ZnO NPs (60 mg/kg). The second division is infected groups were allocated into three groups. Group 1: vehicle, group 2: ZnO NPs (30 mg/kg), and group 3: ZnO NPs (60 mg/kg).

FINDINGS

Ten days post-infection, two larvae per gram of liver tissue were present in the vehicle group compared to the control group. No larvae were recovered from ZnO NPs (30 mg/kg), and one larva/g.tissue from ZnO NPs (60 mg/kg)-treated groups compared to untreated infected animals. Green-synthesized ZnO NPs caused a significant decrease in liver functions, low-density lipoprotein (LDL), cholesterol, triglycerides, malondialdehyde (MDA), and nitric oxide (NO). While it caused a significant increase in hemoglobin (HB), high-density lipoprotein (HDL), butyrylcholinesterase (BCHE), glutathione (GSH), catalase (CAT), and glutathione S-transferase (GST) in infected treated rats. The histological inflammation and fibroplasia scores showed a significant enhancement during the treatment with ZnO NPs (30, 60 mg/kg) compared to the infected untreated animals that scored the highest pathological destruction score. Immunohistochemical markers of NF-κB showed a significant decrease during the treatment with ZnO NPs (30, 60 mg/kg) compared to the infected untreated animals.

Paeoniflorin recued hepatotoxicity under zinc oxide nanoparticles exposure via regulation on gut-liver axis and reversal of pyroptosis

The risks of Zinc oxide nanoparticles (ZnO NPs) applications in biological medicine, food processing industry, agricultural production and the biotoxicity brought by environmental invasion of ZnO NPs both gradually troubled the public due to the lack of research on detoxification strategies. TFEB-regulated autophagy-pyroptosis pathways were found as the crux of the hepatotoxicity induced by ZnO NPs in our latest study. Here, our study served as a connecting link between preceding toxic target and the following protection mechanism of Paeoniflorin (PF). According to a combined analysis of network pharmacology/molecular docking-intestinal microbiota-metabolomics first developed in our study, PF alleviated the hepatotoxicity of ZnO NPs from multiple aspects. The hepatic inflammatory injury and hepatocyte pyroptosis in mice liver exposed to ZnO NPs was significantly inhibited by PF. And the intestinal microbiota disorder and liver metabolic disturbance were rescued. The targets predicted by bioinformatics and the signal trend in subacute toxicological model exhibited the protectiveness of PF related to the SIRT1-mTOR-TFEB pathway. These evidences clarified multiple protective mechanisms of PF which provided a novel detoxification approach against ZnO NPs, and further provided a strategy for the medicinal value development of PF.

Newly fabricated zinc oxide nanoparticles loaded materials for therapeutic nano delivery in experimental cryptosporidiosis

Cryptosporidiosis is a global health problem that threatens the lives of immunocompromised patients. This study targets to fabricate and investigate the efficiency of zinc oxide nanoparticles (ZnO-NPs), nitazoxanide (NTZ)-loaded ZnO-NPs, and Allium sativum (A. sativum)-loaded ZnO-NPs in treating cryptosporidiosis. Further FTIR, SEM, XRD, and zeta analysis were used for the characterization of ZnO-NPs and loaded materials. The morphology of loaded materials for ZnO-NPs changed into wrapped layers and well-distributed homogenous particles, which had a direct effect on the oocyst wall. The charge surface of all particles had a negative sign, which indicated well distribution into the parasite matrix. For anti-cryptosporidiosis efficiency, thirty immunosuppressed Cryptosporidium parvum-infected mice, classified into six groups, were sacrificed on the 21st day after infection with an evaluation of parasitological, histopathological, and oxidative markers. It was detected that the highest reduction percent of Cryptosporidium oocyst shedding was (81.5%) in NTZ, followed by (71.1%) in A. sativum-loaded ZnO-NPs-treated groups. Also, treatment with A. sativum and NTZ-loaded ZnO-NPs revealed remarkable amelioration of the intestinal, hepatic, and pulmonary histopathological lesions. Furthermore, they significantly produced an increase in GSH values and improved the changes in NO and MDA levels. In conclusion, this study is the first to report ZnO-NPs as an effective therapy for treating cryptosporidiosis, especially when combined with other treatments that enhance their antioxidant activity. It provides an economical and environment-friendly approach to novel delivery synthesis for antiparasitic applications.

Elucidating the significance of molecular interaction between sulphur doped zinc oxide nanoparticles and serum albumin using multispectroscopic approach

Ingenious nanomaterials with improved biocompatibility and multifunctional properties are gaining vital significance in biomedical applications, including advanced drug delivery and nanotheranostics. In a biological system, these nanoparticles interact with serum proteins forming a dynamic corona that affects their biological or toxicological properties producing undesirable effects. Thus, the current study focuses on the synthesis of sulphur-doped zinc oxide nanoparticles (ZnO/S NPs) and characterizing their mechanism of interaction with serum proteins using multispectroscopic approach. ZnO/S NPs were synthesized by employing a co-precipitation approach and characterized using various analytical techniques. The results of interaction studies demonstrated that ZnO/S NPs interact with serum albumins via the static quenching process. Analysis of thermodynamic parameters (ΔG, ΔH and ΔS) revealed that the binding process is spontaneous, exothermic and van der Waals force or hydrogen bonding plays a major role. The interaction of ZnO/S NPs with tyrosine residue in bovine serum albumin was established by synchronous fluorescence spectroscopy. In addition, the results of UV-visible, circular dichroism, Fourier transform infrared, Forster's resonance energy transfer theory and dynamic light scattering spectroscopic studies revealed that the ZnO/S NPs interact with albumin by inducing the conformational changes in secondary structure and reducing the α-helix content.

Antileishmanial, cellular mechanisms, and cytotoxic effects of green synthesized zinc nanoparticles alone and in combined with glucantime against Leishmania major infection

BACKGROUND

We decided to investigate the antileishmanial, cellular mechanisms, and cytotoxic effects of green synthesized Zinc nanoparticles (ZnNPs) alone and combined with glucantime against Leishmania major infection.

METHODS

The effect of green synthesized ZnNP on L. major amastigote was studied through macrophage cells. The mRNA expression level of iNOS and IFN-γ followed by the exposure of J774-A1 macrophage cells to ZnNPs was assessed by Real-time PCR. The Caspase-3-like activity of promastigotes exposed to ZnNPs was studied. Effects of ZnNPs alone and combined with glucantime (MA) were studied on cutaneous leishmaniasis in BALB/c mice.

RESULTS

ZnNPs displayed the spherical shape with sizes ranging from 30 to 80 nm. The obtained IC₅₀ values for ZnNPs, MA, and ZnNPs + MA were 43.2, 26.3, and 12.6 µg/mL, respectively; indicating the synergistic effects of ZnNPs in combination with MA. CL lesions had completely improved in the mice received with ZnNPs in combination with MA. The mRNA expression level of iNOS, TNF-α, and IFN-γ was dose-dependently (p < 0.01) upregulated; whereas it was downregulated in IL-10. ZnNPs markedly stimulated the caspase-3 activation with no significant toxicity on normal cells.

CONCLUSION

Based on these in vitro and in vivo results, green synthesized ZnNPs, mainly along with MA, showed that has the potential to be introduced as a new drug for CL therapy. Triggering of NO production, and inhibition of infectivity rate are revealed as mechanisms of action ZnNPs on L. major. But, supplementary investigations are necessary to clear the efficacy and safety of these agents.

Evaluation of scolicidal potential of salicylate coated zinc nanoparticles against Echinococcus granulosus protoscoleces

Echinococcosis is a zoonotic disease caused by larval stages of the Echinococcus genus (metastasis). In this study, salicylate-coated Zinc oxide nanoparticles (SA-ZnO-NPs) were fabricated and characterized by SEM, FTIR and XRD analytical techniques. After that, different doses of SA-ZnO-NPs, SA and ZnO-NPs were taken to assess scolicidal potency. Scanning electron microscopy (SEM) micrographs were also used to evaluate the morphological deformities of treated protoscoleces. Furthermore, Caspase-3&7 inductions were examined in protoscoleces cysts treated with all formulations. Based on SEM and DLS analyses, the size of SA-ZnO-NPs was between 30 and 40 nm, with a spherical shape. The FTIR spectrum verified the presence of SA functional groups on the ZnO coating. At 20 min, SA-ZnO-NPs at 2000 μg/ml exhibited the greatest activity on protoscolices with 100% mortality, followed by ZnO-NPs at 1500 μg/ml at 10 min and SA alone at 2000 μg/ml at 30 min. The activation of Caspase-3&7 apoptotic enzyme was determined for 2000 μg/ml of SA-ZnO-NPs, ZnO-NPs and SA to be 16.4, 31.4, and 35.7%, respectively. The SEM image revealed apoptogenic alterations and the induction of tegument surface wrinkles, as well as abnormalities in rostellum protoscolices. According to the current study, SA-ZnO-NPs have a high mortality rate against hydatid cyst protoscolices. As a result, further studies on the qualitative assessment of these nanoformulations in vivo and preclinical animal trials seem to be required. Furthermore, the adoption of nano-drugs potentially offers alternative therapeutic approaches to combat hydatid cysts.

Oxidative stress-related canonical pyroptosis pathway, as a target of liver toxicity triggered by zinc oxide nanoparticles

Zinc oxide nanoparticles (ZnO NPs) have been widely used in the fields of daily necessities, clinical diagnosis, drug delivery and agricultural production. The improper use of ZnO NPs could pose a risk to ecological environment and public health. Liver has been known as a critical toxic target of ZnO NPs. However, the question whether ZnO NPs lead to hepatocyte death through pyroptosis has not been answered yet, and the effect of oxidative stress on ZnO NPs-induced pyroptosis remains a mystery. We revealed that ZnO NPs disrupted zinc homeostasis and induced oxidative stress impairment in rat liver. Meanwhile, ZnO NPs triggered the assembly of NLRP3-ASC-Caspase-1 inflammatory complex and pyroptosis in both rat liver and HepG2 cells, further causing the activation of GSDMD, promoting the leakage of inflammatory cytokines including IL-1β and IL-18. Importantly, the inhibition of oxidative stress was found to provide protection against pyroptosis in hepatocyte exposed to ZnO NPs. We identified a novel mechanism of liver damage induced by ZnO NPs, demonstrating the activation of canonical Caspase-1-dependent pyroptosis pathway and clarifying the protection of antioxidation against pyroptosis damage. Our discovery provided a support for risk assessment of ZnO NPs and target exploration for clinical treatment related to pyroptosis.

Inhibitory Effects of Selected Medicinal Plants on Bacterial Growth of Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious threat to global public health due to its capacity of tolerate conventional antibiotics. Medicinal plants are traditionally used to treat infectious diseases caused by bacterial pathogens. In the present study, 16 medicinal plants were screened for antibacterial activities to preselect more effective species. Ethanol extracts of selected medicinal plants (Caesalpinia sappan L., Glycyrrhiza uralensis Fisch., Sanguisorba officinalis L., and Uncaria gambir Roxb) were partitioned successively with different solvents (n-hexane, chloroform, ethyl acetate, 1-butanol, and water). Disc diffusion assay and broth microdilution were performed to evaluate the antibacterial activities of plant extracts and fractions against Staphylococcus aureus strains. Furthermore, the cytotoxicity of the extracts and fractions was determined against the human hepatoma (HepG2) and human lung carcinoma (A549) cell lines using a trypan blue exclusion method. A few extracts and fractions showed significant inhibitory effects on the bacterial growth of all tested strains, including multidrug-resistance (MDR) clinical isolates. The ethyl acetate fraction of C. sappan had the most potent effects with minimum inhibitory/bactericidal concentrations (MIC/MBC) of 31.2/62.5 μg/mL and showed low cytotoxicity with over 90% cell viability in both cells. Our results suggest that medicinal plants have considerable potential as alternatives to conventional antibiotics.

Lethality of Zinc Oxide Nanoparticles Surpasses Conventional Zinc Oxide via Oxidative Stress, Mitochondrial Damage and Calcium Overload: A Comparative Hepatotoxicity Study

Zinc oxide nanoparticles (ZnO NPs) with high bioavailability and excellent physicochemical properties are gradually becoming commonplace as a substitute for conventional ZnO materials. The present study aimed to investigate the hepatotoxicity mechanism of ZnO NPs and traditional non-nano ZnO particles, both in vivo and in vitro, and identify the differences in their toxic effects. The results showed that the extent and conditions of zinc ion release from ZnO NPs were inconsistent with those of ZnO. The RNA-seq results revealed that the expression quantity of differentially expressed genes (DEGs) and differentially expressed transcripts (DETs) affected by ZnO NPs was more than in ZnO, and the overall differences in genes or transcripts in the ZnO NPs group were more pronounced than in the ZnO group. Furthermore, the cell inactivation, oxidative stress, mitochondrial damage, and intracellular calcium overload induced by ZnO NPs were more serious than ZnO in HepG2 cells. Moreover, compared with traditional ZnO, the rat liver damage induced by ZnO NPs was more significant, with evidence of higher AST and ALT levels, weaker antioxidant capacity, and more serious histopathological damage (p < 0.05). In summary, the hepatotoxicity of ZnO NPs was more serious than that of conventional ZnO, which is helpful to understand the hepatotoxicity mechanism of Zn compounds in different states and improve the risk assessment of novel nano ZnO products in a variety of applications.

Effects of green synthesized zinc nanoparticles alone and along with albendazole against hydatid cyst protoscoleces

Background

The current investigation aims to green synthesized the zinc nanoparticles (ZnNPs) using Lavandula angustifolia extract by microwave technique and its protoscolicidal effects alone and combined with albendazole against hydatid cyst protoscoleces.

Methods

Different concentrations of the ZnNPs (50, 100, and 200 μg/ml) alone and combined with albendazole (ALZ, 100 μg/ml) were treated with hydatid cyst protoscoleces obtained from liver of infected sheep for 5–60 min in vitro and ex vivo. Eosin exclusion examination was used to assess the viability of protoscoleces. The induction of apoptosis in hydatid cyst protoscoleces was assessed by measurement of the Caspase-3 activity of protoscoleces treated with various concentrations of ZnNPs.

Results

The size of green synthesized ZnNPs was ranged from 30 to 80 nm, most of these nanoparticles were between 50 and 60 nm in size. In vitro, the highest scolicidal effect of ZnNPs was observed at the concentration of 200 μg/ml, where it killed 81.6% of protoscolices. While the combination of these nanoparticles with ALZ, especially at the concentration of 200 μg/ml, completely killed the protoscolices after 10 min’ exposure. However, compared to in vitro assay, the drugs tested took longer to show their protoscolicidal effect.

Conclusion

Based on the obtained results, ZnNPs particularly in combination with albendazole displayed the potent protoscolicidal in vitro and ex vivo as an intraperitoneal model of administration of agents to hydatid cyst treatment; nevertheless, additional investigations are mandatory to evaluate the efficacy and safety Zn NPs as a favorable protoscolicidal agent in clinical setting.

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ZnNPs particularly in combination with albendazole displayed the relevant protoscolicidal in vitro effects.

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ZnNPs particularly in combination with albendazole displayed the potent protoscolicidal ex vivo effects.

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ZnNPs induced the apoptosis through the activation of caspase-3 enzyme.

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Additional investigations are mandatory to evaluate the its efficacy and safety in clinical setting.

Nanomedicine in leishmaniasis: A promising tool for diagnosis, treatment and prevention of disease - An update overview

Leishmaniasis is a neglected tropical disease that has a wide spectrum of clinical manifestations, ranging from visceral to cutaneous, with millions of new cases and thousands of deaths notified every year. The severity of the disease and its various clinical forms are determined by the species of the causative agent, Leishmania, as well as the host's immune response. Major challenges still exist in the diagnosis and treatment of leishmaniasis, and there is no vaccine available to prevent this disease in humans. Nanotechnology has emerged as a promising tool in a variety of fields. In this review, we highlight the main and most recent advances in nanomedicine to improve the diagnosis and treatment, as well as for the development of vaccines, for leishmaniasis. Nanomaterials are nanometric in size and can be produced by a variety of materials, including lipids, polymers, ceramics, and metals, with varying structures and morphologies. Nanotechnology can be used as biosensors to detect antibodies or antigens, thus improving the sensitivity and specificity of such immunological and molecular diagnostic tests. While in treatment, nanomaterials can act as drug carriers or, be used directly, to reduce any toxic effects of drug compounds to the host and to be more selective towards the parasite. Furthermore, preclinical studies show that different nanomaterials can carry different Leishmania antigens, or even act as adjuvants to improve a Th1 immune response in an attempt to produce an effective vaccine.

Metallic Nanoparticles: A New Frontier in the Fight Against Leishmaniasis

Abstract:

Leishmaniasis is a cutaneous, mucocutaneous, or visceral parasitic disease caused by protozoa of the Leishmania genus. According to the World Health Organization, Leishmaniasis causes approximately 20–40 thousand deaths annually, and Brazil, India, and some countries in Africa are the most affected by this neglected disease. In addition to parasite’s ability to evade the host’s immune system, the incidence of vectors, the genetics of different hosts, and the large number of deaths are mainly due to failures in conventional treatments that have high toxicity, low effectiveness, and prolonged therapeutic regimens. Thus, the development of new alternative therapeutics with more effective and safer actions has become one of the main challenges for researchers studying leishmaniasis. Among the many research and tested options, metallic nanoparticles, such as gold, silver, zinc oxide, and titanium dioxide, have been shown to be one of the most promising therapeutic tool because they are easily prepared and chemically modified, have a broad spectrum of action, low toxicity, and can generate reactive oxygen species and other immune responses that favor their use against different species of Leishmania. This review explores the progress of the use of metallic nanoparticles as a new tool in the treatment of leishmaniasis, as well as discusses the gaps in knowledge that need to be addressed to consolidate a safe, effective, and definitive therapeutic intervention against these infections.

Green synthesis of zinc nanoparticles using Lavandula angustifolia Vera. Extract by microwave method and its prophylactic effects on Toxoplasma gondii infection

Background

Today, a suitable vaccine has not yet been discovered to prevent Toxoplasma gondii infection. Therefore, prophylaxis can be suggested as the preferred approach to prevent toxoplasmosis. This study aims to evaluate the prophylactic effects of synthesized zinc nanoparticles (ZnNPs) using Lavandula angustifolia Vera., by microwave method on chronic toxoplasmosis in mice.

Methods

BALB/c Mice orally administrated with ZnNPs the doses of 32.5, 75, 150 mg/kg/day for two weeks. On the 15th day, the mice were intraperitoneally infected with the Tehran strain of T. gondii (25 tissue cysts). The mean diameter and the numbers of brain tissue cysts, as well as the mRNA levels of inducible nitric oxide synthesize (iNOs), and interferon-gamma (IFN-γ) in mice of each experimental group were evaluated.

Results

The synthesized ZnNPs represent a spherical form with a size ranging from 30 to 80 nm. The results revealed that oral administration of Zn NPs at the doses of 32.5 (p < 0.001) and 75 mg/kg/day (p < 0.001) for 14 days significantly reduced the mean number and diameter of the brain tissue cysts in tested mice. No T. gondii tissue cyst was observed after oral administration of Zn NPs at the doses of 150 mg/kg. Based on the results of Real-time PCR analysis, the expression level of IFN-γ and iNOs was significantly increased (p < 0.001) in mice treated with 32.5, 75, 150 mg/kg/day for two weeks.

Conclusion

The obtained findings of the current investigation exhibit the significant prophylactic effects of ZnNPs against chronic toxoplasmosis in mice; so that oral administration of ZnNPs the doses 32.5, 75, 150 mg/kg reduced the parasite load and even completely controlled the infection in mice. The results show that the ZnNPs had strengthened the innate immune system which could be the reason for its strong prophylactic effects. However, further in vivo and clinical investigations are required to confirm these results as well as other possible mechanisms that can trigger these pharmacological properties.

Antiprotozoal and anthelmintic activity of zinc oxide nanoparticles

Nanomaterials represent a wide alternative for the treatment of several diseases that affect both human and animal health. The use of these materials mainly involves trying to solve the problem of resistance that pathogenic organisms acquire to conventional drugs. A well-studied example that represents a potential component for biomedical applications is the use of zinc oxide (ZnO) nanoparticles (NPs). Its antimicrobial function is related, especially the ability to generate/induce ROS that affects the homeostasis of the pathogen in question. Protozoa and helminths that harm human health and the economic performance of animals have already been exposed to this type of nanoparticle. Thus, through this review, our goal is to discuss the state-of-the-art effect of ZnO NPs on these parasites.

Nanotechnology-aided diagnosis, treatment and prevention of leishmaniasis

Leishmaniasis is a prevalent parasitic infection belonging to neglected tropical diseases. It is caused by Leishmania protozoan parasites transmitted by sandflies and it is responsible for increased morbidity/mortality especially in low- and middle-income countries. The lack of cheap, portable, easy to use diagnostic tools exhibiting high efficiency and specificity impede the early diagnosis of the disease. Furthermore, the typical anti-leishmanial agents are cytotoxic, characterized by low patient compliance and require long-term regimen and usually hospitalization. In addition, due to the intracellular nature of the disease, the existing treatments exhibit low bioavailability resulting in low therapeutic efficacy. The above, combined with the common development of resistance against the anti-leishmanial agents, denote the urgent need for novel therapeutic strategies. Furthermore, the lack of effective prophylactic vaccines hinders the control of the disease. The development of nanoparticle-based biosensors and nanocarrier-aided treatment and vaccination strategies could advance the diagnosis, therapy and prevention of leishmaniasis. The present review intends to highlight the various nanotechnology-based approaches pursued until now to improve the detection of Leishmania species in biological samples, decrease the side effects and increase the efficacy of anti-leishmanial drugs, and induce enhanced immune responses, specifically focusing on the outcome of their preclinical and clinical evaluation.

In vitro effects of bis(N-[4-(hydroxyphenyl)methyl]-2-pyridinemethamine)zinc perchlorate monohydrate 4 on the physiology and interaction process of Leishmania amazonensis

Leishmaniasis is one of the most relevant neglected tropical diseases in the world, affecting 14 million people. Despite the high morbidity, mortality and socio-economic impact, few therapeutic options are available for this disease. To make matters worse, the available molecules have several limitations such as limited efficacy, high cost, side effects and increased resistance. In this context, our group previously synthesized new compounds with anti-leishmania potential being the bis(N-[4-(hydroxyphenyl)methyl]-2-pyridinemethamine)zinc perchlorate monohydrate 4 (complex 4) the most promising one. Therefore, this present work revealed some morphological and physiological changes promoted by complex 4 on Leishmania amazonensis promastigotes as well as it was evidenced its potential against intramacrophage amastigotes. Complex 4 promoted a progressive reduction on the promastigotes size and a remarkable increase on the granularity/complexity as judged by flow cytometry. Transmission electron microscopy (TEM) analysis revealed extensive mitochondrial and plasma membrane alterations, although plasma membrane integrity remained. The mitochondrial changes observed by TEM were accompanied by a decrease in the activity of mitochondrial dehydrogenases with increased production of reactive oxygen species. Interestingly, promastigotes also showed changes in lipid metabolism. Besides the very low toxicity to macrophages, complex 4 had a great effect on intramacrophage amastigotes, displaying an IC₅₀ of 3.91 μM. Collectively, the data presented here reinforce the potential of aminopyridyl compounds complexed to zinc against L. amazonensis. Thus, our work serves as a basis for in vivo assays to be designed or even the synthesis of more selective/effective compounds with lower cost.

Biocompatibility of several colloidal solutions containing nanoparticles on human gingival fibroblasts

BACKGROUND

There is little information concerning the biocompatibility of mouthwashes containing metal nanoparticles. This study was conducted to assess the biocompatibility of colloidal solutions containing zinc oxide (ZnO), copper oxide (CuO), titanium dioxide (TiO2), and silver (Ag) nanoparticles compared with chlorhexidine (CHX) in a culture of human gingival fibroblasts (HGFs).

MATERIALS AND METHODS

This was an in vitro, experimental study. Nanoparticles, including ZnO, CuO, TiO2, and Ag, were purchased and added to a water-based solution to produce mouthwashes. The colloidal solutions and CHX were prepared at the minimum inhibitory concentration (MIC) against Streptococcus mutans and Streptococcus sanguis. Cytotoxicity was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on HGFs at the concentrations of MIC, 0.1 MIC, and 0.01 MIC. To determine apoptosis, DNA fragmentation was assessed as "sub-G1" peak on DNA content histogram. The data were analyzed using repeated measures analysis at P < 0.05.

RESULTS

At all concentrations, the highest and lowest mean of cell viability was related to TiO2 and ZnO groups, respectively. At MIC, the mean cell viability was significantly greater in the TiO2 group than the other groups (except the Ag group) (P < 0.05). At the concentration of 0.01 MIC, the mean cell viability in the colloidal solution containing ZnO nanoparticles was significantly lower than the other solutions (P < 0.05). The CHX and CuO-containing solution displayed the highest rate of apoptosis among the groups.

CONCLUSION

The TiO2-containing solution can be suggested as a suitable alternative to CHX to provide antiseptic effects with minimal toxicity.

Impact of zinc oxide nanoparticles and thymoquinone in Ehrlich ascites carcinoma induced in mice

BACKGROUND

The field of nanotechnology offers great opportunities for cancer therapy.

OBJECTIVE

This study aimed to compare the therapeutic impact of Zn oxide nanoparticles (ZnO NPs) and thymoquinone (TQ) alone or as cotherapy in Ehrlich ascites carcinoma (EAC) induced in mice.

MATERIALS AND METHODS

This study was performed on 75 female albino mice divided into Group I: EAC-bearing control group, Group II: EAC treated with TQ, Group III: EAC treated with low-dose ZnO NPs, Group IV: EAC treated with high-dose ZnO NPs, Group V: EAC treated with TQ and low-dose ZnO NPs. All groups were subjected to measurement of cell viability, ascites fluid volume, Bcl2 protein expression by Western blot analysis, cyclooxygenase 2 (COX2) gene expression by a real-time polymerase chain reaction, enzyme-linked immunosorbent assay levels of Beclin 1, interferon γ (INFγ), interleukin 13 (IL-13), and estimation of Zn concentrations in EAC cells and liver homogenate to evaluate its toxicity.

RESULTS

Cotherapy has an efficient anticancer effect by enhancing apoptosis and autophagy, resulting in reducing tumor cell viability and ascites fluid volume together with downregulation of Bcl2 protein expression. This cotherapy increases Beclin 1 and INFγ and decreases IL-13. ZnO NPs upregulate COX2 expression, whereas TQ downregulates its expression. High-dose ZnO NPs have more toxic effects on liver enzymes. Using TQ together with ZnO NPs can eliminate ZnO NPs liver toxicity.

CONCLUSION

The cotherapy has an efficient anticancer effect by enhancing apoptosis and autophagy. High-dose ZnO NPs have more toxic effects on liver enzymes. Using TQ together with ZnO NPs can eliminate ZnO NP liver toxicity.

Facile Use of ZnO Nanopowders to Protect Old Manual Paper Documents

One of the main problems faced by libraries, archives and collectors is the mold degradation of the paper-based documents, books, artworks etc. Microfungi (molds) emerge in regular storage conditions of such items (humidity, usually over 50%, and temperatures under 21 °C). If the removal of the visible mycelium is relatively easy, there is always the problem of the subsequent appearance of mold as the spores remain trapped in the cellulosic, fibrillary texture, which acts as a net. Moreover, due to improper hand hygiene bacteria contamination, old books could represent a source of biohazard, being colonized with human pathogens. An easy and accessible method of decontamination, which could offer long term protection is therefore needed. Here, we present a facile use of the ZnO nanopowders as antimicrobial agents, suitable for cellulose-based products, conferring an extended antibacterial and anti-microfungal effect. The proposed method does not adversely impact on the quality of the cellulose documents and could be efficiently used for biodegradation protection.

Pharmaceutical agents for treatment of leishmaniasis: a patent landscape

INTRODUCTION

Leishmaniasis is a neglected tropical disease caused by protozoa of the genus Leishmania. Worldwide, approximately 1.5-2 million new cases of leishmaniasis and 20,000-30,000 deaths occurs each year. Effective treatment for all forms of leishmaniasis have numerous adverse effects contributing to poor adherence and/or treatment interruption by the patient. Development of novel therapies, as multitarget drugs, for example, can contribute to accelerate discover safer, more active, and patient-compliant drugs for leishmaniasis treatment.

AREAS COVERED

In this review, authors summarize pharmaceutical agents for treatment of leishmaniasis developed between 2014 and 2019, which includes synthetic and natural drugs for specific treatments, as well as considering new approaches and strategies using drug delivery system.

EXPERT OPINION

Universities or public research institutes produced most of the patents related to pharmaceutical agents for treatment of leishmaniasis in this review, and the majority of the inventions disclosed did not conduct clinical trials. In other words, there is still a lot of investment to be done for the identification of new drugs.