Effect of chitosan on Toxoplasma gondii infection: A systematic review

Linalool-zinc oxide nanocomposite controls Toxoplasma gondii infection through inhibiting inflammation, oxidative stress, and pathogenicity

The present in vitro and in vivo study aimed to fabricate and characterize linalool-zinc oxide nanoparticles (Lin-ZNP) and evaluate their effectiveness against Toxoplasma gondii infection in terms of inflammation, oxidative stress, and pathogenicity. Lin-ZNP was synthesized using an ethanolic solution of polyvinyl alcohol. The anti-Toxoplasma and cytotoxicity activities of Lin-ZNP were investigated, along with its effects on nitric oxide (NO) production, caspase-3 activity, and pro-inflammatory genes. After treating T. gondii-infected mice with Lin-ZNP for 14 days, the number and size of tissue cysts, antioxidant potential, pro-inflammatory cytokines, and T. gondii pathogenicity-related genes were evaluated by real-time polymerase chain reaction and Western blot analysis. The Lin-ZNP composite showed a reduced tendency with an average size of 105 nm. Lin-ZNP significantly reduced the viability of tachyzoites. The obtained selectivity index higher than 10, indicating high specificity for parasites with low cytotoxicity to normal cells. The Lin-ZNP significantly (p < 0.05) increased the production of NO, caspase-3 activity, and the expression levels of pro-inflammatory genes. Lin-ZNP significantly (p < 0.001) decreased the size and number of tissue cysts and caused a significant reduction in the level of malondialdehyde and a considerable increase (p < 0.001) in antioxidant enzymes and their expression genes. Lin-ZNP significantly downregulated both mRNA and protein expression of the inflammation-related markers associated with the TLRs/NF-κB pathway. The expression levels of the T. gondii pathogenicity-related genes were significantly downregulated (p < 0.05). The recent survey indicated that Lin-ZNP manages T. gondii infection by its antioxidant activity and inhibiting the TLRs/NF-κB pathway without toxicity in mice.

Spiramycin-loaded maltodextrin nanoparticles as a promising treatment of toxoplasmosis on murine model

Despite being the initial choice for treating toxoplasmosis, sulfadiazine and pyrimethamine have limited effectiveness in eliminating the infection and were linked to a variety of adverse effects. Therefore, the search for new effective therapeutic strategies against toxoplasmosis is still required. The current work is the first research to assess the efficacy of spiramycin-loaded maltodextrin nanoparticles (SPM-loaded MNPs) as a novel alternative drug therapy against toxoplasmosis in a murine model. Fifty laboratory-bred Swiss albino mice were divided into five groups: normal control group (GI, n = 10), positive control group (GII, n = 10), orally treated with spiramycin (SPM) alone (GIII, n = 10), intranasal treated with SPM-loaded MNPs (GIV, n = 10), and orally treated with SPM-loaded MNPs (GV, n = 10). Cysts of Toxoplasma gondii ME-49 strain were used to infect the mice. Tested drugs were administered 2 months after the infection. Drug efficacy was assessed by counting brain cysts, histopathological examination, and measures of serum CD19 by flow cytometer. The orally treated group with SPM-loaded MNPs (GV) showed a marked reduction of brain cyst count (88.7%), histopathological improvement changes, and an increasing mean level of CD19 (80.2%) with significant differences. SPM-loaded MNPs showed potent therapeutic effects against chronic toxoplasmosis. Further research should be conducted to assess it in the treatment of human toxoplasmosis, especially during pregnancy.

The effect of infection with Toxoplasma gondii in inducing interferon-gamma in breast cancer patients

Toxoplasmosis is one of the most widespread zoonotic diseases in the world. Human infection rates range from 10% to 80% in many countries. Female cancer patients receiving chemotherapy are more susceptible to developing acute forms of toxoplasmosis, which can cause brain defects, neurological damage, and encephalitis. The aim of the present study was to investigate the effect of Toxoplasma gondii infection on the induction of interferon-gamma in breast cancer patients from Iraq. This descriptive cross-sectional study was performed on women had breast cancer in Al-Haboubi Teaching Hospital in Nasiriya City-Thi-Qar Province (Iraq) during the period from January to September 2022. Approximately three ml of blood was drawn from all participants and sera were collected. The Sera were then tested for Toxoplasma IgM, IgG, and IFN-γ (Nova Tec Immunodiagnostica GmbH, Germany) using the enzyme-linked immunosorbent assay (ELISA) kits according to the protocols of the manufacturer. Before blood collection, participants completed a printed questionnaire with some demographic information, such as age and place of residence. The total number of positive T. gondii infections from breast cancer patients in the current study was 60 (85.7%). The results of sample analysis by ELISA assay showed that 85.7% and 74.2% of patients were positive for IgG and IgM, respectively. The mean IFN-γ levels in breast cancer patients with toxoplasmosis, without toxoplasmosis, and in the control group were 47.66, 0.00, and 0.57 pg/ ml, respectively. Higher IgG and interferon gamma levels were detected in the group of breast cancer patients with toxoplasmosis than in the group without toxoplasmosis. According to the ELISA findings, T. gondii was the most common parasite in female cancer patients.

Immunomodulatory, Antioxidant, and Anti-Inflammatory Activities of Green Synthesized Copper Nanoparticles for Treatment of Chronic Toxoplasma gondii Infection

BACKGROUND

Nowadays, interest in the use of nanotechnology for medical purposes is increasing. The current experimental investigation is planned for the green synthesis, characterization, and efficacy of copper nanoparticles (CLN) against chronic Toxoplasma gondii infection.

METHODS

Green synthesis of CNP was performed using the Lupinus arcticus extract via the precipitation method. The effects of CNP on tachyzoites, infectivity rate, parasites inside THP-1 cells, nitric oxide (NO) triggering, iNOS, and IFN-γ expression genes were evaluated. Following toxoplasmosis in BALB/c mice via the T. gondii ME49 strain, mice received CNP at 5 and 10 mg/kg/day alone and combined with pyrimethamine (PYM) at 5 mg/kg for two weeks. CNP's in vivo effects were evaluated by analyzing the load and size of cysts, oxidant/antioxidant enzymes, and bradyzoite surface antigen 1 (BAG1) expression gene levels.

RESULTS

CNP displayed a circular shape ranging from 10 to 85 nm. The IC50 value of CNP and PYM against tachyzoites was 37.2 and 25.7 µg/mL, respectively, whereas the CC50 value of CNP and pyrimethamine against THP-1 cells was 491.4 μg/mL and 269.5 μg/mL, respectively. The rate of infectivity and parasite load among THP-1 cells exposed to CNP was obviously reduced (p < 0.05). CNP at the doses of 5 and 10 mg/kg predominantly along with PYM evidently (p < 0.05) reduced the number and size of the T. gondii cysts in the infected mice. The levels of NO, iNOS, and IFN-γ genes were remarkably (p < 0.001) boosted compared with the cells without treatment. CNP at the doses of 10 and 20 mg/kg drastically (p < 0.05) reduced the oxidative stress markers in the infected mice, whereas CNP significantly elevated the level of antioxidant factors. CNP also revealed no toxicity in the liver and kidney at the tested doses in healthy mice.

CONCLUSIONS

Our experimental study reported the beneficial effects of CNP principally along with existing chemical drugs against latent toxoplasmosis in mice, whereas the possible action mechanisms of CNP are controlling oxidative stress, refining antioxidant enzymes, and increasing the production of immunomodulatory cytokines with no toxicity to the function of vital organs. But, additional trials are required to confirm these results, as well as to clarify the accurate mechanisms and their toxicity.

Nanoemulsion of Spiramycin against Tachyzoites of Toxoplasma gondii, RH Strain: Preparation, Toxicology, and Efficacy Studies

Background

Toxoplasma infection is caused by Toxoplasma gondii, which is an intracellular protozoan parasite. This infection consequently lead various congenital disabilities during pregnancy in patients. Spiramycin (Spi), a macrolide antibiotic, is typically recommended for T. gondii infection in pregnant women. We aimed to prepare the nanoemulsion of spiramycin (NE-Spi) and to evaluate the activity of this formulation in tachyzoites of T. gondii, RH strain.

Methods

This study was conducted in 2019-2021 at the School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. NE-Spi was prepared by spontaneous emulsification. The effects of this nanoemulsion on the viability of cultured cells were measured using MTT assay. To estimate the effects of NE-Spi on tachyzoites of T. gondii, RH strain, different concentrations of NE-Spi, S-Spi (suspension of spiramycin), and NE (nanoemulsion without any spiramycin) were added to tachyzoites and then stored for 30, 60, 90, 120 min and 24 h in 250 µg/ml concentration at room temperature. Finally, Tachyzoites mortality rates were evaluated by trypan blue staining. Of note, flow cytometry was conducted to confirm the obtained results.

Results

The final particle size of NE-Spi was calculated to be 11.3 nm by DLS and TEM. Thereafter, using MTT assay, in 62.5 µg/ml concentration of NE-Spi, the Vero cells viability was obtained as 82%. The highest mortality rates of tachyzoites of T.gondii, RH strain were observed at 250 µg/ml concentration and after 120 min of exposure, but it was not significantly different from 24 h of exposure.

Conclusion

NE-Spi has lethal efficacy on T. gondii RH strain in-vitro.

Nanotechnology: A promising strategy for the control of parasitic infections

Annually 3.5 billion people are affected by the parasitic infections that results around 200,000 deaths per annum. Major diseases occur due to the neglected tropical parasites. Variety of methods have been used to treat the parasitic infections but now these methods have become ineffective due to the development of resistance in the parasites and some other side effects of traditional treatment methods. Previous methods include use of chemotherapeutic agents and ethnobotanicals for the treatment of parasites. Parasites have developed resistance against the chemotherapeutic agents. A major problem related to Ethnobotanicals is the unequal availability of drug at the target site which is responsible for the low efficacy of drug. Nanotechnology technology involves the manipulation of matter on a nanoscale level and has the potential to enhance the efficacy and safety of existing drugs, develop new treatments, and improve diagnostic methods for parasitic infections. Nanoparticles can be designed to selectively target parasites while minimizing toxicity to the host, and they can also be used to improve drug delivery and increase drug stability. Some important nanotechnology-based tools for parasitic control include nanoparticle-based drug delivery, nanoparticle diagnostics, nanoparticle vaccines, nanoparticle insecticides. Nanotechnology has the potential to revolutionize the field of parasitic control by providing new methods for detection, prevention and treatment of parasitic infections. This review discusses the current state of nanotechnology-based approaches for controlling parasitic infections and highlights their potential to revolutionize the field of parasitology.

Contribution of the TIM-3/Gal-9 immune checkpoint to tropical parasitic diseases

Neglected tropical parasitic diseases (NTD) are prevalent in many countries and cost-effective treatments remain urgently needed. Novel approaches have been proposed to address these diseases through an action on immune co-inhibitory checkpoints which are exploited by parasites to evade the immune system. Among these checkpoints, TIM-3 has been shown to play a key role in antiparasitic immunity via a repression and functional attenuation of CD4⁺ and/or CD8⁺ T-cells. The present review discusses the role of the TIM-3/galectin-9 checkpoint in seven major NTD: Chagas disease, leishmaniasis and malaria (3 trypanosomatid infections), schistosomiasis, toxoplasmosis, echinococcosis and filariasis (4 helminth infections). In each case, the role of the checkpoint has been analyzed and the use of anti-TIM-3 antibodies evaluated as a potential therapeutic approach. In general, the parasitic infection is coupled with an upregulation of TIM-3 expressed on T cells, but not necessarily with an exhaustion of those T cells. In several cases, the use of anti-TIM-3 antibodies represent a possible strategy to reinforce the clearance and to reduce the parasite load. Promising data have been reported in cases of leishmaniasis, malaria and schistosomiasis, whereas a similar approach proved much less efficient (if not deleterious) in cases of echinococcosis and the Chagas disease. Nevertheless, the TIM-3 checkpoint warrants further consideration as a potential immune target to combat these pathologies, using antibodies or drugs capable of reducing directly or indirectly the expression and function of the checkpoint, to restore an immune control.

Potential effects of alpha-pinene, a monoterpene commonly found in essential oils against Toxoplasma gondii infection; an in vitro and in vivo study

This survey designed to assess the in vitro and in vivo activity of α-pinene, a monoterpene commonly originated in essential oils on Toxoplasma gondii. The in vitro effect of various concentration of α-pinene against tachyzoites of T. gondii Rh strain was assessed by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The activity of α-pinene on the stimulation of apoptosis in tachyzoites of T. gondii was also examined using the caspase 3 colorimetric activity assay. In vivo assay, mice were orally received α-pinene at 2 and 4 mg/kg/day for 14 days, then, pre-treated mice were daily tested and the rate of death was recorded. α-pinene meaningfully declined (p < 0.001) the tachyzoites viability with the IC50 value of 23.3 µg/mL. α-pinene induced the apoptosis through increasing the caspase-3 activity by 35.6%. Oral treatment with α-pinene significantly (p < 0.01) improved the survival rate infected mice with by 9th day. α-pinene + atovauone (50 mg/kg) significantly (p < 0.01) improved the survival rate infected mice up to 11 days compared with the control groups. α-pinene especially in combined atovaquone at 50 mg/kg for 2 weeks meaningfully (p < 0.05) declined oxidative stress. We found the promising in vitro anti-Toxoplasma effects of α-pinene on T. gondii RH strain. In addition, we found that α-pinene therapy particularly along with the reference drug declined the mortality rate of infected mice. Although, we just confirmed the stimulation of apoptosis and anti-inflammatory effects as the main anti-Toxoplasma mechanisms of α-pinene; however, more surveys concerning the accurate mechanisms, toxicity, and efficacy on other T. gondii strains are required to confirm these results.

Nanoparticles: Synthesis and Their Role as Potential Drug Candidates for the Treatment of Parasitic Diseases

Protozoa, helminths and ectoparasites are the major groups of parasites distributed worldwide. Currently, these parasites are treated with chemotherapeutic antiprotozoal drugs, anti-helminthic and anti-ectoparasitic agents, but, with the passage of time, resistance to these drugs has developed due to overuse. In this scenario, nanoparticles are proving to be a major breakthrough in the treatment and control of parasitic diseases. In the last decade, there has been enormous development in the field of nanomedicine for parasitic control. Gold and silver nanoparticles have shown promising results in the treatments of various types of parasitic infections. These nanoparticles are synthesized through the use of various conventional and molecular technologies and have shown great efficacy. They work in different ways, that include damaging the parasite membrane, DNA (Deoxyribonucleic acid) disruption, protein synthesis inhibition and free-radical formation. These agents are effective against intracellular parasites as well. Other nanoparticles, such as iron, nickel, zinc and platinum, have also shown good results in the treatment and control of parasitic infections. It is hoped that this research subject will become the future of modern drug development. This review summarizes the methods that are used to synthesize nanoparticles and their possible mechanisms of action against parasites.

Nano vaccines for T. gondii Ribosomal P2 Protein With Nanomaterials as a Promising DNA Vaccine Against Toxoplasmosis

Caused by Toxoplasma gondii, toxoplasmosis has aroused great threats to public health around the world. So far, no effective vaccine or drug is commercially available, and the demands for a safe and effective therapeutic strategy have become more and more urgent. In the current study, we constructed a DNA vaccine encoding T. gondii ribosomal P2 protein (TgP2) and denoted as TgP2-pVAX1 plasmid. To improve the immunoprotection, nanomaterial poly-lactic-co-glycolic acid (PLGA) and chitosan were used as the delivery vehicle to construct TgP2-pVAX1/PLGA and TgP2-pVAX1/CS nanospheres. Before vaccinations in BALB/c mice, TgP2-pVAX1 plasmids were transiently transfected into Human Embryonic Kidney (HEK) 293-T cells, and the expression of the eukaryotic plasmids was detected by laser confocal microscopy and Western blotting. Then the immunoprotection of naked DNA plasmids and their two nano-encapsulations were evaluated in the laboratory animal model. According to the investigations of antibody, cytokine, dendritic cell (DC) maturation, molecule expression, splenocyte proliferation, and T lymphocyte proportion, TgP2-pVAX1 plasmid delivered by two types of nanospheres could elicit a mixed Th1/Th2 immune response and Th1 immunity as the dominant. In addition, TgP2-pVAX1/PLGA and TgP2-pVAX1/CS nanospheres have great advantages in enhancing immunity against a lethal dose of T. gondii RH strain challenge. All these results suggested that TgP2-pVAX1 plasmids delivered by PLGA or chitosan nanomaterial could be promising vaccines in resisting toxoplasmosis and deserve further investigations and applications.

Nano DNA Vaccine Encoding Toxoplasma gondii Histone Deacetylase SIR2 Enhanced Protective Immunity in Mice

The pathogen of toxoplasmosis, Toxoplasma gondii (T. gondii), is a zoonotic protozoon that can affect the health of warm-blooded animals including humans. Up to now, an effective vaccine with completely protection is still inaccessible. In this study, the DNA vaccine encoding T. gondii histone deacetylase SIR2 (pVAX1-SIR2) was constructed. To enhance the efficacy, chitosan and poly (d, l-lactic-co-glycolic)-acid (PLGA) were employed to design nanospheres loaded with the DNA vaccine, denoted as pVAX1-SIR2/CS and pVAX1-SIR2/PLGA nanospheres. The pVAX1-SIR2 plasmids were transfected into HEK 293-T cells, and the expression was evaluated by a laser scanning confocal microscopy. Then, the immune protections of pVAX1-SIR2 plasmid, pVAX1-SIR2/CS nanospheres, and pVAX1-SIR2/PLGA nanospheres were evaluated in a laboratory animal model. The in vivo findings indicated that pVAX1-SIR2/CS and pVAX1-SIR2/PLGA nanospheres could generate a mixed Th1/Th2 immune response, as indicated by the regulated production of antibodies and cytokines, the enhanced maturation and major histocompatibility complex (MHC) expression of dendritic cells (DCs), the induced splenocyte proliferation, and the increased percentages of CD4⁺ and CD8⁺ T lymphocytes. Furthermore, this enhanced immunity could obviously reduce the parasite burden in immunized animals through a lethal dose of T. gondii RH strain challenge. All these results propose that pVAX1-SIR2 plasmids entrapped in chitosan or PLGA nanospheres could be the promising vaccines against acute T. gondii infections and deserve further investigations.

Toxoplasma gondii Proteasome Subunit Alpha Type 1 with Chitosan: A Promising Alternative to Traditional Adjuvant

As an important zoonotic protozoan, Toxoplasma gondii (T. gondii) has spread around the world, leading to infections in one-third of the population. There is still no effective vaccine or medicine against T. gondii, and recombinant antigens entrapped within nanospheres have benefits over traditional vaccines. In the present study, we first expressed and purified T. gondii proteasome subunit alpha type 1 (TgPSA1), then encapsulated the recombinant TgPSA1 (rTgPSA1) in chitosan nanospheres (CS nanospheres, rTgPSA1/CS nanospheres) and incomplete Freund’s adjuvant (IFA, rTgPSA1/IFA emulsion). Antigens entrapped in CS nanospheres reached an encapsulation efficiency of 67.39%, and rTgPSA1/CS nanospheres showed a more stable release profile compared to rTgPSA1/IFA emulsion in vitro. In vivo, Th1-biased cellular and humoral immune responses were induced in mice and chickens immunized with rTgPSA1/CS nanospheres and rTgPSA1/IFA emulsion, accompanied by promoted production of antibodies, IFN-γ, IL-4, and IL-17, and modulated production of IL-10. Immunization with rTgPSA1/CS nanospheres and rTgPSA1/IFA emulsion conferred significant protection, with prolonged survival time in mice and significantly decreased parasite burden in chickens. Furthermore, our results also indicate that rTgPSA1/CS nanospheres could be used as a substitute for rTgPSA1/IFA emulsion, with the optimal administration route being intramuscular in mass vaccination. Collectively, the results of this study indicate that rTgPSA1/CS nanospheres represent a promising vaccine to protect animals against acute toxoplasmosis.

Albalawi A, Alanazi AD, Baharvand P, Moghaddam A, Mahmoudvand H. Chitosan-Based Nanomaterials as Valuable Sources of Anti-Leishmanial Agents: A Systematic Review

BACKGROUND

The current chemotherapy agents against various forms of leishmaniasis have some problems and side effects, including high toxicity, high cost, and the emergence of resistant strains. Here, we aimed to review the preclinical studies (in vitro and in vivo) on the anti-leishmanial activity of chitosan and chitosan-based particles against Leishmania spp.

METHODS

This study was conducted based on the 06-PRISMA guidelines and registered in the CAMARADES-NC3Rs Preclinical Systematic Review and Meta-Analysis Facility (SyRF) database. Various English databases such as PubMed, Google Scholar, Web of Science, EBSCO, ScienceDirect, and Scopus were used to find the publications related to the anti-leishmanial effects of chitosan and its derivatives and other pharmaceutical formulations, without a date limitation, to find all the published articles. The keywords included "chitosan", "chitosan nanoparticles", "anti-leishmanial", "Leishmania", "leishmaniasis", "cutaneous leishmaniasis", "visceral leishmaniasis", "in vitro", and "in vivo". The language for data collection were limited to English.

RESULTS

Of 2669 papers, 25 papers, including 7 in vitro (28.0%), 7 in vivo (28.0%), and 11 in vitro/in vivo (44.0%) studies conducted up to 2020 met the inclusion criteria for discussion in this systematic review. The most common species of Leishmania used in these studies were L. major (12, 48.0%), L. donovani (7, 28.0%), and L. amazonensis (4, 16.80%). In vivo, the most used animals were BALB/c mice (11, 61.1%) followed by hamsters (6, 33.3%) and Wistar rats (1, 5.5%), respectively. In vitro, the most used Leishmania form was amastigote (8, 44.4%), followed by promastigote (4, 22.2%), and both forms promastigote/amastigote (6, 33.3%).

CONCLUSION

According to the literature, different types of drugs based on chitosan and their derivatives demonstrated considerable in vitro and in vivo anti-leishmanial activity against various Leishmania spp. Based on the findings of this review study, chitosan and its derivatives could be considered as an alternative and complementary source of valuable components against leishmaniasis with a high safety index. Nevertheless, more investigations are required to elaborate on this result, mainly in clinical settings.