Extracts of Tectona grandis and Vernonia amygdalina have anti-Toxoplasma and pro-inflammatory properties in vitro

Anti-Toxoplasma Activities of Some Egyptian Plant Extracts: An In Vitro Study

Purpose

Toxoplasmosis is a globally widespread parasitic disease which causes major health problems in human and animals. This research was conducted to assess the effect of some Egyptian herbal extracts against Toxoplasma gondii (T. gondii) tachyzoites in vitro.

Methods

The methanol extracts of Withania somnifera, Cyper rotundus, Acacia nilotica,Chrysanthemum cinerariae folium, Anethum graveolens, Raphanus sativus, Ceratonia siliqua, Elettaria cardamomum and Cuminum cyminum were tested against T. gondii tachyzoites.

Results

Among the tested plants, the extracts from Raphanus sativus, Cuminum cyminum, and Ceratonia siliqua exhibited high anti-Toxoplasma activities at 50 µg/ml, relative to sulfadiazine. They showed low IC50 values on T. gondii (7.92, 9.47 and 13.52 µg/ml, respectively) and high selectivity index values (100.79, 59.19, and 29.05, respectively). Scanning electron microscopy (SEM) findings indicated evident morphological changes in tachyzoites treated with these three herbal extracts.

Conclusion

Raphanus sativus, Ceratonia siliqua, and Cuminum cyminum methanol extracts could be promising sources of new medicament for toxoplasmosis.

The Experimental Role of Medicinal Plants in Treatment of Toxoplasma gondii Infection: A Systematic Review

BACKGROUND

Toxoplasma gondii is the global protozoa that could cause contamination in warm-blooded animals and is considered among the opportunistic pathogens in immunocompromised patients. Among the people at risk, toxoplasmosis infection can lead to the incidence of severe clinical manifestations, encephalitis, chorioretinitis, and even death.

PURPOSE

The present research is focused on the new research for the treatment of toxoplasmosis parasitic disease using medicinal herbs.

METHODS

The search was performed in five English databases, including Scopus, PubMed, Web of Science, EMBASE, and Google Scholar up from 2010 to December 2019. Studies in any language were entered in the searching step if they had an English abstract. The words and terms were used as a syntax with specific tags of each database.

RESULTS

Out of 1832 studies, 36 were eligible to be reviewed. The findings showed that 17 studies (47%) were performed in vitro, 14 studies (39%) in vivo, and 5 studies (14%) both in vivo and in vitro.

CONCLUSION

The studies showed that the plant extracts can be a good alternative in reducing the toxoplasmosis effects in the host and the herbal extracts can be used to produce natural product-based drugs affecting toxoplasmosis with fewer side-effects than synthetic drugs.

Antibacterial, anti-inflammatory and antioxidant activities of Mahanintangtong and its constituent herbs, a formula used in Thai traditional medicine for treating pharyngitis

Background

Mahanintangtong is listed in the Thailand’s National List of Essential Medicines (NLEM). It is used to treat non-specific fevers and illnesses such as pharyngitis and chickenpox. In this study, we investigated the biological activities of the different medicinal plants used in the Mahanintangtong formula.

Methods

The plant materials were extracted by maceration and decoction. Antimicrobial activity, assessed by disc diffusion method, the minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were compared with commercially available standard antibiotics. To elucidate the anti-inflammatory mechanisms, inhibition of nitric oxide (NO), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) production was tested by Griess and ELISA techniques. Antioxidant activity was measured by ABTS and DPPH scavenging assays.

Results

The extracts with the best antimicrobial activities were carbonized Tectona grandis showing against Streptococcus pyogenes, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. The ethanol extract of Dracaena loureiroi wood exhibited the highest NO and IL-6 inhibitory activity with IC₅₀ values of 9.42 ± 1.81 and 12.02 ± 0.30 μg/mL, respectively. The ethanol extract of Pogostemon cablin had the highest TNF-α inhibitory with IC₅₀ values of 10.68 ± 0.02 μg/mL. In anti-free radical testing, the ethanol extract of D. loureiroi displayed high antioxidant activity by both ABTS and DPPH assays.

Conclusion

The ethanol extracts from carbonized T. grandis and Mahanintangtong showed good antimicrobial activity, especially against S. pyogenes, and good anti-inflammatory activity. These findings are relevant to the pathogenesis of pharyngitis and justify additional studies to see if Mahanintangtong could have clinical utility.

Copaifera spp. oleoresins impair Toxoplasma gondii infection in both human trophoblastic cells and human placental explants

The combination of pyrimethamine and sulfadiazine is the standard care in cases of congenital toxoplasmosis. However, therapy with these drugs is associated with severe and sometimes life-threatening side effects. The investigation of phytotherapeutic alternatives to treat parasitic diseases without acute toxicity is essential for the advancement of current therapeutic practices. The present study investigates the antiparasitic effects of oleoresins from different species of Copaifera genus against T. gondii. Oleoresins from C. reticulata, C. duckei, C. paupera, and C. pubiflora were used to treat human trophoblastic cells (BeWo cells) and human villous explants infected with T. gondii. Our results demonstrated that oleoresins were able to reduce T. gondii intracellular proliferation, adhesion, and invasion. We observed an irreversible concentration-dependent antiparasitic action in infected BeWo cells, as well as parasite cell cycle arrest in the S/M phase. The oleoresins altered the host cell environment by modulation of ROS, IL-6, and MIF production in BeWo cells. Also, Copaifera oleoresins reduced parasite replication and TNF-α release in villous explants. Anti-T. gondii effects triggered by the oleoresins are associated with immunomodulation of the host cells, as well as, direct action on parasites.

The Mechanism of Action of Ursolic Acid as a Potential Anti-Toxoplasmosis Agent, and Its Immunomodulatory Effects

This study was performed to investigate the mechanism of action of ursolic acid in terms of anti-Toxoplasma gondii effects, including immunomodulatory effects. We evaluated the anti-T. gondii effects of ursolic acid, and analyzed the production of nitric oxide (NO), reactive oxygen species (ROS), and cytokines through co-cultured immune cells, as well as the expression of intracellular organelles of T. gondii. The subcellular organelles and granules of T. gondii, particularly rhoptry protein 18, microneme protein 8, and inner membrane complex sub-compartment protein 3, were markedly decreased when T. gondii was treated with ursolic acid, and their expressions were effectively inhibited. Furthermore, ursolic acid effectively increased the production of NO, ROS, interleukin (IL)-10, IL-12, granulocyte macrophage colony stimulating factor (GM-CSF), and interferon-β, while reducing the expression of IL-1β, IL-6, tumor necrosis factor alpha (TNF-α), and transforming growth factor beta 1 (TGF-β1) in T. gondii-infected immune cells. These results demonstrate that ursolic acid not only causes anti-T. gondii activity/action by effectively inhibiting the survival of T. gondii and the subcellular organelles of T. gondii, but also induces specific immunomodulatory effects in T. gondii-infected immune cells. Therefore, this study indicates that ursolic acid can be effectively utilized as a potential candidate agent for developing novel anti-toxoplasmosis drugs, and has immunomodulatory activity.

Risk Assessment of Etanercept in Mice Chronically Infected With Toxoplasma gondii

Toxoplasma gondii (T. gondii) is a zoonotic parasite that severely harms the health of the host. The cysts of T. gondii can reactivate from bradyzoites to tachyzoites, if the individual develops low or defective immunity, causing lethal toxoplasmosis. The host resists T. gondii infection by mediating Th1-type cellular immunity to generate pro-inflammatory cytokines. Tumor necrosis factor (TNF) is an important pro-inflammatory cytokine, which can induce lysosomal fusion of parasitophorous vacuole (PV) to kill parasites. Etanercept is a soluble TNF receptor fusion protein, which is widely used clinically to cure autoimmune diseases. The effects and specific molecular mechanisms of etanercept treatment on patients co-infected with autoimmune diseases and chronic toxoplasmosis are rarely reported. In our study, a mouse model of chronic infection with T. gondii and murine macrophages RAW264.7 cells infected with T. gondii were employed to investigate the impact of etanercept on the status of chronic infection. The cytokines levels and a series of phenotypic experiments in vivo and in vitro were measured. In the present study, the expression levels of TNF, IL-1β, and IL-6 were decreased and the brain cysts number was increased in mice chronically infected with T. gondii after being treated with etanercept. In vivo experiments confirmed that etanercept caused a decrease in the immune levels of the mice and activated the brain cysts, which would lead to conversion from chronic infection to acute infection, causing severe clinical and pathological symptoms. Murine macrophages RAW264.7 cells were pretreated with etanercept, and then infected with T. gondii. In vitro experiments, the expression levels of cytokines were decreased, indicating that etanercept could also reduce the cells’ immunity and promote the transformation of bradyzoites to tachyzoites, but did not affect the intracellular replication of tachyzoites. In summary, etanercept treatment could activate the conversion of bradyzoites to tachyzoites through reducing host immunity in vivo and in vitro. The results obtained from this study suggest that the use of etanercept in patients co-infected with autoimmune diseases and chronic toxoplasmosis may lead to the risk of activation of chronic infection, resulting in severe acute toxoplasmosis.