Evaluation of the inhibitory effect of Zingiber officinale rhizome on Babesia and Theileria parasites

Camellia sinensis Aqueous Extract: A Promising Candidate for Hepatic Eimeriosis Treatment in Rabbits

Eimeria stiedae (E. stiedae) is a common coccidian species that infects the liver and causes economic losses for the rabbit industry. This study aimed to determine the efficiency of green tea aqueous extract (GTE) as a natural treatment for eimeriosis caused by E. stiedae. Male rabbits Cuniculus L. (Oryctolagus) of the New Zealand White rabbit strain (4-4.5 months) were used, as they are suitable for research and conducting experiments. Thirty rabbits were allocated into six groups, with five rabbits in each group; the G1 group (non-infected untreated) served as a negative control group; the G2 group was not infected and treated with 250 mg GTE; the G3 group was not infected and treated with 500 mg GTE; the G4 group was untreated and was infected with 3 × 104 Sporulated E. stiedae oocysts, which served as a positive control group; the G5 group was infected and treated with 250 mg GTE; and the G6 group was infected and treated with 500 mg GTE. The hematological and biochemical analyses of each group of rabbit sera were carried out. Phytochemical analysis was performed to evaluate the active components in GTE leaves using the following methods: IR spectroscopy, liquid chromatography-mass spectrometry (LC-MS), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy. The infected rabbit groups treated with GTE at both doses of 250 and 500 mg/kg exhibited a significant decrease in the extent of E. stiedae oocyst shedding compared with the infected untreated group at 14, 21, and 28 days post-infection. Also, treatment with green tea showed improvement in liver weight compared with the enlarged livers of infected, untreated rabbits. The disturbance in serum liver enzymes' gamma-glutamyl transferase (GGT) and aspartate aminotransferase (AST/GOT) levels, as well as serum glucose, potassium, uric acid, cholesterol, and urea levels, were improved after the treatment of infected rabbit groups with green tea compared with the infected untreated group. Moreover, in this study, the images of the egg stages of the parasite were taken using a fluorescence microscope at 25 µm and 26 µm magnifications. This study provides promising results for the effective cell absorption of the aqueous extract of green tea, which was confirmed in the analyzed images using a scanning electron microscope at 5 µm and 20 µm magnifications.

Diminazene aceturate and imidocarb dipropionate-based combination therapy for babesiosis – A new paradigm

In the present study, the effect of a combination therapy consisting of diminazene aceturate (DA) and imidocarb dipropionate (ID) on the in vitro growth of several parasitic piroplasmids, and on Babesia microti in BALB/c mice was evaluated using a fluorescence-based SYBR Green I test. We evaluated the structural similarities between the regularly used antibabesial medications, DA and ID, and the recently found antibabesial drugs, pyronaridine tetraphosphate, atovaquone, and clofazimine, using atom pair fingerprints (APfp). The Chou-Talalay approach was used to determine the interactions between the two drugs. A Celltac MEK-6450 computerized hematology analyzer was used to detect hemolytic anemia every 96 hours in mice infected with B. microti and in those treated with either mono- or combination therapy. According to the APfp results, DA and ID have the most structural similarities (MSS). DA and ID had synergistic and additive interactions against the in vitro growth of Babesia bigemina and Babesia bovis, respectively. Low dosages of DA (6.25 mg kg^-1) and ID (8.5 mg kg^-1) in conjunction with each other inhibited B. microti growth by 16.5 %, 32 %, and 4.5 % more than 25 mg kg^-1 DA, 6.25 mg kg^-1 DA, and 8.5 mg kg^-1 ID monotherapies, respectively. In the blood, kidney, heart, and lung tissues of mice treated with DA/ID, the B. microti small subunit rRNA gene was not detected. The obtained findings suggest that DA/ID could be a promising combination therapy for treating bovine babesiosis. Also, such combination may overcome the potential problems of Babesia resistance and host toxicity induced by utilizing full doses of DA and ID.

Evaluating the inhibitory effect of resveratrol on the multiplication of several Babesia species and Theileria equi on in vitro cultures, and Babesia microti in mice

Introduction: Histone post-translational modification is one of the most studied factors influencing epigenetic regulation of protozoan parasite gene expression, which is mediated by histone deacetylases (KDACs) and acetyltransferases (KATs). Objective and methods: The present study investigated the role of resveratrol (RVT) as an activator of histone deacetylases in the control of various pathogenic Babesia sp. and Theileria equi in vitro, as well as B. microti infected mice in vivo using fluorescence assay. Its role in mitigating the side effects associated with the widely used antibabesial drugs diminazene aceturate (DA) and azithromycin (AZM) has also been investigated. Results: The in vitro growth of B. bovis, B. bigemina, B. divergens, B. caballi and Theileria equi (T. equi) was significantly inhibited (P < 0.05) by RVT treatments. The estimated IC50 values revealed that RVT has the greatest inhibitory effects on B. bovis growth in vitro, with an IC50 value of 29.51 ± 2.46 µM. Reverse transcription PCR assay showed that such inhibitory activity might be attributed to resveratrol's stimulatory effect on B. bovis KDAC3 (BbKADC3) as well as its inhibitory effect on BbKATS. RVT causes a significant decrease (P < 0.05) in cardiac troponin T (cTnT) levels in heart tissue of B. microti- infected mice, thereby indicating that RVT may play a part in reducing the cardiotoxic effects of AZM. Resveratrol showed an additive effect with imidocarb dipropionate in vivo. Treatment of B. microti-infected mice with a combined 5 mg/kg RVT and 8.5 mg/kg ID resulted in an 81.55% inhibition at day 10 postinoculation (peak of parasitemia). Conclusion: Our data show that RVT is a promising antibabesial pharmacological candidate with therapeutic activities that could overcome the side effects of the currently used anti-Babesia medications.

In vivo activity and atom pair fingerprint analysis of MMV665941 against the apicomplexan parasite Babesia microti, the causative agent of babesiosis in humans and rodents

The effect of MMV665941 on the growth of Babesia microti (B. microti) in mice, was investigated in this study using a fluorescence-based SYBR Green I test. Using atom Pair signatures, we investigated the structural similarity between MMV665941 and the commonly used antibabesial medicines diminazene aceturate (DA), imidocarb dipropionate (ID), or atovaquone (AV). In vitro cultures of Babesia bovis (B. bovis) and, Theileria equi (T. equi) were utilized to determine the MMV665941 and AV interaction using combination ratios ranged from 0.75 IC50 MMV665941:0.75 IC50 AV to 0.50 IC50 MMV665941:0.50 IC50 AV. The used combinations were prepared depending on the IC50 of each drug against the in vitro growth of the tested parasite. Every 96 h, the hemolytic anemia in the treated mice was monitored using a Celltac MEK-6450 computerized hematology analyzer. A single dose of 5 mg/kg MMV665941 exhibited inhibition in the B. microti growth from day 4 post-inoculation (p.i.) till day 12 p.i. MMV665941 caused 62.10%, 49.88%, and 74.23% inhibitions in parasite growth at days 4, 6 and 8 p.i., respectively. Of note, 5 mg/kg MMV665941 resulted in quick recovery of hemolytic anemia caused by babesiosis. The atom pair fingerprint (APfp) analysis revealed that MMV665941 and atovaquone (AV) showed maximum structural similarity. Of note, high concentrations (0.75 IC50) of MMV665941 and AV caused synergistic inhibition on B. bovis growth. These findings suggest that MMV665941 might be a promising drug for babesiosis treatment, particularly when combined with the commonly used antibabesial drug, AV.

In Vitro Inhibitory Effects and Bioinformatic Analysis of Norfloxacin and Ofloxacin on Piroplasm

PURPOSE

The in vitro inhibitory effect of two fluroquinolone antibiotics, norfloxacin and ofloxacin, was evaluated in this study on the growth of several Babesia and Theileria parasites with highlighting the bioinformatic analysis for both drugs with the commonly used antibabesial drug, diminazene aceturate (DA), and the recently identified antibabesial drugs, luteolin, and pyronaridine tetraphosphate (PYR).

METHODS

The antipiroplasm efficacy of screened fluroquinolones in vitro and in vivo was assessed using a fluorescence-based SYBR Green I assay. Using atom Pair signatures, we investigated the structural similarity between fluroquinolones and the antibabesial drugs.

RESULTS

Both fluroquinolones significantly inhibited (P < 0.05) the in vitro growths of Babesia bovis (B. bovis), B. bigemina, B. caballi, and Theileria equi (T. equi) in a dose-dependent manner. The best inhibitory effect for both drugs was observed on the growth of T. equi. Atom Pair fingerprints (APfp) results and AP Tanimoto values revealed that both fluroquinolones, norfloxacin with luteolin, and ofloxacin with PYR, showed the maximum structural similarity (MSS). Two drug interactions findings confirmed the synergetic interaction between these combination therapies against the in vitro growth of B. bovis and T. equi.

CONCLUSION

This study helped in discovery novel potent antibabesial combination therapies consist of norfloxacin/ofloxacin, norfloxacin/luteolin, and ofloxacin/PYR.

Imidazo[1,2-a]pyridine: a Highly Potent Therapeutic Agent Clears Piroplasm Infection In Vitro

BACKGROUND AND PURPOSE

The imidazo[1,2-a] pyridines have huge applications in medicinal chemistry with potent activity against wide spectrum of infectious agents. The efficacy of imidazo[1,2-a]pyridine on the in vitro growth of different piroplasms, including Babesia bovis, B. bigemina, B. divergens, B. caballi, and Theileria equi, was investigated in this study.

METHODS

The anti-piroplasm efficacy of imidazo[1,2-a] pyridines was assessed using a fluorescence-based SYBR Green I assay. Furthermore, efficacy of imidazo[1,2-a]pyridine against piroplasms following discontinuation of treatment was also assessed using a viability assay. In vitro cultures of B. bovis and T. equi were used to assess the imidazo[1,2-a]pyridine and diminazene aceturate (DA) interaction.

RESULTS

In vitro, imidazo[1,2-a]pyridine inhibited the growth of B. bovis, B. bigemina, B. caballi, and T. equi in a dose-dependent manner. The highest inhibitory effects of imidazo[1,2-a]pyridine were detected on the growth of B. caballi with IC₅₀ value of 0.47 ± 0.07. Interestingly, the efficacy of imidazo[1,2-a]pyridine was higher against B. bigemina (IC₅₀: 1.37 ± 0.15) compared to the positive-control DA (IC₅₀: 2.29 ± 0.06). The viability test findings indicate that imidazo[1,2-a]pyridine had a long-lasting inhibitory effect on bovine Babesia parasites in vitro growth up to 4 days after treatment. Notably, when coupled with DA at 0.75 or 0.50 IC₅₀, a high concentration (0.75 IC₅₀) of imidazo[1,2-a]pyridine produced additive suppression of B. bovis growth which suggest that imidazo[1,2-a]pyridine/DA could be a promising combination therapy for the treatment of B. bovis.

CONCLUSION

The obtained encouraging findings pave the way for in vitro and in vivo efficacy trials of imidazo[1,2-a]pyridine derivatives against several piroplasmids.

Impact of Thermal Processing on the Composition of Secondary Metabolites of Ginger Rhizome-A Review

Ginger (Zingiber officinale Rosc.) is both a commonly used spice, and an ingredient of various dietary supplements and medications. Its diverse applications result from the range of health benefits that this plant brings thanks to the presence of active compounds (secondary metabolites) in the matrix. Even if several studies underline a stronger pharmacological activity of fresh ginger rhizomes, the unprocessed plant is relatively rarely used. Ginger rhizomes are subjected to thermal processing, such as boiling, blanching, steam drying and others, at different temperature and time settings. Additionally, freeze-drying of the rhizomes is used as the first step in the preparation of raw material. It was proved that the composition of secondary metabolites of the Zingiber officinale rhizome changes upon the influence of temperature. Therefore, the aim of the review was to put together scientific results on the impact of traditional and unconventional methods of heat treatment on ginger rhizomes and to show the compositional differences that they induce in the plant matrix. Variations in the content and the transformation of some compounds into other metabolites will be also discussed, with particular attention paid to two major groups of secondary metabolites present in the plant, namely, phenolics and terpenes.

Repurposing of the Malaria Box for Babesia microti in mice identifies novel active scaffolds against piroplasmosis

Background

An innovative approach has been introduced for identifying and developing novel potent and safe anti-Babesia and anti-Theileria agents for the control of animal piroplasmosis. In the present study, we evaluated the inhibitory effects of Malaria Box (MBox) compounds (n = 8) against the growth of Babesia microti in mice and conducted bioinformatics analysis between the selected hits and the currently used antibabesial drugs, with far-reaching implications for potent combinations.

Methods

A fluorescence assay was used to evaluate the in vivo inhibitory effects of the selected compounds. Bioinformatics analysis was conducted using hierarchical clustering, distance matrix and molecular weight correlation, and PubChem fingerprint. The compounds with in vivo potential efficacy were selected to search for their target in the piroplasm parasites using quantitative PCR (qPCR).

Results

Screening the MBox against the in vivo growth of the B. microti parasite enabled the discovery of potent new antipiroplasm drugs, including MMV396693 and MMV665875. Interestingly, statistically significant (P < 0.05) downregulation of cysteine protease mRNA levels was observed in MMV665875-treated Theileria equi in vitro culture in comparison with untreated cultures. MMV396693/clofazimine and MMV665875/atovaquone (AV) showed maximum structural similarity (MSS) with each other. The distance matrix results indicate promising antibabesial efficacy of combination therapies consisting of either MMV665875 and AV or MMV396693 and imidocarb dipropionate (ID).

Conclusions

Inhibitory and hematology assay results suggest that MMV396693 and MMV665875 are potent antipiroplasm monotherapies. The structural similarity results indicate that MMV665875 and MMV396693 have a similar mode of action as AV and ID, respectively. Our findings demonstrated that MBox compounds provide a promising lead for the development of new antibabesial therapeutic alternatives.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05430-4.

Pomegranate (Punica granatum) Peel Inhibits the In Vitro and In Vivo Growth of Piroplasm Parasites

Pomegranate (Punica granatum) peel has seen a rapid surge in attention as a medical and nutritional product over the last decade. The impact of pomegranate peel methanolic extract monotherapy and combination therapy on the in vitro growth of Babesia (B.) bovis, B. bigemina, B. divergens, B. caballi, and Theileria (T.) equi, as well as B. microti in mice, was investigated in this work. Fluorescence-based SYBR green I assay was used for evaluating the inhibitory antibabesial efficacy of pomegranate (Punica granatum) peel against the growth of several piroplasm parasites in vitro and in vivo. Celltac α MEK-6450 computerized haematology analyzer was used for monitoring the haematological parameters of treated mice every 4 days. Pomegranate peel inhibited the in vitro growth of B. bovis, B. bigemina, B. divergens, T. equi, and B. caballi in a dose-dependent manner, with IC₅₀ values of 154.45 ± 23.11, 40.90 ± 9.35, 72.71 ± 14.77, 100 ± 16.20, and 77.27 ± 16.94 μg/ml, respectively. On a B. bovis culture, the in vitro inhibitory effect of pomegranate peel was amplified when it was combined with diminazene aceturate (DA). Combination therapy of pomegranate peel and a low dose of DA (15 mg kg⁻¹) inhibited B. microti growth significantly (P < 0.05) higher than the treatment with the full dose of DA (25 mg kg⁻¹) in B. microti-infected mice. These findings suggest that pomegranate peel might be a potential medicinal plant for babesiosis treatment, especially when combined with a low dosage of DA.

Discovering the Potent Inhibitors Against Babesia bovis in vitro and Babesia microti in vivo by Repurposing the Natural Product Compounds

In the present study, we screened 502 natural product compounds against the in vitro growth of Babesia (B.) bovis. Then, the novel and potent identified compounds were further evaluated for their in vitro efficacies using viability and cytotoxicity assays. The in vivo inhibitory effects of the selected compounds were evaluated using B. microti “rodent strain” in mice model. Three potent compounds, namely, Rottlerin (RL), Narasin (NR), Lasalocid acid (LA), exhibited the lowest IC₅₀ (half-maximal inhibitory concentration) as follows: 5.45 ± 1.20 μM for RL, 1.86 ± 0.66 μM for NR, and 3.56 ± 1.41 μM for LA. The viability result revealed the ability of RL and LA to prevent the regrowth of treated parasite at 4 × IC₅₀ and 2 × IC₅₀, respectively, while 4 × IC₅₀ of NR was sufficient to stop the regrowth of parasite. The hematology parameters of B. microti in vivo were different in the NR-treated groups as compared to the infected/untreated group. Interestingly, intraperitoneal administration of NR exhibiting inhibition in the growth of B. microti in mice was similar to that observed after administration of the commonly used antibabesial drug, diminazene aceturate (DA) (76.57% for DA, 74.73% for NR). Our findings indicate the richness of natural product compounds by novel potent antibabesial candidates, and the identified potent compounds, especially NR, might be used for the treatment of animal babesiosis.