Search bioRxivSearch

bioRxiv · 10.1101/480657

The effects of trans-chalcone and chalcone hydrate on the growth of Babesia and Theileria

Abstract

BackgroundChemotherapy is a principle tool for the control and prevention of piroplasmosis. The search for a new chemotherapy against Babesia and Theileria parasites has become increasingly urgent due to the toxic side effects of and developed resistance to the current drugs. Chalcones have attracted much attention due to their diverse biological activities. With the aim to discover new drugs and drug targets, in vitro and in vivo antibabesial activity of trans-chalcone (TC) and chalcone hydrate (CH) alone and combined with diminazene aceturate (DA), clofazimine (CF) and atovaquone (AQ) were investigated.\n\nMethodology/Principal findingsThe fluorescence-based assay was used for evaluating the inhibitory effect of TC and CH on five of Babesia and Theileria species, including B. bovis, B. bigemina, B. divergens, B. caballi, and T. equi, the combination with DA, CF, and AQ on in vitro cultures, and on the multiplication of a B. microti-infected mouse model. The cytotoxicity of compounds was tested on Madin- Darby bovine kidney (MDBK), mouse embryonic fibroblast (NIH/3T3), and human foreskin fibroblast (HFF) cell lines. The half maximal inhibitory concentration (IC50) values of TC and CH against B. bovis, B. bigemina, B. divergens, B. caballi, and T. equi were 69.6 {+/-} 2.3, 33.3 {+/-} 1.2, 64.8 {+/-} 2.5, 18.9 {+/-} 1.7, and 14.3 {+/-} 1.6 {micro}M and 138.4 {+/-} 4.4, 60.9 {+/-} 1.1, 82.3 {+/-} 2.3, 27.9 {+/-} 1.2, and 19.2 {+/-} 1.5 {micro}M, respectively. In toxicity assays, TC and CH affected the viability of MDBK, NIH/3T3, and HFF cell lines the with half maximum effective concentration (EC50) values of 293.9 {+/-} 2.9, 434.4 {+/-} 2.7, and 498 {+/-} 3.1 {micro}M and 252.7 {+/-} 1.7, 406.3 {+/-} 9.7, and 466 {+/-} 5.7 {micro}M, respectively. In the mouse experiment, TC reduced the peak parasitemia of B. microti by 71.8% when administered intraperitoneally at 25 mg/kg. Combination therapies of TC-diminazene aceturate and TC-clofazimine were more potent against B. microti infection in mice than their monotherapies.\n\nConclusions/SignificanceIn conclusion, both TC and CH inhibited the growth of Babesia and Theileria in vitro, and TC inhibited the growth of B. microti in vivo. Therefore, TC and CH could be candidates for the treatment of piroplasmosis after further studies.\n\nAuthor summaryProtozoa of the genus Babesia are the second most common blood-borne parasites of mammals after the trypanosomes. Babesia and Theileria are the etiological agents of piroplasmosis, a tick-transmitted disease causing substantial losses of livestock and companion animals worldwide and has recently gained attention as one of the emerging zoonosis in humans. Diminazene aceturate and imidocarb dipropionate are still the first choices for the treatment of animals. However, these drugs cause many adverse effects. Furthermore, they are not approved for human medicine. Therefore, the development of alternative treatment remedies against babesiosis is urgently required. In the present study we evaluated the effects chalcone hydrate (CH) and trans-chalcone (TC), against the growth of four species of Babesia and T. equi. Furthermore, we studied the chemotherapeutic potential of TC on B. microti in mice. The effects of the combined treatment of TC with DA, CF and AQ revealed that TC was found to diminish the adverse effects of these drugs

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Batiha, G. E.-S., Beshbishy, A. M., Tayebwa, D. S., Adeyemi, O. S., Shaheen, H. M., Yokoyama, N., Igarashi, I.. 2018-11-27. The effects of trans-chalcone and chalcone hydrate on the growth of Babesia and Theileria. https://doi.org/10.1101/480657

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A conserved cysteine-histidine-glutamate metal site identifies DUF501 (Rv1025), an essential uncharacterised protein family of Mycobacterium tuberculosis, as a candidate metalloenzyme and drug target

A substantial fraction of the Mycobacterium tuberculosis proteome remains functionally uncharacterised. Rv1025, a 155-residue protein carrying the domain of unknown function DUF501 (Pfam PF04417), is essential by transposon mutagenesis and vulnerable by CRISPR interference, an attractive but neglected drug target, yet has never been functionally described. The family (4,370 proteins, no Gene Ontology term, no solved structure) is uncharacterised across all organisms and essential in three Actinobacterial genera. A Foldseek search of the AlphaFold model against complete structural databases finds no significant homolog, indicating a novel fold. The operon eno-divIC-Rv1025-ppx2 is conserved across the Actinobacteria phylum, yet AlphaFold-Multimer finds no direct complex between Rv1025 and its neighbour DivIC. Instead, conservation across 8,700 homologous sequences reveals a near-invariant Cys113-His115-Glu59 cluster forming a pocket. Holo AlphaFold3 predictions with Zn, Fe and Mn confidently place a divalent metal on this triad at 2.25-2.47 A; mutating the triad relocates the metal, and an independent backbone-geometry predictor recovers the same site, confirming specificity. The triad is universal across the family: present in all 1,472 near-complete bacterial sequences of the Pfam alignment, with no non-conservative substitution among the 2,228 sequences examined, a defining feature of bacterial DUF501 rather than a mycobacterial peculiarity. We propose that DUF501 is a metal-binding protein and candidate metalloenzyme, the first functional hypothesis for this family, whose conserved, essential metal pocket is a promising drug target. As the predictions build on a conservation-defined site within a fully computational study, they are supportive rather than proof of metal occupancy and warrant experimental validation.

microbiology

Mycoplasmal endosymbionts of Trichomonas vaginalis are associated with reduced risk for Chlamydia trachomatis endometrial infection in asymptomatic, coinfected, women.

Trichomonas vaginalis is a protozoan parasite that causes trichomoniasis, the most common curable non-viral sexually transmitted infection, and Chlamydia trachomatis is a bacterial pathogen that can ascend to the upper genital tract and cause pelvic inflammatory disease, infertility, and ectopic pregnancy. T. vaginalis harbors bacterial endosymbionts, including Candidatus Malacoplasma girerdii, an obligate symbiont, and Metamycoplasma hominis, which can live freely or symbiotically. In a 16S rRNA sequencing study of the cervicovaginal microbiome of women at high risk for chlamydial infection, Ca. M. girerdii abundance was one of 13 features predicting lack of chlamydial spread to the endometrium, despite no direct association between T. vaginalis infection and reduced chlamydial ascension. Investigating the relationship between these microorganisms further, we found that T. vaginalis vaginal abundance correlated positively with chlamydial burden in women whose infection was confined to the cervix, while a nonsignificant inverse relationship was seen in women with endometrial spread. Among participants with high chlamydial burden, Ca. M. girerdii was detected exclusively in women without endometrial infection. Both endosymbionts trended toward more frequent detection, and higher abundance, in coinfected women without endometrial spread, while M. hominis abundance correlated strongly with T. vaginalis burden in this group. These findings suggest that mycoplasmal endosymbionts of T. vaginalis, rather than T. vaginalis itself, are microbial factors limiting chlamydial ascension, and point to a three-way interaction between parasite, endosymbiont, and bacterial pathogen that shapes upper genital tract C. trachomatis infection risk.

microbiology

Understanding the physiological alterations of Vibrio cholerae upon exposure to L-ascorbic acid

The scourge of cholera remains a major global public health threat. It affects up to 4 million people worldwide and causes tens of thousands of deaths each year. The disease is experiencing a concerning resurgence in many parts of Africa, the Middle East, and Asia. To effectively tackle cholera and circumvent rising antimicrobial resistance, targeted biological and preventive approaches, complementing traditional rehydration, are urgently needed. In this regard, our group has demonstrated the efficacy of L-ascorbic acid in controlling the growth and pathogenesis of Vibrio cholerae in vitro. The present work further provides a mechanistic elucidation of the L-ascorbic acid-mediated physiological changes in V. cholerae and also bolsters such a non-antibiotic approach to control cholera.

microbiology