In vitro antiprotozoal activity of some medicinal plants against sleeping sickness, Chagas disease and leishmaniasis

Correlation between secondary metabolites of Iris confusa Sealy and Iris pseudacorus L. and their newly explored antiprotozoal potentials

BACKGROUND

In the last few decades, the use of plant extracts and their phytochemicals as candidates for the management of parasitic diseases has increased tremendously. Irises are aromatic and medicinal plants that have long been employed in the treatment of different infectious diseases by traditional healers in many cultures. This study aims to explore the potential of three common Iris species (I. confusa Sealy, I. pseudacorus L. and I. germanica L.) against infectious diseases. Their in vitro antiprotozoal potency against Plasmodium falciparum, Trypanosoma brucei brucei, T. b. rhodesiense, T. cruzi and Leishmania infantum beside their cytotoxicity on MRC-5 fibroblasts and primary peritoneal murine macrophages were examined.

METHODS

The secondary metabolites of the tested extracts were characterized by UPLC-HRMS/MS and Pearsons correlation was used to correlate them with the antiprotozoal activity.

RESULTS

Overall, the non-polar fractions (NPF) showed a significant antiprotozoal activity (score: sc 2 to 5) in contrast to the polar fractions (PF). I. confusa NPF was the most active extract against P. falciparum [IC50 of 1.08 μg/mL, selectivity index (S.I. 26.11) and sc 5] and L. infantum (IC50 of 12.7 μg/mL, S.I. 2.22 and sc 2). I. pseudacorus NPF was the most potent fraction against T. b. rhodesiense (IC50 of 8.17 μg/mL, S.I. 3.67 and sc 3). Monogalactosyldiacylglycerol glycolipid (18:3/18:3), triaceylglycerol (18:2/18:2/18:3), oleic acid, and triterpenoid irridals (spirioiridoconfal C and iso-iridobelamal A) were the top positively correlated metabolites with antiplasmodium and antileishmanial activities of I. confusa NPF. Tumulosic acid, ceramide sphingolipids, corosolic, maslinic, moreollic acids, pheophytin a, triaceylglycerols, mono- and digalactosyldiacylglycerols, phosphatidylglycerol (22:6/18:3), phosphatidylcholines (18:1/18:2), and triterpenoid irridal iso-iridobelamal A, were highly correlated to I. pseudacorus NPF anti- T. b. rhodesiense activity. The ADME study revealed proper drug likeness properties for certain highly corelated secondary metabolites.

CONCLUSION

This study is the sole map correlating I. confusa and I. pseudacorus secondary metabolites to their newly explored antiprotozoal activity.

Anti-trypanosomal screening of Salvadoran flora

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, and in Central America, it is considered one of the four most infectious diseases. This study aimed to screen the anti-trypanosomal activity of plant species from Salvadoran flora. Plants were selected through literature search for plants ethnobotanically used for antiparasitic and Chagas disease symptomatology, and reported in Museo de Historia Natural de El Salvador (MUHNES) database. T. cruzi was incubated for 72 h with 2 different concentrations of methanolic extracts of 38 species, among which four species, Piper jacquemontianum, Piper lacunosum, Trichilia havanensis, and Peperomia pseudopereskiifolia, showed the activity (≤ 52.0% viability) at 100 µg/mL. Separation of the methanolic extract of aerial parts from Piper jacquemontianum afforded a new flavanone (4) and four known compounds, 2,2-dimethyl-6-carboxymethoxychroman-4-one (1), 2,2-dimethyl-6-carboxychroman-4-one (2), cardamomin (3), and pinocembrin (5), among which cardamomin exhibited the highest anti-trypanosomal activity (IC₅₀ = 66 µM). Detailed analyses of the spectral data revealed that the new compound 4, named as jaqueflavanone A, was a derivative of pinocembrin having a prenylated benzoate moiety at the 8-position of the A ring.

Boswellic Acids Show In Vitro Activity against Leishmania donovani

In continuation of our search for leads from medicinal plants against protozoal pathogens, we detected antileishmanial activity in polar fractions of a dichloromethane extract from Boswellia serrata resin. 11-keto-β-boswellic acid (KBA) could be isolated from these fractions and was tested in vitro against Leishmania donovani axenic amastigotes along with five further boswellic acid derivatives. 3-O-acetyl-11-keto-β-boswellic acid (AKBA) showed the strongest activity with an IC₅₀ value of 0.88 µM against axenic amastigotes but was inactive against intracellular amastigotes in murine macrophages

Overview of herbal and traditional remedies in the treatment of cutaneous leishmaniasis based on Traditional Persian Medicine

This study aims to describe the herbal and traditional remedies in the treatment of cutaneous leishmaniasis (CL) with an overview on related available evidence in modern medicine. This study is a review that focuses on the most important Traditional Persian Medicine (TPM) sources including Avicenna's Canon of Medicine, Jorjani's Zakhīra-yi Khārazmshāhī, and Aazam-Khan's Eksir-e-Aazam, as well as pertinent information from Embase, PubMed, Scopus, Scientific Information Database, and Google Scholar by using the keywords salak, rīsh-e-balkhi, cutaneous leishmaniasis, and leishmaniasis for selected remedies. Several oral and topical herbal remedies, such as Vitis vinifera L. (Unripe grapes), Berberis vulgaris L., Rheum ribes L., Santalum album L., Cinnamomum camphora (L.) J.Presl (Camphor), Brassica nigra (L.) K. Koch, Crocus sativus L., Juniperus excelsa M. Bieb, honey, and Alum root, were mentioned in TPM resources for the treatment of CL. Furthermore, cauterization, cupping, and leech therapy were considered for this purpose. In this review, some evidence-based studies will also be presented that have demonstrated the therapeutic properties of some of these products. In conclusion, the sages of TPM have recommended several systemic or topical medications, in addition to physical procedures, for treatment of CL, all of which could be a base for conducting further research on its efficacy.

Mining Sudanese Medicinal Plants for Antiprotozoal Agents

Neglected tropical diseases are major health hazards in developing countries. Annually, up to 30 million people are affected by either Chagas disease, African trypansomiasis or leishmaniasis, and more than 200 million by malaria. Most of the currently available drugs have drawbacks in terms of toxicity, limited oral availability, development of resistance, or non-affordability. Tropical plants of the arid zones are a treasure chest for the discovery of bioactive secondary metabolites. This study aims to compile Sudanese medicinal plants, validate their antiprotozoal activities, and identify active molecules. We have performed a survey of medicinal plants of Sudan and selected 62 that are being used in Sudanese traditional medicine. From these, we collected materials such as leaves, stem, bark, or fruit. The plant materials were extracted in 70% ethanol and further fractionated by liquid-liquid partitioning using solvents of increasing polarity. This resulted in a library of 235 fractions. The library was tested in vitro against Plasmodium falciparum (erythrocytic stages), Trypanosoma brucei rhodesiense (bloodstream forms), Trypanosoma cruzi (intracellular amastigotes), and Leishmania donovani (axenic amastigotes). Active fractions were also tested for cytotoxicity. Of the 235 fractions, 125 showed growth inhibitory activity >80% at 10 μg/ml, and >50% at 2 μg/ml against at least one of the protozoan parasites. Plasmodium falciparum was the most sensitive of the parasites, followed by T. b. rhodesiense and L. donovani. Only few hits were identified for T. cruzi, and these were not selective. Contrary to expectation based on phylogeny, but in agreement with previous results, a large number of extracts displayed mutual activity against T. brucei and P. falciparum. HPLC-based activity profiling for selected active extracts was performed to identify the bioactive principles. Active compounds identified by dereplication were guieranone A from Guiera senegalensis J.F.Gmel.; pseudosemiglabrin from Tephrosia apollinea (Delile) DC; ellagic acid and quercetin from Terminalia leiocarpa (DC.) Baill.; and catechin, ethyl gallate, and epicatechin gallate from Vachellia nilotica (L.) P.J.H.Hurter & Mabb. Also the extracts of Croton gratissimus var. gratissimus and Cuscuta hyalina Roth ex Schult. exhibited promising antitrypanosomatid activity. This assessment provides a comprehensive overview of Sudanese medicinal plants and supports the notion that they are a potential source of bioactive molecules against protozoan parasites.