Licochalcone A induces morphological and biochemical alterations in Schistosoma mansoni adult worms

In vivo efficacy of uvangoletin from Piper aduncum (Piperaceae) against Schistosoma mansoni and in silico studies targeting SmNTPDases

Schistosomiasis stands as one of the most significant parasitic diseases on a global scale, with approximately 250 million infections worldwide. It is imperative to address this pressing issue by developing new antischistosomal drugs. Chalcones have emerged as a promising class of natural compounds, demonstrating noteworthy effects observed in vitro experiments with Schistosoma mansoni, and demonstrating the ability to inhibit SmNTPDases and apyrase from potatoes. In this study, we focused on uvangoletin, a naturally occurring dihydrochalcone from Piper aduncum. We isolated uvangoletin from P. aduncum fruits and conducted in vivo experiments to evaluate the efficacy of uvangoletin against adult Schistosoma parasites. Furthermore, we explored the inhibitory effects of uvangoletin on potato apyrase and employed molecular docking analyses to investigate its interactions with apyrase from potato and the two isoforms SmNTPDase 1 and 2 through in silico studies. Uvangoletin (400 mg/kg, p. o.), exhibited significant in vivo antiparasitic effects against adult S. mansoni, leading to a decrease of 53.7% in worm burden and 54.3% in egg production. The treatment also reduced hepatomegaly and splenomegaly. In silico investigations and ADMET studies indicated that uvangoletin possesses favorable drug-like properties and may interact with key residues involved in apyrase and SmNTPDases activities. Furthermore, uvangoletin demonstrated a substantial reduction in potato apyrase activity. These results suggest the potential for exploring other dihydrochalcones as promising candidates for antischistosomal agents.

Licochalcone a: A promising antiparasitic drug against giardiasis

Giardiasis, caused by Giardia duodenalis, is a prevalent and significant zoonotic disease. While nitroimidazole drugs are primarily used to treat giardiasis, the urgent need for the development and formulation of new drugs has arisen due to increasing drug resistance. Several plant derived medicine have been employed as antiparasitic drugs. This study has evaluated the anti-Giardia effect of Licochalcone A (Lic A) through both in vitro and in vivo experiments. We determined the 50% inhibitory concentration (IC50) of Lic A, analyzed the adhesive ability of G. duodenalis, and assessed intestinal morphology and various indicators in the gerbil model. The in vitro assays demonstrated that the IC50 value of Lic A against G. duodenalis was 27.42 μM. Additionally, Lic A significantly inhibited the adhesiveability of G. duodenalis trophozoites, impairing their cell structure and cytoskeleton. In vivo experiments showed that Lic A significantly mitigated weight loss due to G. duodenalis infection, and lowered the intestinal parasite load. Histopathological examinations in gerbils indicated that Lic A could reduce intestinal damage, increase the height of intestinal villi, decrease crypt depth, and maintain the integrity of intestinal structure. Furthermore, Lic A altered cytokine levels and enhanced the body's antioxidant capacity. In conclusion, Lic A exbibits significant anti-Giardia effects both in vitro and in vivo, suggesting its potential as a promising antiparasitic drug candidate against giardiasis.

Combination Therapy and Phytochemical-Loaded Nanosytems for the Treatment of Neglected Tropical Diseases

Background: Neglected tropical diseases (NTDs), including leishmaniasis, trypanosomiasis, and schistosomiasis, impose a significant public health burden, especially in developing countries. Despite control efforts, treatment remains challenging due to drug resistance and lack of effective therapies. Objective: This study aimed to synthesize the current research on the combination therapy and phytochemical-loaded nanosystems, which have emerged as promising strategies to enhance treatment efficacy and safety. Methods/Results: In the present review, we conducted a systematic search of the literature and identified several phytochemicals that have been employed in this way, with the notable efficacy of reducing the parasite load in the liver and spleen in cases of visceral leishmaniasis, as well as lesion size in cutaneous leishmaniasis. Furthermore, they have a synergistic effect against Trypanosoma brucei rhodesiense rhodesain; reduce inflammation, parasitic load in the myocardium, cardiac hypertrophy, and IL-15 production in Chagas disease; and affect both mature and immature stages of Schistosoma mansoni, resulting in improved outcomes compared to the administration of phytochemicals alone or with conventional drugs. Moreover, the majority of the combinations studied demonstrated enhanced solubility, efficacy, and selectivity, as well as increased immune response and reduced cytotoxicity. Conclusions: These formulations appear to offer significant therapeutic benefits, although further research is required to validate their clinical efficacy in humans and their potential to improve treatment outcomes in affected populations.

Licochalcone A: a review of its pharmacology activities and molecular mechanisms

Licorice, derived from the root of Glycyrrhiza uralensis Fisch, is a key Traditional Chinese Medicine known for its detoxifying, spleen-nourishing, and qi-replenishing properties. Licochalcone A (Lico A), a significant component of licorice, has garnered interest due to its molecular versatility and receptor-binding affinity. This review explores the specific roles of Lico A in various diseases, providing new insights into its characteristics and guiding the rational use of licorice. Comprehensive literature searches using terms such as "licorice application" and "pharmacological activity of Lico A" were conducted across databases including CNKI, PubMed, and Google Scholar to gather relevant studies on Lico A's pharmacological activities and mechanisms. Lico A, a representative chalcone in licorice, targets specific mechanisms in anti-cancer and anti-inflammatory activities. It also plays a role in post-transcriptional regulation. This review delineates the similarities and differences in the anti-cancer and anti-inflammatory mechanisms of Lico A, concluding that its effects on non-coding RNA through post-transcriptional mechanisms deserve further exploration.

Using our understanding of interactions between helminth metabolism and host immunity to target worm survival

Helminths can adapt to environmental conditions in the host, utilising anaerobic processes like fermentation and malate dismutation to produce energy from carbohydrate. Although targeting carbohydrate metabolism is an established therapeutic strategy to combat helminth infection, questions remain over the metabolic pathways they employ as adults to survive and evade host immunity. Helminths also use amino acid, polyunsaturated fatty acid (PUFA), and cholesterol metabolism, a possible strategy favouring the production of immunomodulatory compounds that may influence survival in the host. Here, we discuss the significance of these differing metabolic pathways and whether targeting of helminth metabolic pathways may allow for the development of novel anthelmintics.

Therapeutic Potential of Natural Products in the Treatment of Schistosomiasis

It is estimated that 250 million people worldwide are affected by schistosomiasis. Disease transmission is related to the poor sanitation and hygiene habits that affect residents of impoverished regions in tropical and subtropical countries. The main species responsible for causing disease in humans are Schistosoma Mansoni, S. japonicum, and S. haematobium, each with different geographic distributions. Praziquantel is the drug predominantly used to treat this disease, which offers low effectiveness against immature and juvenile parasite forms. In addition, reports of drug resistance prompt the development of novel therapeutic approaches. Natural products represent an important source of new compounds, especially those obtained from plant sources. This review compiles data from several in vitro and in vivo studies evaluating various compounds and essential oils derived from plants with cercaricidal and molluscicidal activities against both juvenile and adult forms of the parasite. Finally, this review provides an important discussion on recent advances in molecular and computational tools deemed fundamental for more rapid and effective screening of new compounds, allowing for the optimization of time and resources.

Recent approaches in nanocarrier-based therapies for neglected tropical diseases

Neglected tropical diseases (NTDs) remain major public health problems in developing countries. Reducing the burden of NTDs requires sustained collaborative drug discovery efforts to achieve the goals of the new NTDs roadmap launched by the World Health Organization. Oral drugs are the most convenient choice and usually the safest and least expensive. However, the oral use of some drugs for NTDs treatment has many drawbacks, including toxicity, adverse reactions, drug resistance, drug low solubility, and bioavailability. Since there is an imperative need for novel and more effective drugs to treat the various NTDs, in recent years, several compound-loaded nanoparticles have been prepared with the objective of evaluating their application as an oral drug delivery system for the treatment of NTDs. This review focuses on the various types of nanoparticle drug delivery systems that have been recently used against the major NTDs caused by parasites such as leishmaniasis, Chagas disease, and schistosomiasis. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

Salt-Tolerant Plants as Sources of Antiparasitic Agents for Human Use: A Comprehensive Review

Parasitic diseases, especially those caused by protozoans and helminths, such as malaria, trypanosomiasis, leishmaniasis, Chagas disease, schistosomiasis, onchocerciasis, and lymphatic filariasis, are the cause of millions of morbidities and deaths every year, mainly in tropical regions. Nature has always provided valuable antiparasitic agents, and efforts targeting the identification of antiparasitic drugs from plants have mainly focused on glycophytes. However, salt-tolerant plants (halophytes) have lately attracted the interest of the scientific community due to their medicinal assets, which include antiparasitic properties. This review paper gathers the most relevant information on antiparasitic properties of halophyte plants, targeting human uses. It includes an introduction section containing a summary of some of the most pertinent characteristics of halophytes, followed by information regarding the ethnomedicinal uses of several species towards human parasitic diseases. Then, information is provided related to the antiprotozoal and anthelmintic properties of halophytes, determined by in vitro and in vivo methods, and with the bioactive metabolites that may be related to such properties. Finally, a conclusion section is presented, addressing perspectives for the sustainable exploitation of selected species.

Neolignans isolated from Saururus cernuus L. (Saururaceae) exhibit efficacy against Schistosoma mansoni

Schistosomiasis, a parasitic disease caused by the blood fluke of the genus Schistosoma, affects over 230 million people, especially in developing countries. Despite the significant economic and public health consequences, only one drug is currently available for treatment of schistosomiasis, praziquantel. Thus, there is an urgent demand for new anthelmintic agents. Based on our continuous studies involving the chemical prospection of floristic biodiversity aiming to discover new bioactive compounds, this work reports the in vitro antiparasitic activity against Schistosoma mansoni adult worms of neolignans threo-austrobailignan-6 and verrucosin, both isolated from Saururus cernuus L. (Saururaceae). These neolignans showed a significant in vitro schistosomicidal activity, with EC50 values of 12.6-28.1 µM. Further analysis revealed a pronounced reduction in the number of S. mansoni eggs. Scanning electron microscopy analysis revealed morphological alterations when schistosomes were exposed to either threo-austrobailignan-6 or verrucosin. These relevant antischistosomal properties were accompanied by low cytotoxicity potential against the animal (Vero) and human (HaCaT) cell lines, resulting in a high selectivity index. Considering the promising chemical and biological properties of threo-austrobailignan-6 and verrucosin, this research should be of interest to those in the area of neglected diseases and in particular antischistosomal drug discovery.

Pharmacological Effects and Underlying Mechanisms of Licorice-Derived Flavonoids

Glycyrrhizae Radix et Rhizoma is the most frequently prescribed natural medicine in China and has been used for more than 2,000 years. The flavonoids of licorice have garnered considerable attention in recent decades due to their structural diversity and myriad pharmacological effects, especially as novel therapeutic agents against inflammation and cancer. Although many articles have been published to summarize different pharmacological activities of licorice in recent years, the systematic summary for flavonoid components is not comprehensive. Therefore, in this review, we summarized the pharmacological and mechanistic data from recent researches on licorice flavonoids and their bioactive components.

In vitro schistosomicidal activities of the leaf extracts from Casearia sylvestris varieties

Schistosomiasis, a tropical disease caused by flatworms, may affect the liver, spleen, bladder, and intestine. Casearia sylvestris Swartz, a medicinal plant, displays antiprotozoal, antimicrobial, antifungal, and antiulcer activities. We have evaluated the in vitro schistosomicidal activity of two C. sylvestris varieties against Schistosoma mansoni adult worms at concentrations between 12.5 and 200 μg/mL of and var. lingua . At 100 and 200 μg/mL, the ethanolic C. sylvestris var. sylvestris leaf extract enriched in casearin-like diterpenes eliminated 100% of the parasites after incubation for 72 h and 48 h, respectively, whilst the same extract at 200 μg/mL eliminated 96%, 100%, and 100% of the parasites after incubation for 24, 48, and 72 h, respectively. On the other hand, the hydroalcoholic C. sylvestris var. lingua leaf extract at 200 μg/mL eliminated 60.4 and 66.7% of the parasites after incubation for 48 and 72 h, respectively. The presence of casearin-like diterpenes and glycosylated flavonoids was confirmed based on chromatographic techniques and mass spectrometry data.

E-NTPDases: Possible Roles on Host-Parasite Interactions and Therapeutic Opportunities

Belonging to the GDA1/CD39 protein superfamily, nucleoside triphosphate diphosphohydrolases (NTPDases) catalyze the hydrolysis of ATP and ADP to the monophosphate form (AMP) and inorganic phosphate (Pi). Several NTPDase isoforms have been described in different cells, from pathogenic organisms to animals and plants. Biochemical characterization of nucleotidases/NTPDases has revealed the existence of isoforms with different specificities regarding divalent cations (such as calcium and magnesium) and substrates. In mammals, NTPDases have been implicated in the regulation of thrombosis and inflammation. In parasites, such as Trichomonas vaginalis, Trypanosoma spp., Leishmania spp., Schistosoma spp. and Toxoplasma gondii, NTPDases were found on the surface of the cell, and important processes like growth, infectivity, and virulence seem to depend on their activity. For instance, experimental evidence has indicated that parasite NTPDases can regulate the levels of ATP and Adenosine (Ado) of the host cell, leading to the modulation of the host immune response. In this work, we provide a comprehensive review showing the involvement of the nucleotidases/NTPDases in parasites infectivity and virulence, and how inhibition of NTPDases contributes to parasite clearance and the development of new antiparasitic drugs.

Synthetic Aurones: New Features for Schistosoma mansoni Therapy

In this work, two synthetic aurones revealed moderate schistosomicidal potential in in vitro and in vivo assays. Aurones (1) and (2) promoted changes in tegument integrity and motor activity, leading to death of adult Schistosoma mansoni worms in in vitro assays. When administered orally (two doses of 50 mg/kg) in experimentally infected animals, synthetic aurones (1) and (2) promoted reductions of 56.20 % and 57.61 % of the parasite load and stimulated the displacement towards the liver of the remaining adult worms. The oogram analysis revealed that the treatment with both aurones interferes with the egg development kinetics in the intestinal tissue. Seeking an action target for compounds (1) and (2), the connection with NTPDases enzymes, recognized as important therapeutic targets for S. mansoni, was evaluated. Molecular docking studies have shown promising results. The dataset reveals the anthelmintic character of these compounds, which can be used in the development of new therapies for schistosomiasis.

Licochalcone A-loaded solid lipid nanoparticles improve antischistosomal activity in vitro and in vivo

Aim: To isolate licochalcone A (LicoA) from licorice, prepare LicoA-loaded solid lipid nanoparticles (L-SLNs) and evaluate the L-SLNs in vitro and in vivo against Schistosoma mansoni. Materials & methods: LicoA was obtained by chromatographic fractionation and encapsulated in SLNs by a modified high shear homogenization method. Results: L-SLNs showed high encapsulation efficiency, with satisfactory particle size, polydispersity index and Zeta potential. Transmission electron microscopy revealed that L-SLNs were rounded and homogenously distributed. Toxicity studies revealed that SLNs decreased the hemolytic and cytotoxic properties of LicoA. Treatment with L-SLNs showed in vivo efficacy against S. mansoni. Conclusion: L-SLNs are efficient in reducing worm burden and SLNs may be a promising delivery system for LicoA to treat S. mansoni infections.

Licochalcone A, a licorice flavonoid: antioxidant, cytotoxic, genotoxic, and chemopreventive potential

Licochalcone A (LicoA) is a flavonoid derived from Glycyrrhiza spp. plants. The present study aimed to investigate the antioxidant, cytotoxic, genotoxic, and chemopreventive effects of LicoA in in vitro and in vivo systems. The results showed that LicoA (197.1 μM) scavenged 77.92% of free radicals. Concentrations of 147.75 µM or higher LicoA produced cytotoxicity in Chinese hamster ovary (CHO) fibroblasts. LicoA treatments of 4.43 to 10.34 µM did not exert genotoxic activity, but at 11.8 µM significantly lowered nuclear division indexes, compared to negative control, revealing cytotoxicity. Lower concentrations (1.85 to 7.39 µM) exhibited protective activity against chromosomal damage induced by doxorubicin (DXR) or methyl methanesulfonate (MMS) in CHO cells. LicoA exerted no marked influence on DXR-induced genotoxicity in mouse erythrocytes, but reduced pre-neoplastic lesions induced by 1,2-dimethylhydrazine (DMH) in rat colon at 3.12 to 50 mg/kg b.w. Biochemical markers and body weight indicated no apparent toxicity. These findings contribute to better understanding the mechanisms underlying LicoA-initiated activity as a promising chemopreventive compound.

ABBREVIATIONS

AC, aberrant crypts; ACF, aberrant crypt foci; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BOD, biochemical oxygen demand; CHO, Chinese hamster ovary fibroblast; DMH, 1,2-dimethylhydrazine; DMSO, dimethyl sulfoxide; DPPH, 2,2-diphenyl-1-picrylhydrazyl; DXR, doxorubicin hydrochloride; EDTA, ethylenediaminetetraacetic acid; GA, gallic acid; LicoA, licochalcone A; MMS, methyl methanesulfonate; MNBC, micronucleated binucleated cells; MNPCE, micronucleated polychromatic erythrocyte; NCE, normochromatic erythrocyte; NDI, nuclear division index; PBS, phosphate-buffered saline; PCE, polychromatic erythrocyte; XTT, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide.

Chemotherapy for human schistosomiasis: how far have we come? What's new? Where do we go from here?

Globally, schistosomiasis threatens more than 700 million lives, mostly children, in poor localities of tropical and sub-tropical areas with morbidity due to acute and chronic pathological manifestations of the disease. After a century since the first antimonial-based drugs were introduced to treat the disease, anti-schistosomiasis drug development is again at a bottleneck with only one drug, praziquantel, available for treatment purposes. This review focuses on promising chemotypes as potential starting points in a drug discovery effort to meet the urgent need for new schistosomicides.

ATP-Diphosphohydrolases in Parasites: Localization, Functions and Recent Developments in Drug Discovery

ATP-diphosphohydrolases (EC 3.6.1.5), also known as ATPDases, NTPases, NTPDases, EATPases or apyrases, are enzymes that hydrolyze a variety of nucleoside tri- and diphosphates to their respective nucleosides, being their activities dependent on the presence of divalent cations, such as calcium and magnesium. Recently, ATP-diphosphohydrolases were identified on the surface of several parasites, such as Trypanosoma sp, Leishmania sp and Schistosoma sp. In parasites, the activity of ATPdiphosphohydrolases has been associated with the purine recuperation and/or as a protective mechanism against the host organism under conditions that involve ATP or ADP, such as immune responses and platelet activation. These proteins have been suggested as possible targets for the development of new antiparasitic drugs. In this review, we will comprehensively address the main aspects of the location and function of ATP-diphosphohydrolase in parasites. Also, we performed a detailed research in scientific database of recent developments in new natural and synthetic inhibitors of the ATPdiphosphohydrolases in parasites.

In Vitro and in Vivo Antischistosomal Activities of Chalcones

In this study, we evaluated the in vitro and in vivo schistosomicidal activities of chalcones against Schistosoma mansoni worms. In vitro assays revealed that chalcones 1 and 3 were the most active compounds, without affecting significantly mammalian cells. Confocal laser scanning microscopy and scanning electron microscopy studies revealed reduction on the numbers of tubercles and morphological alterations in the tegument of S. mansoni worms after in vitro incubation with chalcones 1 and 3. In a mouse model of schistosomiasis, the oral treatment (400 mg/kg) with chalcone 1 or 3 significantly caused a total worm burden reduction in mice. Chalcone 1 showed significant inhibition of the S. mansoni ATP diphosphohydrolase activity, which was corroborated by molecular docking studies. The results suggested that chalcones could be explored as lead compounds with antischistosomal properties.