In Vitro Assessment of Anthelmintic Activities of Rauwolfia vomitoria (Apocynaceae) Stem Bark and Roots against Parasitic Stages of Schistosoma mansoni and Cytotoxic Study

Human schistosomiasis in Nigeria: present status, diagnosis, chemotherapy, and herbal medicines

Schistosomiasis is a neglected tropical disease caused by a parasitic, trematode blood fluke of the genus Schistosoma. With 20 million people infected, mostly due to Schistosoma haematobium, Nigeria has the highest burden of schistosomiasis in the world. We review the status of human schistosomiasis in Nigeria regarding its distribution, prevalence, diagnosis, prevention, orthodox and traditional treatments, as well as snail control strategies. Of the country's 36 states, the highest disease prevalence is found in Lagos State, but at a geo-political zonal level, the northwest is the most endemic. The predominantly used diagnostic techniques are based on microscopy. Other methods such as antibody-based serological assays and DNA detection methods are rarely employed. Possible biomarkers of disease have been identified in fecal and blood samples from patients. With respect to preventive chemotherapy, mass drug administration with praziquantel as well as individual studies with artemisinin or albendazole have been reported in 11 out of the 36 states with cure rates between 51.1 and 100%. Also, Nigerian medicinal plants have been traditionally used as anti-schistosomal agents or molluscicides, of which Tetrapleura tetraptera (Oshosho, aridan, Aidan fruit), Carica papaya (Gwanda, Ìbẹ́pẹ, Pawpaw), Borreria verticillata (Karya garma, Irawo-ile, African borreria), and Calliandra portoricensis (Tude, Oga, corpse awakener) are most common in the scientific literature. We conclude that the high endemicity of the disease in Nigeria is associated with the limited application of various diagnostic tools and preventive chemotherapy efforts as well as poor knowledge, attitudes, and practices (KAP). Nonetheless, the country could serve as a scientific base in the discovery of biomarkers, as well as novel plant-derived schistosomicides and molluscicides.

In Vitro Cercaricidal Activity, Acute Toxicity, and GC/MS Analysis of Some Selected Ghanaian Medicinal Plants

Schistosomiasis is a human parasitic disease caused by the Schistosoma species and is recognised in public health as second to malaria in terms of its socioeconomic impact on humans. Four local plants native to many tribes in Ghana and known for their medicinal properties against some diseases were assessed for their cercaricidal activity against Schistosoma mansoni cercariae. The plants, namely, Newbouldia laevis stem bark (NLSB), Spathodea campanulata stem bark (SCSB), Momordica charantia leaves (MCL), and Ocimum viride leaves (OVL), were extracted for their active metabolites using methanol. Preliminary phytochemical screening was carried out on all plant extracts and powdered samples. The crude extracts were tested against S. mansoni cercariae in vitro using Balanites aegyptiaca as the positive control. The percentage of mortalities for each extract was recorded. Gas chromatography/mass spectrometry (GC/MS) analysis was conducted on all the plant extracts. Phytochemical analysis revealed the presence of saponins, glycosides, triterpenoids, sterols, alkaloids, flavonoids, and tannins in almost all the extracts. GC/MS analysis showed the presence of medicinally important active volatile compounds in each extract such as thymol, n-hexadecanoic acid, phytol, and maltol. All four plants showed relatively different levels of activity against S. mansoni cercariae at different times and concentrations. The LC50 values of the plant extracts were determined at the end of the assay. At 240 min, NLSB, SCSB, MCL, and OVL extracts had LC50 values of 487.564, 429.898, 197.696, and 0.129 μg/mL, respectively. Hence, this study revealed the potency of Ocimum viride leaves, Momordica charantia leaves, Spathodea campanulata stem bark, and Newbouldia laevis stem bark against S. mansoni. These plants could therefore be exploited as possible candidates for curbing schistosomiasis.

Ethnobotanical Survey and Cercaricidal Activity Screening of Medicinal Plants Used for Schistosomiasis Treatment in Atwima-Nwabiagya District, Ashanti Region, Ghana

This study focused on documenting and evaluating the cercaricidal activity of medicinal plants used for schistosomiasis treatment in an endemic area in Ghana. Through semistructured questionnaires, personal interviews with herbalists in communities surrounding the Barekese dam in the Atwima-Nwabiagya district, where the disease is endemic, were carried out. Thirty medicinal plants distributed in 19 families were reported to be used for schistosomiasis treatment in the survey. Information on the plants, including scientific names, common names, families, and the used plant part were recorded. The families Apocynaceae and Euphorbiaceae recorded the highest number of plants (14% each), followed by Asteraceae (10%), Loranthaceae (7%), and Rubiaceae (7%). In vitro cercaricidal activity of methanol extracts of nine out of the thirty plants was performed by exposing human Schistosoma mansoni cercariae obtained from Biomphalaria pfeifferi to various concentrations of extracts over a duration of 240 minutes. All the plants tested demonstrated time- and concentration-dependent cercaricidal activity. With lethality being set at <1000 μg/mL, the cercaricidal activity in order of decreasing potency was as follows: Withania somnifera (LC₅₀ = 1.29) > Balanites aegyptiaca (LC₅₀ = 7.1) > Xylia evansii (LC₅₀ = 11.14) > Jathropha multifida (LC₅₀ = 12.9) > Justicia flava (LC₅₀ = 22.9) > Anopyxis klaineana (LC₅₀ = 182.81) > Ximenia americana (LC₅₀ = 194.98) > Loranthus lecardii (LC₅₀ = 223.87) > Bridelia tenufolia (LC₅₀ = 309.03) > Zanthoxylium zanthoxyloides (LC₅₀ = 851.94). Phytochemicals, including alkaloids, tannins, triterpenes, saponins, phytosterols, and flavonoids were identified in the plants. The result of this study gives scientific credence to the traditional use of these plants in the treatment of schistosomiasis and proves that the rich botanical knowledge of medicinal plants provides an incredible starting point for the discovery of new anti-schistosomal drugs for the local population.

Vernonia britteniana Root Phytochemical Studies, In Vitro Cercaricidal Activity on the Larval Stage of Schistosoma mansoni and Antioxidant Activities

Vernonia britteniana Hiern. (Asteraceae) is a medicinal plant used in traditional Angolan medicine against schistosomiasis. Our study aimed to investigate the phytochemical composition and the cercaricidal and antioxidant activities in vitro of a traditional herbal preparation (Water-Vbr) and a 70% hydroethanolic extract (EtOH70%-Vbr) prepared with this medicinal plant. The activity of the extracts against Schistosoma mansoni cercariae was assessed at different extract concentrations (500, 438, and 125 µg/mL) and at different time intervals, and the phytochemical profiles were obtained by LC-UV-ESI/MS-MS. In addition, the major chemical classes of the identified metabolites were quantified by colorimetry, and the antioxidant potential was assessed using the DPPH and FRAP methods. After 30 min, 100% cercarial mortality was observed at a concentration of 500 μg/mL after exposure, and after 120 min, an LC₅₀ of 438 μg/mL was observed for both extracts. Phenolic acid derivatives (chlorogenic acid, caffeic acid; 3,4-di-O-caffeoylquinic acid; 3,5-di-O-caffeoylquinic acid; and 4,5-di-O-caffeoylquinic acid) and triterpenoids (stigmastane-type steroidal saponins; vernoamyoside D and vernonioside D1; vernoamyoside B; and vernoniamyoside A and C) were identified as the main secondary metabolites. The Water-Vbr extract showed the highest antioxidant activity-DPPH: IC₅₀ = 1.769 ± 0.049 µg/mL; FRAP: mean = 320.80 ± 5.1325 µgAAE/g.

An Inventory of Anthelmintic Plants across the Globe

A wide range of novelties and significant developments in the field of veterinary science to treat helminth parasites by using natural plant products have been assessed in recent years. To the best of our knowledge, to date, there has not been such a comprehensive review of 19 years of articles on the anthelmintic potential of plants against various types of helminths in different parts of the world. Therefore, the present study reviews the available information on a large number of medicinal plants and their pharmacological effects, which may facilitate the development of an effective management strategy against helminth parasites. An electronic search in four major databases (PubMed, Scopus, Web of Science, and Google Scholar) was performed for articles published between January 2003 and April 2022. Information about plant species, local name, family, distribution, plant tissue used, and target parasite species was tabulated. All relevant studies meeting the inclusion criteria were assessed, and 118 research articles were included. In total, 259 plant species were reviewed as a potential source of anthelmintic drugs. These plants can be used as a source of natural drugs to treat helminth infections in animals, and their use would potentially reduce economic losses and improve livestock production.

In Vivo Evaluation of the Anti-Schistosomal Potential of Ginger-Loaded Chitosan Nanoparticles on Schistosoma mansoni: Histopathological, Ultrastructural, and Immunological Changes

Chemotherapy is the most widely advocated method of Schistosome control. However, repeated chemotherapy leads to the emergence of drug-resistant Schistosoma strains. Therefore, efforts to find alternative drugs, especially those of natural origin, have risen globally. Nanoparticles (NPs) have received special interest as efficient drug delivery systems. This work aimed to investigate the anti-schistosomal potential of Zingiber officinale (ginger, Zingiberaceae)-loaded chitosan nanoparticles (GCsNPs) on Schistosoma mansoni experimentally infected mice that were exposed to 80 ± 10 cercariae/mouse. The study groups are: (G1) negative control; (G2) positive control; (G3) praziquantel in a dose of 500 mg/kg/day for two consecutive days; (G4) ginger in a dose of 500 mg/kg treated; (G5) chitosan nanoparticles in a dose 3 mg/kg (G6) GCsNPs in a dose 250 mg/kg; and (G7) GCsNPs in a dose 500 mg/kg. The anti-schistosome potential was assessed using histopathological scanning electron microscopically and immunological parameters. The results showed that there was a significant decrease in cellular granuloma count (p < 0.05) and granuloma diameter (p < 0.001) in all infected treated mice groups, in comparison to the infected non-treated group with the highest reduction in both G3 and G7. SEM of S. mansoni adult worm recovered from G3 showed mild edema of oral and ventral suckers with some peeling and blebs around them, while that recovered from G7 showed abnormal oedematous oral and retracted ventral sucker, edema of the tegument, rupture of many tubercles with vacuolation and complete loss of spines. All infected treated mice groups, in comparison to positive control G2, showed a significant reduction in IL-4, IL-10, and TNF-α levels (p-value < 0.001), especially groups G6 and G7 (p-value < 0.05); both G6 and G7 values were nearer to the normal that indicated recovery of the liver tissue.

In Vitro Cercaricidal and Schistosomicidal Activities of the Raffia Wine and Hydroethanolic Extracts of Pedilanthus tithymaloides Linn (Poit). Stem Barks

Schistosomiasis control remains a public health concern, and there is a need to evaluate new strategies for targeting larval and adult stages of the parasite. As Pedilanthus tithymaloides is empirically used to treat schistosomiasis, it becomes essential to know its effective action scientifically. This study assessed the cercaricidal and schistosomicidal activity of P. tithymaloides stem barks raffia wine extract (RwPt) and hydroethanolic extract (HePt). Different concentrations of these extracts were tested against cercariae (31.25–1000 μg/mL) and adult worms (62.5–2000 μg/mL) of Schistosoma mansoni. Niclosamide-olamine 5% (1 μg/mL) and praziquantel (10 μg/mL) were used as pharmacological controls. Cercariae viability was determined every 30 min for 180 min, and adult worms’ motor activity and viability after 24 and 48 h incubation. In addition, cytotoxicity and phytochemical analysis were performed. HePt was lethal to cercariae and adult worms with LC50 of 73.91 μg/mL after 60 min of incubation and 731.17 μg/mL after 48 h of incubation, respectively. Furthermore, a significant reduction of 94.44% in motor activity was observed in surviving worms at the concentration of 2000 μg/mL. RwPt was less effective on S. mansoni cercariae with an LC50 of 617.86 μg/mL after 180 min and on adult worms with a mortality rate of 9.83% at 2000 μg/mL for 48 h incubation. Both extracts showed a weak cytotoxicity profile with an IC50 of 983.50 μg/mL for HePt and more than 1000 μg/mL for RwPt. The LC-MS analysis of HePt allowed the detection of two annotated diterpenoids. Based on the selectivity index, the hydroethanolic extract of P. tithymaloides stem barks disclosed an intense cercaricidal activity and a moderate schistosomicidal effect with low cytotoxicity. These findings may support the potential use of Pedilanthus tithymaloides as a natural product or a source of natural-derived compounds for interrupting schistosomiasis transmission.

Genus Rauvolfia: A review of its ethnopharmacology, phytochemistry, quality control/quality assurance, pharmacological activities and clinical evidence

ETHNOPHARMACOLOGICAL RELEVANCE

The plants are from the genus Rauvolfia Plum. ex L. (Apocynaceae), which is represented by 74 species with many synonyms, and distributed worldwide, especially in the Asian, and African continents. Traditionally, some of them are used for the treatment of various disorders related to the central nervous system (CNS), cardiovascular diseases (CVD), and as an antidote due to the presence of monoterpene indole alkaloids (MIAs) such as ajmaline (144), ajmalicine (164) serpentine (182), yohimbine (190) and reserpine (214).

AIM

The present review provides comprehensive summarization and critical analysis of the traditional to modern applications of Rauvolfia species, and the major focus was to include traditional uses, phytochemistry, quality control, pharmacological properties, as well as clinical evidence that may be useful in the drug discovery process.

MATERIALS AND METHODS

Information related to traditional uses, chemical constituents, separation techniques/analytical methods, and pharmacological properties of the genus Rauvolfia were obtained using electronic databases such as Web of Science, Scopus, SciFinder, PubMed, PubChem, ChemSpider, and Google Scholar between the years 1949-2021. The scientific name of the species and its synonyms were checked with the information of The Plant List.

RESULTS

A total of seventeen Rauvolfia species have been traditionally explored for various therapeutic applications, out of which the roots of R. serpentina and R. vomitoria are used most commonly for the treatment of many diseases. About 287 alkaloids, seven terpenoids, nine flavonoids, and four phenolic acids have been reported in different parts of the forty-three species. Quality control (QC)/quality assurance (QA) of extracts/herbal formulations of Rauvolfia species was analyzed by qualitative and quantitative methods based on the major MIAs such as compounds 144, 164, 182, 190, and 214 using HPTLC, HPLC, and HPLC-MS. The various extracts of different plant parts of thirteen Rauvolfia species are explored for their pharmacological properties such as antimicrobial, antioxidant, antiprotozoal, antitrypanosomal, antipsychotic, cardioprotective, cholinesterase inhibitory, and hepatoprotective. Of which, clinical trials of herbal formulations/extracts of R. serpentina and MIAs have been reported for CVD, CNS, antihypertensive therapy, antidiabetic effects, and psoriasis therapy, while the extracts and phytoconstituents of remaining Rauvolfia species are predominantly significant, owning them to be additional attention for further investigation under clinical trials and QC/QA.

CONCLUSION

The present communication has provided a comprehensive, systematic, and critically analyzed vision into the traditional uses, phytochemistry, and modern therapeutic applications of the genus Rauvolfia are validated by scientific evidence. In addition, different plant parts from this genus, especially raw and finished herbal products of the roots of R. serpentina have been demonstrated for the QC/QA.

Protective role of Balanities aegyptiaca fruit aqueous extract in mice infected with Schistosoma mansoni

the target of this research was to investigate the effect of Balanities aegyptiaca fruit aqueous extract (200 mg/kg BW), alone or in combination with Praziquantel PZQ (300 mg/kg BW) on some biochemical, parasitological, liver histopathology and immunohistochemical parameters in mice infected with Schistosoma mansoni. Results showed that treatment of S. mansoni-infected mice with B. aegyptiaca alone or in combination with PZQ significantly reduced the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) as compared to that of the S. mansoni-infected mice group. Treatment of S. mansoni-infected mice with B. aegyptiaca or PZQ and their combination led to a significant reduction in the activity of malondialdehyde (MDA) as compared with the infected control group. While a significant elevation was observed in the activities of antioxidant enzymes glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and nitric oxide (NO) compared with the infected. Results revealed that the diameter and number of egg granuloma were significantly condensed after treatment of S. mansoni-infected mice with B. aegyptiaca, PZQ or their combination in hepatic and intestinal tissue. The histopathological alterations observed in the liver of S. mansoni-infected mice were remarkably recovered after B. aegyptiaca treatments. The reduction in angiogenesis was mostly observed in the group receiving the combination of B. aegyptiaca and PZQ. The alterations in vascular endothelial growth factor (VEGF) expression were significantly less in the liver sinusoids. Overall, B. aegyptiaca significantly inhibited the liver and intestinal damage accompanied by schistosomiasis. It demonstrated potent antioxidant and immunoprotective activities. This study advises that B. aegyptiaca can be considered promising for the development of a complementary and/or alternative against schistosomiasis.

In Silico Study of Cucurbita maxima Compounds as Potential Therapeutics Against Schistosomiasis

Schistosomiasis, a disease usually related to poverty and poor sanitation, affects more than 200 million people worldwide. Since the 1970s, the medical sector has depended on a single drug, praziquantel, for the treatment of the disease. The emerging evidence of resistance of the Schistosoma parasite to praziquantel and the drug’s inefficacy against juvenile stages of the parasite makes the need to find alternative drugs an urgent matter. In this study, we explored the inhibition potential of compounds from Cucurbita maxima using molecular docking studies on Schistosoma mansoni purine nucleoside phosphorylase ( SmPNP) and Schistosoma haematobium 28-kDa glutathione S-transferase ( Sh28kDaGST). Following molecular docking studies and analysis of the active sites, the primary amino acids that were observed and shown to be involved in the SmPNP-ligand interaction are CYS 33, ARG 86, HIS 88, TYR 90, ALA 118, ALA 119, PRO 200, TYR 202, GLU 203, VAL 219, MET 221, THR 244, ASN 245, PRO 257 and HIS 259. For the Sh28dKa-ligand interaction, the primary amino acids were PHE 11, ARG 16, TRP 41, LEU 53, GLU 70 and SER 71. Momordicoside I aglycone binds to SmPNP with the lowest binding affinity of -7.9 kcal/mol by pi sigma bond interactions with HIS 88. Balsaminoside B binds to Sh28kDaGST with a binding affinity of −7.6 kcal/mol by hydrogen bond interaction with TRP 41, LEU 53 and SER 71. Pharmacokinetic studies showed favourable drug-like properties for the 10 compounds that exhibited the lowest binding energies. Therefore, we propose that bioactive compounds from C. maxima be considered as potential novel drug hits in the treatment of schistosomiasis.

Traditional Kenyan herbal medicine: exploring natural products' therapeutics against schistosomiasis

Praziquantel (PZQ) remains the only drug of choice for the treatment of schistosomiasis, caused by parasitic flatworms. The widespread use of PZQ in schistosomiasis endemic areas for about four decades raises concerns about the emergence of resistance of Schistosoma spp. to PZQ under drug selection pressure. This reinforces the urgency in finding alternative therapeutic options that could replace or complement PZQ. We explored the potential of medicinal plants commonly used by indigenes in Kenya for the treatment of various ailments including malaria, pneumonia, and diarrhoea for their antischistosomal properties. Employing the Soxhlet extraction method with different solvents, seven medicinal plants Artemisia annua, Ajuga remota, Bredilia micranta, Cordia africana, Physalis peruviana, Prunus africana and Senna didymobotrya were extracted. Qualitative phytochemical screening was performed to determine the presence of various phytochemicals in the plant extracts. Extracts were tested against Schistosoma mansoni newly transformed schistosomula (NTS) and adult worms and the schistosomicidal activity was determined by using the adenosine triphosphate quantitation assay. Phytochemical analysis of the extracts showed different classes of compounds such as alkaloids, tannins, terpenes, etc., in plant extracts active against S. mansoni worms. Seven extracts out of 22 resulted in <20% viability against NTS in 24 h at 100 μg/ml. Five of the extracts with inhibitory activity against NTS showed >69.7% and ≥72.4% reduction in viability against adult worms after exposure for 24 and 48 h, respectively. This study provides encouraging preliminary evidence that extracts of Kenyan medicinal plants deserve further study as potential alternative therapeutics that may form the basis for the development of the new treatments for schistosomiasis.

Antischistosomal effects of Ficus carica leaves extract and/or PZQ on Schistosoma mansoni infected mice

Currently, praziquantel (PZQ) is the only drug of choice used for treatment of human schistosomes because of its safety and broad-spectrum activity. It is reported that the repeated chemotherapy is complicated by the occurrence of drug resistance to schistosomiasis. So there is an urgent need to develop new drug combinations therapy. The current study aimed to evaluate antischistosomal activity of F. carica leaves extract alone or in combination with PZQ on Schistosoma mansoni infected mice. Mice were experimentally infected with Schistosoma mansoni and orally administrated 6 weeks' post-infection with Fig leaves extract and/or PZQ. Schistosoma mansoni (S. mansoni)-infected mice were separated into four groups: untreated (I), treated with PZQ in dose of 200 mg/kg bw (II), treated with Fig leaves extract dose of 400 mg/kg bw (III). Group IV was treated with dose of Fig leaves extract-PZQ as in groups II and III, respectively. The effect was detected parasitologically using ova count technique and oogram pattern in intestine and liver. The greatest antischistosomal effect was achieved using orally administered Fig leaves extract-PZQ as indicated by total worm burden, tissue egg count and oogram pattern. Fig leaves extract + PZQ induced the therapeutic efficacy over the PZQ dose alone in intestine and liver as shown by a complete absence of immature worms, a very high reduction in the total numbers of tissue egg load (59.81% vs. 61.43% & 67.96% vs. 73.46%), mature eggs (37.86 ± 1.4 vs. 34.14 ± 1.9) and increasing in the total number of dead eggs (62.14 ± 1.4vs.67.29 ± 1.76). The results suggested the curcumin in combination with PZQ as a strong schistosomicidal regimen against S. mansoni. In addition, F. carica leaves extract is a promising for PZQ potentiating its antischistosomal action in animal model infected with S. mansoni. Therefore, the present work conclude that combined treatment has a synergetic effect and could be more promising in the management of schistosomiasis.

In Vitro Assessment of the Cercaricidal Activity of Sida acuta Burm. F. and Sida rhombifolia Linn. (Malvaceae) Hydroethanolic Extracts, Cytotoxicity, and Phytochemical Studies

Despite the global efforts, schistosomiasis remains a public health problem in several tropical and subtropical countries. One of the major challenges in the fight against schistosomiasis is the interruption of the parasite life cycle. Here, we evaluated the anticercarial, cytotoxicity, and phytochemical profiles of Sida acuta (HESa) and Sida rhombifolia (HESr) hydroethanolic extracts (Malvaceae). Schistosoma mansoni cercaria was collected from fifteen Biomphalaria pfeifferi-infected snails. Twenty-five cercariae were incubated in duplicate with different concentrations (31.25-1,000 μg/mL) of HESa or HESr. The cercaria viability was monitored at 30 min time intervals for 150 min, and the concentration-response curve of each plant extract was used to determine their respective lethal concentration 50 (LC50). Additionally, the cytotoxicity profile of each plant extract was evaluated on the Hepa 1-6 cell line at a concentration range of 15.625-1,000 µg/mL using the WST-8 assay method and its inhibitory concentration 50 (IC50) was calculated. Moreover, phytochemical characterization of each plant extract was carried out by HPLC-MS. Both extracts exhibited cercaricidal activity in a time- and concentration-dependent manner. At 30 min time point, HESa (LC50 = 28.41 ± 3.5 µg/mL) was more effective than HESr (LC50 = 172.42 ± 26.16 µg/mL) in killing S. mansoni cercariae. Regarding the cytotoxicity effect of both extracts, the IC50 of HESa (IC50 = 109.67 µg/mL) was lower than that of HESr (IC50 = 888.79 µg/mL). The selectivity index was 3.86 and 5.15 for HESa and HESr, respectively. Fifteen compounds were identified from HESa and HESr after HPLC-MS analysis. N-Feruloyltyramine, a polyphenol, and thamnosmonin, a coumarin, were identified in both extracts. HESa and HESr displayed cercaricidal activity and were not toxic on Hepa 1-6 cell line. Based on the selectivity index of these extracts, S. rhombifolia extract could be more effective on S. mansoni cercariae than S. acuta extract. This study could provide baseline information for further investigations aiming to develop plant-based alternative drugs against S. mansoni.

The Activity of Plant Crude Extracts against Schistosoma mansoni

Background

Schistosoma mansoni remains a significant health problem in low-income countries. Praziquantel (PZQ) is the only drug available to treat schistosomiasis, and PZQ resistance is a potential threat towards control of the disease although PZQ is currently effective against all species of schistosomes. Moreover, PZQ is less efficacious against larval stages. In response to these challenges, multiple in vivo/in vitro studies evaluated the anti-S. mansoni activity of crude plant extracts in a bid for novel drug(s). However, these studies appear fragmented and patchy. This systematic review explored the extent of such studies in the past 11 years (2010-2020).

Methods

A systematic web search analysis and review of the literature on crude plant extracts tested against S. mansoni was done. Data from 17 articles meeting eligibility criteria were extracted and analyzed. Forty-three plant species have been tested by the 17 studies. The leaves, barks, stems, flowers, rhizomes, and roots of the plants as well as the whole plant part were used for the experiments.

Conclusion

Nearly all of the plants significantly reduced schistosome egg output, killed adult worms, and improved liver histology and function. Further studies are required to assess the therapeutic potential of more promising plant species.

Hepatosplenic Protective Actions of Spirulina platensis and Matcha Green Tea Against Schistosoma mansoni Infection in Mice via Antioxidative and Anti-inflammatory Mechanisms

Schistosomiasis, a major parasitic illness, has high morbidity and negative financial effects in subtropical and tropical countries, including Egypt. The present study investigated the therapeutic effects of Spirulina platensis (SP) and matcha green tea (MGT) in Schistosoma mansoni-infected mice combined with tracing their possible antioxidant and anti-inflammatory impacts and their protective potency. A total of 60 Swiss albino mice were randomly allocated into six groups (n = 10): control group (CNT, received normal saline); SP–MGT group [received oral SP (3 g/kg bodyweight/day) plus MGT (3 g/kg bodyweight/day)]; S. mansoni group (infected with S. mansoni cercariae, 100 ± 10/mouse, using the tail immersion method); SP-infected group (infected with S. mansoni and received oral SP); MGT-infected group (received oral MGT after S. mansoni infection); and SP–MGT-infected group (received combined treatment of SP and MGT after S. mansoni infection). Treatment with SP and MGT started 4 weeks after S. mansoni infection and ended 10 weeks after. SP and MGT treatment (SP-infected and MGT-infected groups) and the combined treatment (SP–MGT-infected group) minimized the hepatic damage induced by S. mansoni; circulating alanine aminotransferase and aspartate transaminase decreased, and total protein, albumin, and globulin serum levels increased. The serum level of malondialdehyde significantly declined, and catalase, glutathione peroxidase, superoxide dismutase, and total antioxidant capacity increased in SP-infected, MGT-infected, and SP–MGT-infected groups compared with the infected group. Co-administration of SP and MGT reduced serum cytokine levels (tumor necrosis factor-alpha, interferon-gamma, and interleukin-13) and increased interleukin-10 levels after S. mansoni infection compared with the infected group. Moreover, treatment with SP and/or MGT decreased the number of granulomas in hepatic and splenic tissues compared with the infected group. Collectively, our results suggest that combined SP and MGT treatment is effective for S. mansoni infection. Liver and spleen tissue alterations were improved, the antioxidant systems were stimulated, and the inflammatory response was suppressed. Further research is recommended to investigate the mechanisms of the combined SP and MGT treatment effects to facilitate the development of novel therapies against this disease.

Antischistosomal Activity of Zingiber officinale, Piper nigrum, and Coriandrum sativum Aqueous Plant Extracts on Hamster Infected with Schistosoma mansoni

Schistosomiasis continues to affect the health and quality of life of millions of people around the world. Schistosomiasis has been ranked the second disease after malaria in terms of importance as a targeted tropical disease. Praziquantel (PZQ) is the only drug approved by the World Health Organization (WHO) for the treatment of schistosomiasis. Being the only drug, parasite resistance to this drug has developed. Therefore, the search for new alternatives has been the goal of many researchers. In this study, the effects of aqueous extracts of Zingiber officinale, Piper nigrum, and Coriandrum sativum on Schistosoma mansoni infected golden hamsters (Egyptian strain) were evaluated in vitro and in vivo at different doses of 500, 250, 125, 62.5, and 31.25 μg/ml. In vitro, adult worms of S. mansoni were tested in RPMI-1640 medium for 48 hrs. The results showed that the concentrations 500, 250, and 125 μg/ml of Zingiber officinale and Piper nigrum caused dead of 100% of adult worms within 6 and 12 hrs of incubation, respectively. Although, aqueous extract of Coriandrum sativum at concentrations 500, 250, and 125 μg/ml resulted dead of 100% parasites after 12 to 24 hrs of incubation. In conclusion, Zingiber officinale and Piper nigrum showed efficacy against schistosomiasis in both in vitro and biological experiments of Egyptian schistosome strain, while Coriandrum sativum gave less effective results than the previous ones. Therefore, Zingiber officinale and Piper nigrum may become an innovative treatment for schistosomiasis.

The immunomodulatory activity of Chenopodium ambrosioides reduces the parasite burden and hepatic granulomatous inflammation in Schistosoma mansoni-infection

ETHNOPHARMACOLOGICAL RELEVANCE

Folk medicine reports have described the use of Chenopodium ambrosioides as an anti-inflammatory, analgesic, and anthelmintic herb. These effects, including its activity against intestinal worms, are already scientifically observed. However, the immunological mechanisms of this species in the treatment of Schistosoma mansoni infection are unknown.

AIM OF THE STUDY

To evaluate the immunological and anti-Schistosoma mansoni effects of a crude Chenopodium ambrosioides hydro-alcoholic extract (HCE).

MATERIALS AND METHODS

For the in vitro analysis, cercariae and adult worms were exposed to different concentrations (0 to 10,000 μg/mL) of the HCE. For the in vivo evaluation, Swiss mice were infected with 50 cercariae of S. mansoni and separated into groups according to treatment as follows: a negative control (without treatment), a positive control (treated with Praziquantel®), HCE1 Group (treated with HCE during the cutaneous phase), HCE2 Group (treated with HCE during the lung phase), HCE3 Group (treated with HCE during the young worm phase), and HCE4 Group (treated with HCE during the adult worm phase). The animals treated with HCE received daily doses of 50 mg/kg, by gavage, for seven days, corresponding to the different developmental stages of S. mansoni. For comparison, a clean control group (uninfected and untreated) was also included. All animals were euthanized 60 days post-infection to allow the following assessments to be performed: a complete blood cells count, counts of eggs in the feces and liver, the quantification of cytokines and IgE levels, histopathological evaluations of the livers, and the analysis of inflammatory mediators.

RESULTS

HCE treatment increased the mortality of cercariae and adult worms in vitro. The HCE treatment in vivo reduced the eggs in feces and liver. The number and area of liver granulomas, independent of the phase of treatment, were also reduced. The treatment with HCE reduced the percentage of circulating eosinophils, IgE, IFN-γ, TNF-α, and IL-4. In contrast, the treatment with the HCE, dependent on the phase, increased IL-10 levels and the number of peritoneal and bone marrow cells, mainly of T lymphocytes, B lymphocytes, and macrophages. This effect could be due to secondary compounds presents in this extract, such as kaempferol, quercetin and derivatives.

CONCLUSIONS

This study demonstrates that Chenopodium ambrosioides has antiparasitic and immunomodulatory activity against the different phases of schistosomiasis, reducing the granulomatous inflammatory profile caused by the infection and, consequently, improving the disease prognosis.

Assessment of the In Vitro Antischistosomal Activities of the Extracts and Compounds from Solidago Microglossa DC (Asteraceae) and Aristolochia Cymbifera Mart. & Zucc. (Aristolochiaceae)

Schistosomiasis, caused by helminth flatworms of the genus Schistosoma, is a neglected tropical disease that afflicts over 230 million people worldwide. Currently, treatment is achieved with only one drug, praziquantel (PZQ). In this regard, the roots of Solidago microglossa (Asteraceae) and Aristolochia cymbifera (Aristolochiaceae) are popularly used as anthelmintic. Despite their medicinal use against helminthiasis, such as schistosomiasis, A. cymbifera, and S. microglossa have not been evaluated against S. mansoni. Then, in this work, the in vitro antischistosomal activity of the crude extracts of A. cymbifera (Ac) and S. microglossa (Sm) and their isolated compounds were investigated against S. mansoni adult worms. Sm (200 μg/mL) and Ac (100–200 μg/mL) were lethal to all male and female worms at the 24 h incubation. In addition, Sm (10–50 μg/mL) and Ac (10 μg/mL) caused significant reduction in the parasite's movements, showing no significant cytotoxicity to Vero cells at the same range of schistosomicidal concentrations. Confocal laser scanning microscopy revealed that Sm and Ac caused tegumental damages and reduced the numbers of tubercles of male schistosomes. Chromatographic fractionation of Sm leads to isolation of bauerenol, α-amirin, and spinasterol, while populifolic acid, cubebin, 2-oxopopulifolic acid methyl ester, and 2-oxopopulifolic acid were isolated from Ac. At concentrations of 25–100 μM, bauerenol, α-amirin, spinasterol, populifolic acid, and cubebin showed significant impact on motor activity of S. mansoni. 2-oxopopulifolic acid methyl ester and 2-oxopopulifolic acid caused 100% mortality and decreased the motor activity of adult schistosomes at 100 μM. This study has reported, for the first time, the in vitro antischistosomal effects of S. microglossa and A. cymbifera extracts, also showing promising compounds against adult schistosomes.

Botanical Products in the Treatment and Control of Schistosomiasis: Recent Studies and Distribution of Active Plant Resources According to Affected Regions

Schistosomiasis, a parasitic disease caused by trematodes of the genus Schistosoma, is the second most prevalent parasitic disease in the world. It affects around 200 million people. Clinical treatment, prophylaxis, and prevention are performed in countries susceptible to schistosomiasis. In the pharmacological treatment for an acute form of schistosomiasis, the use of antiparasitics, mainly praziquantel, is more common. As an alternative way, prevention methods such as reducing the population of intermediate hosts (mollusks) with molluscicides are important in the control of this disease by interrupting the biological cycle of this etiological parasite. Despite the importance of pharmacological agents and molluscicides, they have side effects and environmental toxicity. In addition, they can lead to the development of resistance enhancing of parasites, and lead to the search for new and effective drugs, including resources of vegetal origin, which in turn, are abundant in the affected countries. Thus, the purpose of this review is to summarize recent studies on botanical products with potential for the control of schistosomiasis, including anti-Schistosoma and molluscicide activities. In addition, species and plant derivatives according to their origin or geographical importance indicating a possible utility of local resources for countries most affected by the disease are presented.

In vitro activities of crude extracts and triterpenoid constituents of Dichapetalum crassifolium Chodat against clinical isolates of Schistosoma haematobium

Dichapetalum crassifolium Chodat (Dichapetalaceae) is widely distributed in Africa, Tropical Asia and Latin America. As part of our quest for potential bioactive lead compounds for various neglected tropical diseases, we report the anti-schistosomal potential of the crude extracts and chemical constituents of the stems and roots of Dichapetalum crassifolium. Column chromatography of extracts of the stems and roots led to the isolation and identification of three oleanane-type triterpenoids, friedelan-3β-ol (1), friedelan-3-one (2), and maslinic acid (3); the ursane-type tritepenoid, pomolic acid (4) and the dammarane-type tetracyclic triterpenoids, dichapetalin A (5) and dichapetalin M (6). Dichapetalin A was isolated from only the roots. Isolated compounds were identified by comparison of their physico-chemical and spectral data with published data. The highest in vitro anti-schistosomal activity (IC₅₀) of the crude extracts against clinical isolates of Schistosoma haematobium (Bilharz 1852) was 248.6 μg/ml for the ethyl acetate extract of the root while dichapetalin A gave the highest activity at 151.1 μg/ml among the compounds compared with the 15.5 μg/ml for the standard drug, praziquantel. The rest of the compounds showed activities in the order 177.9, 191.0, and 378.1 μg/ml respectively for mixture of β-sitosterol/stigmasterol, dichapetalin M and friedelan-3-one. The least active extract was the methanol extract of the stem (893.7 μg/ml). The constituents of D. crassifolium showed activity against the S. haematobium that are below praziquantel. It is envisaged that the presence of multiple layers and the minute sizes of pores in the egg shells, may preclude penetration of eggs by the compounds.

Review on medicinal plants and natural compounds as anti-Onchocerca agents

Onchocerciasis is a filarial vector borne disease which affects several million people mostly in Africa. The therapeutic approach of its control was based on a succession of drugs which always showed limits. The last one: ivermectin is not the least. It was shown to be only microfilaricidal and induced resistance to the human parasite Onchocerca volvulus. The approach using medicinal plants used in traditional medicine is a possible alternative method to cure onchocerciasis. Onchocerca ochengi and Onchocerca gutturosa are the parasite models used to assess anthelmintic activity of potentially anthelmintic plants. Numerous studies assessed the in vitro and/or in vivo anthelmintic activity of medicinal plants. Online electronic databases were consulted to gather publications on in vitro and in vivo studies of anti-Onchocerca activity of plants from 1990 to 2017. Globally, 13 plant families were investigated for anti-Onchocerca activity in 13 studies. The most active species were Anacardium occidentale, Euphorbia hirta and Acacia nilotica each with an LC₅₀ value of 2.76, 6.25 and 1.2 μg/mL, respectively. Polycarpol, voacamine, voacangine, ellagic acid, gallic acid, gentisic acid, 3-O-acetyl aleuritolic acid and (-)-epigallocatechin 3-O-gallate were the isolated plant compounds with anti-Onchocerca activity. Most of the assessed extract/compounds showed a good safety after in vivo acute toxicity assays and/or in vitro cytotoxicity test. The exception was the ethanol extract of Trichilia emetica, which killed completely and drastically mice at a dose of 3000 mg/kg. Several plant groups of compounds were shown active against Onchocerca sp. such as tannins, alkaloids, triterpenoids and essential oils. Nevertheless, none of the active compounds was subjected to clinical trial, to assessment of its diffusibility through nodular wall or its capability to induce genetic resistance of Onchocerca sp.

Schistosomicidal, antifibrotic and antioxidant effects of Cucurbita pepo L. seed oil and praziquantel combined treatment for Schistosoma mansoni infection in a mouse model

Despite the seriousness of schistosomiasis, its treatment depends only on praziquantel (PZQ), which has begun to lose its efficacy against the emergent Schistosoma mansoni-resistant strains. Therefore, the discovery of a novel schistosomicidal drug is an urgent priority. This study was designed to evaluate treatment with Cucurbita pepo L. (pumpkin) seed oil (PSO) alone and combined with PZQ against S. mansoni in experimentally infected mice. The study involved five groups: GI was the normal control; GII was the infected control; GIII was treated with an oral dose of PZQ of 500 mg/kg/day for two successive days, starting in the sixth week post infection; GIV was treated with an oral dose of PSO of 50 mg/kg/day for four weeks, starting in the fourth week post infection; and GV was treated with combined PSO–PZQ. Worm burden, tissue egg load and oogram pattern were estimated, and the ultrastructure alterations were examined. Histopathological examination of granuloma diameters, collagen deposition (Picro Sirius red stain), and angiogenesis (immunohistochemical expression of CD34+) was conducted and serum liver enzymes were measured to assess the liver condition. Moreover, the oxidative stress was evaluated by determining the amounts of malondialdehyde and superoxide dismutase in liver homogenates. The results revealed significant changes in all the assessed parameters with PSO administration. However, PZQ was significantly more effective as an antiparasitic agent, whereas PSO was better in terms of fibrosis and oxidative stress. The most significant results were obtained in group V, which may be attributed to a synergy between PZQ and PSO, with antiparasitic, antioxidant and antifibrotic properties.

In vivo schistosomicidal activity of 7-epiclusianone and its quantification in the plasma of healthy and Schistosoma mansoni infected mice using UPLC-MS/MS

BACKGROUND

The tetraprenylated benzophenone 7-epiclusianone (7-epi) is a substance isolated from the fruits of Garcinia brasiliensis and in vitro studies have demonstrated that 7-epi is effective against Schistosoma mansoni adult worms.

HYPOTHESIS/PURPOSE

Here we report the in vivo evaluation of 7-epi and its pharmacokinetic in healthy and Schistosoma mansoni infected mice.

STUDY DESIGN AND METHODS

In this work, we assayed the schistosomicidal activity of 7-epi at the dose of 100 mg/kg and 300 mg/kg body weight/day in S. mansoni experimentally infected mice. Besides, two groups of animals were treated and a detailed analysis of plasma samples was performed by liquid chromatography coupled to mass spectrometry (LC-MS/MS).

RESULTS

The worm burden showed a reduction in the infected mice after treatment with 300 mg/kg for five days (p < .05). And we found an increase of AUC^0-∞ (20846 vs. 32438 ng.h/ml) and a decrease of total apparent clearance (0.006 vs. 0.004 l/h/kg) of 7- epi in the infected group compared to the healthy group. Consequently, the half-life increased (1.73 vs. 6.11 h) and Cmax was reduced (5427.5 vs. 3321.0 ng/ml) in the infected group compared to the healthy group. In addition, histopathological investigations were performed analysing liver samples from healthy and infected mice.

CONCLUSION

The results showed significant schistosomicidal in vivo activity at 300 mg/kg. In addition, livers from S. mansoni infected mice showed a greater number of egg granulomas and the changes in the pharmacokinetic parameters in this group could be associated with the pathology of the murine experimental schistosomiasis.