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Parasite (Paris, France) 2018The purpose of this review is to survey the antiparasitic plants of the Asteraceae family and their applicability in the treatment of parasites. This review is divided... (Review)
Review
The purpose of this review is to survey the antiparasitic plants of the Asteraceae family and their applicability in the treatment of parasites. This review is divided into three major parts: (a) literature on traditional uses of Asteraceae plants for the treatment of parasites; (b) description of the major classes of chemical compounds from Asteraceae and their antiparasitic effects; and (c) antiparasitic activity with special reference to flavonoids and terpenoids. This review provides detailed information on the reported Asteraceae plant extracts found throughout the world and on isolated secondary metabolites that can inhibit protozoan parasites such as Plasmodium, Trypanosoma, Leishmania, and intestinal worms. Additionally, special attention is given to the Asteraceae plants of Odisha, used by the tribes of the area as antiparasitics. These plants are compared to the same plants used traditionally in other regions. Finally, we provide information on which plants identified in Odisha, India and related compounds show promise for the development of new drugs against parasitic diseases. For most of the plants discussed in this review, the active compounds still need to be isolated and tested further.
Topics: Animals; Antiparasitic Agents; Asteraceae; Helminths; Humans; India; Leishmania; Phytotherapy; Plant Extracts; Plants, Medicinal; Plasmodium; Population Groups; Trypanosoma; Trypanosomatina
PubMed: 29528842
DOI: 10.1051/parasite/2018008 -
Applied and Environmental Microbiology Oct 2023Temperature affects growth, metabolism, and interspecific interactions in microbial communities. Within animal hosts, gut bacterial symbionts can provide resistance to...
Temperature affects growth, metabolism, and interspecific interactions in microbial communities. Within animal hosts, gut bacterial symbionts can provide resistance to parasitic infections. Both infection and populations of symbionts can be shaped by the host body temperature. However, the effects of temperature on the antiparasitic activities of gut symbionts have seldom been explored. The -rich gut microbiota of facultatively endothermic honey bees is subject to seasonal and ontogenetic changes in host temperature that could alter the effects of symbionts against parasites. We used cell cultures of a symbiont and an important trypanosomatid gut parasite of honey bees to test the potential for temperature to shape parasite-symbiont interactions. We found that symbionts showed greater heat tolerance than parasites and chemically inhibited parasite growth via production of acids. Acceleration of symbiont growth and acid production at high temperatures resulted in progressively stronger antiparasitic effects across a temperature range typical of bee colonies. Consequently, the presence of symbionts reduced both the peak growth rate and heat tolerance of parasites. Substantial changes in parasite-symbiont interactions were evident over a temperature breadth that parallels changes in diverse animals exhibiting infection-related fevers and the amplitude of circadian temperature variation typical of endothermic birds and mammals, implying the frequent potential for temperature to alter symbiont-mediated resistance to parasites in endo- and ectothermic hosts. Results suggest that the endothermic behavior of honey bees could enhance the impacts of gut symbionts on parasites, implicating thermoregulation as a reinforcer of core symbioses and possibly microbiome-mediated antiparasitic defense. IMPORTANCE Two factors that shape the resistance of animals to infection are body temperature and gut microbiota. However, temperature can also alter interactions among microbes, raising the question of whether and how temperature changes the antiparasitic effects of gut microbiota. Honey bees are agriculturally important hosts of diverse parasites and infection-mitigating gut microbes. They can also socially regulate their body temperatures to an extent unusual for an insect. We show that high temperatures found in honey bee colonies augment the ability of a gut bacterial symbiont to inhibit the growth of a common bee parasite, reducing the parasite's ability to grow at high temperatures. This suggests that fluctuations in colony and body temperatures across life stages and seasons could alter the protective value of bees' gut microbiota against parasites, and that temperature-driven changes in gut microbiota could be an underappreciated mechanism by which temperature-including endothermy and fever-alters animal infection.
Topics: Bees; Animals; Parasites; Temperature; Microbiota; Gastrointestinal Microbiome; Bacteria; Lactobacillus; Antiparasitic Agents; Mammals
PubMed: 37791764
DOI: 10.1128/aem.01023-23 -
Parasites & Vectors Aug 2018Increasing drug resistance in gastrointestinal (GI) parasites of livestock and concerns about chemical residues in animal products and the environment are driving the... (Review)
Review
Increasing drug resistance in gastrointestinal (GI) parasites of livestock and concerns about chemical residues in animal products and the environment are driving the development of alternative control strategies that are less reliant on the use of synthetic drugs. An increasingly investigated approach is the use of bioactive forages with antiparasitic properties as part of the animal's diet (nutraceuticals) or as potential sources of novel, natural parasiticides. Chicory (Cichorium intybus) is a multi-purpose crop and one of the most promising bioactive forages in temperate regions, and numerous in vivo trials have explored its potential against parasitic nematodes in livestock. However, it is unclear whether chicory can induce a direct and broad activity against various GI parasites in different livestock species, and the levels of chicory in the diet that are required to exert an efficient antiparasitic effect. Moreover, the mechanisms leading to the reported parasiticidal activity of chicory are still largely unknown, and its bioactive phytochemicals have only recently been investigated. In this review, we summarise the progress in the study of the antiparasitic activity of chicory and its natural bioactive compounds against GI parasites in livestock, through examination of the published literature. The available evidence indicates that feeding chicory can reduce faecal egg counts and/or worm burdens of abomasal nematodes, but not infections with intestinal worms, in ruminants. Highly chicory-rich diets (≥ 70% of chicory dry matter in the diet) may be necessary to directly affect abomasal parasitism. Chicory is known to synthesise several bioactive compounds with potential antiparasitic activity, but most research has been devoted to the role of sesquiterpene lactones (SL). Recent in vitro studies have confirmed direct and potent activity of SL-rich extracts from chicory against different GI helminths of livestock. Chicory SL have also been reported to exhibit antimalarial properties and its potential antiprotozoal activity in livestock remains to be evaluated. Furthermore, the detailed identification of the main antiparasitic metabolites of chicory and their pharmacokinetics need further confirmation. Research gaps and perspectives on the potential use of chicory as a nutraceutical forage and a source of bioactive compounds for parasite control in livestock are discussed.
Topics: Animal Feed; Animals; Anthelmintics; Antiparasitic Agents; Cattle; Cichorium intybus; Dietary Supplements; Feces; Gastrointestinal Tract; Helminthiasis; Humans; Intestinal Diseases, Parasitic; Livestock; Nematoda; Parasite Egg Count; Sheep
PubMed: 30134991
DOI: 10.1186/s13071-018-3012-4 -
International Health Mar 2018In the past few years, efforts to eliminate onchocerciasis from Africa have intensified. These efforts are primarily based on the mass distribution of the... (Review)
Review
In the past few years, efforts to eliminate onchocerciasis from Africa have intensified. These efforts are primarily based on the mass distribution of the anti-helminthic drug Mectizan™ (ivermectin). This program has led to the development of new guidelines by the World Health Organization for the verification that transmission has been suppressed and eventually eliminated. The requirements of diagnostic tools for this purpose differ in many ways from tests used to diagnose infection in individuals. In this review, we summarize the progress that has been made to identify diagnostics that meet the specialized requirements needed to verify onchocerciasis elimination, discuss why these tests were selected and summarize the needs that still exist to complete the arsenal of diagnostic tools that will be useful as the goal of elimination is achieved.
Topics: Africa; Animals; Antiparasitic Agents; Disease Eradication; Humans; Ivermectin; Onchocerca volvulus; Onchocerciasis
PubMed: 29471336
DOI: 10.1093/inthealth/ihx047 -
International Journal of Antimicrobial... Aug 2020Ivermectin (IVM) is a robust antiparasitic drug with an excellent tolerance and safety profile. Historically it has been the drug of choice for onchocerciasis and... (Review)
Review
Ivermectin (IVM) is a robust antiparasitic drug with an excellent tolerance and safety profile. Historically it has been the drug of choice for onchocerciasis and lymphatic filariasis global elimination programs. IVM is an oral insecticide and is a standard treatment against intestinal helminths and ectoparasites. The current humanitarian crisis in Venezuela is a regional public health threat that requires immediate action. The public health system in Venezuela has crumbled because of a 70% shortage of medicines in public hospitals, low vaccination campaigns, and the mass exodus of medical personnel. Herein we discuss the repurposing of IVM to attenuate the burden imposed by the most prevalent neglected tropical diseases (NTDs) in Venezuela, including soil-transmitted helminths, ectoparasites and, possibly, vector-borne diseases, such as malaria. In addition, novel experimental evidence has shown that IVM is active and efficacious in vitro against Chagas disease, Leishmaniases, arboviruses, and SARS-CoV-2. In crisis-hit Venezuela, all these infectious diseases are public health emergencies that have long been ignored and require immediate attention. The versatility of IVM could serve as a powerful tool to tackle the multiple overlapping endemic and emergent diseases that currently affect Venezuela. The repurposing of this multipurpose drug would be a timely therapeutic approach to help mitigate the tremendous burden of NTDs nationwide.
Topics: Antiparasitic Agents; Drug Repositioning; Humans; Ivermectin; Parasitic Diseases; Venezuela
PubMed: 32479893
DOI: 10.1016/j.ijantimicag.2020.106037 -
Chemistry & Biodiversity Jan 2016Pyridoacridines are a class of strictly marine-derived alkaloids that constitute one of the largest chemical families of marine alkaloids. During the last few years,... (Review)
Review
Pyridoacridines are a class of strictly marine-derived alkaloids that constitute one of the largest chemical families of marine alkaloids. During the last few years, both natural pyridoacridines and their analogues have constituted excellent targets for synthetic works. They have been the subject of intense study due to their significant biological activities; cytotoxic, antibacterial, antifungal, antiviral, insecticidal, anti-HIV, and anti-parasitic activities. In the present review, 95 pyridoacridine alkaloids isolated from marine organisms are discussed in term of their occurrence, biosynthesis, biological activities, and structural assignment.
Topics: Acridines; Alkaloids; Animals; Anti-HIV Agents; Anti-Infective Agents; Antineoplastic Agents; Antiparasitic Agents; Cell Proliferation; Humans; Insecticides; Molecular Structure; Phenanthrolines
PubMed: 26765351
DOI: 10.1002/cbdv.201400434 -
Viruses Oct 2016Griffithsin (GRFT), an algae-derived lectin, is one of the most potent viral entry inhibitors discovered to date. It is currently being developed as a microbicide with... (Review)
Review
Griffithsin (GRFT), an algae-derived lectin, is one of the most potent viral entry inhibitors discovered to date. It is currently being developed as a microbicide with broad-spectrum activity against several enveloped viruses. GRFT can inhibit human immunodeficiency virus (HIV) infection at picomolar concentrations, surpassing the ability of most anti-HIV agents. The potential to inhibit other viruses as well as parasites has also been demonstrated. Griffithsin's antiviral activity stems from its ability to bind terminal mannoses present in high-mannose oligosaccharides and crosslink these glycans on the surface of the viral envelope glycoproteins. Here, we review structural and biochemical studies that established mode of action and facilitated construction of GRFT analogs, mechanisms that may lead to resistance, and in vitro and pre-clinical results that support the therapeutic potential of this lectin.
Topics: Animals; Antiparasitic Agents; Antiviral Agents; Drug Evaluation, Preclinical; Humans; Microbial Sensitivity Tests; Plant Lectins; Virus Internalization
PubMed: 27783038
DOI: 10.3390/v8100296 -
The Korean Journal of Parasitology Dec 2010Due to the possible emergence of resistance and safety concerns on certain treatments, development of new drugs against parasites is essential for the effective control... (Review)
Review
Due to the possible emergence of resistance and safety concerns on certain treatments, development of new drugs against parasites is essential for the effective control and subsequent eradication of parasitic infections. Several drug targets have been identified which are either genes or proteins essential for the parasite survival and distinct from the hosts. These include the phosphagen kinases (PKs) which are enzymes that play a key role in maintenance of homeostasis in cells exhibiting high or variable rates of energy turnover by catalizing the reversible transfer of a phosphate between ATP and naturally occurring guanidine compounds. PKs have been identified in a number of important human and animal parasites and were also shown to be significant in survival and adaptation to stress conditions. The potential of parasite PKs as novel chemotherapeutic targets remains to be explored.
Topics: Animals; Antiparasitic Agents; Humans; Parasites; Phosphotransferases
PubMed: 21234228
DOI: 10.3347/kjp.2010.48.4.281 -
Indian Pediatrics Nov 2005
Topics: Animals; Antiparasitic Agents; Cryptosporidiosis; Cryptosporidium parvum; Diarrhea; Giardia lamblia; Giardiasis; Humans; Nitro Compounds; Thiazoles
PubMed: 16340060
DOI: No ID Found -
The Cochrane Database of Systematic... Jul 2021Ivermectin, an antiparasitic agent used to treat parasitic infestations, inhibits the replication of viruses in vitro. The molecular hypothesis of ivermectin's antiviral...
BACKGROUND
Ivermectin, an antiparasitic agent used to treat parasitic infestations, inhibits the replication of viruses in vitro. The molecular hypothesis of ivermectin's antiviral mode of action suggests an inhibitory effect on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication in the early stages of infection. Currently, evidence on efficacy and safety of ivermectin for prevention of SARS-CoV-2 infection and COVID-19 treatment is conflicting.
OBJECTIVES
To assess the efficacy and safety of ivermectin compared to no treatment, standard of care, placebo, or any other proven intervention for people with COVID-19 receiving treatment as inpatients or outpatients, and for prevention of an infection with SARS-CoV-2 (postexposure prophylaxis).
SEARCH METHODS
We searched the Cochrane COVID-19 Study Register, Web of Science (Emerging Citation Index and Science Citation Index), medRxiv, and Research Square, identifying completed and ongoing studies without language restrictions to 26 May 2021.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) comparing ivermectin to no treatment, standard of care, placebo, or another proven intervention for treatment of people with confirmed COVID-19 diagnosis, irrespective of disease severity, treated in inpatient or outpatient settings, and for prevention of SARS-CoV-2 infection. Co-interventions had to be the same in both study arms. We excluded studies comparing ivermectin to other pharmacological interventions with unproven efficacy.
DATA COLLECTION AND ANALYSIS
We assessed RCTs for bias, using the Cochrane risk of bias 2 tool. The primary analysis excluded studies with high risk of bias. We used GRADE to rate the certainty of evidence for the following outcomes 1. to treat inpatients with moderate-to-severe COVID-19: mortality, clinical worsening or improvement, adverse events, quality of life, duration of hospitalization, and viral clearance; 2. to treat outpatients with mild COVID-19: mortality, clinical worsening or improvement, admission to hospital, adverse events, quality of life, and viral clearance; (3) to prevent SARS-CoV-2 infection: SARS-CoV-2 infection, development of COVID-19 symptoms, adverse events, mortality, admission to hospital, and quality of life.
MAIN RESULTS
We found 14 studies with 1678 participants investigating ivermectin compared to no treatment, placebo, or standard of care. No study compared ivermectin to an intervention with proven efficacy. There were nine studies treating participants with moderate COVID-19 in inpatient settings and four treating mild COVID-19 cases in outpatient settings. One study investigated ivermectin for prevention of SARS-CoV-2 infection. Eight studies had an open-label design, six were double-blind and placebo-controlled. Of the 41 study results contributed by included studies, about one third were at overall high risk of bias. Ivermectin doses and treatment duration varied among included studies. We identified 31 ongoing and 18 studies awaiting classification until publication of results or clarification of inconsistencies. Ivermectin compared to placebo or standard of care for inpatient COVID-19 treatment We are uncertain whether ivermectin compared to placebo or standard of care reduces or increases mortality (risk ratio (RR) 0.60, 95% confidence interval (CI) 0.14 to 2.51; 2 studies, 185 participants; very low-certainty evidence) and clinical worsening up to day 28 assessed as need for invasive mechanical ventilation (IMV) (RR 0.55, 95% CI 0.11 to 2.59; 2 studies, 185 participants; very low-certainty evidence) or need for supplemental oxygen (0 participants required supplemental oxygen; 1 study, 45 participants; very low-certainty evidence), adverse events within 28 days (RR 1.21, 95% CI 0.50 to 2.97; 1 study, 152 participants; very low-certainty evidence), and viral clearance at day seven (RR 1.82, 95% CI 0.51 to 6.48; 2 studies, 159 participants; very low-certainty evidence). Ivermectin may have little or no effect compared to placebo or standard of care on clinical improvement up to 28 days (RR 1.03, 95% CI 0.78 to 1.35; 1 study; 73 participants; low-certainty evidence) and duration of hospitalization (mean difference (MD) -0.10 days, 95% CI -2.43 to 2.23; 1 study; 45 participants; low-certainty evidence). No study reported quality of life up to 28 days. Ivermectin compared to placebo or standard of care for outpatient COVID-19 treatment We are uncertain whether ivermectin compared to placebo or standard of care reduces or increases mortality up to 28 days (RR 0.33, 95% CI 0.01 to 8.05; 2 studies, 422 participants; very low-certainty evidence) and clinical worsening up to 14 days assessed as need for IMV (RR 2.97, 95% CI 0.12 to 72.47; 1 study, 398 participants; very low-certainty evidence) or non-IMV or high flow oxygen requirement (0 participants required non-IMV or high flow; 1 study, 398 participants; very low-certainty evidence). We are uncertain whether ivermectin compared to placebo reduces or increases viral clearance at seven days (RR 3.00, 95% CI 0.13 to 67.06; 1 study, 24 participants; low-certainty evidence). Ivermectin may have little or no effect compared to placebo or standard of care on the number of participants with symptoms resolved up to 14 days (RR 1.04, 95% CI 0.89 to 1.21; 1 study, 398 participants; low-certainty evidence) and adverse events within 28 days (RR 0.95, 95% CI 0.86 to 1.05; 2 studies, 422 participants; low-certainty evidence). None of the studies reporting duration of symptoms were eligible for primary analysis. No study reported hospital admission or quality of life up to 14 days. Ivermectin compared to no treatment for prevention of SARS-CoV-2 infection We found one study. Mortality up to 28 days was the only outcome eligible for primary analysis. We are uncertain whether ivermectin reduces or increases mortality compared to no treatment (0 participants died; 1 study, 304 participants; very low-certainty evidence). The study reported results for development of COVID-19 symptoms and adverse events up to 14 days that were included in a secondary analysis due to high risk of bias. No study reported SARS-CoV-2 infection, hospital admission, and quality of life up to 14 days.
AUTHORS' CONCLUSIONS
Based on the current very low- to low-certainty evidence, we are uncertain about the efficacy and safety of ivermectin used to treat or prevent COVID-19. The completed studies are small and few are considered high quality. Several studies are underway that may produce clearer answers in review updates. Overall, the reliable evidence available does not support the use ivermectin for treatment or prevention of COVID-19 outside of well-designed randomized trials.
Topics: Antiparasitic Agents; Antiviral Agents; COVID-19; Cause of Death; Humans; Ivermectin; Placebos; Post-Exposure Prophylaxis; Randomized Controlled Trials as Topic; Respiration, Artificial; SARS-CoV-2; Time Factors; Treatment Outcome; COVID-19 Drug Treatment
PubMed: 34318930
DOI: 10.1002/14651858.CD015017.pub2