Antiparasitic Properties of Cantharidin and the Blister Beetle Berberomeloe majalis (Coleoptera: Meloidae)

In vitro immune-depression and anti-inflammatory activities of cantharidin on gilthead seabream (Sparus aurata) leucocytes activated by λ-carrageenan

Cantharidin is a natural compound with known therapeutic applications in humans. The aim of this study was to investigate the in vitro effects of cantharidin on gilthead seabream (Sparus aurata) head kidney leucocytes (HKL) stimulated with λ-carrageenan. HKLs were incubated for 24 h with cantharidin (0, 2.5 and 5 μg mL-1) and λ-carrageenan (0 and 1000 μg mL-1). The results showed that HKL viability only decreased by 15.2% after incubated with 5 μg mL-1 of cantharidin and λ-carrageenan. Cantharidin increased the peroxidase activity of HKLs only when incubated in combination with λ-carrageenan. Besides this, cantharidin inhibited the respiratory burst and phagocytic activities. Furthermore, cantharidin induced morphological changes in HKLs (apoptotic and vacuolization signs) that were enhanced when incubated with λ-carrageenan. Considering the analysis of the selected gene expression studied in HKLs [NF-κB subunits (rela, relb, crel, nfkb1, nfkb2), proinflammatory cytokines (il1b, tnfa), anti-inflammatory cytokines (il10, tgfb) and caspases (casp1, casp3, casp8, casp9)], although λ-carrageenan up-regulated the expression of the proinflammatory gene il1b, λ-carrageenan and cantharidin down-regulated its expression in HKLs. In addition, cantharidin up-regulated casp3 and casp9 expression. The casp3 and casp9 gene expression was down-regulated while casp1 gene expression was up-regulated in HKLs incubated with both cantharidin and λ-carrageenan. All the effects of cantharidin are related to its inhibitory effect on protein phosphatases, which induce apoptosis at long exposure times, and minimize the effects of λ-carrageenan. The present results provide detailed insight into the immune-depressive and anti-inflammatory properties of cantharidin on immune cells, which could be of interest to the aquaculture sector.

A Comprehensive Review of Various Therapeutic Strategies for the Management of Skin Cancer

Skin cancer (SC) poses a global threat to the healthcare system and is expected to increase significantly over the next two decades if not diagnosed at an early stage. Early diagnosis is crucial for successful treatment, as the disease becomes more challenging to cure as it progresses. However, identifying new drugs, achieving clinical success, and overcoming drug resistance remain significant challenges. To overcome these obstacles and provide effective treatment, it is crucial to understand the causes of skin cancer, how cells grow and divide, factors that affect cell growth, and how drug resistance occurs. In this review, we have explained various therapeutic approaches for SC treatment via ligands, targeted photosensitizers, natural and synthetic drugs for the treatment of SC, an epigenetic approach for management of melanoma, photodynamic therapy, and targeted therapy for BRAF-mutated melanoma. This article also provides a detailed summary of the various natural drugs that are effective in managing melanoma and reducing the occurrence of skin cancer at early stages and focuses on the current status and future prospects of various therapies available for the management of skin cancer.

The Influence of Substance Properties on Arthropod Chemical Defenses: A Meta-Analysis

Among defenses against predation, chemical defenses are possibly the most studied. However, when addressing the effectiveness of those chemical defenses, previous studies did not include properties of the chemical substances themselves. Lipophilicity, for instance, may facilitate crossing membranes, and boiling point may define the duration of the substances in the air. Moreover, other variables may also be relevant: the predator taxon; the prey model chosen to conduct experiments; whether the prey is presented grouped or not in experiments; and whether the chemical defense is a mixture of many substances or only one. To understand how those factors influence chemical defenses' effectiveness, we conducted a multilevel meta-analysis with 43 studies (127 effect sizes), accounting for different types of dependence. We used Akaike Information Criterion (AICc) to select the best model. The model with the lowest AICc value included only the boiling point, which defines how quickly a chemical substance volatilizes. This model indicated that the most effective chemical defenses had lower boiling point values, i.e., higher volatility. Moreover, we did not find chemicals with very low boiling points, suggesting there might be an optimum range of volatility. Other models, including the intercept-only model, were also recovered among the best models, therefore further studies are needed to confirm the relationship between volatility and chemical defenses' effectiveness. Our results highlight the value of incorporating physicochemical properties in the ecological and evolutionary study of chemical defense.

Zootoxins and Domestic Animals: A European View

Zootoxins are produced by venomous and poisonous species and are an important cause of poisoning in companion animals and livestock in Europe. Little information about the incidence of zootoxin poisoning is available in Europe, with only a few case reports and review papers being published. This review presents the most important zootoxins produced by European venomous and poisonous animal species responsible for poisoning episodes in companion animals and livestock. The main zootoxin-producing animal species, components of the toxins/venoms and their clinical effects are presented. The most common zootoxicoses involve terrestrial zootoxins excreted by the common toad, the fire salamander, the pine processionary caterpillar, and vipers. The lack of a centralized reporting/poison control system in Europe makes the evaluation of the epidemiology of zootoxin-induced poisonings extremely difficult. Even if there are many anecdotal reports in the veterinary community about the exposure of domestic animals to terrestrial and marine zootoxins, the number of published papers regarding these toxicoses is low. Climate change and its consequences regarding species distribution and human-mediated transportation are responsible for the emerging nature of some intoxications in which zootoxins are involved. Although new venomous or poisonous animal species have emerged in regions where they were previously unreported, zootoxins produced by native species remain the main concern in Europe. The diversity of poisonous and venomous animal species and the emerging nature of certain poisonings warrant the continuous update to such knowledge by veterinary professionals and animal owners. This review offers an overview about zootoxin-related poisonings in domestic animals in Europe and also provides important information from a health perspective.

Blister Beetle Dermatitis Outbreaks in Mali

INTRODUCTION

Meloidae are distributed in temperate and arid regions but are also common in subtropical and tropical savannahs. These insects contain cantharidin, a vesicant substance that can cause poisoning by ingestion and dermatitis by direct contact.

MATERIAL AND METHODS

We describe recurrent Meloidae-related dermatitis outbreaks and their health impact by analyzing medical consultation records and meteorological data.

RESULTS

Between 2015 and 2019, dermatitis outbreaks took place at a French military base at the end of the rainy season, from July to August, with 100 cases reported in 2015, 74 in 2017, 100 in 2018, and 36 in 2019. In 2017, the incidence rate was 4.4% for the base's population. Initial medical consultations represented 31.5% of total medical care activity. Meloidae were identified as Cyaneolytta fryi.

CONCLUSIONS

These outbreaks of burn-like lesions, although clinically benign, can place a considerable burden on the medical activity of health care facilities. The diagnosis of Meloidae dermatitis is exclusively anamnestic and clinical and requires reported contact with the insect. The treatment protocol is that of standard burn care, and the best preventive measure is to avoid bright white lights. Military personnel, foreign workers, and travelers venturing into the Sahel should be warned of the risks associated with these beetles.

Unravelling the potential of insects for medicinal purposes - A comprehensive review

Entomotherapy, the use of insects for medicinal purposes, has been practised for centuries in many countries around the world. More than 2100 edible insect species are eaten by humans, but little is known about the possibility of using these insects as a promising alternative to traditional pharmaceuticals for treating diseases. This review offers a fundamental understanding of the therapeutic applications of insects and how they might be used in medicine. In this review, 235 insect species from 15 orders are reported to be used as medicine. Hymenoptera contains the largest medicinal insect species, followed by Coleoptera, Orthoptera, Lepidoptera, and Blattodea. Scientists have examined and validated the potential uses of insects along with their products and by-products in treating various diseases, and records show that they are primarily used to treat digestive and skin disorders. Insects are known to be rich sources of bioactive compounds, explaining their therapeutic features such as anti-inflammatory, antimicrobial, antiviral, and so on. Challenges associated with the consumption of insects (entomophagy) and their therapeutic uses include regulation barriers and consumer acceptance. Moreover, the overexploitation of medicinal insects in their natural habitat has led to a population crisis, thus necessitating the investigation and development of their mass-rearing procedure. Lastly, this review suggests potential directions for developing insects used in medicine and offers advice for scientists interested in entomotherapy. In future, entomotherapy may become a sustainable and cost-effective solution for treating various ailments and has the potential to revolutionize modern medicine.

Bioactivity of plants eaten by wild birds against laboratory models of parasites and pathogens

Plants are not only used as energy and nutrient resources for herbivores. Plants can be ingested because of their activity against host parasites and other pathogens. This so-called medicinal role of plants is well reported in ethnopharmacology and under-reported in wild animals. More studies on wild animals are needed because any plant in the world contains bioactive compounds, and probably all plants, no matter how toxic they are, experience herbivory. For example, we tested the activity of extracts and essential oils from Papaver rhoeas and Echium plantagineum against a selection of laboratory pathogens because Great bustards Otis tarda preferred these plants during the mating season, with male fecal droppings showing a higher frequency of P. rhoeas particles than the fecal droppings of females. We hypothesized that P. rhoeas could be helpful for males in the mating season if any part of this plant harbors bioactivity against parasites and other pathogens. Males’ immune system is weakened during the mating season because of their investment in secondary sexual characters and sexual display. As a first exploration of the bioactivity of these plants, we evaluated extracts of both plants against a sample of laboratory models, including a flagellated protozoon (Trichomonas gallinae), a nematode (Meloidogyne javanica) and a fungus (Aspergillus niger). Non-polar and polar extracts of the aerial parts of P. rhoeas, especially the extracts of flowers and capsules, and the extracts of leaves and flowers of E. plantagineum showed activity against nematodes and trichomonads. The bioactivity of plants against parasites could explain the foraging behavior of stressed animals. The chemical communication underpinning the capacity of fauna to recognize those plants is far less known.

Network Pharmacology Integrated Molecular Docking to Explore the Mechanism of Blister Beetle Therapy for Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is one of the major causes of cancer death in the world. Studies show that the effective anticancer component in blister beetles is cantharidin, which can improve chemotherapy efficacy, median survival, and prognosis of LUAD. However, the antitumor mechanism of blister beetles has not been fully clarified. This study aimed to identify the key targets of the treatment of LUAD by blister beetles based on the principle of network pharmacology. An integrated approach including network pharmacology and a molecular docking technique was conducted, which mainly comprises target prediction, weighted gene correlation network analysis (WGCNA) analysis, network construction, gene ontology, and pathway enrichment analysis. 35 key targets were obtained and significantly associated with response to external stimuli, collagen binding, cyclin binding, organic acid binding, pyruvate metabolism, glycolysis, and amino acid biosynthesis pathways. Both LASSO regression and the RF model had a high predictive ability, and 9 candidate genes were screened, among which BIRC5 and PLK1 were the key targets for the treatment of LUAD by using blister beetles and showed significant survival significance. Cantharidin exerts its antitumor effects through 8 targets in 32 pathways, while BIRC5 and PLK1 have obvious survival significance.

New Evidence of Canthariphily: Tilloidea transversalis (Coleoptera: Cleridae) Sequestering Cantharidin From Lydus trimaculatus (Coleoptera: Meloidae)

Cantharidin (CTD) is a defensive compound autogenously and exclusively produced by two phylogenetically related beetle families: Meloidae and Oedemeridae. Although this molecule usually acts as a strong deterrent against potential predators and parasites, some arthropod species, collectively named 'canthariphilous species', are attracted to CTD. Some species can sequester CTD from the CTD-producing species, using it as a chemical defense against enemies. The present paper focuses on the first-ever description of canthariphilous interactions between a checkered beetle species (Coleoptera: Cleridae) and a CTD -producing species. Field observations revealed individuals of the phytophagous beetle Tilloidea transversalis (Charpentier, 1825) (Coleoptera: Cleridae) biting individuals of the blister beetle Lydus trimaculatus (Fabricius, 1775) (Coleoptera: Meloidae). Laboratory behavioral experiments followed to verify if this peculiar behavior of T. transversalis also occurs on other co-occurring species. Moreover, chemical analyses were performed to assess whether T. transversalis can sequester CTD. Our results show that T. transversalis only attacks CTD-producing species. However, while chemical analyses prove that T. transversalis can sequester CTD from the hemolymph of L. trimaculatus, some clues (based on a CTD-baited traps sampling) suggest that this beetle, contrarily to other canthariphilous species, does not appear to show a high attraction to pure synthetic CTD. Thus, other unknown signals, alone or in combination with CTD, could be implicated in triggering the canthariphilous behaviors of T. transversalis.

In vitro effects of cantharidin on gilthead seabream (Sparus aurata) head-kidney leucocytes

Cantharidin is a toxic vesicant terpene used in folk and traditional medicine due to its various therapeutic effects. Since there are no previous data on the effect of cantharidin in fish, this study aimed to investigate the in vitro related-inflammatory effects of cantharidin in gilthead seabream (Sparus aurata L.) head-kidney leucocytes (HKLs). In the first experiment, the HKLs were incubated with 0, 5 and 10 μg mL^-1 of cantharidin for 24 h to delimit its possible toxic effects. In a second experiment, leucocytes were incubated with ranging concentrations from 0 to 10 μg mL^-1 for 3, 6, or 12 h. Cell viability was higher in acidophilic granulocytes than in monocytes/macrophages and lymphocytes. Cantharidin caused apoptosis as was evidenced by transmission electron microscopy. In addition, cantharidin produced a time- and dose-dependent decrease of respiratory burst and phagocytic activities in HKLs, while their peroxidase activity was increased at 24 h of incubation with 5 and 10 μg mL^-1 of cantharidin. Different changes in the gene expression were observed after incubation with cantharidin. While the gene expression of tnfa, il1b and crel was up-regulated in HKLs, the nfkb1 and igmh genes were down-regulated in comparison to the expression found in control HKLs. Present results offer a first view of the possible effects and action mechanisms of cantharidin in HKLs, as well as its implication in the inflammatory process, which could be of interest not only for basic research but also in the aquaculture sector.

Metabarcoding insights into the diet and trophic diversity of six declining farmland birds

Knowledge of feeding ecology of declining species, such as farmland birds, is essential to address their conservation requirements, especially when their habitats are suffering important reductions of trophic resources. In this study, we apply a metabarcoding approach to describe the diet composition of six of the most significant farmland birds inhabiting European cereal pseudo-steppes: little bustard, great bustard, pin-tailed sandgrouse, black-bellied sandgrouse, red-legged partridge, and common quail. We further studied seasonal diet variations (autumn to spring) in all species but the common quail, whose diet was studied during spring and summer. We show that study species´ diets mostly consisted of plants, although in the case of little bustard and great bustard arthropods are also highly relevant. Among arthropods, we found high proportions of thrips, arachnids, and springtails, which were previously unreported in their diet, and some taxa that could be used as antiparasitic food. Moreover, we report that little bustard's diet is the least rich of that of all studied species, and that diet of all these species is less diverse in winter than in autumn and spring. Diet composition of these declining species supports the importance of natural and semi-natural vegetation and landscape mosaics that can provide a wide variety of arthropods, plants, and seeds all year-round.

Antiparasitic Effects of Potentially Toxic Beetles (Tenebrionidae and Meloidae) from Steppe Zones

Arthropods and specifically beetles can synthesize and/or sequester metabolites from dietary sources. In beetle families such as Tenebrionidae and Meloidae, a few studies have reported species with toxic defensive substances and antiparasitic properties that are consumed by birds. Here we have studied the antiparasitic activity of extracts from beetle species present in the habitat of the Great Bustard (Otis tarda) against four pathogen models (Aspergillus niger, Meloidogyne javanica, Hyalomma lusitanicum, and Trichomonas gallinae). The insect species extracted were Tentyria peiroleri, Scaurus uncinus, Blaps lethifera (Tenebrionidae), and Mylabris quadripunctata (Meloidae). M. quadripunctata exhibited potent activity against M. javanica and T. gallinae, while T. peiroleri exhibited moderate antiprotozoal activity. The chemical composition of the insect extracts was studied by gas chromatography coupled with mass spectrometry (GC-MS) analysis. The most abundant compounds in the four beetle extracts were hydrocarbons and fatty acids such as palmitic acid, myristic acid and methyl linoleate, which are characteristic of insect cuticles. The presence of cantharidin (CTD) in the M. quadripunctata meloid and ethyl oleate (EO) in T. peiroleri accounted for the bioactivity of their extracts.

Dietary Phytochemicals as a Potential Source for Targeting Cancer Stem Cells

The tumor microenvironment is composed of various types of cells that lead to tumor heterogeneity. In the middle of these populations, cancer stem cells play a vital role in the initiation and progression of cancer cells and are capable of self-renewal and differentiation processes. These cancer stem cells are resistant to conventional therapy such as chemotherapy and radiotherapy. To eradicate the cancer stem cells in the tumor environment, various natural product has been found in recent years. In this review, we have selected some of the natural products based on anticancer potential including targeting cancer cells and cancer stem cells. Further, this review explains the molecular mechanism of action of these natural products in various cancer stem cells. Therefore, targeting a multi-drug resistant cancer stem cell by natural products is a novel method to reduce drug resistance and adverse effect during conventional therapy.

Entomological Surveillance and Cantharidin Concentrations in Mylabris variabilis and Epicauta rufidorsum Blister Beetles in Slovenia

True blister beetles (genus Epicauta, family Meloidae) produce cantharidin, which can cause toxicosis in humans and animals. Some recent reports suggest that poisoning by the blister beetle has occurred in the Mediterranean part of Slovenia, which has never been reported before. Drought and modern harvesting techniques are thought to increase the likelihood of blister beetle forage contamination and cantharidin intoxication in animals. A survey of fields associated with blister beetle contamination was conducted and the Meloid species present were identified. Entomological surveillance was conducted for Mylabris variabilis and Epicauta rufidorsum. Cantharidin concentrations were also measured in both blister beetle species. Cantharidin concentration in Mylabris variabilis (n = 17) ranged from 0.038 to 0.354 µg/mg (mean 0.151 µg/mg). Cantharidin concentration in Epicauta rufidorsum (n = 36) ranged from 0.055 to 0.341 µg/mg (mean 0.142 µg/mg). Both species exhibited variable concentrations of cantharidin that could not be associated with their biology, sex, age, size, and/or reproductive status. Epicauta rufidorsum have never previously been studied as a possible source of forage contamination, nor have cantharidin concentrations been determined in this species. It is the most likely source of forage contamination due to its abundance in the investigated fields, its swarming activity, and its tendency to reside in the green parts of plants immediately after cutting. Delaying the simultaneous processing and storage of forage after cutting would reduce the likelihood of forage contamination by blister beetles, as they can then retreat to the ground or fly away.

Anticancer Attributes of Cantharidin: Involved Molecular Mechanisms and Pathways

Cancer is a preeminent threat to the human race, causing millions of deaths each year on the Earth. Traditionally, natural compounds are deemed promising agents for cancer treatment. Cantharidin (CTD)-a terpenoid isolated from blister beetles-has been used extensively in traditional Chinese medicines for healing various maladies and cancer. CTD has been proven to be protein phosphatase 2A (PP2A) and heat shock transcription factor 1 (HSF-1) inhibitor, which can be potential targets for its anticancer activity. Albeit, it harbors some toxicities, its immense anticancer potential cannot be overlooked, as the cancer-specific delivery of CTD could help to rescue its lethal effects. Furthermore, several derivatives have been designed to weaken its toxicity. In light of extensive research, the antitumor activity of CTD is evident in both in vitro as well as in vivo cancer models. CTD has also proven efficacious in combination with chemotherapy and radiotherapy and it can also target some drug-resistant cancer cells. This mini-review endeavors to interpret and summarize recent information about CTD anticancer potential and underlying molecular mechanisms. The pertinent anticancer strength of CTD could be employed to develop an effective anticarcinogenic drug.

Antiplasmodial activity of Cocos nucifera leaves in Plasmodium berghei-infected mice

Plasmodium falciparum (P. falciparum) malaria presents serious public health problems worldwide. The parasite´s resistance to antimalarial drugs has proven to be a significant hurdle in the search for effective treatments against the disease. For this reason, the study of natural products to find new antimalarials remains a crucial step in the fight against malaria. In this study, we aimed to study the in vivo performance of the decoction of C. nucifera leaves in P. berghei-infected mice. We analyzed the effectiveness of different routes of administration and the acute toxicity of the extract. Additionally, we determined the suppressive, curative and prophylactic activity of the extract. The results showed that the decoction of leaves of C. nucifera is most effective when administered intramuscularly to mice in comparison to intraperitoneal, subcutaneous and intragastric methods. We also found that organ signs of acute toxicity appear at 2000 mg/kg/day as evidenced by necropsy examination. Additionally, we found that the prophylactic effect of the extract is of 48% inhibition, however, there is no curative effect. Finally, in a 4-day suppressive assay, we found that the extract can inhibit the growth of the parasite by up to 54% at sub-toxic doses when administered intramuscularly.

Arthropod Venom Components and Their Potential Usage

Arthropods comprise a predominant and well-succeeded phylum of the animal kingdom that evolved and diversified in millions of species grouped in four subphyla, namely, Chelicerata (arachnids), Crustacea, Myriapoda (centipedes), and Hexapoda (insects) [...].