Peppermint (Mentha piperita) and albendazole against anisakiasis in an animal model

Re-evaluation of certain aspects of the EFSA Scientific Opinion of April 2010 on risk assessment of parasites in fishery products, based on new scientific data. Part 1: ToRs1-3

Surveillance data published since 2010, although limited, showed that there is no evidence of zoonotic parasite infection in market quality Atlantic salmon, marine rainbow trout, gilthead seabream, turbot, meagre, Atlantic halibut, common carp and European catfish. No studies were found for greater amberjack, brown trout, African catfish, European eel and pikeperch. Anisakis pegreffii, A. simplex (s. s.) and Cryptocotyle lingua were found in European seabass, Atlantic bluefin tuna and/or cod, and Pseudamphistomum truncatum and Paracoenogonimus ovatus in tench, produced in open offshore cages or flow-through ponds or tanks. It is almost certain that fish produced in closed recirculating aquaculture systems (RAS) or flow-through facilities with filtered water intake and exclusively fed heat-treated feed are free of zoonotic parasites. Since the last EFSA opinion, the UV-press and artificial digestion methods have been developed into ISO standards to detect parasites in fish, while new UV-scanning, optical, molecular and OMICs technologies and methodologies have been developed for the detection, visualisation, isolation and/or identification of zoonotic parasites in fish. Freezing and heating continue to be the most efficient methods to kill parasites in fishery products. High-pressure processing may be suitable for some specific products. Pulsed electric field is a promising technology although further development is needed. Ultrasound treatments were not effective. Traditional dry salting of anchovies successfully inactivated Anisakis. Studies on other traditional processes - air-drying and double salting (brine salting plus dry salting) - suggest that anisakids are successfully inactivated, but more data covering these and other parasites in more fish species and products is required to determine if these processes are always effective. Marinade combinations with anchovies have not effectively inactivated anisakids. Natural products, essential oils and plant extracts, may kill parasites but safety and organoleptic data are lacking. Advanced processing techniques for intelligent gutting and trimming are being developed to remove parasites from fish.

The Inhibitory Effect of Wood Creosote on the Movement of Anisakis Larvae: An Implication for the Treatment of Acute Anisakiasis

INTRODUCTION

Anisakiasis is a common disease in countries such as Japan, where raw or undercooked marine fish are frequently consumed. The disease is caused by accidental ingestion of a live larva of Anisakis in raw or undercooked marine fish. In typical cases, it causes abrupt gastrointestinal symptoms, such as epigastric pain, nausea, and vomiting. According to a published report, the disease was alleviated by oral ingestion of an over-the-counter drug containing wood creosote.

METHODS

We performed an in vitro experiment to elucidate whether wood creosote can inhibit the motor activity of Anisakis larvae, using infrared locomotion tracking and agarose gel penetration techniques.

RESULTS

Our results clearly demonstrate that wood creosote inhibits the motor activity of Anisakis larvae. The concentration of wood creosote used in our experiment is similar to that found in stomach juice when a usual oral dose is taken of the medicine containing wood creosote.

DISCUSSION/CONCLUSION

Our results suggest the potential usefulness of the medicine containing wood creosote in the treatment of acute Anisakis infection of the gastrointestinal tract.

Acute Anisakiasis: Pharmacological Evaluation of Various Drugs in an Animal Model

BACKGROUND

The accidental ingestion of the third larval stage of Anisakis can cause acute clinical symptoms, which are relieved via extraction of the larvae. Although this is a highly effective technique, it can only be practiced when the larvae are found in accessible areas of the gastrointestinal tract, and therefore instead the condition has often been treated using various different drugs.

AIMS

This study evaluates the effectiveness of gastric acid secretion inhibitors (omeprazole and ranitidine), gastric mucosal protectants (sucralfate) and anthelmintics (mebendazole and flubendazole) in treating anisakiasis in Wistar rats.

METHODS

Rats were infected with Anisakis-type I larvae and administered the drugs via a gastric probe. Data were recorded regarding the number of live and dead larvae, their location both within the animal and in its feces, and the presence of gastrointestinal lesions. Additionally, gastric pH was measured and histology performed.

RESULTS

While rats in all experimental groups exhibited lesions; those treated with ranitidine and mebendazole showed significantly fewer lesions (50% and 35% of rats exhibited lesions, respectively). Histological examination of the gastric lesions revealed infection-induced changes, but no significant differences were observed between the treated and untreated rats.

CONCLUSIONS

Mebendazole was found to be most efficacious in preventing gastrointestinal lesions, followed by ranitidine, which was the most effective antacid of those studied. Both these drugs could thus be considered as part of the conservative management of anisakiasis.

Correlation of NHR-48 Transcriptional Modulator Expression with Selected CYP Genes’ Expression during Thiabendazole Treatment of Anisakis simplex (s.l.)?—An In Vitro Study

Anisakis simplex (s.l.) is a complex of three sibling (biological) species of parasitic nematodes of marine mammals, including A. berlandi, A. pegreffii and A. simplex (s.s.). It is characterized by a complex life cycle in which humans can become accidental hosts by consuming dishes made of raw or undercooked fish containing L3 larvae, which in many regions of the world is related to the national or regional culinary tradition. This has spurred scientific efforts to develop new methods for treating the disease, called anisakiasis, and to neutralize invasive L3. Thiabendazole (TBZ) is a wide-spectrum anthelminthic with a higher efficacy than albendazole, a drug whose long-term use induces resistance in many parasitic species. Cytochromes P450 participate in TBZ metabolism, and the expression of their genes is controlled by nuclear hormone receptors (NHR). This study aimed to examine the effects of TBZ on the above-described pathway in invasive larvae of A. simplex (s.l.). The efficacy of TBZ against A. simplex (s.l.) larvae was observed for the first time. Larvae were cultured in vitro for 72 h in a medium containing TBZ at five concentrations from 0.5 to 1.5 mM. However, the survival curves did not significantly differ from each other. This means that all of the concentrations of TBZ had a similar effect on the A. simplex (s.l.) L3 larvae during in vitro culture. Nevertheless, TBZ modified the expression of nhr-48, cyp13a3 and cyp1a1 genes in the L3 of A. simplex (s.l.).

Mentha villosa Hubs., M. x piperita and their bioactives against gastrointestinal nematodes of ruminants and the potential as drug enhancers

Parasitic diseases caused by gastrointestinal nematodes (GIN) are responsible for a major impact on ruminant welfare. Although the available anthelmintics have a safe margin of toxicity to the animals, their indiscriminate use has increased the selection of resistant parasite populations. In this scenario, essential oils (EO) stand out as a promising ecofriendly therapeutic alternative against GIN. The objective of this work was to determine the effect of the EO of Mentha villosa Hubs (MVEO) collected in 2017 and 2018, M. x piperita (MPEO) and their main components, carvone and limonene, against the third stage larvae (L3) of Haemonchus spp. and Trichostrongylus spp. The solutions, including in nanoemulsion preparations, were tested in a range of concentrations using the larval migration inhibition test (LMIT). The EO and carvone were also tested in combination with nitroxynil (NTX) to determine their effect as drug enhancers (additive or synergy). MVEO/2017, MVEO/2018, MPEO and carvone showed 70.6 (73.4 mg/mL), 86.3 (74.9 mL/mL), 95.5 (143.6 mg/mL), and 88.2 % (38.3 mg/mL) efficacy against L3, respectively. Carvone alone had approximately a 3-fold higher efficacy when compared to its concentration in each EO: 68.8 % in MVEO/2017 and 83.9 % in MVEO/2018. Limonene did not show any significant effect on inhibiting L3 migration. The combination of MPEO and NTX, and carvone and NTX showed a statistically significantly (P <  0.05) synergic and additive effect, respectively, when compared to the isolated treatment. The nanoemulsion of MVEO/2017 at 0.367 mg/mL, inhibited L3 migration by 83.1 %, demonstrating to be highly effective (concentration ratio of 1:0.004), when compared to the MVEO/2017 (70.6 % at 73.4 mg/mL) extraction. The in vitro data from the combination of MPEO or carvone plus NTX suggest that these products can be considered for in vivo experiments against the most important GIN of ruminants as drug enhancers, possibly reducing the final concentration of NTX`. The efficacy of carvone was higher (EC₅₀ = 1.96 mg/mL) than its expected efficacy, based on its concentrations on both EO. Therefore, this component does not need the entire EO composition to exert its L3 motility action. The remarkable efficacy demonstrated by the MVEO/2017/nanoemulsion (EC₅₀ = 0.10 mg/mL), supports its potential to be a candidate to the next-generation therapy to alleviate clinical parasite infections and combat GIN resistant populations.

Efficacy of Origanum syriacum Essential Oil against the Mosquito Vector Culex quinquefasciatus and the Gastrointestinal Parasite Anisakis simplex, with Insights on Acetylcholinesterase Inhibition

Developing effective and eco-friendly antiparasitic drugs and insecticides is an issue of high importance nowadays. In this study, we evaluated the anthelminthic and insecticidal potential of the leaf essential oil obtained from Origanum syriacum against the L3 larvae of the parasitic nematode Anisakis simplex and larvae and adults of the mosquito Culex quinquefasciatus. Tests on A. simplex were performed by standard larvicidal and penetration assays, while mosquito toxicity was assessed relying on larvicidal, tarsal contact, and fumigation tests. To shed light on the possible mode of action, we analyzed the oil impact as acetylcholinesterase (AChE) inhibitor. This oil was particularly active on L3 larvae of A. simplex, showing a LC₅₀ of 0.087 and 0.067 mg mL^-1 after 24 and 48 h treatment, respectively. O. syriacum essential oil was highly effective on both larvae and adults of C. quinquefasciatus, showing LC₅₀ values of 32.4 mg L^-1 and 28.1 µg cm^-2, respectively. Its main constituent, carvacrol, achieved larvicidal LC₅₀₍₉₀₎ of 29.5 and 39.2 mg L^-1, while contact toxicity assays on adults had an LC₅₀₍₉₀₎ of 25.5 and 35.8 µg cm^-2, respectively. In fumigation assays, the LC₅₀ was 12.1 µL L^-1 after 1 h and decreased to 1.3 µL L^-1 in 24 h of exposure. Similarly, the fumigation LC₅₀ of carvacrol was 8.2 µL L^-1 after 1 h of exposure, strongly decreasing to 0.8 µL L^-1 after 24 h of exposure. These results support the folk usage of Lebanese oregano as an antiparasitic agent, providing new insights about its utilization for developing new effective and eco-friendly nematocidal and insecticidal products.

Easy Detection and Fast Removal of Gastric Anisakis during Narrow-Band Imaging Endoscopy with L-Menthol Administration

Anisakiasis is a parasitic disease caused by the ingestion of raw or uncooked seafood infected with third-stage larvae of the anisakid nematodes. A 45-year-old Japanese man presented with epigastric pain and itchy skin with rash on his arm, chest, and back after eating vinegar-marinated raw mackerel sushi. He underwent an emergent endoscopic examination using narrow-band imaging (NBI) that revealed two anisakid larvae. NBI showed the larvae more clearly than white light imaging on the cardiac region of the stomach. We sprayed L-menthol on the larvae for stopping their movement and then easily removed them using biopsy forceps. The macroscopic examination and genotype analysis of the specimens revealed the two larvae as belonging to A. simplex sensu stricto. Our case demonstrates the usefulness of endoscopic examination with NBI and of the L-menthol spray in visualizing and immobilizing the larvae for removal.

Efficiency of Target Larvicides Is Conditioned by ABC-Mediated Transport in the Zoonotic Nematode Anisakis pegreffii

Anisakiasis is among the most significant emerging foodborne parasitoses contracted through consumption of thermally unprocessed seafood harboring infective Anisakis species larvae. The efficacy of the currently applied anthelminthic therapy in humans and in model organisms has not proven sufficient, so alternative solutions employing natural compounds combined with chemical inhibitors should be explored. By testing toxicity of the natural monoterpenes nerolidol and farnesol and the conventional anthelminthics abamectin and levamisole in the presence/absence of MK-571 and Valspodar, which inhibit the ABC transporter proteins multidrug resistance protein (MRP-like) and P-glycoprotein (P-gp), we determined the preliminary traits of Anisakis detoxifying mechanisms. We found that Anisakis P-gp and MRP-like transporters have a role in the efflux of the tested compounds, which could be useful in the design of novel anthelminthic strategies. As expected, transporter activation and efflux fluctuated over time; they were synchronously active very early postexposure, whereas the activity of one transporter dominated over the other in a time-dependent manner. MRP-like transporters dominated in the efflux of farnesol, and P-gp dominated in efflux of nerolidol, while both were active in effluxing levamisole. The highest toxicity was exerted by abamectin, a P-gp inhibitor per se, which also elicited the highest oxidative stress in treated Anisakis larvae. We suggest that β-tubulin, observed for the first time as a core element in Anisakis cuticle, might represent an important target for the tested compounds.

Green drugs in the fight against Anisakis simplex-larvicidal activity and acetylcholinesterase inhibition of Origanum compactum essential oil

Anisakiasis is a fish-borne parasitic disease caused by the consumption of raw or undercooked fish, as well as cephalopods, contaminated by third instar larvae (L3) of species belonging to the genus Anisakis (Anisakidae). Origanum compactum is a small herbaceous aromatic plant endemic to Spain and Morocco. In Morocco, the plant is used under infusion to treat heart diseases and intestinal pains or as preservative for foodstuffs. This is the first time that the O. compactum essential oil is tested against the parasitic nematode Anisakis simplex. The phytochemical analysis by GC-MS revealed carvacrol (50.3%) and thymol (14.8%) as the major oil constituents. The essential oil and its major constituents carvacrol and thymol were tested against A. simplex L3 larvae isolated from blue whiting fish (Micromesistius poutassou). A. simplex mortality (%) after 24 and 48 h of treatment at 1 μl/ml was 100%, with a low LD₅₀ compared with other essential oils and extracts, and the penetration in the agar assay was also reduced, if compared with control wells. The oil, as well as its major constituents, demonstrated a dose-dependent larvicidal activity. Inhibition of the enzyme acetylcholinesterase through a colorimetric assay in 96-well plates was used to elucidate the pharmacological mechanism as this enzyme plays a key role in nematodes neuromuscular function. Interestingly, O. compactum essential oil, carvacrol and thymol inhibited the enzyme, confirming that this could be one of the mechanisms involved in the anthelmintic activity. To the best of our knowledge, this is the first time that O. compactum essential oil is reported as a larvicidal agent against A. simplex L3 larvae.

Evaluation of different Mediterranean essential oils as prophylactic agents in anisakidosis

CONTEXT

Anisakis Dujardin 1845 (Anisakidae) nematodes can cause gastrointestinal and allergic diseases when humans eat raw or undercooked seafood containing larvae. There is currently no drug available in the market against this parasitic disease, and the study of plant-derived molecules could be useful in the discovery of effective compounds.

OBJECTIVE

This research assesses the biocidal activity of a range of essential oils (EOs) from some Mediterranean plants against larvae found in the musculature of fresh fish.

MATERIALS AND METHODS

EOs composition was analyzed by gas chromatography-mass spectroscopy. All the EOs were diluted at 5% v/v in olive oil to cover the fish with the solutions for 24 h. The larvae that abandoned the muscle and the larvae obtained from the artificial digestion of the fish were collected. Controls were carried out in parallel. Furthermore, Wistar rats were infected with the live larvae collected from the in vitro trials in order to find any larvae that may have penetrated the gastrointestinal wall.

RESULTS

Between 60.8% and 87.6% of parasites treated with EOs abandoned the fish muscle, and the highest in vitro mortality rate was achieved with oregano EO (53.9%). Rats previously treated with oregano, cumin and Spanish lavender EOs showed no detectable lesions in the digestive tract due to the infection with larvae.

CONCLUSIONS

Oregano (Origanum vulgare L. Lamiaceae), cumin (Cuminum cyminum L. Apiaceae) and Spanish lavender (Lavender stoechas L. Lamiaceae) EOs could be used as promising ingredients in the development of products for the control of anisakiasis.

Natural products: Perspectives in the pharmacological treatment of gastrointestinal anisakiasis

OBJECTIVE

To evaluate the activity of different natural products against L3 larvae of Anisakis type I.

METHODS

Information on investigations into the activity of natural products against the L3 larvae of Anisakis simplex was collected from scientific journals, books, theses and reports via a library and electronic search (using Pubmed, Scopus, Medline, Web of Science and ScienceDirect). The search terms included: natural products, medicinal plants, essential oils, terpenic derivatives, Anisakis, antinematodal activity.

RESULTS

In the literature reviewed numerous papers were found concerning the in vitro and in vivo activity against Anisakis type I of various natural products (plant extracts, essential oils and their major components). Analysis of the results showed that in vitro tests the Melaleuca alternifolia essential oil and the ar-turmerone isolated from Curcuma longa displayed the greatest activity. In vivo, the most active compound was perillaldehyde, the main component of Perilla frutescens essential oil.

CONCLUSIONS

This study shows that some natural products exhibited promising antianisakis properties.