In vitro evaluation of the protoscolicidal effect of Eucalyptus globulus essential oil on protoscolices of hydatid cyst compared with hypertonic saline, povidone iodine and silver nitrate

In vitro and ex vivo protoscolicidal effects of hydroalcoholic extracts of Eucalyptus microtheca on protoscoleces of Echinococcus granulosus sensu stricto: A light and scanning electron microscopy (SEM) study

BACKGROUND

Cystic echinococcosis (CE) is one of the most widespread and important global helminth zoonoses. Treatment relies mainly on surgery and, or percutaneous interventions. However, spillage of live protoscoleces (PSCs) leading to recurrence is a problem during surgery. So, the application of protoscolicidal agents before surgery is required. This study aimed to investigate the activity and safety of hydroalcoholic extracts of E. microtheca against PSCs of Echinococcus granulosus sensu stricto (s.s.) both in vitro and also ex vivo, which is a simulation to Puncture, Aspiration, Injection, and Re-aspiration (PAIR) method.

METHODS

Considering the effects of heat on the protoscolicidal effecacy of Eucalyptus leaves, hydroalcoholic extraction was performed by both soxhlet extraction at 80 °C and percolation at room temperature. The protoscolicidal action of hydroalcoholic extracts was assessed by in vitro and ex vivo assessments. Infected sheep livers were collected from the slaughterhouse. Then, the genotype of hydatid cysts (HCs) was confirmed by sequencing and, isolates were limited to E. granulosus s.s. In the next step, ultrastructural changes of Eucalyptus-exposed PSCs were studied by scanning electron microscopy (SEM). Finally, a cytotoxicity test was conducted by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay to evaluate the safety of E. microtheca.

RESULTS

The prepared extracts by soxhlet extraction and percolation were, successfully exerted strong protoscolicidal effects in both in vitro and ex vivo tests. The results of in vitro assessment indicated that hydroalcoholic extract of E. microtheca prepared by percolation at room temperature (EMP) and hydroalcoholic extract of E. microtheca prepared by soxhlet extraction at 80 °C (EMS) killed all PSCs (100%) at concentrations of 10 and 12.5 mg/mL, respectively. Also, EMP showed 99% protoscolicidal action after 20 min in an ex vivo setting compared to EMS. SEM micrographs confirmed potent protoscolicidal and destructive effects of E. microtheca against PSCs. The cytotoxicity of EMP was tested on the Hela cell line using MTT assay. The value of 50% cytotoxic concentration (CC50) was calculated at 46.5 μg/mL after 24h.

CONCLUSION

Both hydroalcoholic extracts showed potent protoscolicidal activity and, especially EMP produced remarkable protoscolicidal effects compared to the control group.

Chemical composition, antileishmanial, and cytotoxic effects Ferula macrecolea essential oil against Leishmania tropica

Background

The current study was aimed to evaluate the chemical composition, as well as antileishmanial and cytotoxic effects of the essential oil of Ferula macrecolea and its main compound, terpinolene, against promastigotes and amastigotes of Leishmania tropica.

Methods

The chemical composition of the essential oil was analyzed by a gas chromatograph connected to a mass spectrometer (GC/MS). The MTT (3-(4.5-dimethylthiazol-2-yl) - 2.5-diphenyl tetrazolium bromide) assay was used to study the effects of the essential oil and terpinolene against promastigotes while the macrophage model was used for evaluating the effect of F. macrecolea essential oil against amastigotes of L. tropica as well as assessing cytotoxicity. The Griess reaction assay was employed to study the nitric oxide (NO) produced by treating macrophage cells with the essential oil and terpinolene. Furthermore, the effect of the essential oil and terpinolene on plasma membrane permeability and inhibition of infection in macrophages was evaluated.

Results

The main compounds were terpinolene (77.72%), n-nonanal (4.47%), and linalool (4.35%), respectively. The 50% inhibitory concentrations (IC₅₀) of the essential oil, terpinolene, and glucantime against promastigotes were 27.6, 11.6, and 32.8 μg/mL, respectively; however, their IC₅₀ values against amastigotes were 42.3, 19.6, and 56.9 μg/mL, respectively. The 50% cytotoxic concentrations of the essential oil, terpinolene, and glucantime were 471.3, 207.3, and 1165.3 μg/mL, respectively. The production of NO in macrophage cells after treatment with the essential oil and terpinolene was increased in a dose-dependent manner (p < 0.001). The results revealed that by increasing the concentration of the essential oil and terpinolene, the permeability of the parasites' plasma membrane was significantly changed (p < 0.001). The pre-incubation of Leishmania parasites with F. macrecolea essential oil and terpinolene significantly declined the rate of cell infection by 74.8% and 79.4%, respectively (p < 0.001).

Conclusion

The results of the present study indicated that F. macrecolea essential oil, especially its main compound, i.e., terpinolene, has a potent antiparasitic effect on the promastigote and amastigote stages of L. tropica. Considering the advantages of medicinal plant products over their chemical counterparts, it is suggested that in the continuation of this study, the effect of F. macrecolea essential oil, especially terpinolene, on laboratory animals, and in case of high efficiency, in humans be evaluated.

A systematic appraisal of the use of carvacrol-rich plants to treat hydatid cysts

Hydatid cysts occur in the larval stage of Echinococcus granulosus worms in vital organs such as the liver, lung, brain, kidney, heart and spleen. As a result, the formation of these cysts in humans and animals is considered one of the most catastrophic common infections in humans and animals. So far, there is no definitive effective treatment strategy for this disease in humans. Cyst eradication through surgery is the only treatment, which might be difficult or impossible in some cases. The most difficult aspect of cyst removal surgery is recurrence and anaphylactic shock. As a result, many scolicidal medications are ineffective at inactivating the content of hydatid cysts in vivo. Herbal medicines are now considered a potential treatment for the treatment of hydatid cysts due to their effective anti-cystic activities, minimal side effects, and ability to improve immunity. In the present review study, the anti-cystic role of carvacrol as one of the main constituents of the Lamiaceae family on hydatid cyst has been discussed. The results demonstrate that carvacrol-containing essential oils may be utilized as a hydatid cyst inhibitor. This study has also shown the synergistic activity of carvacrol, thymol and other active plant metabolites.

Herbal Medicines against Hydatid Disease: A Systematic Review (2000-2021)

Echinococcosis is a serious public health issue that affects people and livestock all over the world. Many synthetic and natural products have been examined in vitro and in vivo on Echinococcus species but only a few are used clinically, however, they may cause some complications and side effects. To overcome these limitations, new horizons of herbal drugs to cure echinococcosis are opening with every passing day. To summarize the developments during the last 21 years, we conducted this review of the literature to identify medicinal herbs utilized throughout the world that have anti-Echinococcus activity. From 2000 to 2021, data were carefully obtained from four English databases: Science Direct, PubMed, Scopus, and OpenGrey. Botanical name, extraction technique, extract quantities, efficacy, duration of treatment, year of publication, and half-maximal inhibitory concentration (IC50) values were all well noted. Ninety-one published papers, with 78 in vitro and 15 in vivo, fulfilled our selection criteria. Fifty-eight different plant species were thoroughly tested against Echinococcus granulosus. Zataria multiflora, Nigella sativa, Berberis vulgaris, Zingiber officinale (ginger), and Allium sativum were the most often utilized anti-Echinococcus herbs and the leaves of the herbs were extensively used. The pooled value of IC50 was 61 (95% CI 60−61.9) according to the random effect model and a large degree of diversity among studies was observed. The current systematic study described the medicinal plants with anti-Echinococcus activity, which could be investigated in future experimental and clinical studies to identify their in vivo efficacy, lethal effects, and mechanisms of action.

Evaluation of the scolicidal activities of eugenol essential oil and its nanoemulsion against protoscoleces of hydatid cysts

BACKGROUND

Cystic echinococcosis caused by the cestode Echinococcus granulosus remains a serious helminthic zoonosis affecting humans and animals in many endemic developing countries. Surgical intervention is the best management choice, although it is associated with high recurrence rates and serious complications. Also, the commonly used chemotherapeutics exhibited serious side effects. This study aimed to evaluate the protoscolicidal effects of eugenol (Eug) essential oil and its nanoemulsion (Eug-NE) against protoscoleces (PCs) of hydatid cysts in vitro.

METHODS

Eug-NE was prepared and characterized. Their cytotoxicity on macrophages was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. E. granulosus PCs were treated with various concentrations of Eug and Eug-NE at different exposure times. The viability of protoscoleces was evaluated by the eosin exclusion test, and the changes in the morphology of protoscoleces were assessed. Albendazole (ABZ) was used as a positive control.

RESULTS

The cellular cytotoxicity of Eug and Eug-NE on macrophage cells, in minimum and maximum concentrations (0.2 and 1 μl/mL), were nearly negligible ranging from 4.7% to 8.3% and 3.7% to 7.2%, respectively. The results showed highly significant activity of Eug-NE and Eug against hydatid PCs compared to ABZ (P < 0.05). Eug and Eug-NE have similar protoscolicidal effects at all used concentrations. Their highest scolicidal activity (100% mortality rate) was recorded at 1 μl/ml after 30 min incubation (LC50 = 0.298-LC90 = 0.521 and LC50 = 0.309-LC90 = 0.646, respectively). Both formulations showed time- and dose-dependent effects.

CONCLUSIONS

This study suggested the potent scolicidal activities of Eug and Eug-NE as promising alternative scolicidal agents. Future studies are recommended to explore the mechanism of action and treatment response in vivo and clinical settings.

In vivo and in vitro efficacy of crocin against Echinococcus multilocularis

Background

Alveolar echinococcosis (AE) is a fatal zoonosis caused by the larvae of Echinococcus multilocularis. However, current chemotherapy treatment options are based on benzimidazoles [albendazole (ABZ) and mebendazole], which have limited efficacy. Therefore, novel drugs are necessary for the treatment of this disease.

Methods

The anthelmintic effects of crocin were tested on E. multilocularis metacestodes, germinal cells and protoscoleces in vitro. Human foreskin fibroblasts (HFFs) and Reuber rat hepatoma (RH) cells were used to assess cytotoxicity. The in vivo efficacy of crocin was investigated in mice following secondary infection with E. multilocularis. Furthermore, collagen deposition and degradation in host tissues around the metacestodes were evaluated.

Results

In vitro, crocin had a median effective concentration of 11.36 μM against cultured E. multilocularis metacestodes, while it reduced germinal cell viability at a median inhibitory concentration of 10.05 μM. Crocin was less toxic to HFFs and RH mammalian cell lines than to metacestodes. Transmission electron microscopy revealed that crocin treatment resulted in structural damage in the germinal layer. In addition, 60.33 ± 3.06% of protoscoleces were killed by treatment with 10 μM crocin for 7 days, indicating that crocin has a parasiticidal effect. In vivo, the metacestode weight was significantly reduced after the administration of crocin at 50 mg/kg and 100 mg/kg (55.1 and 68.1%, respectively). Metacestode pathology showed structural disruption of the germinal and laminated layers after crocin treatment. The crocin- and ABZ-treated groups presented significant increases in the levels of interleukin (IL)-2 and IL-4. Furthermore, crocin inhibited the expression of matrix metalloproteinases (MMPs) (MMP2 and MMP9) and promoted collagen deposition in the metacestode.

Conclusions

Crocin was demonstrated to exert parasiticidal activity against E. multilocularis in vitro and in vivo, and can be developed as a novel drug for the treatment of AE.

Graphical abstract

Supplementary information

The online version contains supplementary material available at 10.1186/s13071-021-04866-4.

In Vitro Cytotoxicity and Apoptotic Assay of Eucalyptus globulus Essential Oil in Colon and Liver Cancer Cell Lines

PURPOSE

Toxic effects of vegetables have been the subject of numerous investigations in recent years. Eucalyptus globulus of the Myrtaceae family has been traditionally used in the treatment of various infectious disorders. This study aims to assay the potential anticancer effect of Eucalyptus globulus essential oil, in vitro, and compare its cytotoxic effects on cancerous and non-cancerous cell lines.

METHODS

The cytotoxicity of the Eucalyptus globulus essential oil was evaluated in colon cancer cell line SW48, liver cancer cell line HepG2, HEK293t, and skin fibroblast using the MTT assay. We used 5-FU as the control treatment for cancer. The essential oil was diluted by phosphate buffer saline in cell culture.

RESULTS

Eucalyptus globulus essential oil with the concentration of 0.01% did not reduce the cell viability of SW48 (IC50 = 0.2%) and fibroblast cells (IC50 = 5%) after a 48-h treatment period. Eucalyptus globulus essential oil did not also exhibit any toxic effects on HEK293t and HEPG2 cell lines, except in high dose (0.5%) with IC50 = 0.2% for both of the cell lines.

CONCLUSION

Eucalyptus essential oil showed some side effects and might not be safe to use for treatment at high doses (0.5% and 5%). Moreover, the findings of the present study show that eucalyptus essential oil suppressed the proliferation of human colon cancer cells by inducing apoptosis. Eucalyptus essential oil might be a good candidate for the treatment of colon cancer.

Chemical Composition, Apoptotic Activity, and Antiparasitic Effects of Ferula macrecolea Essential Oil against Echinococcus granulosus Protoscoleces

Background: Today, the present protoscolicidals used to minimize the serious risks during hydatid cyst surgery are not completely safe and have various adverse side effects. The present study aimed to evaluate the chemical composition and apoptotic activity of Ferula macrecolea essential oil (FMEO) as well as its in vitro and ex vivo protoscolicidal effects against hydatid cyst protoscoleces. Methods: Gas chromatography/mass spectrometry (GC/MS) analysis was performed to determine the chemical composition of FMEO. Protoscoleces of hydatid cysts were collected from liver fertile hydatid cysts of infected sheep and were then treated with various concentrations of the essential oil (75, 150, and 300 µL/mL) for 5–60 min in vitro and ex vivo. Then, by using the eosin exclusion test, the viability of the protoscoleces was studied. The caspase-3-like activity of the FMEO-treated protoscoleces was also evaluated through the colorimetric protease assay Sigma Kit based on the manufacturer’s instructions. Results: According to GC/MS, the main constituents of the essential oil were terpinolene (77.72%), n-nonanal (4.47%), and linalool (4.35%), respectively. In vitro, the maximum protoscolicidal activity of FMEO was observed at the concentrations of 150 and 300 µL/mL, such that 100% of the protoscoleces were killed after 30 and 20 min of exposure, respectively. Based on the obtained findings, the results demonstrate that FMEO required a longer time to kill protoscoleces ex vivo; after 12 min of exposure to FMEO, only 13.4% of the protoscoleces remained alive. After 48 h of the treatment of protoscoleces, FMEO, in a dose-dependent manner and at doses of 75, 150, and 300 µL/mL, induced the activation of the caspase enzyme by 24.3, 35.3, and 48.3%, respectively. Conclusions: Our findings demonstrate the potent protoscolicidal effects of FMEO in vitro and ex vivo; however, further studies are required to assess the safety and the efficiency of FMEO as a promising scolicidal agent in a preclinical model and clinical setting.

In vitro scolicidal activity of synthesised silver nanoparticles from aqueous plant extract against Echinococcus granulosus

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Silver nanoparticles were biosynthesised using plant extract derived from Piper nigrum, Ziziphus Spina-Christi and Eucalyptus globulus.

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The scolicidal activity of synthesised silver nanoparticles against Echinococcus granulosus has been investigated.

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The Eucalyptus globulus extract exhibits outstanding activity comparing to Piper nigrum and Ziziphus Spina-Christi plant extracts.

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Silver nanoparticles exhibited reasonably results compared to that obtained from treatment with 10 μg/mL of Albendazole.

At present, biosynthesis of AgNPs is a very effective method to produce less toxic nanoparticles. The vision of this research is to use three different plant extracts derived from leaves of Piper nigrum, Ziziphus Spina-Christi and Eucalyptus globulus for rapid biosynthesis of AgNPs. This is in addition to investigating the scolicidal activity against Echinococcus granulosus. The methods of UV–vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDX) were employed to characterise the nanoparticles. UV spectra disclosed a maximum absorption at 437 nm for the biosynthesised AgNPs using EUCGLO extract. The XRD patterns revealed the (fcc) structure of the AgNPs with slightly shifted characteristic peaks at 2θ degree of 37.3˚ and 43.4˚, respectively. The scolicidal activity against E. granulosus revealed that the AgNPs, which were synthesised using Eucalyptus globulus, have powered scolicidal of 47.8 % after 45 min. which is comparable to the treatment by Albendazole.

A systematic review of medicinal plants used against Echinococcus granulosus

Cystic echinococcosis (CE) is a zoonotic helminthiasis caused by different species of the genus Echinococcus, and is a major economic and public health concern worldwide. Synthetic anthelmintics are most commonly used to control CE, however, prolonged use of these drugs may result in many adverse effects. This study aims to discuss the in vitro/in vivo scolicidal efficacy of different medicinal plants and their components used against Echinococcus granulosus. Google Scholar, ScienceDirect, PubMed and Scopus were used to retrieve the published literature from 2000-2020. A total of 62 published articles met the eligibility criteria and were reviewed. A total of 52 plant species belonging to 22 families have been reported to be evaluated as scolicidal agents against E. granulosus worldwide. Most extensively used medicinal plants against E. granulosus belong to the family Lamiaceae (25.0%) followed by Apiaceae (11.3%). Among various plant parts, leaves (36.0%) were most commonly used. Essential oils of Zataria multiflora and Ferula asafetida at a concentration of 0.02, and 0.06 mg/ml showed 100% in vitro scolicidal activity after 10 min post application, respectively. Z. multiflora also depicted high in vivo efficacy by decreasing weight and size while also causing extensive damage to the germinal layer of the cysts. Plant-based compounds like berberine, thymol, and thymoquinone have shown high efficacy against E. granulosus. These plant species and compounds could be potentially used for the development of an effective drug against E. granulosus, if further investigated for in vivo efficacy, toxicity, and mechanism of drug action in future research.

Evaluation the Effects of Eucalyptus Essential Oil and Hypertonic Saline as Scolicidal Agents in Induction of Sclerosing Cholangitis in Rabbits

Background

There are several scolicidal agents for inactivation of hydatid cyst protoscolices during surgery, but most of them are associated with adverse side effects such as sclerosing cholangitis (SC) and liver necrosis. The present study aimed to evaluate the adverse effects of Eucalyptus essential oil to induce SC in animal models.

Materials and Methods

Eighteen rabbits weighting 2000-3500 g were included in three groups for this study. About 0.3 ml of Eucalyptus essential oil (1%), or 5% hypertonic saline, or normal saline was injected for 5 min in the gallbladder. After 4 months, the liver, common bile duct, and duodenum were resected and immediately sent for cholangiography and pathologic studies.

Results

According to pathological studies, inflammation is more common in Eucalyptus and hypertonic saline groups. Due to cholangiographic studies, stricture was slightly higher in the hypertonic saline group than the Eucalyptus group.

Conclusion

Thus, 1% Eucalyptus essential oil is at least as safe as 5% hypertonic saline, but for clinical uses, it must be confirmed with further studies.