Clara María Albani

Purpose Cystic echinococcosis is a parasitic zoonosis caused by the larval stage of Echinococcus granulosus sensu lato. Albendazole (ABZ) is the drug of choice, although its efficacy is variable. The present research aimed to assess the in vitro and in vivo efficacy of a full-spectrum extract of Cannabis sativa inflorescences against E. granulosus sensu stricto (s.s.). Methods Protoscoleces and cysts were incubated in vitro with the C. sativa extract, achieving final CBD concentrations of 1, 5, 10, and 50 µg/ml. Viability was evaluated periodically. Structural and ultrastructural alterations were also recorded. For the clinical efficacy study, female CF-1 mice were infected. Six months later, mice were divided into groups (n = 10): (a) water control; (b) ABZ; (c) C. sativa extract, and (d) ABZ + C. sativa extract. Treatments were administered every 24 h for 30 days. The efficacy of the treatments was evaluated according to the weight of the cysts collected and the ultrastructural alterations observed. Results The C. sativa extract caused a significant decrease in the viability of protoscoleces and cysts in vitro. The greatest effect was observed with 50 µg/ml, which generated the reduction in protoscoleces viability to 0% between 6 and 24 h post-incubation (pi) and the collapse of 92 ± 13% of the cysts after 24 h pi. All the in vivo treatments reduced the weight of the cysts and caused ultrastructural alterations, especially the combination of ABZ + C. sativa extract. Conclusion We demonstrated the in vitro and in vivo efficacy of a full-spectrum extract of C. sativa inflorescences against E. granulosus s.s.

The larval stage of the parasite Echinococcus granulosus sensu lato (s.l) is responsible for cystic echinococcosis (CE), a long-term infection affecting humans and animals worldwide, and constitutes a serious public health concern. If left untreated, CE can cause serious damage to multiple organs, especially the liver and lungs. Regarding the treatment, in the last few years, the use of pharmacological treatment has increased, suggesting that in the future, drug therapy may replace surgery for uncomplicated cysts. However, the only available anthelmintic drug to treat this infection is the albendazole, which has an efficacy that does not exceed 50%. On the basis of the above-mentioned evidence, new and improved alternative treatments are urgently needed. The use of natural products and their active fractions and components holds great promise as a valuable resource for the development of novel and effective therapies. Hop (Humulus lupulus L.) is a bittering agent in the brewing industry for which the sedative, digestive, anti-inflammatory, and antimicrobial effects have been reported. The purpose of this study was to assess the in vitro efficacy of methanolic extracts from the leaves of hop varieties against E. granulosus sensu stricto (s.s) protoscoleces. Varieties Mapuche and Victoria caused a stronger protoscolicidal effect compared to the Bullion, Cascade, and Traful varieties ( ), coinciding with their highest content of flavonoids, total polyphenols, and saponins. The viability of protoscoleces treated with the varieties Mapuche and Victoria decreased to approximately 50% at days 5 y 8, respectively, showing alterations such as soma contraction and impaired microtriches. After 18 days of treatment with both varieties, protoscoleces were completely altered both structurally and ultrastructurally. In conclusion, the methanolic extracts of the H. lupulus varieties Mapuche and Victoria demonstrated a marked in vitro effect against E. granulosus s.s. protoscoleces. The beer-making industry exclusively uses hop cones, leaving behind large amounts of hop leaves as an agricultural by-product that is not being utilized. On the basis of our study, we propose that hop leaves could also be used as a source of secondary metabolites with anthelmintic activity.

Cystic echinococcosis is a global parasitic zoonosis caused by infection with the larval stage of Echinococcus granulosus sensu lato. Cystic echinococcosis affects more than 1 million people worldwide, causing important economic costs in terms of management and livestock associated losses. Albendazole is the main drug used in treating human cystic echinococcosis. In spite of this, its low aqueous solubility, poor absorption, and consequently erratic bioavailability are the cause of its chemotherapeutic failures. Based on the described problem, new treatment alternatives urgently need to be developed. The aim of the present research was to study the in vitro and in vivo efficacy of cannabidiol (CBD), the second most abundant component of the Cannabis sativa plant, was demonstrated against E. granulosus sensu stricto. CBD (50 µg/mL) caused a decrease in protoscoleces viability of 80 % after 24 h of treatment which was consistent with the observed tegumental alterations. Detachment of the germinal layer was observed in 50 ± 10% of cysts treated with 50 µg/mL of CBD during 24 h. In the clinical efficacy study, all treatments reduced the weight of cysts recovered from mice compared with the control group. However, this reduction was only significant with ABZ suspension and the CBD + ABZ combination. As we could observe by the SEM study, the co-administration of CBD with ABZ suspension caused greater ultrastructural alteration of the germinal layer in comparison with that provoked with the monotherapy. Further in vivo research will be conducted by changing the dose and frequency of CBD and CBD + ABZ treatments and new available CBD delivery systems will also be assayed to improve bioavailability in vivo.

Cystic echinococcosis is a zoonotic disease caused by the parasite Echinococcus granulosus sensu lato (s.l.), which is worldwide distributed and causes long-lasting infections in animals and humans. The existing treatment is limited to the use of benzimidazoles, mainly albendazole (ABZ). However, it has unwanted side effects and its efficacy is about 50. The Asteraceae family includes plants that have therapeutic applications (medicinal species) and has an important role in new drug development. The species belonging to a different genus of this family show a wide range of anti-inflammatory, antimicrobial, antioxidant, hepatoprotective, and antiparasitic activities, among others. The aim of the present study was to evaluate the in vitro efficacy of extracts of four Asteraceae species against protoscoleces of E. granulosus sensu stricto (s.s.). On the other hand, the Stevia aristata extract was assessed on the murine cyst of E. granulosus (s.s.) and the efficacy of S. aristata extract was investigated in a murine model of CE. Stevia satureiifolia, S. aristata, Grindelia pulchella, and G. chiloensis extracts at 100μg/mL caused a decrease in protoscoleces viability; however, S. aristata extract produced the greatest in vitro protoscolicidal effect. After 20 days of treatment with the highest concentration (100μg/mL) of S. aristata extract, protoscoleces viability decreased to 0. The tegumental changes observed by scanning electron microscopy were consistent with the reduction in vitality. The collapse of the germinal layer was registered in 60±5.8 and 83.3±12.0 of cysts treated during 4 days with 50 and 100μg/ml, respectively. The half maximal effective concentration (EC50) value of the S. aristata extract against E. granulosus (s.s.) cysts was 47.86μg/mL (96h). The dosage of infected animals with the 50mg kg⁻¹ dose of S. aristata extract resulted in a significant reduction in cyst weight in comparison with the control group. In conclusion, S. aristata extract was demonstrated to exert a marked effect, both in vitro and in the murine model.

Cystic echinococcosis is a zoonotic disease caused by the larval stage of the parasiteEchinococcus granulosus sensu lato. The available anti-parasitic treatment is mostly limited to a continuous administration of albendazole. However, due to its numerous side-effects and efficacy of around 50%, there is a need to find new drugs to improve the treatment for this disease. In the current study, thein vitroandin vivoefficacy of aStevia multiaristataextract againstE. granulosus sensu stricto(s.s.) was demonstrated.Stevia multiaristataextract (100 and 50μg mL⁻¹) caused a quick viability decrease on protoscoleces which was consistent with the observed tegumental alterations. Loss of turgidity was detected in 95 ± 3.4% of cysts incubated withS. multiaristataextract during 2 days (100μg mL⁻¹) and the collapse of the germinal layer was observed in 60 ± 9.3% of cysts treated with 100μg mL⁻¹of theS. multiaristataextract during 4 days. The half maximal effective concentration value was 69.6μg mL⁻¹and the selectivity index forE. granulosus s.s.cysts was 1.9. In this clinical efficacy study, the treatment of infected mice with theS. multiaristataextract (50 mg kg⁻¹) caused a significant decrease in the weight of the cysts compared with the control group. These results coincided with the tissue damage observed in the cysts at the ultrastructural level. In conclusion, we observed high protoscolicidal and cysticidal effects, and significant reduction in the weight of the cysts in experimentally infected mice following treatment with theS. multiaristataextract.

Human cystic echinococcosis remains a major public health problem on several countries and the treatment strategies are not solved. The aim of the present work was to determine the in vitro effect of thymol andMentha piperita,M. pulegium,andRosmarinus officinalisessential oils on the proliferation ofE. granulosuslarval cells. Isolated cells and cellular aggregates were obtained from hydatid cyst’s germinal layer and exposed to 1, 5, and 10 μg/ml of thymol and the different essential oils for 7 days. Drug effect was evaluated using test viability and scanning electron microscopy. Control cell culture viability was 2.1 x 10⁶(100%) after 7 days of incubation. At day 7, thymol 5 μg/ml caused a reduction in cell viability of 63% and the essential oils ofM. piperita10 μg/ml,M. pulegium10 μg/ml, andR. officinalis10 μg/ml produced a reduction in the viability of 77, 82, and 71%, respectively. Moreover essential oils caused reduction in cell number, collapsed cells, and loss of normal tridimensional composition of the aggregates. Due to the inhibitory effect caused by essential oils onE. granulosuscells we suggested that it would be an effective means for suppression of larval growth.