Extracts and Terpenoids from Stevia Species as Potential Anthelmintics for Neglected Tropical Diseases Caused by Cestode Parasites.

Cestodes are etiological agents of neglected diseases such as echinococcosis and cysticercosis, which are major public health problems. Antiparasitic treatment relies on a small number of approved drugs, which are often only partially effective, poorly tolerated and require prolonged administration. Thus, the discovery of novel potential treatments is critical. The Stevia genus (Asteraceae) includes species that are recognized as a source of bioactive compounds, with many species associated with medicinal uses. In this study, the cestocidal activity of four South American Stevia species that previously showed antiprotozoal activity was analyzed using a motility assay on the laboratory cestode model, Mesocestoides vogae. The four Stevia extracts showed cestocidal activity, with S. alpina var. alpina as the most active. The sesquiterpene lactones estafietin and eupatoriopicrin were purified from S. alpina var. alpina and S. maimarensis, respectively, and tested on M. vogae. Estafietin showed cestocidal activity, inhibiting parasite viability in a dose-dependent manner, even from the first day of incubation. Consistent with the motility effects, the extract of S. alpina var. alpina and estafietin induced marked alterations in the morphology of the parasite. The results of this report show that Stevia species represent a source of new molecules with potential for the treatment of neglected tropical diseases caused by cestodes.

The spectrum of parasitic infections with emphasis on the clinico-epidemiological characteristics and risk factors among immunocompromised and immunocompetent patients at a university hospital in Northern India.

Introduction: Intestinal parasitic infections pose a substantial threat to public health and are a huge burden to the economic development of a developing country. We aimed to identify the spectrum of intestinal parasitic infections with an emphasis on demographic and clinical characteristics observed among immunocompromised and immunocompetent patients. Materials and Methods: This observational study was performed in the Parasitology section of the Department of Microbiology from January 2022 to July 2022. A total of 2628 stool samples were obtained from patients presenting with chief complaints of abdominal pain, distension, vomiting, and foul-smelling feces. All the clinical and diagnostic data of the patients enrolled in the above-mentioned period were extracted from the ward files, hospital electronic records, and laboratory registers. Result: A total of 2628 stool samples were sent to the Parasitology section of the Department of Microbiology. Out of the above-mentioned samples, 70 (70/2628, 2.66%) samples yielded gastrointestinal parasites on microscopic examination. The mean age of the patients included in our cohort study was 32.53 ± 16.21 years with a male predominance of 72.86% (51/70, 72.86%). The most common gastrointestinal parasite identified from stool samples was Giardia lamblia (61/70, 87.14%). All cases of opportunistic gastrointestinal infection caused by Cryptosporidium spp. (4/70, 5.71%) in our study cohort were found to infest the immunocompromised patients. Conclusion: This study determines the spectrum of intestinal parasitic infections among the immunocompromised and immunocompetent individuals and guides physicians in starting appropriate anti-parasitic treatment along with the instillation of strict hand hygiene techniques.

The anti-echinococcal activity of crocin in mice experimentally infected with Echinococcus granulosus.

Herbal preparations have good medicinal value for potential use as therapeutic agents in cystic echinococcosis. The efficiency of crocin in the case of cystic echinococcosis was investigated, and compared with that of albendazole, one of the few licensed anti-echinococcosis drugs that served as a positive control. Five months after infecting BALB/C mice with E. granulosus sensu lato the experimental group was divided into 7 subgroups containing 10 animals each: 1- Crocin 80 (80 mg/kg), 2- Crocin 40 (40 mg/kg), 3- Crocin 10 (10 mg/kg), 4- Albendazole (200 mg/kg), 5- Crocin 10 (10 mg/kg) +Albendazole (100 mg/kg), 6- Crocin 20 (20 mg/kg) +Albendazole (50 mg/kg), 7- the control (infected and untreated). After two weeks of daily treatment, significant reductions of cysts' weights, sizes, and total numbers concerning the control group were achieved by treatment with crocin 80, crocin 40, crocin 10, crocin 10 + ABZ100, crocin 20+ ABZ50 and ABZ200 (p < 0.05). Moreover, there was no difference concentrations of crocin and those treated with albendazole,. The concentration of bilirubin was higher in the control group than all treated groups with crocin, significantly. However, the ALT activity showeda significant decrease in the crocin 10 group, compared to the crocin 80, crocin 40, crocin 10 + ABZ100, crocin 20 + ABZ50, control groups (p < 0.05). Based on our results, the administration of crocin used at 10 mg/kg concentrations seems a hopeful applicant for the treatment of cystic echinococcosis.

Anthelmintic activity of Stevia multiaristata extract against Echinococcus granulosus sensu stricto.

Cystic echinococcosis is a zoonotic disease caused by the larval stage of the parasite Echinococcus 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, the in vitro and in vivo efficacy of a Stevia multiaristata extract against E. granulosus sensu stricto (s.s.) was demonstrated. Stevia multiaristata extract (100 and 50 µg 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 with S. multiaristata extract during 2 days (100 µg mL−1) and the collapse of the germinal layer was observed in 60 ± 9.3% of cysts treated with 100 µg mL−1 of the S. multiaristata extract during 4 days. The half maximal effective concentration value was 69.6 µg mL−1 and the selectivity index for E. granulosus s.s. cysts was 1.9. In this clinical efficacy study, the treatment of infected mice with the S. multiaristata extract (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 the S. multiaristata extract.

Clinical tolerance and efficacy of anti-parasitic treatment with albendazole in patients with alveolar echinococcosis: long-term follow-up observation in 117 patients.

Alveolar echinococcosis is the most severe worm disease primarily detected in the liver. This study aimed to determine the clinical tolerance and efficacy of albendazole in patients with alveolar echinococcosis, depending on the volume of previous surgical treatment or its absence and the duration of anti-parasitic therapy. We retrospectively (over the last 15 years) analyzed the data of 117 patients, who were divided into 4 groups according to curability: R0 (radical resection), R1+2 (incomplete resection), Nr (unresectable), and Rr (recurrence). All of them received albendazole from 3 months to 11 years, depending on the volume of resection. We evaluated patients' tolerability of albendazole according to the level of hepatic transaminases and blood cell count. The effectiveness of anti-parasitic treatment was evaluated by imaging studies and the absence of serum antibodies. There was no direct relationship between the frequency of adverse reactions and the duration of taking albendazole (r - 0.20229). Adverse reactions were significantly more often observed in unresectable patients (p < 0.01), which is most likely associated with the general serious condition of the patients and with individual drug intolerance. The effectiveness of the anti-parasitic treatment was manifested in the inhibition of tumor development in 88% of patients in group R1+2 and 60% in group Nr. Follow-up of group R0 patients from 3 to 14 years did not reveal new lesions of the liver and other organs. The chance of a complete cure depends on the early detection of a parasitic tumor and can reach 50%.

Ten-year follow-up of the largest oral Chagas disease outbreak. Laboratory biomarkers of infection as indicators of therapeutic failure.

Trypanosoma cruzi uses various mechanisms of infection to access humans. Since 1967, food contaminated with metacyclic trypomastigotes has triggered several outbreaks of acute infection of Chagas disease by oral transmission. Follow-up studies to assess the effectiveness of anti-parasitic treatment of oral outbreaks are rather scarce. Here, we report a 10-year laboratory follow-up using parasitological, serological, and molecular tests of 106 individuals infected in 2007 of the largest known outbreak of orally transmitted Chagas disease, which occurred in Caracas city, Venezuela. Before treatment (2007), specific IgA, IgM and IgG, were found in 71% (75/106), 90% (95/106) and 100% (106/106), respectively, in addition to 21% (9/43) parasitemia, Complement Mediated Lysis (CML) in 98% (104/106) and 79% (34/43) parasitic DNA for PCR. Blood culture detected parasitemia up to 18 months post-treatment in 6% (6/106) of the patients. In 2017, the original number of cases in the follow-up decreased by 46% and due to the country's economic situation, not all the trials could be carried out in the entire population. During follow-up, IgA and IgM disappeared promptly, with IgM persisting in 19% (20/104) of the patients three years after treatment. The anti-T. cruzi IgG remained positive 10 years later in 41% (20/49) of the individuals evaluated. CML remained positive seven years later in 79% (65/82) of the cases. PCR positive cases decreased after treatment but progressively recovered, being positive in 69% (32/46) of the individuals evaluated in 2017. The group of children (under 18 years of age) showed the highest PCR positivity with 76% (26/34) of the cases, but their parasitic load tended to diminish, while in adults the parasitic load regained their initial values. The simultaneous evaluation of serological tests and PCR of the patients allowed us to separate patients among responders and non-responders to the anti-parasitic treatment, and this information prompted us to apply a second anti-parasitic treatment in the group of non-responders. In this population not subjected to the like lihood of re-infection, adult patients were more likely to be non-responders when compared to children. These results suggest that rigorous laboratory follow-up with T. cruzi infectious biomarkers is essential to detect cases of parasite persistence.

Outbreak of trichinellosis related to eating imported wild boar meat, Belgium, 2014.

Trichinellosis is a rare parasitic zoonosis caused by Trichinella following ingestion of raw or undercooked meat containing Trichinella larvae. In the past five years, there has been a sharp decrease in human trichinellosis incidence rates in the European Union due to better practices in rearing domestic animals and control measures in slaughterhouses. In November 2014, a large outbreak of trichinellosis occurred in Belgium, related to the consumption of imported wild boar meat. After a swift local public health response, 16 cases were identified and diagnosed with trichinellosis. Of the 16 cases, six were female. The diagnosis was confirmed by serology or the presence of larvae in the patients' muscle biopsies by histology and/or PCR. The ensuing investigation traced the wild boar meat back to Spain. Several batches of imported wild boar meat were recalled but tested negative. The public health investigation allowed us to identify clustered undiagnosed cases. Early warning alerts and a coordinated response remain indispensable at a European level.