PLGA-PEG-COOH nanoparticles are efficient systems for delivery of mefloquine to Echinococcus multilocularis metacestodes.

Alveolar echinococcosis (AE) is a severe disease caused by the infection with the larval stage of Echinococcus multilocularis, the metacestode. As there is no actual curative drug therapy, recommendations to manage AE patients are based on radical surgery and prophylactic administration of albendazole or mebendazole during 2 years to prevent relapses. There is an urgent need for new therapeutic strategies for the management of AE, as the drugs in use are only parasitostatic, and can induce toxicity. This study aimed at developing a drug delivery system for mefloquine, an antiparasitic compound which is highly active against E. multilocularis in vitro and in experimentally infected mice. We formulated mefloquine-loaded PLGA-PEG-COOH (poly-(lactic-co-glycolic acid)) nanoparticles that exhibit stable physical properties and mefloquine content. These nanoparticles crossed the outer acellular laminated layer of metacestodes in vitro and delivered their content to the inner germinal layer within less than 5 min. The in vitro anti-echinococcal activity of mefloquine was not altered during the formulation process. However, toxicity against hepatocytes was not reduced when compared to free mefloquine. Altogether, this study shows that mefloquine-loaded PLGA-PEG-COOH nanoparticles are promising candidates for drug delivery during AE treatment. However, strategies for direct parasite-specific targeting of these particles should be developed.

Evaluation of the efficacy of albendazole sulfoxide (ABZ-SO)-loaded chitosan-PLGA nanoparticles in the treatment of cystic echinococcosis in laboratory mice.

Albendazole is known as the drug of choice for medical treatment of cystic echinococcosis (CE). Albendazole sulfoxide (ABZ-SO), as the main active metabolite of albendazole, has low efficacy in the disease due to low water solubility and poor absorptivity. PLGA nanoparticles (NPs) enhance the dissolution of poorly soluble drugs, and chitosan (CS) coating enhances oral drug delivery of NPs. In this study, the efficacy of ABZ-SO-loaded CS-PGLA NPs in the treatment of CE was evaluated in laboratory mice. ABZ-SO-loaded CS-PGLA NPs were prepared by nanoprecipitation and characterized by dynamic light scattering method and scanning electron microscopy. Thirty mice were intraperitoneally infected by 1000 protoscoleces of Echinococcus granulosus. Ten months later, the mice were allocated into 3 groups: groups 1 and 2 were treated with ABZ-SO and ABZ-SO-loaded CS-PGLA NPs, respectively, and the mice in group 3 remained untreated as the control group. The drugs were administered by gavage for 45 days at a daily dose of 10 mg/kg. Finally, all mice were opened and the cysts were collected, counted, weighed, and measured separately. The therapeutic effect of ABZ-SO in the number, weight, and volume of the cysts were not statistically significant compared with those in ABZ-SO-loaded CS-PGLA NPs and the control group. However, the therapeutic effect of ABZ-SO-loaded CS-PGLA NPs in the weight and volume of cysts were statistically significant when compared with that in the control group (p ˂ 0.05). In conclusions, this study revealed that ABZ-SO-loaded CS-PGLA NPs could enhance the therapeutic efficacy of ABZ-SO in the treatment of CE in laboratory mice.

Enhanced Oral Bioavailability and Anti-Echinococcosis Efficacy of Albendazole Achieved by Optimizing the "Spring" and "Parachute".

Maximizing the pharmacological efficacy of albendazole (ABZ), an anti-echinococcosis drug, is essential in the long-term treatment of patients with echinococcosis. As a weakly alkaline drug, ABZ has a pH-dependent solubility that decreases dramatically from gastric fluid (pH 1.4) to intestinal fluid (pH 6.5), where it is absorbed. In this study, we endeavored to develop an optimized tablet formulation of ABZ to improve its dissolution and oral bioavailability from two aspects: a faster initial dissolution in the gastric pH condition (i.e., the "spring") and a more prolonged drug supersaturation in the intestinal pH condition (i.e., the "parachute"). To achieve this goal, ABZ-HCl salt was selected first, which demonstrated a higher intrinsic dissolution rate under pH 1.4 compared with the ABZ free base that is used in the commercial product Albenda. Second, by comparing the ABZ supersaturation kinetics under pH 6.5 in the presence of various polymers including poly(vinylpyrrolidone) (PVP), PVP/VA, hydroxypropyl methylcellulose (HPMC), and HPMC acetate succinate (HPMC-AS), HPMC-AS was found to be the most effective crystallization inhibitor for ABZ, likely due to the hydrophobic interaction between ABZ and HPMC-AS in an aqueous environment. The newly designed tablet formulation containing ABZ-HCl and HPMC-AS showed ∼3 times higher oral bioavailability compared with that of Albenda in Beagle dogs. More significantly, the anti-echinococcosis efficacy of the improved formulation was 2.4 times higher than that of Albenda in a secondary hepatic alveolar echinococcosis Sprague-Dawley rat model. The strategy of simultaneously improving the spring and parachute of an oral formulation of ABZ, by using a highly soluble salt and an effective polymeric crystallization inhibitor, was once again proven to be a viable and readily translatable approach to optimize the unsatisfactory oral medicines due to solubility and bioavailability limitations.

Scolicidal and apoptotic activities of albendazole sulfoxide and albendazole sulfoxide-loaded PLGA-PEG as a novel nanopolymeric particle against Echinococcus granulosus protoscoleces.

Treatment failures of human cystic echinococcosis (CE) with albendazole (ABZ) have attributed to its low solubility and poor drug absorption rate, resulting in low drug level in plasma. The scolicidal effects of ABZ-loaded liposome nanoparticles have recently evaluated; however, these particles have several challenges due to their low encapsulated load. This investigation was designed to evaluate and compare in vitro apoptotic activities of ABZ sulfoxide (ABZs) and ABZs-loaded poly(lactic-co-glycolic acid) (PLGA)-PEG against protoscoleces (PSCs). ABZs-loaded PLGA-PEG was prepared by a double-emulsion method (W1/O/W2). Various concentrations of ABZs and ABZs-loaded PLGA-PEG (50, 100, 150, and 200 µg/ml) were experimentally tested against PSC of CE at different exposure times (5, 10, 20, 30, and 60 min). ABZs-loaded PLGA-PEG at concentrations of 150 and 200 µg/ml was able to act at a 100 % scolicidal rate in all exposure times (5 to 60 min), while ABZs at a concentration of 200 µg/ml demonstrated 94, 100, and 100 % mortality rates following 20, 30, and 60 min of exposure times, respectively. The messenger RNA (mRNA) expression of caspase-3 was assessed by semi-quantitative RT-PCR after 15 h of exposure. Caspase-3 mRNA expression was higher in both PSC treated with ABZs and PSC treated with ABZs-loaded PLGA-PEG than that in control groups (P < 0.05). No significant difference was observed between the apoptotic intensity of PSC treated with ABZs and that of PSC treated with ABZs-loaded PLGA-PEG (P > 0.05). DNA fragmentation assay and ultrastructural changes revealed that ABZs and ABZs-loaded PLGA-PEG induced the apoptosis of PSC by activation of caspase-3. The higher permeability and scolicidal rate of ABZs-loaded PLGA-PEG can be addressed as an effectual alternative strategy to improve the treatment of human CE.

In vitro and in vivo treatments of Echinococcus granulosus with Huaier aqueous extract and albendazole liposome.

The aim of this study was to investigate the in vitro and in vivo efficacies of chemotherapy employing albendazole liposome (L-ABZ), Huaier aqueous extract, and a Huaier aqueous extract/L-ABZ combination against Echinococcus granulosus. Protoscolices of E. granulosus were incubated in vitro with the two drugs, either separately or in combination, at the following final concentrations: 2 mg/mL Huaier aqueous extract, 10 µg/mL L-ABZ, and 2 mg/mL Huaier aqueous extract + 10 µg/mL L-ABZ. Huaier aqueous extract and L-ABZ displayed slower protoscolicidal activity when applied separately than when used in combination. The maximum protoscolicidal effect was found with the combination Huaier aqueous extract + L-ABZ. Despite the low Huaier aqueous extract + L-ABZ concentrations used, protoscolex viability dropped rapidly. In vivo studies were performed on mice injected with protoscolices of E. granulosus. Huaier aqueous extract and L-ABZ were administered three times a week for a period of 4 months by the oral route. Huaier aqueous extract in E. granulosus-infected mice was effective. Combined application of both drugs did increase the treatment efficacy. In conclusion, the outcomes obtained clearly demonstrated that in vitro and in vivo treatment with Huaier aqueous extract and L-ABZ is effective against E. granulosus.

Hydatid Disease in Children from Diagnosis to Treatment: A 10-year Single Center Experience

Objective: Hydatid disease caused by Echinococcus granulosus is a parasitic zoonosis and is endemic in Turkey. Clinical manifestations vary and are related to the anatomical location. In this report, we shared the diagnosis, treatment and follow-up of hydatid disease in children with a 10-year experience. Methods: A total of fifty-seven children diagnosed with hydatid disease were analyzed retrospectively from hospital records. Diagnosis was based on clinical, serological and radiological findings. Treatment response was evaluated with clinical, radiological and serological findings. Results: The male/female ratio of 57 cases was 2.4:1 and the mean age was 113.6±45.9 months. The most common presenting complaint was abdominal pain (42.1%). While 22 (38.6%) of the cases had eosinophilia; indirect hemagglutination test positivity was detected in 27 cases (47.4%). Multiple organ involvement was present in 18 cases (31.6%). In patients with multiple organ involvement, the possibility of cysts being located in the abdomen was higher (p=0.005). Of the 50 cases (87.7%), 45 (78.9%) were operated with open surgery and 5 (8.8%) with percutaneous aspiration-injection-reaspiration method for treatment. There were 52 (91.2%) patients who were given albendazole in conservative treatment and the mean duration of treatment was 15.5±17.2 months. There were 10 cases (17.5%) who developed cyst rupture and the symptom duration was shorter than the cases without cyst rupture (p=0.017). Cyst rupture was more common in cases with dyspnea and fluid discharge from the mouth called rock water (p=0.001, p=0.005, respectively). Recurrence was observed in five cases (8.8%) during follow-up. Conclusion: In areas where the disease is endemic, despite prevention and control programs consisting of personal habits and health education, active transmission of hydatid disease is seen in children and continues to be an important public health problem. Hydatid disease should definitely be considered in the presence of suspicious radiological and clinical findings in endemic areas. Controlled clinical studies are required for diagnosis and treatment procedures.

[Clinical effect and safety of liposomal-albendazole and tablet-albendazole for the treatment of human cystic echinococcosis].

OBJECTIVE: To explore and compare the clinical effect and safety of liposomal albendazole (L-ABZ) and tablet-albendazole (T-ABZ) in the treatment of cystic echinococcosis (CE1, CE2, and CE3). METHODS: A total of 269 cases treated with cystic echinococcosis (CE) in Xinjiang Medical University the First Affiliated Hospital from 1998 to 2008 were reviewed. 51 cases were excluded and 218 cases were enrolled in this research by retrospective case-control method. Among 110 cases were treated with L-ABZ and 108 cases were treated with T-ABZ for short-term (3 months) and long-term courses (6 months) respectively. The effects and safety of the two medicines were compared by analyzing the clinical symptoms, imaging check and serologic test results. RESULTS: In short-term effect evaluation, the total effective rates and curative rates of L-ABZ group and T-ABZ group were 77.9% and 49.1% vs 28.4% and 13.9%, respectively. The effects of L-ABZ group was better than that of T-ABZ group, with remarkable difference in total effective rates and curative rates (x2 value was 19.581, 6.877, respectively, P is less than 0.05). In long-term effect evaluation, the total effective rates and curative rates of L-ABZ and T-ABZ group were 81.7% and 49.0% vs 47.6% and 20.6%, respectively. There was significant difference between L-ABZ group and T-ABZ group in total effective rates and curative rates (x2 value was 20.977, 15.049, respectively, P is less than 0.05). In T-ABZ group the short-term curative rates were 50.0% (15/30), 8.8% (8/91) and 33.3% (7/21) respectively in CE1, CE2, and CE3, the short-term total effective rates were 56.7% (17/30), 35.2% (32/91) and 61.9% (13/21) respectively in CE1, CE2, and CE3. The long-term curative rates were 58.3% (7/12), 28.6% (12/42) and 70.0% (7/10) respectively in CE1, CE2 and CE3, the long-term total effective rates were 75.0% (9/12), 69.0% (29/42) and 100.0% (10/10) respectively in CE1, CE2, and CE3. When compared with CE2, differences existed in CE1 (x2 = 24.887, 4.329; P is less than 0.05) and CE3 groups (x2 = 8.860, 5.076; P is less than 0.05) in terms of short-term effects. In L-ABZ group, the short-term curative rates were 47.4% (18/38), 12.2% (12/98) and 61.5% (8/13) respectively in CE1, CE2 and CE3, the short-term total effective rates were 92.1% (35/38), 65.3% (64/98) and 92.3% (12/13) respectively in CE1, CE2 and CE3, the long-term curative rates were 79.3% (23/29), 35.9% (23/64) and 50.0% (3/6) respectively in CE1, CE2 and CE3, the long-term total effective rates were 96.6% (28/29), 84.4% (54/64) and 100% (6/6) respectively in CE1, CE2 and CE3. When compared with CE2, there were significant differences in CE1 (x2 = 19.648, 9.930; P is less than 0.05) and CE3 groups (x2 = 18.880, 3.876; P is less than 0.05) in terms of short-term effect. In L-ABZ and T-ABZ groups, the drug-related adverse effects were 11.1% (12/108) and 12.7% (14/110) respectively without significant difference (x2 = 0.155, P is more than 0.05). CONCLUSION: L-ABZ and T-ABZ were both effective anti-echinococcosis drugs without dominant side-effects. The clinical effect of L-ABZ was better than that of T-ABZ.

[Immunorehabilitation in patients with paecilomycosis-complicated echinococcosis and asthma].

Paecilomycosis is a new type of systemic mycosis caused by different species of fungi of the genus Paecilomyces. Paecilomycosis-complicated echinococcosis and asthma run a severe course. A complication of mycosis is accompanied by secondary immunodeficiency. A good result was obtained in the treatment of ill children by using the fungicide diflucan and the immunomodulator polyoxidonium. In the examinees with paecilomycosis-complicated echinococcosis, secondary immunodeficiency was characterized by a statistical significant reduction in the blood levels of the lymphoid cells CD3+, CD4+, CD8+, CD16+, CD21+, by phagocytosis, a decrease in its quantitative parameters, and an increase in the counts of immunoglobulins and circulating immunocomplexes. To normalize the immune status in patients with paecilomycosis-complicated echinococcosis, it is expedient to postsurgicallyuse fungicides, such as nizoral, diflucan, orungal, mycosyst, and the immunomodulators polyoxidonium and irillen.

The immunotherapy with hMASP-2 DNA nanolipoplexes against echinococcosis in experimentally protoscolex-infected mice.

Cystic echinococcosis (CE), a complex and neglected zoonotic infectious disease, is mainly caused by larval tapeworm Echinococcus granulosus with a worldwide distribution. For CE, an effective drug treatment is not yet available. The present study was conducted to evaluate the efficacy of hMASP-2-based immunotherapy against hydatid cysts by using murine model. Eighteen weeks after infection with 2000 viable protoscoleces intraperitoneally, the infected mice were treated with hMASP-2 DNA nanolipoplexes (pcDNA3.1-hMASP-2) and albendazole respectively. After six weeks treatment, a significant reduction in the weight of cysts was observed both in the pcDNA3.1-hMASP-2 group and albendazole group compared with the untreated group (P < 0.05). The hMASP-2 DNA nanolipoplexes not only inhibited the development of germinal layer, but also induced the extensive degeneration and damage of the germinal layer cells. Furthermore, compared with the untreated group, the number of CD4+T cells and CD8+T cells and the level of serum IFN-γ were significantly increased (P < 0.05). The frequency of PD-1+T-cell subpopulations including CD4+PD-1+T cells and CD8+PD-1+T cells and the level of serum IL-4 were notably decreased (P < 0.05) in the pcDNA3.1-hMASP-2 treatment group. Therefore, the hMASP-2 DNA nanolipoplexes displayed an effective treatment for echinococcosis through inhibiting the development of cysts and up-regulatory T-cell immunity. This new hMASP-2-based immunotherapeutic strategy could be a potential alternative for the treatment of CE, but further studies are recommended to evaluate the full potential of these hMASP-2 DNA nanolipoplexes in the treatment of human CE.

Pharmacokinetics and tissue distribution study of liposomal albendazole in naturally Echinococcus granulosus infected sheep by a validated UPLC-Q-TOF-MS method.

Albendazole (ABZ) is the first-line drug in treating echinococcosis, which is recommended by WHO. To address the poor bioavailability of albendazole, liposomal albendazole was formulated and is available in our hospital for many years. In this study, a sensitive, reliable and accurate UPLC-Q-TOF-MS method was developed and validated for the determination of albendazole and its metabolites, albendazole sulfoxide (ABZSO), albendazole sulfone (ABZSO2) and albendazole-2-aminosulfone (ABZSO2NH2) in naturally echinococcus granulosus (E. granulosus) infected sheep plasma and tissues with mebendazole (MBZ) as the internal standard (IS). Plasma and tissues samples were prepared by protein precipitation method. The separation was performed on an ACQUITY UPLC® BEH C18 column (2.1 × 50 mm, 1.7 µm) with a gradient mobile phase consisting of methanol and water containing 0.1% formic acid at 0.4 mL/min. The detection was performed on a quadrupole time-of-flight (Q-TOF) high-resolution mass spectrometer using positive electrospray ionization (ESI) source with a chromatographic run time of 6.0 min. The detection was operated using target ions of [M + H]+ at m/z 266.096 for ABZ, m/z 282.091 for ABZSO, m/z 298.086 for ABZSO2, m/z 240.081 for ABZSO2NH2 and m/z 296.104 for IS in selective ion mode, respectively. This method was validated in terms of selectivity, linearity, precision, accuracy, recovery, matrix effect, dilution effect, carryover effects, stability, calibration curve and LLOQ. All validation parameter results were within the acceptable range described in guideline for bioanalytical method validation. This method has been successfully applied to the pharmacokinetic study following single and multiple oral dose of 10 mg/kg liposomal albendazole, and tissue distribution study following multiple oral dose of 10 mg/kg, with emulsion albendazole as the reference preparation. The results in the article will provide valuable information for use in clinical applications of liposomal albendazole and also be beneficial for further development of liposomal albendazole in future studies.

[Effect of the liposome albendazole and Huai-Er fungus extract on hepatic infection of Echinococcus granulosus in mice].

OBJECTIVE: To explore the effect of Huai-Er fungus extract (HEF) and liposome albendazole (L-ABZ) on the hepatic infection of Echinococcus granulosus (Eg) in mice, and understand the influence of improved host immunity on postoperative recurrence. METHODS: Female Kunming mice were immune by intraperitoneal injection Eg cyst fluid from sheep, IgG positive mice were divided into drug treatment groups (A, B and C) and control group (D). Mice in group A were administered by gavage with single L-ABZ (75 mg/kg), group B with single HEF (15,000 mg/kg), and group C with combination therapy (L-ABZ 75 mg/kg plus HEF 15,000 mg/kg), once every two days for one week. The protoscoleces were treated with balanced solution for 20 minute and inoculated in the liver by open abdomen of the anesthetized mice. Imitating to an "open sub-adventitial total exocystectomy", protoscoleces outside the cyst led to a reinfection. 72 hours later, groups A, B and C were re-treated for a month. Mice in group D were given with distilled water (0.3 ml per mouse). Group E was set as blank control (n=8). Another 120 IgG positive mice were divided as groups F, G, H and I, and treated in parallel with the groups A, B, C and D respectively; these mice were inoculated with protoscoleces which were treated in advance with 75% alcohol, 20% hypertonic saline, L-ABZ and PBS for 20 min respectively. In 3 months after infection, all the mice were sacrificed to evaluate the efficacy, which covered infection rate, pathological change, spleen index, level of IgG and IgE, CD4+ and CD8+ cells. RESULTS: The recurrence rate in group C (5.7%) was lower than that of groups A (17.1%) and B (24.2%), with hydatid cysts in white colour and nodular, showing degeneration of the germinal and laminated layers. Groups A, B and C showed lower spleen index (A: 3.84+/-0.86, B: 3.95+/-1.01, and C: 3.27+/-0.52), and lower IgE level (A: 0.06+/-0.08, B: 0.07+/-0.08 and C: 0.03+/-0.03) than group D (5.46+/-0.52 and 0.20+/-0.02, respectively) (P<0.05), especially in group C; and also lowerCD8+ in groups A (16.61+/-3.89), B (18.18+/-3.90) and C (15.38+/-2.63) than group D (32.90+/-4.71) (P<0.05), but higher CD4+/CD8+ in groups A (3.21+/-0.70), B (3.05+/-0.66) and C (3.53+/-0.57) than group D (1.57+/-0.26) (P<0.05), especially in group C. The infection rate of mice in group F, Gand H was 0, 0 and 23.1% respectively, and that of group I, 31.2% (P<0.01). CONCLUSION: The combination of HEF and L-ABZ considerably improves the immunity of the hosts and HEF may have a synergetic action to L-ABZ in reducing the recurrence of "sub-adventitial total exocystectomy". 75% alcohol and 20% hypertonic saline show better effect of inactivating protoscoleces than L-ABZ in surgical operation.

[Particular localisation of hydatic disease--sternum]. / Localizare particulara a bolii hidatice la om--sternul.

Bones localization of hydatic disease is extremely rare (0.5-2.5 %). In approximative 50% of the cases of bones hydatidosis, the cysts are localized at spines vertebrae, broad bones and mandible. We present a case of a 38 years old female. The patient related an insidious beginning of symptoms, about 3-4 years before, with anterior chest pain, and 3-4 month before hospitalization, the presence of a sternal tumor, in upper portion of the bone. Clinical examination of the patient showed a sternal tumor, at manubrium, painful at palpation, increased consistency, with local inflammation signs. Also, the patient related pain at sterno-clavicular articulation, increased by left upper limb motions, but without mobility restriction. Biochemical analysis revealed an moderate inflammatory syndrome: blood cell sedimentation speed = 40 mm/h, WBC = 9600/mmc, E = 3%, Hb = 11.8g/100ml, alcaline and acid phosphatase - normal range. Thoracic scan: sternal tumor at manubrium with invasion at sternoclavicular joint and bone destruction. Intraoperative we discovered that the sternal tumor was in fact an hydatic cysts, confirmed by the anatomo-pathological exam; we performed cysts removal and resection of osteitic bone. Postoperative outcome was favorable, with antiparasitic treatment after surgery; no recurrence of the hydatic disease or secondary localization.

Efficiency of flubendazole-loaded mPEG-PCL nanoparticles: A promising formulation against the protoscoleces and cysts of Echinococcus granulosus.

None of the existing drugs can effectively treat the human cystic echinococcosis. This study aimed to improve the efficacy of flubendazole (FLBZ) against the protoscoleces and cysts of Echinococcus granulosus by preparing polymeric FLBZ-loaded methoxy polyethylene glycol-polycaprolactone (mPEG-PCL) nanoparticles. The protoscoleces and microcysts were treated with FLBZ-loaded mPEG-PCL nanoparticles (FLBZ-loaded nanoparticles) and free FLBZ at the final concentrations of 1, 5, and 10 µg/mL for 27 and 14 days, respectively. The chemoprophylactic efficacy of the drugs was evaluated in experimentally infected mice. The nanoparticles were stable for 1 month, with an average size of 101.41 ± 5.14 nm and a zeta potential of -19.13 ± 2.56 mV. The drug-loading and entrapment efficiency of the FLBZ-loaded nanoparticles were calculated to be 3.08 ± 0.15% and 89.16 ± 2.93%, respectively. The incubation of the protoscoleces with the 10 µg/mL nano-formulation for 15 days resulted in 100% mortality, while after incubation with the 10 µg/mL free FLBZ, the viability rate of the protoscoleces was only 44.0% ± 5.22%. Destruction of the microcysts was observed after 7 days' exposure to the FLBZ-loaded nanoparticles at a concentration of 10 µg/mL. The in vivo challenge showed a significant reduction in the weight and number of the cysts (P < 0.05) in the mice treated with the FLBZ-loaded nanoparticles, yielding efficacy rates of 94.64% and 70.21%, correspondingly. Transmission electron microscopy revealed extensive ultrastructural damage to the cysts treated with the FLBZ-loaded nanoparticles. The results indicated that the FLBZ-loaded nanoparticles were more effective than the free FLBZ against the protoscoleces and cysts of E. granulosus both in vitro and in vivo.

The use of tetracycline in anthelmintic baits to assess baiting rate and drug efficacy against Echinococcus multilocularis in foxes.

Anthelmintic (praziquantel) baiting of wild red foxes against Echinococcus multilocularis infection was studied in a highly epizootic suburban area of Otaru, Hokkaido (the northern island of Japan) during the summer and autumn in the years 1999-2004. Acceptance of baits containing the biomarker tetracycline (TC) was evaluated. The prevalence of E. multilocularis infection in foxes before baiting (1999-2000) was 58% (88/153), whereas in the fourth year of bait distribution year (2004), it decreased to 11% (5/45). Analysis of TC marking in the teeth of foxes showed that 39% (77/195) of those captured after baiting were estimated to have consumed baits in the year of capture. Importantly, more juvenile (56%, 49/87) than adult foxes (26%, 28/108) were marked, indicating efficient baiting of juveniles, which tended to have a higher worm burden of E. multilocularis. Of 77 marked foxes, E. multilocularis and Alaria alata (monitored as the second indicator species of deworming) were not detected in 70 (90%) and 76 (99%) foxes, respectively. The results suggest effective deworming by bait consumption. However, it was also demonstrated that 9% of the marked foxes were infected or re-infected after bait consumption, suggesting high infection pressure and the importance of frequent baiting.

Effect of treatment with free and liposomized albendazole on selected immunological parameters and cyst growth in mice infected with Echinococcus multilocularis.

Selected immunological parameters in healthy mice and mice infected with Echinococcus multilocularis and the effect of free and liposomized albendazole (lip.ABZ) upon these parameters in relation to the reduction of parasite growth were investigated over 26 weeks. Proliferative response of splenic T and B lymphocytes, number of CD4+ and CD8+ spleen T cell subpopulations, serum concentration of IFN-gamma and IL-5, and generation of superoxide anion (O2-) by peritoneal macrophages were the chosen parameters. Both drug forms were given to mice at a dose of 10 mg kg(-1) twice a week from week 4 to week 10 post infection (p.i.) (6 weeks in total). The reduction of cyst growth after treatment with ABZ and lip.ABZ was similar up to week 4 after last dose, but the parasitostatic effect of lip.ABZ lasted 4 weeks longer than the effect of free drug. After administration of both drug forms, the proliferative responses of T and B cells were restored, and also the number of CD4+ and CD8+ increased markedly. In lip.ABZ-treated mice, stimulation of mentioned lymphocyte parameters, except that of CD8+ numbers, persisted for longer period than after ABZ therapy, where values peaked at week 12 p.i., then declined more rapidly. A very strong stimulatory effect was seen on B lymphocytes during the period of lip.ABZ administration, although interestingly, numbers of CD8+ cells were higher in free ABZ-treated group. Low concentrations of IFN-gamma (Th1 response) were present in infected, untreated mouse serum. Only moderate IFN-gamma elevation was observed after treatment with free ABZ. A profound increase of its concentration was seen shortly after administration of lip.ABZ, and persisted until the experiment ended. In infected untreated mice, concentration of IL-5 (Th2 response) was highest on week 2 p.i. Significantly more IL-5 was recorded in serum of mice treated with free ABZ treatment than with lip.ABZ from week 12 to 18 p.i. (weeks 2-8 after the last dose). After the initial increase of superoxide anions (weeks 4-11 p.i.), generation of O2- by peritoneal macrophages was gradually inhibited by E. multilcoularis infection. In general, treatment abolished this suppression and macrophages from lip.ABZ-treated mice produced elevated amounts of O2- over a longer period than macrophages from ABZ-treated mice. Our data indicate that anthelmintic potency of ABZ could be increased after incorporation into liposomes, not only because of improved pharmacokinetics and consequent bioavailability, but also because of significant stimulation of Th1-type cytokine IFN-gamma response and effector macrophage functions.

Lipidic matrix of albendazole: an alternative for systemic infections.

Albendazole is a poorly water soluble drug, with low oral bioavailability, used in pharmacological treatment of a systemic disease as hydatid parasitosis. Lipidic matrices of Gelucires (44/14 and 35/02) were developed. After "in vitro" studies, one formulation was chosen for a single dose study in 8 healthy volunteers, with a cross-over and randomised design, taking a commercially available tablet as reference. Drug absorption was followed by albendazole sulphoxide dosage in urine by high pressure liquid chromatography. Neither albendazole nor albendazole sulphoxide were recovered in urine after tablet administration while 0.18% (+/- 0.06) of dose was recovered after lipidic matrix administration in the first 24 hours. Besides ageing control were performed up to 18 months post-elaboration. Lipidic matrix with Gelucire 44/14 was revealed as a promising attempt for oral pharmaceutical form in albendazole systemic treatment.

[Efficacy of albendazole immunoliposome against echinococcosis granulosus in mice].

OBJECTIVE: To evaluate the effect of albendazole immunoliposome (IL-Alb) against Echinococcus granulosus. METHODS: Mice infected with protoscolices of E. granulosus were divided into five groups. Four groups were treated with albendazole (Alb), albendazole liposome (L-Alb), albendazole sulfoxide liposome (L-Albso), and IL-Alb respectively at a dosage of 100 mg (Alb)/(kg.d) x 5 d for 3 courses. The fifth group was established as control. The major criteria for evaluating the effects included a reduction rate of E. granulosus tissue wet weight, histopathological examination of the cysts by both light microscopy and electron-microscopy, and the content of albendazole-sulfoxide in cysts detected by HPLC. RESULTS: The efficacy of albendazole immunoliposome was significantly higher than that of albendazole liposome, and much higher than that of albendazole. The reduction rates of cyst tissue weight of IL-Alb group, L-Alb group and Alb group were 91.5%, 80.3%, 61.2% respectively as compared to control group; the concentration of Albso in cyst tissue of the above groups were 5.15 micrograms/g, 2.18 micrograms/g, 0.76 microgram/g respectively (P < 0.01). The histopathological damages of cysts were also found most severely in the group of IL-Alb. CONCLUSION: Immunoliposome as a targeting carrier may significantly strengthen the therapeutic effect of albendazole on echinococcosis granulosus.

[The experimental chemotherapy of larval alveolar echinococcosis. The search for an optimal regimen of albendazole use]. / Eksperimental'naia khimioterapiia larval'nogo al'veoliarnogo ékhinokokkoza. Poisk optimal'nogo rezhima primeneniia al'bendazola.

The antiechinococcal activity of albendazole resynthesized at the E. I. Martsinovskii Institute of Medical Parasitology and Tropical Medicine was studied on infection models in rats and mouse in different experimental modifications. The efficiency of the therapy was determined in relation to the dose of the drug and its routes administrations, to the single or intermittent daily dose, to the presence or absence of intervals in the treatment regimen, to dosage forms. The trials indicated that albendazole was most active against larval alveolar echinococcosis of mice or cotton rats when it was used with their feed, i.e. through the gastrointestinal tract.

Enhanced chemoprophylactic and clinical efficacy of albendazole formulated as solid dispersions in experimental cystic echinococcosis.

Cystic echinococcosis is a chronic, complex, and still neglected disease. Although albendazole has demonstrated efficacy, only about one-third of patients experience complete remission or cure and 30-50% of treated patients develop some evidence of a therapeutic response. Different strategies have been developed in order to improve the albendazole water solubility and dissolution rate. The aim of the current work was to investigate the chemoprophylactic and clinical efficacy of an albendazole:poloxamer 188 solid dispersion formulation on mice infected with Echinococcus granulosus metacestodes. Albendazole formulated as solid dispersion had greater chemoprophylactic and clinical efficacy than albendazole alone. The improved in therapeutic efficacy could be a consequence of the increase in the systemic availability of albendazole sulfoxide. The work reported here demonstrates that in vivo treatment with albendazole:poloxamer 188 impairs the development of the hydatid cysts. This new pharmacotechnically based strategy could be a suitable alternative for treating cystic echinococcosis in humans.

Povidone-iodine in experimental peritoneal hydatidosis.

The effect of polyvinylpyrrolidone-iodine (PVP-I) on experimental peritoneal hydatidosis was evaluated in this randomized blind controlled study. Seventy-five white, 3-month-old rats were subjected to laparotomy. After the intraperitoneal inoculation of viable scolices, the rats were randomly divided into three groups. Their peritoneal cavities were irrigated with either 1 per cent PVP-I solution (the PVP-I group), hypertonic saline (the HS group) or Ringer's lactate (the control group). Each group was assigned a separate code number; observers blind to the meaning of the code numbers noted all findings during a period of 4 months, after which the rats were killed to allow assessment of the abdominal cavity. The results were decoded after the statistical analyses were completed. The incidence of peritoneal cysts was found to be lower (8.7 per cent) in the PVP-I group compared with the HS (50 per cent) and control (90.9 per cent) groups; the mean number of hydatid cysts per animal was also lower in the PVP-I group compared with the other two groups. We conclude that the scolicidal activity of PVP-I is significantly higher than that of hypertonic saline and that it can be employed as a prophylactic agent against peritoneal hydatidosis.