Surgical removal of intact hydatid cyst is the most effective treatment for hydatid disease. Recurrence of hydatid cyst is mainly due to dissemination of protoscolices (PSCs) rich fluid during the surgical operation. Therefore, preoperative instillation of a scolicidal agent into the cyst is a common practice with adverse side effects of the used drugs. All-trans retinoic acid (atRA) is the physiological mediator of most of the functions of vitamin A, particularly as a cellular differentiation and apoptosis regulating factor. We hypothesized that instillation of atRA could provide an alternative safe scolicidal approach. We tested the scolicidal effects and ultrastructural changes imposed by atRA on human hydatid cyst PSCs in vitro. Freshly isolated hydatid cyst PSCs were subjected to atRA (at 16.7, 1.67, 0.167 µM and 16.7 nM/L). Changes in protoscolices viability (0.1% eosin exclusion) and morphology (scanning and transmission electron microscopy; SEM and TEM) were investigated. Dose-dependent PSCs death within few minutes to 7 days of exposure to atRA was observed. SEM demonstrated ultrastructural damages including rosteller disorganization, loss of hooks and distortion of hooks morphology. TEM revealed loss of the integrity of the internal tissues of PSCs, an increased vacuolization, formation of large lipid droplets in the distal cytoplasm and aberrant, rounded abnormally large sized mitochondria. atRA is a promising alternative to the available synthetic and chemical scolicidal agents. However, in vivo scolicidal activities of atRA and the possible side effects necessitate further studies

Background: Giardia lamblia is one of the most common protozoal infections in human especially children. Metronidazol (MTZ) is the drug of choice for treatment of giardiasis; its chemical composition possesses major threats and is becoming less sensitive. This study aimed to search for natural extracts alternative to MTZ. Methods: In-vivo effects of dichloromethane extracts of ginger and cinnamon in doses of 10 and 20 mg/kg/day separately were studied on 30 experimentally infected albino rats divided into 6 groups (5 rats each). Plant extracts were started on the 6th day post infection for 7 successive days. The study was evaluated by fecal cyst and intestinal trophozoite counts, histopathology, scanning and transmission electron microscopic examinations of the small intestinal mucosa. Results: Ginger and cinnamon caused reduction of fecal cyst and trophozoites counts. Histopathology, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) after exposure to each extract revealed evident improvement of intestinal mucosal damage produced by G. lamblia infection and direct structural injury to the trophozoites. However, these results were more obvious after exposure to cinnamon extracts. Conclusion: We confirmed the potential therapeutic effects of ginger and cinnamon extracts on G. lamblia infection in albino rats as a promising alternative therapy to the commonly used antigiardial drugs