Potential effect of methanol leaf extracts from three Podocarpus species on experimental cryptosporidiosis.

Cryptosporidiosis causes diarrhea in both immunocompetent and immunocompromised individuals, with acute manifestations occurring particularly in children and the elderly. Up till now, there is no curative therapy for cryptosporidiosis, so discovery of new classes of drugs are of great importance. This study aimed to examine the effect of methanol leaves extracts of the three Podocarpus species; P. macrophyllus (Thunb.), P. gracilior (Pilg.) and P. elongatus (Aiton) L' Hér. ex Pers and their combination on Cryptosporidium parvum (C. parvum) in experimentally infected mice in comparison with the commercially used drug, Nitazoxanide. As well as spectrophotometric estimation of the total phenolic and flavonoid content of these extracts was done. Results revealed that treatment with these three Podocarpus extracts and their combination showed a significant reduction of the number of C. parvum oocyst shed in the stool of infected mice compared to infected control group and Nitazoxanide- infected treated group at P < 0.001. The combination of the three Podocarpus extracts was the most effective treatment showing the lowest number of oocysts shedding in comparison with other used extracts and Nitazoxanide. Histopathological inspection of sections from ilium and colon displayed signs of improvement after treatment with P. macrophyllus and P. gracilior extracts and more remarkable improvement when the three extracts were combined. It was concluded that the three Podocarpus species extracts used in this study had a promising anti-Cryptosporidium activity especially when they were combined.

Potential effect of methanol leaf extracts from three Podocarpus species on experimental cryptosporidiosis

@#Cryptosporidiosis causes diarrhea in both immunocompetent and immunocompromised individuals, with acute manifestations occurring particularly in children and the elderly. Up till now, there is no curative therapy for cryptosporidiosis, so discovery of new classes of drugs are of great importance. This study aimed to examine the effect of methanol leaves extracts of the three Podocarpus species; P. macrophyllus (Thunb.), P. gracilior (Pilg.) and P. elongatus (Aiton) L’ Hér. ex Pers and their combination on Cryptosporidium parvum (C. parvum) in experimentally infected mice in comparison with the commercially used drug, Nitazoxanide. As well as spectrophotometric estimation of the total phenolic and flavonoid content of these extracts was done. Results revealed that treatment with these three Podocarpus extracts and their combination showed a significant reduction of the number of C. parvum oocyst shed in the stool of infected mice compared to infected control group and Nitazoxanideinfected treated group at P < 0.001. The combination of the three Podocarpus extracts was the most effective treatment showing the lowest number of oocysts shedding in comparison with other used extracts and Nitazoxanide. Histopathological inspection of sections from ilium and colon displayed signs of improvement after treatment with P. macrophyllus and P. gracilior extracts and more remarkable improvement when the three extracts were combined. It was concluded that the three Podocarpus species extracts used in this study had a promising anti-Cryptosporidium activity especially when they were combined.

Complementary Effect of Capparis Spinosa L. and Silymarin With/without Praziquantel on Mice Experimentally Infected with Schistosoma Mansoni.

Schistosomiasis remains to be the most common fibrotic disease resulting from inflammation and deposition of scar tissue around trapped parasitic eggs in the liver. Though chemotherapy eradicates matured worms efficiently and prevents the accumulation of schistosome eggs, fewer effective drugs are directed to reverse the present hepatic fibrosis. Therefore, treatment targeting hepatic fibrosis associated with schistosomiasis remains a challenging proposition. The present study was designed to investigate the potential complementary schistosomicidal and hepatoprotective activities of the methanol extract of Capparis spinosa L. (C. spinosa) with or without praziquantel (PZQ) and compare results with silymarin (Milk thistle), a known hepatoprotective and antifibrotic agent, on induced liver fibrosis by experimental Schistosoma mansoni (S. mansoni) infection. Total polyphenols in the extract were determined using colorimetric assay. C. spinosa L. caused a partial decrease in worm burden; a statistically significant reduction in hepatic and intestinal tissue egg load, what was associated histopathologically with decreasing in both the number and diameter of granulomas, as well as restoring serum aminotransferases (AST & ALT), alkaline phosphatase (ALP) and improving liver albumin synthesis. The best results were obtained in the group of mice treated with C. spinosa L. and PZQ together. Quantitative estimation of total polyphenols content using colorimetric assay showed that C. spinosa L. leaves contain higher concentration of polyphenolic compounds than fruits. It was concluded that C. spinosa L. has a promising hepatoprotective and antifibrotic properties and could be introduced as a safe and effective therapeutic tool with PZQ in the treatment of schistosomal liver fibrosis. Nevertheless further studies on the mechanism of action of C. spinosa L. in chronic liver diseases may shed light on developing therapeutic methods in clinical practice.

Effects of an intravitreal daunomycin implant on experimental proliferative vitreoretinopathy: simultaneous pharmacokinetic and pharmacodynamic evaluations.

Intravitreal daunomycin (D) effectively suppresses cellular proliferation in experimental proliferative vitreoretinopathy (PVR) but has a narrow therapeutic safety range. Studies were undertaken to reduce toxicity of D by preparing a slow-release implant using polysulfone capillary fiber (PCF). Fabrication of the implant involved loading PCF with 1% D in tristearin (w/w), an excipient with diffusion-retardant properties. Two dose levels of the PCF-D device (15 micrograms and 30 micrograms/device) were prepared and sterilized prior to use. To examine the kinetics and efficacy of the device, rabbits were randomized and eyes were implanted as follows: 1) control group (PCF vehicle); 2) PCF-D (15 micrograms/device); 3) PCF-D (30 micrograms/device). Immediately after implantation, all eyes received an intravitreal injection of 2.5 x 10(5) retinal pigmented epithelial (RPE) cells. Thereafter, tractional retinal detachments (TRD) were graded by ophthalmoscopic examination. Also, fluorophotometry scanning from the retina to the anterior chamber was performed to determine the intraocular bioavailability of D. Results showed a therapeutically sustained level of D up to 21 days after device implantation. Midvitreous concentration of D was greater in group 3 than group 2 at all time points examined, indicating a dose-proportional increase in D release. Results of the PVR study showed that by 7 days after treatment, all eyes implanted with the PCF vehicle developed stage 2 TRD or greater; only 1 eye in each of groups 2 and 3 developed stage 2. By 2 weeks, most eyes in groups 2 and 3 remained in stages 1 and 2 with only 2 eyes progressing to stages 3 and 4 TRD. By 5 weeks, all eyes in group 1 showed stages 4 and 5 TRD, while most eyes in groups 2 and 3 remained in stages 1 and 2. The device with 30 micrograms D was more effective in preventing TRD. In conclusion, these data indicate that PCF can reduce the toxicity of D and may be a useful implant for treatment of PVR.