In Vitro/In Vivo Hepatoprotective and Antioxidant Effects of Defatted Extract and a Phenolic Fraction Obtained from Phlomis Tuberosa.

An in vitro/in vivo hepatotoxicity and hepatoprotection evaluation of a defatted extract and a phenolic fraction from Phlomis tuberosa, administered alone and in a carbon tetrachloride (CCl4)-induced metabolic bioactivation model, was performed. The extract and the phenolic fraction were analysed by high performance liquid chromatography (HPLC) to determine the total flavonoid content, to identify flavonoids and to quantify verbascoside. In addition, total polyphenolics in the samples were expressed as gallic acid equivalents. Applied alone, the extract and the fraction (5, 10 and 50 µg/mL) did not show a statistically significant hepatotoxic effect on isolated rat hepatocytes in vitro. In a CCl4-induced hepatotoxicity model, the samples exhibited a concentration-dependent, statistically significant hepatoprotective effect, which was most pronounced at 50 µg/mL for both. The phenolic fraction exhibited a more pronounced hepatoprotective effect compared to the extract. Data from the in vitro study on the effects of the extract were also confirmed in the in vivo experiment conducted in a CCl4-induced hepatotoxicity model in rats. A histopathological study showed that the animals treated with CCl4 and the extract had an unaltered histoarchitecture of the liver. The effects of the extract were the same as those of silymarin.

Antiproliferative and antitumour activity of saponins from Astragalus glycyphyllos on myeloid Graffi tumour.

ETHNOPHARMACOLOGICAL RELEVANCE: Astragalus glycyphyllos L. has been extensively used in Bulgarian folk medicine as an antihypertensive, diuretic, anti-inflammatory, anti-tumour, in cases of cardiac insufficiency, renal inflammation, calculosis, etc. AIM OF THE STUDY: To evaluate the possible in vitro/in vivo anti-proliferative/anti-tumour activity of a purified saponins' mixture (PSM) obtained from the plant. MATERIALS AND METHODS: Viability and proliferative activity of the Graffi myeloid tumour cells was assessed by MTT test. The morphological alterations were visualized and analysed by fluorescent microscopy after intravital double staining. An in vivo model of Graffi tumour bearing hamsters was used to examine the influence of PSM on transplantability, tumour growth, survival and mortality as well as to observe pathomorphological changes. RESULTS: Graffi tumour cells were sensitive to purified saponins' mixture after 24 and 48 h treatment. The treatment induced a statistically significant decrease of the viability/proliferation of the Graffi tumour cells. These effects were concentration- and time-dependent. Fluorescent microscopy studies showed that these antiproliferative effects were connected to the induction of apoptosis. The in vivo study showed the presence of a stromal component, single mononuclear cells in the stroma. Multiple incorrect mitotic figures were observed in the tumour tissue from the control group. Well-formed stroma with accumulation of mononuclear cells and mitotic cells were found in the group, treated with PSM. The tumour weight was decreased in the group, treated with PMS. CONCLUSION: The results indicate that PSM exhibited in vitro/in vivo antiproliferative/anti-tumour effects.

Contact Sensitization to Formaldehyde in Veterinary Medicine - An Unexplored Field in Occupational Health.

BACKGROUND: Veterinary staff and students could be exposed to formaldehyde - a ubiquitous agent, common cause of contact allergy. AIM: To evaluate the incidence of contact sensitization to formaldehyde in exposures in veterinary medicine. SETTINGS AND DESIGN: A cross-sectional study was conducted during July-December 2017. MATERIALS AND METHODS: A total of 206 individuals were included, patch tested with formaldehyde 1.0%/aq - 36 veterinary medicine students, 20 veterinarians, 47 students and 28 trainees of dental medicine, 41 dental professionals, and 35 non-occupationally exposed individuals. RESULTS: The incidence of contact sensitization to formaldehyde among the whole studied population was 48.1%, highest being among the students of veterinary medicine (94.4%) and the veterinarians (85%). With very high significance, the sensitization incidence was higher in the groups of students of veterinary medicine and veterinarians, if compared to the control group (P < 0.001); (P = 0.004), dental professionals (P < 0.001); (P = 0.001), trainees of dental medicine (P < 0.001); (P = 0.005), and students of dental medicine three-fourth year of education (P < 0.001); (P = 0.001). Significantly, higher was the incidence of contact allergy in the control group if compared to those of dental professionals (P = 0.033) and dental students three-fourth year of education (P = 0.028). CONCLUSIONS: The exposure to formaldehyde during the education in veterinary medicine and practice could be an important risk factor for the onset of contact sensitization. Stricter preventive measures are needed to reduce veterinary student's and lecturer's exposures. Equipment of dissection tables with local exhaust ventilation system could reduce the concentration of formaldehyde in the gross anatomy laboratory.

In silico and in vivo studies of Astragalus glycyphylloides saponin(s) with relevance to metabolic syndrome modulation.

Triterpenoids are well known modulators of metabolic syndrome. One of the suggested modes of action (MoAs) involves peroxisome proliferator-activated receptor gamma (PPARγ) binding. In this study we aimed to: (i) evaluate in silico potential metabolites and PPARγ-mediated MoA of the sapogenin of the main saponin present in a purified saponins' mixture (PSM) from Astragalus glycyphylloides; (ii) estimate in silico and in vivo PSM's toxicity; and (iii) investigate in vivo antihyperglycaemic, hypolipidaemic, antioxidant and hepatoprotective effects of PSM. Metabolites and toxicity were predicted using Meteor and Derek Nexus expert systems (Lhasa Limited) and PPARγ binding was investigated using the software MOE (CCG Inc.). PSM's acute oral toxicity was evaluated in mice and the pharmacological effects were assessed in streptozotocin-induced diabetic spontaneously hypertensive rats (SHRs). Liver histopathology was studied as well. PPARγ weak partial agonism was predicted in silico for 24 probable/plausible Phase I metabolites which docking poses were clustered in 12 different binding modes with characteristic protein-ligand interactions. PSM's beneficial effects on the levels of blood glucose, triglycerides, and total cholesterol, on oxidative stress markers and liver histology in diabetic SHRs were comparable to those of the PPARγ ligand pioglitazone. PSM's safety profile was confirmed in silico and in vivo.

Experimental pig yersiniosis to assess attenuation of Yersinia enterocolitica O:8 mutant strains.

An experimental oral pig model was used to assess the pathogenic and immunogenic potential of Yersinia enterocolitica serotype O:8 wild-type strain 8081-L2 and its lipopolysaccharide (LPS) mutant derivatives: a spontaneous rough mutant 8081-R2, strain 8081-DeltawzzGB expressing O-antigen with uncontrolled chain lengths, and strain 8081-wbcEGB expressing semirough LPS with only one O-unit. Microbiological and immunological parameters of the infected pigs were followed from day 7 to 60 postinfection. The wild-type and all LPS mutant strains persisted in the lymphoid tissue of tonsils and small intestines, causing asymptomatic infection without any pathological changes. Although the pig is known as a reservoir of Yersiniae, a precise analysis of pathogenic and immunogenic parameters based on different in vitro tests (hematological response, killing ability of leukocytes and blood sera, antibody response, hydrogen peroxide production by macrophages, classical and alternative pathways of complement activation), revealed significant attenuation in the pathogenicity of the LPS mutant strains but not the loss of immunogenic potential. In comparison with the other strains, strain 8081-DeltawzzGB demonstrated more continuous leucocytosis with monocytosis, higher invasive potential, significant activation of hydrogen peroxide production by macrophages and an effective immunoglobulin G immune response accompanied by relevant histological immunomorphological rearrangements.