RESUMO
Layered VOPO4·2H2O is synthesized by the sonochemical method. An X-ray powder diffraction is used to examine the crystal structure, while scanning electron microscopy is used to reveal the morphology of the powder. The crystal structure refinement is performed in the P4/nmmZ space group. The electrochemical intercalation of several cations (Na+, Mg2+, Ca2+, and Al3+) in saturated nitrate aqueous solutions is investigated. The most notable reversible activity is found for the cycling in aluminium nitrate aqueous solution in the voltage range from -0.1 to 0.8 V vs. SCE. During the preparation of the electrode, it is observed that the structure is prone to changes that have not been recorded in the literature so far. Namely, the use of conventional binder PVDF in NMP solution deteriorates the structure and lowers the powder's crystallinity, while the use of Nafion solution causes the rearrangement of the atoms in a new crystal form that can be described in the monoclinic P21/c space group. Consequently, these structural changes affect electrochemical performances. The observed differences in electrochemical performances are a result of structural rearrangements.
RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: One of the commonly prescribed 'anti-diabetic' polyherbal mixtures by European herbalists is made of Rubus fruticosus and Vaccinium myrtillus leaves, Potentilla erecta roots, Geum urbanum aerial parts and Phaseolus vulgaris pods. AIM OF THE STUDY: This study aimed to evaluate the phytochemical composition, antioxidant capacity, potential toxicity, hypoglycemic, hypolipidemic, nephroprotective and hepatoprotective activities of this polyherbal mixture decoction. MATERIALS AND METHODS: The phytochemical composition was evaluated using HPLC-UV. The antioxidant activity was assessed using the DPPH test. Potential toxicity was evaluated using the acute and sub-chronic oral toxicity method. Diabetes was induced in Wistar female rats with a single intraperitoneal injection of alloxan monohydrate (150â¯mg/kg). The animals whose blood glucose was >20â¯mmol/L for 14 consecutive days were considered diabetic. For the next 14 days, D-10 and D-20 groups were treated with the polyherbal mixture (10 and 20â¯g of dry plant material/kg, respectively). I and M were control groups treated with insulin glargine (13 IU/kg) and metformin (150â¯mg/kg), respectively. Healthy control (HC) and diabetic control (DC) groups were treated with water. The blood glucose level was measured on days 14, 21 and 28. Lipid profile analysis was done on day 28. Pancreas, kidney and liver histopathology was evaluated using the H&E and Masson's trichrome staining. The liver tissue was additionally tested for PAS-positive cells. RESULTS: The HPLC-UV analysis revealed the presence of quinic, gallic and caftaric acid, arbutin, rutin, trifolin, astragalin, hyperoside, isoquercetin and quercitrin. The antioxidant activity of the extract was higher than the reference's one (pâ¯<â¯0.01). Treatment with the polyherbal mixture (10 and 20â¯g/kg) has shown no toxic effects. No major decline in blood sugar was recorded in I and M groups compared to the DC one (22.86⯱â¯2.58, 28.5⯱â¯0.42 and 27.82⯱â¯0.9â¯mmol/L, respectively). The polyherbal mixture lowered the blood glucose level to the normal value (8.64⯱â¯4.09, 5.26⯱â¯1.3 and 6.76⯱â¯1.54â¯mmol/L in D-10, D-20 and HC groups, respectively). Furthermore, it decreased the levels of total cholesterol, triglycerides, VLDL, LDL, atherogenic and cardiovascular risk indices (pâ¯<â¯0.001) compared to the DC group. In addition, the extract restored histopathological changes of the pancreas, kidneys and liver to the healthy animal level. CONCLUSION: Treatment with the polyherbal mixture extract was more effective than the standard drugs (insulin and metformin) in the amelioration of hyperglycemia, hyperlipidemia, and histopathological changes of the pancreas, kidney and liver tissue.