A zinc anode in acidic media is a new oscillatory electrochemical system which manifests interesting behaviors, from steady states to simple oscillations and chaos. This paper presents an experimental study of the influence of metal ions on the shape, amplitude and duration of the cell potential oscillations, and gives a qualitative explanation of the system's behavior. A small quantity of Cu2+, Zn2+ or Fe3+ ions added to the system change dramatically the potential oscillations from chaotic behavior to simple oscillations. The method may be used for chaos attenuation.

Four new methods are described for the determination of ranitidine hydrochloride (RNH) in bulk drug and in formulations employing titrimetric and spectrophotometric techniques and using potassium dichromate as the oxidimetric reagent. In titrimetry (method A), RNH is treated with a measured excess of dichromate in acid medium, and the unreacted oxidant is back titrated with iron (II) ammonium sulfate. The three spectrophotometric methods are also based on the oxidation of RNH by a known excess of dichromate under acidic conditions followed by the determination of surplus oxidant by three different reaction schemes. In one procedure (method B), the residual dichromate is treated with diphenylcarbazide and the absorbance measured at 540 nm. Calculated amount of iron (II) is added to residual dichromate and the resulting iron(III) is complexed with thiocyanate and measured at 470 nm (method C). Method D involves reduction of unreacted dichromate by a calculated amount of iron (II) and estimation of residual iron (II) as its orthophenanthroline complex after raising the pH, and measuring the absorbance at 510 nm. In all the methods, the amount of dichromate reacted corresponds to the drug content. The experimental conditions are optimized. The titrimetric procedure is applicable over 5-10 mg range. In spectrophotometric methods, Beer’s law is obeyed in the ranges 5-50, 5-80, and 10-100 μg ml-1 for method B, method C, and method D, respectively. The methods were validated for accuracy, precision and recovery. The proposed methods were applied to the analysis of RNH in the tablet and the injection forms, and the results were in agreement with those obtained by the reference method.

Background and purpose: Kidney diseases impose significant global health challenges. potassium dichromate (PD) is a heavy metal frequently associated with nephrotoxicity. PD prompts oxidative and inflammatory injuries in renal tissues. L-carnitine is a naturally-occurring amino acid commonly used as a supplement. Experimental approach: Forty rats were randomly allocated into 5 groups. Group 1 (normal) received only saline. Nephrotoxicity was induced in the remaining groups by PD (15 mg/kg,i. p). Group 2 served as a nephrotoxic group. Groups 3-5 received L-carnitine (25, 50, and 100 mg/kg,p. o. ), respectively for 4 weeks. Findings/Results: PD administration resulted in elevated serum creatinine and blood urea nitrogen accompanied by diminished reduced glutathione and elevated malondialdehyde, tumor necrosis factor-alpha, , and transforming growth factor-beta renal tissue contents relative to normal rats. PD also produced apoptotic histopathological injuries and down-regulated PI3K/Akt signaling pathway,signifying ongoing apoptosis. In the current work, L-carnitine use in the selected dose levels resulted in improvement of all the aforementioned serum, renal tissue, and histological parameters relative to nephrotoxic rats. L-carnitine up-regulated PI3K/Akt signaling pathway that was down-regulated post PD use. Conclusion and implications: Collectively, the study highlighted that the possible mechanisms beyond the beneficial effects of L-carnitine are mainly through its antioxidant as well as anti-inflammatory actions. Lcarnitine significantly abrogated apoptosis via up-regulation of PI3K/Akt signaling pathway and signified restoration of normal renal cell proliferation and functionality.

Chromium, which enters the river through anthropogenic sources, is one of the potent heavy metals. The present study is an attempt to determine the LC50 of potassium dichromate for the climbing perch, Anabas testudineus and to study the impact of two sub-lethal concentrations (6 and 12 mg/l) of potassium dichromate the toxic hexavalent Cr(VI) form of Chromium on this fish through investigating hematological and histopathological parameters. Experimental set up included quadruplicate treatments for each dosage, and the results were compared with control treatments. The results showed that the LC50 value at 96 hr was 59. 92 mg/l. The fishes exposed to sub-lethal concentrations showed severe abnormalities such as; degeneration of hepatocytes, necrosis of hepatic tissue and extensive haemorrhage in gills and renal tissue. The present study brings out the harmful impact of Cr(VI) in the aquatic environment and necessitates regulations of its inflow to natural water bodies as a management plan to curb its contamination.

Background and Objective: potassium dichromate, which is a form of hexavalent chromium, has been demonstrated to induce toxicity associated with oxidative stress in humans and animals. Thymoquinone (TQ) isolated from Nigella sativa has a wide spectrum of activities such as antioxidant, anti-inflammatory and anticancer effects. This study aimed to evaluate the protective effect of thymoquinone in an animal model of brain damage caused by potassium dichromate in the mouse.Materials and Methods: In this study, mice were divided into 5 groups: control, control treated with 5 mg/kg thymoquinone, potassium dichromate, and potassium dichromate treated with 1 or 5 mg/kg thymoquinone. To induce neuronal injury, 0.5 mg/kg potassium dichromate was intranasally and daily administrated for two months. Thymoquinone was given orally and daily for seven weeks. After two months, activity of catalase (CAT), level of malondialdehyde (MDA), glutathione (GSH) and nitrite (Nit), and number of neurons in the parietal cortex were evaluated. Data analysis was conducted using one-way ANOVA and Tukey post-test with p<0.05 as significant.Results: potassium dichromate significantly lowered activity of CAT and elevated levels of MDA and Nit, reduced GSH level and decreased neuronal density in the parietal cortex. Treatment with 5 mg/kg thymoquinone significantly increased activity of CAT and reduced MDA level, elevated level of GSH and also prevented reduction of neuronal density in the parietal cortex.Conclusion: Thymoquinone administration can lower oxidative stress and brain injury following potassium dichromate.

Background: Chromium and its salts, as well as chromium-containing compounds, play a major role in numerous manufacturing processes and have been contraindicated in carcinogenic, toxic, and mutagenic conditions in people involved in these processes. Objectives: This study investigated the ameliorative role of Acacia nilotica aqueous leave extract (ANLA) on potassium dichromate-induced liver and blood toxicity in male and female rats. Phytochemical screening and nutrient composition of ANLA were also evaluated. Methods: Phytochemical and proximate analysis of ANLA were carried out. Twenty adult male and female rats each were divided into four groups (n = 10): (1) control; (2) potassium dichromate (PDC; 0. 625 mg/kg body weight); (3) PDC co-treated with ANLA after seven days (650 mg/kg bwt); and (4) PDC co-treated with ANLA (650 mg/kg bwt) simultaneously for 21 days. Biomarkers of liver injury, lipid, and hematological imbalance were assessed. Tissue histology and toxicant retention were done. Results: Various plant secondary metabolites (flavonoids, terpenoids, tannins, phenols, saponins, cardiac glycosides, alkaloids, and anthraquinones) and nutrients (protein = 67. 41 ± 2. 44%; carbohydrate = 9. 87 ± 1. 87%; fiber = 10. 01 ± 1. 21%; mineral = 6. 41 ± 1. 08%; fat and oil = 6. 63 ± 0. 93%) were identified in the leave. Exposure to chromium significantly (P < 0. 05) increased plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) with a concomitant decrease in the activity of these enzymes in the liver of both male and female rats. The exposure also altered protein, triglyceride, and cholesterol levels in the plasma and liver as well as hematological indices. Organ chromium retention and pathological changes were also observed. ANLA modulated these chromium-induced alterations in the rats. Conclusions: Based on the results, ANLA possesses ameliorative property against PDC-induced toxicity in rats. Thus it may be used to combat chromium poisoning. The nutritive potential of A. nilotica leaves may also be maximized.