Arsenic (As) is toxic for humans, animals, and plants, whereas selenium (Se) is considered as an essential trace element and can cause toxicity during episodic elevated exposure.Interaction between As and Se is a critical factor for a detailed systematic understanding of the transportation, environmental fate, and associated toxicological effects of these metalloids in biological systems. Arsenic and Se induce cytotoxicity and genotoxicity through the generation of reactive oxidation species (ROS). Compared to arsenite (As III ), the methylated arsenicals, including methylarsonous acid (MAs III ) and dimethylarsinous acids (DMAs III ) exhibit more cytotoxic and genotoxic potentials to inhibit more potent enzymes and activate AP˗1 protein, which is a critical marker for genetic stability.Methylated As III and associated metabolites are well-known potential carcinogens that induce toxicity by blocking Se metabolism pathway. Low concentrations of Se compounds under reducing conditions inhibit the DNA repairing process and constraint the binding of zinc finger protein to DNA and ultimately cause the release of zinc from the motif of the zinc finger. Imbalance of Se compounds can lead to the generation of ROS, which can inhibit or decrease genomic stability. Arsenic and Se nexus also affect cellular signaling through activation of the transcription factors such as NFҡB and AP-1. In a nutshell, this review highlights As and Se sources in the environment, their uptake in soil-plant system, interactions between these metals and associated toxicity in major biological compartments, which may assist in addressing the hazardous impacts associated with As and Se contamination. Last but not the lease, this review also summarizes the available remedial measures and future research directions to cope with this critical issue.

The antioxidant activity of thuja (Thuja occidentalis) cones extract (TCE) and peach (Prunus armeniaca) seeds extract (PSE) were estimated by DPPH free radical scavenging activity method. Total phenolics, total flavonoids and reducing power were also estimated in these extracts. Antioxidant potential of these by products was also evaluated in raw chicken ground meat (GM) during refrigerated (4±1°C) storage. Total phenolics in TCE and PSE were 7.80±0.04 and 1.92± 0.04 mg TAE/gdw respectively. Both extract also showed remarkable DPPH radical scavenging activity (25.52±1.92% and 24.99±0.32%). The reducing power OD700 was observed more in TCE as compared to PSE (3.32±0.01 and 0.49±0.01). Total flavonoids contents were 7.48±0.02 and 0.85±0.01 mg CE/gdw respectively. Addition of these extract significantly (P<0.01) affected cooking losses and WHC of GM. During refrigerated storage (4°C) the TBARS values at 8 d were significantly (P<0.01) more in control than TCE and PSE treated groups.

The aim of the current study is to evaluate the occurrence of arsenic in coal collected from Thar coalfield, Pakistan, and its behavior during the combustion. Fractionation of arsenic (As) in coal samples was carried out by Community Bureau of Reference sequential extraction scheme (BCR-SES) and single-step-based BCR method (BCR-SS). These methods are validated using the certified reference material of sediment BCR 701 and standard addition method. The stepwise fractions of As in laboratory-made ash (LMA) have been also investigated. The extractable As content associated with different phases in coal and LMA samples were analyzed by electrothermal atomic absorption spectrophotometer. The extraction efficiency of As by BCR-SS was slightly higher than BCR-SES, while the difference was not significant (p < 0.05). The BCR-SS method is a time-saving method because it can reduce the extraction time from 51 to 22 h. The As contents in LMA revealed that during combustion of the coal, >85 % of As may be released into atmosphere. The relative mobility of As in the coal samples was found in increasing order as follows: oxidizable fraction < reducible fraction < acid soluble fraction. The total and extractable As obtained by BCR-SES and BCR-SS were higher in coal samples of block III as compared to block V (p > 0.05).