Antioxidant effects of kimchi supplemented with black raspberry during fermentation protect against liver cirrhosis-induced oxidative stress in rats

BACKGROUND/OBJECTIVES: Oxidative stress is a major effector of various diseases; accordingly, antioxidants are frequently ingested in order to prevent or alleviate disease symptoms. Kimchi contains various natural antioxidants, and it is known that the functional activity varies depending on the ingredients and fermentation state. Black raspberries (BR) contain various bioactive compounds with antioxidant effects. This study investigated the antioxidant and liver-protection effects of kimchi supplemented with black raspberry juice powder (BJP). MATERIALS/METHODS: BJP-added kimchi (BAK; at 0.5%, 1%, and 2% concentrations of BJP) and control (without BJP) were prepared and fermented at 4℃ for 4 weeks. Changes in the antioxidant effects of BAK during fermentation were investigated. In addition, the protective activity of BAK against oxidative stress was investigated in a liver cirrhosis-induced animal model in vivo. RESULTS: BAK groups showed the acidity and pH of optimally ripened (OR) kimchi at 2 weeks of fermentation along with the highest lactic acid bacterial counts. Additionally, BAK groups displayed a higher content of phenolic compounds and elevated antioxidant activities relative to the control, with the highest antioxidant effect observed at 2 weeks of fermentation of OR 1% BAK. After feeding the OR 1% BAK to thioacetamide-induced liver cirrhosis rats, we observed decreased glutamate oxaloacetate transaminase and glutamate pyruvate transaminase activities and elevated superoxide dismutase activity. CONCLUSIONS: These findings showed that the antioxidant effects of OR BAK and feeding of OR 1% BAK resulted in liver-protective effects against oxidative stress.

Screening of toxic potential of graphene family nanomaterials using in vitro and alternative in vivo toxicity testing systems

OBJECTIVES: The widely promising applications of graphene nanomaterials raise considerable concerns regarding their environmental and human health risk assessment. The aim of the current study was to evaluate the toxicity profiling of graphene family nananomaterials (GFNs) in alternative in vitro and in vivo toxicity testing models. METHODS: The GFNs used in this study are graphene nanoplatelets ([GNPs]-pristine, carboxylate [COOH] and amide [NH2]) and graphene oxides (single layer [SLGO] and few layers [FLGO]). The human bronchial epithelial cells (Beas2B cells) as in vitro system and the nematode Caenorhabditis elegans as in vivo system were used to profile the toxicity response of GFNs. Cytotoxicity assays, colony formation assay for cellular toxicity and reproduction potentiality in C. elegans were used as end points to evaluate the GFNs' toxicity. RESULTS: In general, GNPs exhibited higher toxicity than GOs in Beas2B cells, and among the GNPs the order of toxicity was pristine>NH2>COOH. Although the order of toxicity of the GNPs was maintained in C. elegans reproductive toxicity, but GOs were found to be more toxic in the worms than GNPs. In both systems, SLGO exhibited profoundly greater dose dependency than FLGO. The possible reason of their differential toxicity lay in their distinctive physicochemical characteristics and agglomeration behavior in the exposure media. CONCLUSIONS: The present study revealed that the toxicity of GFNs is dependent on the graphene nanomaterial's physical forms, surface functionalizations, number of layers, dose, time of exposure and obviously, on the alternative model systems used for toxicity assessment.

Screening of toxic potential of graphene family nanomaterials using in vitro and alternative in vivo toxicity testing systems

OBJECTIVES: The widely promising applications of graphene nanomaterials raise considerable concerns regarding their environmental and human health risk assessment. The aim of the current study was to evaluate the toxicity profiling of graphene family nananomaterials (GFNs) in alternative in vitro and in vivo toxicity testing models. METHODS: The GFNs used in this study are graphene nanoplatelets ([GNPs]-pristine, carboxylate [COOH] and amide [NH2]) and graphene oxides (single layer [SLGO] and few layers [FLGO]). The human bronchial epithelial cells (Beas2B cells) as in vitro system and the nematode Caenorhabditis elegans as in vivo system were used to profile the toxicity response of GFNs. Cytotoxicity assays, colony formation assay for cellular toxicity and reproduction potentiality in C. elegans were used as end points to evaluate the GFNs' toxicity. RESULTS: In general, GNPs exhibited higher toxicity than GOs in Beas2B cells, and among the GNPs the order of toxicity was pristine>NH2>COOH. Although the order of toxicity of the GNPs was maintained in C. elegans reproductive toxicity, but GOs were found to be more toxic in the worms than GNPs. In both systems, SLGO exhibited profoundly greater dose dependency than FLGO. The possible reason of their differential toxicity lay in their distinctive physicochemical characteristics and agglomeration behavior in the exposure media. CONCLUSIONS: The present study revealed that the toxicity of GFNs is dependent on the graphene nanomaterial's physical forms, surface functionalizations, number of layers, dose, time of exposure and obviously, on the alternative model systems used for toxicity assessment.