Environmentally relevant lead alters nuclear integrity in erythrocytes and generates oxidative stress in liver of Anabas testudineus: Involvement of Nrf2-Keap1 regulation and expression of biomarker genes

Genotoxic and hepatotoxic effects of lead (Pb) on a freshwater fish, climbing perch (Anabas testudineus) were studied at an environmentally relevant concentration (43.3 ppm). The genotoxic potential of Pb was confirmed by micronucleus study, with increased frequencies of erythrocytic nuclear alterations like lobed, blebbed, notched, fragmented, and micronuclei were observed in erythrocytes in treated groups as compared to control. Inorganic Pb induces oxidative stress which is a consequence of elevated level of Reactive Oxygen Species. Hepatotoxicity was assessed both by the oxidative stress and cellular responses that emerged due to the toxic assault of Pb in the liver, the most important detoxifying organ. Upregulation of xenobiotic metabolizing enzyme like catalase was evident after 15, 30, and 90 days of exposure, and a profound effect was observed on 30th days. The level of lipid peroxidation and reduced glutathione was increased after Pb exposure. Histoarchitectural damages of liver were distinctly evident in treated fish. Western blot analysis confirmed the expressional alterations of stress-responsive marker proteins like Nrf2, Keap1, Hsp70, and Nqo1. Pb exposure resulted in increased expression of Hsp70, Nrf2, and Nqo1, whereas Keap1 was downregulated, suggesting the involvement of Nrf2-Keap1 regulation as a cytoprotective mechanism against Pb toxicity.

Foaming and Emulsifying Properties of Porcine Red Cell Protein Concentrate

This work focuses on studying the effects of pH (7.0 and 4.5) and protein concentration on the foaming and emulsifying properties of fresh (F) and spray-dried (SD) porcine red cell protein (RCP) concentrates in order to evaluate the proper use of this blood protein as a functional food ingredient. Also, protein solubility is measured through the pH range from 3.0 to 8.0. In each case, all concentrates show a high solubility, although this is significantly affected by pH. Spray drying slightly reduces the solubility at mild acid and neutral conditions. The foaming capacity is found to be dependent on pH as well as on the drying treatment. SD-RCP concentrates show better foaming capacity than F-RCP. The minimum protein concentration required to attain the highest foaming capacity is found under acid pH for the spray-dried concentrates. Although F-RCP shows low foam stability at acid and neutral pH, spray drying and protein content enhance the stability of foams. Emulsifying properties show dependence on pH as well as on protein content. Furthermore, spray drying affects the emulsifying properties but in different ways, depending on pH and protein concentration.