The increased interest in achieving, solely through diet, the same effect on iron levels with supplementation, leads to numerous studies on iron absorption of iron binding proteins (IBPs). The characteristics of IBPs from Tegillarca granosa ( T. granosa ) and its iron utilization were determined to analyze their relationship. The results showed in T. granosa , Fe(ӀӀ) was main iron form in hemoglobin (TH) and that Fe(ӀӀ) and Fe(ӀӀӀ) coexisted in ferritin (TF). After in vitro digestion, TH was easier to be digested than TF, bovine hemoglobin, and bovine ferritin. In caco-2 cells model, iron bioavailability of TH also was the best, which related to TH's superior fluid properties, higher ratios of α-helix to β-sheet and amide I to amide II. These suggest TH could be used as a good source of organic iron and provide references for application of T. granosa in human nutrition. Practical applications This research investigated the iron bioavailability and structural properties of iron-binding proteins from Tegillarca granosa ( T. granosa ). Moreover, the effects of iron absorption in bovine hemoglobin and ferritin were compared with those from T. granosa . The results showed the hemoglobin in T. granosa had better iron bioavailability and it could be a good source of iron. These data could provide a basic instruction of the application of T. granosa in functional food production.
The pervasive presence of pentachlorophenol (PCP) in aquatic-benthic ecosystems poses a threat to organisms. However, the toxicological mechanisms of PCP in benthic organisms are limited. In this study, Tegillarca granosa , a representative bivalve species, was treated with environmentally relevant concentrations of PCP (1, 10, and 100 μg/kg) and positive control for 28 days via sediment exposure to investigate bioaccumulation potential, metabolomic profiles, and histopathology. The biota-sediment bioaccumulation factor for PCP was 9.1. Given the capability of PCP to act as an uncoupler of oxidative phosphorylation, studies were performed to determine key events in the adverse outcome pathway associated with this molecular initiating event. Metabolic profiles indicated a disruption in lipid metabolism, as well as imbalances in the quantity of calcium, which was associated with the synthesis of reactive oxygen species (ROS). A reduction in adenosine-5′-triphosphate (ATP) levels were seen in clams treated with PCP and in animals treated with carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP), which served as a positive control. When clams were co-exposed to 100 μg/kg PCP and 500 μg/kg ATP, PCP toxicity was diminished and levels of mitochondrial calcium, as well as ROS, were reduced. These results suggest that mitochondrial impairment is a key event in the toxic mechanism of PCP to T. granosa .