Pathophysiological Changes in Rohu (Labeo rohita, Hamilton) Fingerlings Following Arsenic Exposure

A Review on the Involvement of Heat Shock Proteins (Extrinsic Chaperones) in Response to Stress Conditions in Aquatic Organisms

Heat shock proteins (HSPs) encompass both extrinsic chaperones and stress proteins. These proteins, with molecular weights ranging from 14 to 120 kDa, are conserved across all living organisms and are expressed in response to stress. The upregulation of specific genes triggers the synthesis of HSPs, facilitated by the interaction between heat shock factors and gene promoter regions. Notably, HSPs function as chaperones or helper molecules in various cellular processes involving lipids and proteins, and their upregulation is not limited to heat-induced stress but also occurs in response to anoxia, acidosis, hypoxia, toxins, ischemia, protein breakdown, and microbial infection. HSPs play a vital role in regulating protein synthesis in cells. They assist in the folding and assembly of other cellular proteins, primarily through HSP families such as HSP70 and HSP90. Additionally, the process of the folding, translocation, and aggregation of proteins is governed by the dynamic partitioning facilitated by HSPs throughout the cell. Beyond their involvement in protein metabolism, HSPs also exert a significant influence on apoptosis, the immune system, and various characteristics of inflammation. The immunity of aquatic organisms, including shrimp, fish, and shellfish, relies heavily on the development of inflammation, as well as non-specific and specific immune responses to viral and bacterial infections. Recent advancements in aquatic research have demonstrated that the HSP levels in populations of fish, shrimp, and shellfish can be increased through non-traumatic means such as water or oral administration of HSP stimulants, exogenous HSPs, and heat induction. These methods have proven useful in reducing physical stress and trauma, while also facilitating sustainable husbandry practices such as vaccination and transportation, thereby offering health benefits. Hence, the present review discusses the importance of HSPs in different tissues in aquatic organisms (fish, shrimp), and their expression levels during pathogen invasion; this gives new insights into the significance of HSPs in invertebrates.

Associations of exposure to multiple metals with the risk of age-related cataract in Anhui, China: a case-control study

It's well-known that multiple metal elements can lead to the change of oxidative stress response levels in vivo. However, their relationship with age-related cataract (ARC) had not been well studied. We designed a case-control study including 210 individuals with ARC and 210 matched control group. The metal levels in their urine specimens were measured using graphite furnace atomic absorption spectrometry (GFAAS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to select representative metals into the multi-element model and reduce dimension. Multivariate logic analysis and Bayesian kernel machine regression (BKMR) were subsequently used to explore the association of ARC risk with multiple metal elements. We found that magnesium (Mg), chromium (Cr), arsenic (As), manganese (Mn), and selenium (Se) were positively associated with ARC in the single-element model. The multiple exposure model indicated a positive association between Mg and As, in which the OR in their highest quartile were 3.32 (95% CI: 1.24-8.89) and 7.09 (95% CI: 2.56-19.63). The BKMR model also showed the effect of As increased monotonically with its increasing concentration, and high levels of Mg and As had a significant positive effect on ARC risk. In conclusion, we found that exposure to multiple metals was associated with increased ARC risk. Further research is needed to verify these findings in the future.

Arsenic Bioaccumulation and Identification of Low-Arsenic-Accumulating Food Fishes for Aquaculture in Arsenic-Contaminated Ponds and Associated Aquatic Ecosystems

Arsenic-contaminated food including farmed fish is one of the main routes of human exposure. Fish farmed in contaminated environment accumulates arsenic in different tissues with great variability. Thus, it is utmost important to quantify the risk associated with different farmed fish species in arsenic-contaminated aquaculture systems. In the present study, arsenic content was measured in twelve fish species (Labeo rohita, L. catla, Cirrhinus mrigala, Oreochromis niloticus, O. mossambicus, Liza tade, Puntius javanicus, L. calbasu, Glossogobius giuris, Macrobrachium rosenbergii, Ctenopharyngodon idella, and Bellamya bengalensis (gastropod)) collected from arsenic-contaminated aquaculture systems. Among the studied finfishes, C. idella was found to accumulate the lowest amount of arsenic (< 0.05 ± 0.00 mg kg^-1) whereas the highest accumulation was noticed in O. mossambicus (1.0 ± 0.18 mg kg^-1). However, the estimated carcinogenic and non-carcinogenic risks of human were found to be low for all the studied fishes. The calculated target hazard quotient (THQ) value for adults ranged from 0.01 to 0.08 whereas for children it ranged from 0.05 to 0.27 for low-arsenic-accumulating fishes (arsenic conc. < 0.5 mg kg^-1). Based on these findings, C. mrigala, C. idella, and M. rosenbergii could be recommended as the candidate species for aquaculture in the arsenic-contaminated areas as farming of the low-arsenic-accumulating food fishes would also lower the risk of human exposure through food chain.

Curcumin Has Protective Effect on the Eye Lens Against Arsenic Toxicity

Arsenic is a highly carcinogenic environmental contaminant. Curcumin, the bioactive component of turmeric, exhibits therapeutic efficacy against several chronic inflammatory and infectious diseases. The present study was carried out to investigate the impact of arsenic on eye lens and evaluate the ameliorative potential of curcumin against arsenic toxicity. Gene expression analysis of α, β, and γ-crystallins and fatty acid profile of lens tissues of arsenic-exposed Labeo rohita was examined and the protective effect of curcumin as diet supplement was evaluated. Curcumin-supplemented diet was prepared at 1.5% and 3% and fed to four groups of fish for 7 days prior to arsenic exposure (at 5 ppm and 15 ppm) for 15 days. Gene expression analysis showed downregulation of α and β-crystallins in the eye lens of arsenic-exposed groups (fed basal diet), whereas the groups fed a curcumin-supplemented diet showed insignificant alterations. Similarly, fatty acid fingerprint of lens lipids arsenic-exposed group exhibited reduction in saturated fatty acid and docosahexaenoic acid (DHA) content. However, in 3% curcumin-supplemented diet-fed and arsenic exposed group group, fatty acid profile remained unchanged. Interestingly, concentration of one non-fatty acid, an antioxidant compound (phenol 2,4-bis 1,1 dimethyl; PD) that was identified in the GC-MS fingerprinting through NIST library (version 2.2, 2014), decreased in response to arsenic exposure which was restored to normal level in curcumin-supplemented groups proving the therapeutic potential of curcumin. The findings of the study suggest that curcumin has a protective effect on eye lens against arsenic toxicity.

Identification of potential biomarkers of hepatotoxicity by plasma proteome analysis of arsenic-exposed carp Labeo rohita

Arsenic (As) is a toxic environmental contaminant and potential human carcinogen. Chronic intake of arsenic-contaminated water and food leads to arsenicosis, a major public health problem in many parts of the world. Early detection of arsenic toxicity would greatly benefit patients; however, the detection of arsenicosis needs to be done early before onset of severe symptoms in which case the tools used for detection have to be both sensitive and reliable. In this context, the present study investigated plasma proteome changes in arsenic-exposed Labeo rohita, with the aim of identifying biomarkers for arsenicosis. Changes in the plasma proteome were investigated using gel-based proteomics technology. Using quantitative image analysis of the 2D proteome profiles, 14 unique spots were identified by MALDI-TOF/TOF MS and/or LC-MS/MS which included Apolipoprotein-A1 (Apo-A1) (6 spots), α-2 macroglobulin-like protein (A2ML) (2 spots), transferrin (TF) (3 spots) and warm-temperature acclimation related 65kDa protein (Wap65). The proteome data are available via ProteomeXchange with identifier PXD003404. Highly abundant protein spots identified in plasma from arsenic-exposed fish i.e. Apo-A1 (>10-fold), A2ML (7-fold) and Wap65 (>2-fold) indicate liver damage. It is proposed that a combination of these proteins could serve as useful biomarkers of hepatotoxicity and chronic liver disease due to arsenic exposure.