Ingestion of microplastics and its potential for causing structural alterations and oxidative stress in Indian green mussel Perna viridis- A multiple biomarker approach.

The present study has investigated the distribution of microplastics in sediment and its impact on histological, ultrastructural, and oxidative stress mechanisms in Perna viridis (P. viridis) from Kasimedu, Chennai, India. The results confirmed that fibers were the predominant type of microplastics observed, followed by spheres, flakes, sheets, and fragments. The observed microplastics were confirmed as polyester, polypropylene, polyethylene, cellophane, and rayon using µ-FT-IR. Microplastic particles entangled in gills caused abrasion of ciliated structure and hemocyte infiltration in the hemolymph vessels. The digestive gland showed a shrunken nucleus, dark inclusions, and damage in the nucleoid core structure. Enlarged vacuoles and the presence of clusters of vesicles presumably represented the transformed golgi cisternae. Further, the results confirmed that oxidative stress markers were significantly high in gills and digestive diverticula of P. viridis. Overall, the results indicated that microplastics induced different toxic physiological and structural alterations in gills and digestive diverticula of P. viridis. These findings highlighted the necessity to focus on exposure studies to understand the absolute magnitude of the problem due to microplastic pollution in the urban estuarine ecosystems of Chennai, Tamil Nadu, India.

A focus on resveratrol and ocular problems, especially cataract: From chemistry to medical uses and clinical relevance.

Low vision and blindness are important health problems that affect millions of people throughout the world. The most common and important pathologies are diabetic retinopathy, age-related macular degeneration, glaucoma as well as cataracts. The latter consists of an opacification of the lens of the eye which impedes the passage of light and represents one of the most important causes of vision loss. Among the risk factors for cataract development, there are life-style factors such as the use of tobacco, abuse of alcohol and unhealthy diet. In light of this, dietary components that possess anti-oxidant activity, such as polyphenols for instance, can be considered good candidates for human studies in the prevention and or treatment of such diseases. Among dietary components, the antioxidant capacity of certain polyphenols is well known, and these could be good candidates. In this review we focus our attention on the current scientific literature regarding to the effects of resveratrol on cataracts and other ocular diseases, along with its potential mechanism/s of action. A large number of preclinical studies support the involvement of resveratrol in clinical trials for the prevention and treatment of eye diseases induced by oxidative stress and inflammation, such as age-related cataract.

Apoptosis in liver cancer (HepG2) cells induced by functionalized gold nanoparticles.

An ethnopharmacological approach for biosynthesis of gold nanoparticles is being demonstrated using seed coat of Cajanus cajan. Medicinal value of capping molecule investigated for anticancer activity and results disclose its greater potential. The active principle of the seed coat [3-butoxy-2-hydroxypropyl 2-(2,4-dihydroxyphenyl) acetate] is elucidated. Rapid one-step synthesis yields highly stable, monodisperse (spherical) gold nanoparticles in the size ranging from 9 to 41 nm. Anticancer activity has been studied using liver cancer cells and cytotoxic mechanism has been evaluated using MTT, Annexin-V/PI Double-Staining Assay, Cell cycle, Comet assay and Flow cytometric analysis for apoptosis. The present investigation will open up a new possibility of functionalizing gold nanoparticles for apoptosis studies in liver cancer cells.

Toxicity effect of silver nanoparticles in brine shrimp Artemia.

The present study revealed the toxic effect of silver nanoparticles (AgNPs) in Artemia nauplii and evaluated the mortality rate, hatching percentage, and genotoxic effect in Artemia nauplii/cysts. The AgNPs were commercially purchased and characterized using field emission scanning electron microscope with energy dispersive X-ray spectroscopy. Nanoparticles were spherical in nature and with size range of 30-40 nm. Artemia cysts were collected from salt pan, processed, and hatched in sea water. Artemia nauplii (II instar) were treated using silver nanoparticles of various nanomolar concentrations and LC50 value (10 nM) and mortality rate (24 and 48 hours) was evaluated. Hatching percentage of decapsulated cysts treated with AgNPs was examined. Aggregation of AgNPs in the gut region of nauplii was studied using phase contrast microscope and apoptotic cells in nauplii stained with acridine orange were observed using fluorescence microscope. DNA damage of single cell of nauplii was determined by comet assay. This study showed that as the concentration of AgNPs increased, the mortality rate, aggregation in gut region, apoptotic cells, and DNA damage increased in nauplii, whereas the percentage of hatching in Artemia cysts decreased. Thus this study revealed that the nanomolar concentrations of AgNPs have toxic effect on both Artemia nauplii and cysts.

Ameliorative effect of ferulic acid against renal injuries mediated by nuclear factor-kappaB during glycerol-induced nephrotoxicity in Wistar rats.

The pathogenesis of glycerol-induced myoglobinuric acute renal failure involves ischemia, vascular congestion and reactive oxygen metabolites. In this study, we have investigated for the first time, the role of ferulic acid in attenuating glycerol-induced nephrotoxicity. Male Wistar rats were injected intramuscularly with 8 mL/kg body weight of 50% glycerol, glycerol + ferulic acid at the dose of 5, 10, 15, 20 and 25 mg/kg body weight. After 24 h, the rats were sacrificed and the kidneys were removed for histological and immunohistochemical studies. Furthermore, determinations of lipid peroxidation (LPO) as well as antioxidant enzymes were also analyzed; blood, urine samples were collected in order to quantify renal function and nitric oxide generation, respectively. Glycerol-induced rats showed a significant increase in the level of urinary markers assessed in serum as well as kidney and these were reversed upon ferulic acid treatment. A significant increase in urine nitric oxide, serum as well as kidney LPO, decrease in activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and reduced glutathione were observed in glycerol-induced rats. Immunohistochemical study in glycerol-induced rats demonstrated an increase in the level of nuclear factor-kappaB (NF-κB). All these effects induced by glycerol were reduced upon treatment with ferulic acid in a dose-dependent manner. To conclude, ferulic acid enhances antioxidants and decreases NF-κB, thereby protecting the cells against stress induced by glycerol.

Biomarkers of metal toxicity and histology of Perna viridis from Ennore estuary, Chennai, south east coast of India.

Distribution of heavy metals and its associated histological perturbations were studied in the soft tissues of Perna viridis collected from Ennore estuary and compared with the less polluted Kovalam coast. The concentration of copper, lead, zinc, cadmium, manganese and iron were quantified in gills, digestive gland and adductor muscle. The results showed marked differences between the two sites as well as significant variations within the tissues. Among the heavy metals analyzed, lead and cadmium recorded very low in the soft tissues of mussel. Heavy metal levels in tissues of mussel collected from Ennore estuary were in the order of gills>digestive gland>adductor muscle, while it was digestive gland>gills>adductor muscle in the mussel sampled from Kovalam coast. The decreasing trend of metals in the tissues of mussels sampled from both Ennore estuary and Kovalam coast was in the order of Fe>Mn>Zn>Cu>Pb>Cd. Overall, the highest metal concentrations were found in the mussel collected from Ennore estuary. The metal accumulation in the gills and digestive gland of Perna viridis was found to be quite high in comparison with the adductor muscle. These soft tissues were further investigated by light microscopy and the results were compared with the reference site (Kovalam coast). These results suggest that thickening of the digestive epithelium, hemocytic infiltration in the gills and myodegeneration in the muscle tissue are useful histological biomarkers for heavy metal induced stress, and demonstrate that precautions need to be taken in Ennore estuary in order to prevent heavy metal pollution that can occur in the future.