Curcumin in diet modulates fatty acid levels and mRNA expression of appetite-regulating neuropeptides in brain and enhances growth via the GH-GHR-IGF axis in tilapia, Oreochromis mossambicus.

Curcumin in 0.5% and 1% doses was given as a feed additive to tilapia (Oreochromis mossambicus) for 100 days to evaluate the effect of curcumin on fatty acid levels in brain, appetite and the growth axis-related gene expressions. A total of 180 fish were randomly stocked into 650 l tanks and fed with basal feed during acclimatization. Three treatment groups were established, each having three replicates and each replicate had 20 fish. They were fed twice on the experimental diets of 10% body weight ration per fish. Gas chromatography analysis revealed a significant change in the amount of total saturated fatty acids and total monounsaturated fatty acids in tilapia brain. The present study indicated an increase in n-3 (omega-3) and n-6 (omega-6) polyunsaturated fatty acids in brain. Real-time quantification of appetite-regulating neuropeptides in brain and growth-related gene expressions in muscle revealed a significant modulation in their mRNA expressions. This information obtained in the present study on the beneficial role of curcumin in the regulation of fatty acid levels and the expression of appetite-regulating neuropeptides and growth-regulating factors will contribute to research in feed intake and growth in fish.

MoS2 nanoparticles induce behavioral alteration and oxidative stress mediated cellular toxicity in the social insect Oecophylla smaragdina (Asian weaver ant).

The study evaluates molybdenum disulfide (MoS2) nanoparticles (NPs) induced oxidative stress during cellular toxicity in an invertebrate in vivo system, the weaver ant. The lethal concentration was checked and LC50 was obtained as 50 µg/mL. Feeding assay and the photoluminescence activity confirmed the ingestion of MoS2 NPs by the organism. Behavioral assays showed altered grooming behavior in the MoS2 NP fed ants. A drastic decrease in the hemocyte count in the MoS2 NP fed ants revealed the anti-proliferative role of MoS2. This was further confirmed by 5-bromo-2'-deoxyuridine (BrdU) labeling assay. MoS2 NPs induced apoptotic activity was also observed in the hemocytes by acridine orange/ethidium bromide (AO/EB) staining. The level of oxidative stress during cellular toxicity was observed. An increased reactive oxygen species (ROS) level was observed in the MoS2 NP fed ants when compared to the control group. The increased activity of superoxide dismutase (SOD) and the lipid peroxidation (LPO) product were observed. While, the activities of catalase (CAT) and glutathione-s-transferase (GST) and the glutathione content (GSH) were decreased by MoS2 NPs. The transcript levels of SODs, CAT and GST were up regulated in the treated group. Our results suggest that MoS2 NPs induced oxidative stress mediates the cellular toxicity in the foragers of the weaver ant.

Light and electron microscopic observations on the organization of skin and associated glands of two caecilian amphibians from Western Ghats of India.

We adopted light and electron microscopy to understand the structure of the skin of two species of caecilians, Ichthyophis tricolor and Uraeotyphlus cf. oxyurus, from Western Ghats of Kerala, India. The surface of the skin of these caecilians contains an irregular pattern of microridges. Oval, round and polymorphic glandular openings are randomly distributed all over the skin surface. Most of the openings are funnel shaped. The epithelial cells along the rim of the opening descend into the tunnel of the duct. A few glandular openings protrude slightly above the epithelium of the duct. The skin is formed of epidermis and dermis. Small flat disk-like dermal scales, composed of a basal plate of several layers of unmineralized collagen fibers topped with a discontinuous layer of mineralized globular squamulae, are lodged in pouches in the transverse ridges of the skin. Each pouch contains 1-4 scales, which might differ in size. The scales are almost similar between species, yet the difference can be useful in distinguishing between the two species. Flask cells and Merkel cells are present in the epidermis. Two types of glands, mucous and granular, are present in the dermis. The mucous glands are densely packed with mucous vesicles. Darkly stained mucous producing cells are located around the periphery of the gland. Secretory mucous vesicles differ in their organization and distribution. The granular glands are located perpendicular to the skin surface. The granule producing cells of the gland are located near the periphery. There are differently stained spherical secretory granules of various sizes in the cytoplasm. Thus, the use of different microscopic techniques contributed fascinatingly to the first ever understanding of organization of the skin of two selected caecilian species from Western Ghats, revealing certain features to differ between them.