Evaluation of the toxicological properties of Himantura imbricata Venom using a zebrafish model (Danio rerio).

The stingrays of the genus Himantura imbricata are present in all of the world's oceans, but the toxicity of their venoms has not yet been thoroughly characterized. The zebrafish as a toxicology model can be used for general toxicity testing of drugs and the investigation of toxicological mechanisms. The aim of this study was to evaluate the effect of crude venom from the stingray H. imbricata on the zebrafish Danio rerio. Juvenile zebrafish were injected with different concentrations of venom from H. imbricata via subcutaneous injections. The venom's effects were established via histological examination and hemolytic activity in zebrafish. The histopathological analysis revealed significant tissue damage in the organs of the zebrafish injected with venom, including liver necrosis and kidney degeneration. A blood examination revealed echinocytes, hemolysis, and nuclear abnormalities. Bodyweight estimations and histopathological attributes of the gills, heart, muscle, liver, intestine, eye, and brain were determined. The histological staining studies of the gills, liver, and intestine were measurably higher in the venom groups compared with the other two groups. Aggregately, the result shows that zebrafish may act as a valuable biomarker for alterations impelled by H. imbricata venom. The work delivers a useful model with substantial pharmacological potential for new drugs and a better comprehension of research on stingray venom.

Enhancing the neuroprotective effect of squid outer skin astaxanthin against rotenone-induced neurotoxicity in in-vitro model for Parkinson's disease.

Rotenone is a widely used organic pesticide that induces neurotoxicity via inhibition of mitochondrial complex I and oxidative stress actions for the most of dopaminergic neurons as that occurring in Parkinsonism disease (PD). Astaxanthin (ASX) is a natural pigment (carotenoids) and a potent therapeutic compound due to its antioxidant and anti-inflammatory properties. The commercially important cephalopod Doryteuthis singhalensis is widely distributed in tropical and subtropical waters in World Ocean. D. singhalensis is an important source of astaxanthin that contains valuable biological active compounds with many valuable pharmacological effects. The present study evaluated the effect of astaxanthin in preventing rotenone-induced toxicity of SK-N-SH human neuroblastoma cells in an in vitro model of experimental Parkinsonism. The results revealed the strongly significant antioxidant capability of extracted squid astaxanthin in 1,1- diphenyl- 2- picrylhydrazyl (DPPH) radical scavenging activity. In addition, astaxanthin treatment based on dose dependent manner significantly attenuated rotenone induced cytotoxicity, mitochondrial dysfunction and oxidative stress in SKN- SH cells. It is concluded that the marine squid derived astaxanthin could be used as a potential neuroprotector against rotenone induced toxicity due to its antioxidant, and anti-apoptotic properties. Consequently, it could be a supportive remedy for neurodegenerative diseases like Parkinson's disease.

Screening of antiangiogenic potential of twenty two marine invertebrate extracts of phylum Mollusca from South East Coast of India

<p><b>OBJECTIVE</b>To evaluate the antiangiogenic potential of twenty two marine invertebrate species of Phylum Mollusca from south east coast of India.</p><p><b>METHODS</b>Live specimens of molluscan species were collected and their methanolic extracts were evaluated for preliminary antiangiogenic activity using the in ovo chick chorio-allantoic membrane assay. The extracts were further evaluated for in vivo antiangiogenic activity using chemical cautery induced corneal neovascularization assay in rats and oxygen induced retinopathy assay in rat pups.</p><p><b>RESULTS</b>In the chick chorio-allantoic membrane assay, four methanolic extracts of marine molluscan species viz. Meretrix meretrix, Meretrix casta, Telescopium telescopium and Bursa crumena methanolic extracts exhibited noticeable antiangiogenic activity at the tested concentration of 200 µg whereby they significantly inhibited the VEGF induced proliferation of new blood vessels. Among these four extracts, the methanolic extract of Meretrix casta exhibited relatively higher degree of antiangiogenic activity with an inhibitiory percentage (64.63%) of the VEGF induced neovascularization followed by the methanolic extracts of Telescopium telescopium (62.02%), Bursa crumena (60.48%) and Meretrix meretrix (47.01%). These four methanolic extracts were further evaluated for in vivo antiangiogenic activity whereby the methanolic extract of Telescopium telescopium exhibited most noticeable inhibition (42.58%) of the corneal neovascularization in rats in comparison to the sham treated group, and also exhibited most noticeable inhibition (31.31%) of the oxygen induced retinal neovascularization in rat pups in comparison to the hyperoxia group that was observed for considerable retinal neovascularization.</p><p><b>CONCLUSIONS</b>The significant antiangiogenic activity evinced by the extract of Telescopium telescopium merits further investigation for ocular neovascular diseases.</p>

Isolation and characterization of hyaluronic acid from the liver of marine stingray Aetobatus narinari.

Although hyaluronic acid research pursuits ahead in exploring its biomedical perspective, very limited investigations were carried out in their isolation shape view point, furthermore, most of the investigations were targeted towards the terrestrial source. To swerve from that, the present study was projected through the marine superstore, where in high molecular weight hyaluronic acid of 13, 65,863 Da was isolated from the liver of stingray Aetobatus narinari. The purified HA was confirmed at the preliminary level by their stains all dye binding nature. Their analytical composition including carbon, hydrogen, nitrogen, N-acetyl glucosamine, glucuronic acid contents was analysed. The HA was characterized by agarose-gel electrophoresis, FTIR, HPTLC, and (1)H NMR. The DPPH radical scavenging activity of HA and its reducing power was evident to all the tested concentrations, but lower than that of ascorbic acid. HA showed significant inhibition against the proliferation of cells, substantiating its influence in regulation of cell functions.

In vitro antioxidant properties and FTIR analysis of two seaweeds of Gulf of Mannar

Objective: To evaluate the in vitro antioxidant activity of Sargassum wightii (S. wightii) andUlva lactuca (U. lactuca). Methods: Dried seaweeds of S. wightii and U. lactuca were tested for total phenolic content. In vitro antioxidant activity was determined by DPPH assay and ferric reducing antioxidant power (FRAP) assay. Functional groups of two seaweeds were analysed by fourier transform infrared spectroscopy (FTIR). Results: The highest total phenolic content was observed in S. wightii (0.65±0.02 mg GAE/g) when compared with U. lactuca. In vitro antioxidant activity of S. wightii showed higher activity in all assays than U. lactuca with the higher total antioxidant activity (123.40±4.00 mg ascorbic acid/g), DPPH radical scavenging activity (108.06±1.02)% and ferric reducing antioxidant power (153.40±1.41 mg GAE/g). FITR spectrum of standard gallic acid was compared with seaweeds and same number of peaks lying between 449.32 and 3 495.89 cm-1 and 462.89 and 3 407.05 cm-1 was recorded. Conclusions: These results show that S. wightii has higher antioxidant capacity than U. lactuca. Further study is necessary to exploit the multifunctional properties of seaweeds which will be usefull to treat many diseases.

Efficacy of DL-alpha-lipoic acid on methanol induced free radical changes, protein oxidative damages and hsp70 expression in folate deficient rat nervous tissue.

DL-alpha-Lipoic acid (LPA) was reported to be effective in reducing free radicals generated by oxidative stress. The protective of effect of LPA on methanol (MeOH) induced free radical changes and oxidative damages in discrete regions of rat brain have been reported in this study. Folate deficient rat (FDD) model was used. The five animal groups (saline control, FDD control, FDD+MeOH, FDD+LPA+MeOH, LPA control) were used. The FDD+MeOH and FDD+LPA+MeOH animals were injected intraperitoneally with methanol (3gm/kg). After 24h, the level of free radical scavengers such as, superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione was estimated in six discrete regions of brain, retina and optic nerve. Level of protein thiol, protein carbonyl and lipid peroxidation was also estimated. Expression of heat shock protein 70 mRNA (hsp70) was studied in the cerebellum and hippocampus by reverse transcriptase PCR. All the samples showed elevation in the level of free radical scavenging enzymes and reduced level of glutathione in the FDD+MeOH group in relation to the other groups. hsp70 expression was more in FDD+MeOH group when compared to FDD+LPA+MeOH group. In conclusion, MeOH exposure leads to increased free radical generation and protein oxidative damages in the rat nervous tissue. Treatment with LPA prevents oxidative damage induced by MeOH exposure.

Effects of chronic noise stress on spatial memory of rats in relation to neuronal dendritic alteration and free radical-imbalance in hippocampus and medial prefrontal cortex.

Spatial memory is coordinated with different brain regions especially hippocampus (HIP) and medial prefrontal cortex (mPFC). Influence of noise stress on working and reference memory error in rats was evaluated by radial eight-arm maze experiment. Changes in the dendritic count were observed in the brain regions such as CA1, CA3 regions of HIP and layers II, III of mPFC. In order to understand the possible mechanism behind noise stress-induced changes, free radical status and acetylcholinesterase (AChE) activity in HIP and mPFC were evaluated. Plasma corticosterone level was also evaluated. Results obtained in this study showed that after noise-stress exposure, 100 dBA/4h per day for 30 days, working and reference memory error increased significantly (P < 0.05) when compared to control animals. Neuronal dendritic count in the HIP was reduced in the 2nd and 3rd order dendrites but not in the mPFC. Superoxide dismutase, lipid peroxidation, plasma corticosterone level and AChE activity were significantly increased in the 1 day, 15 days and 30 days stress groups animal significantly. Catalase and glutathione peroxidase activity were increased in the 1 day and 15 days noise-stress groups but decreased in the 30 days noise-stress group and GSH level was decreased in all the stress exposed animals. In conclusion, oxidative stress, increased AChE activity, reduced dendritic count in HIP, mPFC regions and elevated plasma corticosterone level which develops in long-term noise-stress exposed rats, might have caused the impairment of spatial memory.