Samuthirapandian Ravichandran

A checklist of the Cymothoidae (Crustacea, Isopoda) recorded from Indian fishes

A checklist of the parasitic Cymothoidae of Indian fishes was compiled from parasitological records published between 1783 and 2011. The checklist is arranged alphabetically, providing valid names, synonyms and authorities of the parasite species, as well as valid names and synonyms of the host fish, its capture sites, author(s) and date of published records. The host list consists of all parasites species listed under the host species. A total of 47 nominal species corresponding to 36 valid species are listed from 74 host species belonging to 34 families. Several parasites not identified to species level and parasite species without the host data or where the parasite was found not associated with a fish are also included in this checklist.

Cymothoidae (Crustacea, Isopoda) from Indian fishes

Four cymothoid isopods, parasites of fishes, are reported from India. Two new species, Nerocila poruvae and Joryma hilsae are described. A full description of Nerocila longispina Miers, 1880 is included and two hosts are identified. The distribution and hosts of Anilocra dimidiata Bleeker, 1857 are updated. Nerocila poruvae, N. longispina and Anilocra dimidiata were collected from the Southeastern coasts of India and Joryma hilsae from the Southwestern coasts.

New occurrence of parasitic isopods from Indian fishes

Until now, 36 species belonging to the family Cymothoidae (Crustacea, Isopoda) were recorded from Indian fishes. In this study, ten additional cymothoids are reported in India, most of them for the first time. They parasitize nine fish species, several of them being new host species.

Nerocila species (Crustacea, Isopoda, Cymothoidae) from Indian marine fishes

Eleven Nerocila species are recorded from 22 marine fishes belonging to 15 families. Three, Nerocila arres, Nerocila depressa, and Nerocila loveni, are new for the Indian fauna. N. arres and Nerocila sigani, previously synonymized, are redescribed and their individuality is restored. Nerocila exocoeti, until now inadequately identified, is described and distinctly characterized. A neotype is designated. New hosts were identified for N. depressa, N. loveni, Nerocila phaiopleura, Nerocila serra, and Nerocila sundaica. Host–parasite relationships were considered. The parasitologic indexes were calculated. The site of attachment of the parasites on their hosts was also observed. A checklist of the nominal Nerocila species until now reported from Indian marine fishes was compiled.

Catoessa boscii (Crustacea, Isopoda, Cymothoidae) parasitic on Carangoides malabaricus (Pisces, Carangidae) from India. Taxonomy and host-parasite relationships

Catoessa boscii (Bleeker, 1857) (Crustacea, Isopoda, Cymothoidae), is redescribed according to the type specimen observed by Schioedte and Meinert (1884) extant in the Rijksmuseum von Natuurlijke Historie, Leiden (RMNH) and from many additional specimens recently collected in India from Carangoides malabaricus (Pisces, Carangidae). This study allows an updating of the diagnosis of the genus Catoessa and of the species Catoessa boscii. Some parasite-host relationships were studied during the year. Prevalence and sex ratio of parasites varied according to the month, and the sex and size of hosts.

Active compound from the leaves of Vitex negundo L. shows anti-inflammatory activity with evidence of inhibition for secretory Phospholipase A2 through molecular docking

Novel compounds with significant medicinal properties have gained much interest in therapeutic approaches for treating various inflammatory disorders like arthritis, odema and snake bites and the post-envenom (impregnating with venom) consequences. Inflammation is caused by the increased concentration of secretory Phospholipases A2 (sPLA2s) at the site of envenom. A novel compound Tris(2,4-di-tert-butylphenyl) phosphate (TDTBPP) was isolated from the leaves of Vitex negundo and the crystal structure was reported recently. The acute anti-inflammatory activity of TDTBPP was assessed by Carrageenan-induced rat paw odema method. TDTBPP reduced the raw paw odema volume significantly at the tested doses of 50 mg/kg and 70 mg/kg body weight. Molecular docking studies were carried out with the X-ray crystal structures of Daboia russelli pulchellas (Vipera russelli, Indian Russells viper) venom sPLA2 and Human non-pancreatic secretory PLA2 (Hnps PLA2) as targets to illustrate the antiinflammatory and antidote activities of TDTBPP. Docking results showed hydrogen bond (H-bond) interaction with Lys69 residue lying in the anti-coagulant loop of D. russellis venom PLA2, which is essential in the catalytic activity of the enzyme and hydrophobic interactions with the residues at the binding site (His48, Asp49). Docking of TDTBPP with Hnps PLA2 structure showed coordination with calcium ion directly as well as through the catalytically important water molecule (HOH1260) located at the binding site.

Antimicrobial lipids from the hemolymph of brachyuran crabs

The potential of marine crabs as a source of biologically active products is largely unexplored. In the present study, antimicrobial activity of the hemolymph (plasma) and hemocytes (plasma cells) of six brachyuran crabs was investigated against 16 pathogenic strains. Among the 16 strains tested maximum zone of inhibition was recorded in the hemolymph of Hyas araneus against Shigella flexineri. Interestingly Staphylococcus aureus and Salmonella typhi were susceptible to all the hemolymph and hemocytes samples. Likewise, the highest zone of inhibition was exhibited by both hemolymph and hemocytes samples against Vibrio cholerae. On the basis of TLC, 1HNMR, and 13CNMR it may be concluded that the antimicrobial activity in the hemolymph extract is due to the presence of lipids. This observation is further supported by the ESI-MS of the methanolic extract of hemolymph of H. araneus. ESI-MS shows cluster of peaks in the region m/z 445 to m/z 491 due to lysoglycerolipids/glycerides and cluster of signals between m/z 216 and 246, due to fatty acids/esters present in the sample.

Molecular docking and in vitro evaluations of Hippocampus trimaculatus seahorse extracts as the anti-inflammatory compounds

The present study was undertaken to illustrate the anti-inflammatory activity of seahorse Hippocampus trimaculatus extract in carrageenan-induced rat paw oedema model. Molecular docking study was executed with COX-2 and heme oxygenase inhibitor complexes to illustrate the interactions exhibited by seahorse extract metabolite with the target protein. Favourable interactions of seahorse extract metabolite with the active site residues of the COX-2 and heme oxygenase could be correlated with the potency and the compound is proved to be an anti-inflammatory agent as well as an antidote. In vitro anti-inflammatory activity by Human Red Blood Cell HRBC membrane stabilisation method was evaluated. Structure Activity Relationship SAR of the Cpd1-6 with various functional groups was also evaluated. Cpd6 with ketone, amine and four −CH3 found with best activity with a maximum percentage inhibition Mean±SEM 71.72±2.84 and IC

Problems caused by isopod parasites in commercial fishes.

Crustaceans are found in every type of aquatic ecosystem, and there are species adapted to extremes of temperature, pressure, salinity, and even anoxia. Parasitic isopods are typically marine and usually inhabit the warmer seas. They are blood-feeding; several species settle in the buccal cavity of fish, others live in the gill chamber or on the body surface including the fins. Isopods can cause morbidity and mortality in captive fish populations. The damage of gill filaments thus was not only due to the feeding but also by the pressure exerted by the dorsal side of the parasite. Erosion of gill lamellae, damage of gill rakers and pale gills were the severe gross lesions observed as a consequence of isopod infestation. Infested fish exhibited histopathological anomalies such as tissue reactions, primarily associated with the formation of granulomas consisted of macrophages and epithelioid cells, which are occasionally surrounded by a thin rim of fibroblasts. A marked increase in the size of the parasite is associated with the development of marsupium full of juvenile parasite. The infestation usually pressure atrophy often accompanies the presence of larger parasites. They may lead to economic losses in commercial species of fish. Thus, treating fishes infected with isopods without treating their environment may only provide temporary relief. It is also important to recognize the potential for secondary infections associated with severe isopod infections.

Antimicrobial activity of marine sponge Clathria indica (Dendy, 1889)

Sponges are sessile filter feeders that have developed efficient defense mechanisms against foreign invaders such as viruses, bacteria or eukaryotic organisms. Antimicrobial peptides are known as major components of the innate immune defense system in marine invertebrates. The aim of the present work was to study the antimicrobial properties of the Indian sponge Clathria indica with special reference to the identification of antimicrobial peptides. Crude methanolic extract and its chloroform, n-butanol and aqueous fractions were tested against 16 human pathogens which include eleven bacteria with four of them being multidrug resistant and five pathogenic fungi. All fractions showed effective antibacterial activity against common and multidrug-resistant Salmonella typhi and antifungal activity against C. albicans and C. neoformans. However, they were ineffective against Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes and Staphylococcus aureus. Chloroform fraction being the most potent among the fractions tested on chemical investigation was indicative of the presence of peptides as evidenced by ninhydrin positive spots on TLC and presence of peptide bonds by NMR. Its ESI-MS showed presence of several peptides in the range of m/z 850 to 980. Structure of three peptides has been tentatively assigned by ESI-MS/MS or tandem mass analysis, on the basis of the amino acid sequence established. The results clearly show that the sponge C. indica represent an interesting source of marine invertebrates-derived antimicrobial peptides in the development of new strategies to treat various infectious diseases.