Namasivayam Subhapradha

Physicochemical characterisation of β-chitosan from Sepioteuthis lessoniana gladius

β-Chitin and its chitosan from the gladius of Sepioteuthis lessoniana have been isolated, purified, characterised and compared with the commercial chitosan. Ash, moisture, mineral, metal and elemental content were analyzed using standard techniques. The optical activity of chitin was found to be levorotatory. The degree of deacetylation was calculated by potentiometric titration and (1)H NMR. Viscosity average molecular weight of β-chitosan was calculated by viscometry and size average molecular weight by GPC. The structure of β-chitosan was elucidated with FT-IR and NMR. Thermal nature, crystalline structure and morphology of β-chitosan were characterised through DSC, XRD and SEM, respectively. The water and fat binding capacity of β-chitosan presently studied was significantly higher than that of the commercial chitosan. The result of the present study adds that S. lessoniana gladius is also an additional source of β-chitin and chitosan of higher yield, lower molecular weight and higher degree of deacetylation.

Extraction, characterization and antioxidant property of chitosan from cuttlebone Sepia kobiensis (Hoyle 1885).

Chitin was extracted from the cuttlebone of Sepia kobiensis and chitosan was prepared through deacetylation. The chitosan was characterized for its structural, physical and thermal (CHN, DDA, FT-IR, NMR, XRD, Viscometric analysis, SEM and DSC) properties. Further, the chitosan exhibited the antioxidant activity of 50.68-74.36% at 1-10 mg ml(-1) and it also showed the reducing power of 0.28% at 1 mg ml(-1). At 10 mg ml(-1), the chitosan exhibited the scavenging ability of 46.17%, on 1,1-diphenyl-2-picrylhydrazyl radicals, 23.38-73.70% on superoxide radicals at 0.05-1.6 mg ml(-1) and 18.34% to 62.39% (0.1-3.2 mg ml(-1)) on hydroxyl radicals; whereas at 1-10 mg ml(-1) the chelating ability on ferrous ions was calculated as 49.74-73.59%. Based on the potential antioxidant activity, scavenging ability on hydroxyl radicals and chelating abilities on ferrous ions, the chitosan from the cuttlebone of S. kobiensis may not only be used as a potent natural antioxidant but also as a possible food quality enhancer ingredient in the pharmaceutical industry.

Screening of antimicrobial potential of polysaccharide from cuttlebone and methanolic extract from body tissue of Sepia prashadi Winkworth, 1936

Objective: To evaluate the antimicrobial activity of polysaccharide from cuttlebone and methanolic extract from body tissue of Sepia prashadi, against ten human pathogenic bacteria and five fungi. Methods:The activity of polysaccharide and methanolic extract was investigated against Vibrio cholerae, Pseudomonas aeruginosa, Klebsiella pneumoniae, Vibrio alginolyticus, Staphylococcus aureus, Vibrio parahaemolyticus, Streptococcus sp., Streptococcus pneumoniae, Salmonella sp. and Escherichia coli, and five fungal strains such as Alternaria alternata, Candida tropicalis, Penicillium italicum, Fusarium equiseti and Candida albican using disc diffusion method and minimum inhibitory concentration (MIC) were also calculated. Results:Both polysaccharide and methanolic extract was active against gram positive than that of gram negative pathogenic bacteria but inactive against fungi. The MIC of both the extract ranging from 60 to 100 mg/mL. Conclusions: These results suggest that cephalopod polysaccharide and methanolic extract possess relatively good antibacterial activity.

Antioxidant and anticoagulant activity of sulfated polysaccharide from Gracilaria debilis (Forsskal).

Sulfated polysaccharide was isolated from Gracilaria debilis and purified through gel chromatography and their molecular weight was determined through AGE and PAGE. The total sugars in the crude, fractionated and purified polysaccharide were estimated as 52.65%, 59.70% and 67.60%, respectively. The ash and moisture content of crude and purified polysaccharide was found to be 14.2% and 23.5% and the polysaccharide was free from protein contamination. The sulfate and uronic acid contents in the crude, fractionated and purified were estimated as 14.08%, 15.33% and 16.01% and 10.12%, 13.56%, 16.70%. The elemental composition including carbon (crude - 23.12%, purified - 21.05%), hydrogen (crude - 3.4%, purified - 4.13%) and nitrogen (crude - 1.22%, purified - 0.56%) were also analyzed. The anticoagulant activity of the sulfated polysaccharide through APTT and PT was estimated at 14.11 and 8.23IU/mg. The purified polysaccharide with the molecular mass of 20kDa showed highest antioxidant activity (38.57%, 43.48% and 38.88%) in all the assays tested such as DPPH hydroxyl radical, superoxide radical, hydroxyl radical scavenging activities and the structural property was analyzed through FT-IR and (1)H NMR spectrum. The results together suggest that the isolated low molecular weight sulfated polysaccharide will demonstrate as a enormously available alternative natural source of antioxidant for industrial uses.

Protective effect of chitosan from Sepia kobiensis (Hoyle 1885) cuttlebone against CCl4 induced hepatic injury.

Carbon tetrachloride (CCl4) is a potent hepatotoxic agent causing hepatic necrosis and it is widely used in animal models for induction of acute and chronic liver damage. The antioxidative and hepatoprotective effects of chitosan from Sepia kobiensis against CCl4 induced liver toxicity in Wistar rats was studied by measuring the activity of lipid peroxidation (TBARS, lipid hydroperoxides), non enzymatic antioxidant (GSH), antioxidant enzyme activities (SOD, CAT and GPx), liver marker enzymes (ALT and AST), lipid profile (FFA, TG, cholesterol and HDL cholesterol) and histopathological changes. Rats treated with chitosan against CCl4 toxicity showed significantly decreased levels of ALT and AST activities, total cholesterol, triglyceride and free fatty acid in plasma and tissue. Whereas the treatment with chitosan along with CCl4 showed markedly increased level of hepatic and circulatory in SOD, CAT, GPx and reduced glutathione and decreased the malondialdehyde level. Histopathological observations proved the marked hepatoprotective effect of chitosan. The CCl4 induced alterations in circulatory and hepatic antioxidant defense system were normalized by chitosan and it could be concluded that the hepatoprotective effect of chitosan may be due to its antioxidant and antilipidemic properties.

Hepatoprotective Effect of β-Chitosan from Gladius of Sepioteuthis lessoniana Against Carbon Tetrachloride-Induced Oxidative Stress in Wistar Rats

Chitosan has attracted much attention as a biomedical material, owing to its unique biological activities. In this study, hepatoprotective effect of β-chitosan obtained from the gladius of squid Sepioteuthis lessoniana was studied against carbon tetrachloride (CCl4)-induced oxidative stress and liver injury in rats. The rats that received β-chitosan along with the administration of CCl4 showed significantly decreased plasma and tissue alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and total cholesterol, triglyceride (TG) and free fatty acid (FFA) contents, whereas the treatment with β-chitosan alone markedly increased rat hepatic and circulatory superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) and reduced glutathione (GSH) levels and decreased the malondialdehyde level. Histopathological observations recommended the marked hepatoprotective effect of β-chitosan. The CCl4-induced alterations on circulatory and hepatic antioxidant defence system were normalised by β-chitosan, and it could be concluded that the hepatoprotective effect of chitosan may be due to its antioxidant and antilipidemic property. Therefore, β-chitosan could be considered as antihepatotoxic agent.

Fabrication of β-chitosan nanoparticles and its anticancer potential against human hepatoma cells

β-Chitosan from the gladius was enzymatically depolymerized and utilized for the synthesis of β-chitosan nanoparticles using sodium tripolyphosphate by ionotropic gelation. The size and zeta potential of β-Chitosan nanoparticles (β-CNP) were determined. The structural features were evaluated by FT-IR and NMR spectral analysis. The morphological characterization, composition and surface topography of β-CNP were explored by SEM, EDAX and AFM techniques. The thermal and crystallographic nature of β-CNP was also studied. The cell viability of HepG2 cells inhibited by β-CNP was detected in a dose-dependent manner. The inhibitory concentration of β-CNP was 30μg/ml. Various biochemical parameters such as TBARS and lipid hydroperoxides, enzymatic and non-enzymatic antioxidant (SOD, CAT, GPx and GSH) studies proved the anticancer property of β-CNP in HepG2 cells. This study suggests that β-CNP should be a promising drug for treating hepatocellular carcinoma in future.

In vitro evaluation of antimicrobial activity of methanolic extract from selected species of Cephalopods on clinical isolates

Bioactive substances from marine biota have been found useful as special tools in pharmacological and biomedical research. In the present study, the in vitro antimicrobial activity of crude methanolic extracts of six species of cephalopods ( Sepia kobiensis , Sepiella inermis , Sepioteuthis lessoniana , Octopus aegina , Octopus aerolatus , Octopus dollfusi ) from Cuddalore (Southeast coast of India) was studied. The antimicrobial activity was screened against 10 species of clinically isolated human pathogenic bacteria namely Vibrio chlolerae, Pseudomonas aeruginosa, Klebsiella pnemoniae, Vibrio alginolyticus, Staphylococcus aureus, Vibrio parehaemolyticus, Streptococcus sp., Streptococcus pnemoniae, Salmonella sp . and Escherichia coli and five fungal strains such as Alternaria alternata, Candida tropicalis, Pencillium italicum, Fusarium equisetii and Candida albicans . Different concentrations such as 25, 50, 75 and 100% were prepared and tested against the microbial strains for their inhibitory activities, using the disc diffusion method. The minimum inhibitory concentration (MIC) of methanolic extract of cephalopods ranged from 60 to 100 mg/ml. The results were discussed in the light of positive and negative control apart from the concentrations tested.

Characterization of bioactive chitosan and sulfated chitosan from Doryteuthis singhalensis (Ortmann, 1891)

Chitosan was extracted from the pen of squid Doryteuthis singhalensis and characterized using FT-IR, NMR, CHN, SEM and DSC analysis. Purified chitosan was sulfated with chlorosulfonic acid in N,N-dimethylformamide and the added sulfate group was confirmed with FT-IR analysis. The molecular weight and degree of deacetylation (DDA) of chitosan was found 226.6kDa and 83.76% respectively. Chitosan exhibited potent antioxidant activity evidenced by reducing power, chelating ability on ferrous ions and scavenging activity on DPPH, superoxide and hydroxyl radicals. The anticoagulant assay using activated partial thromboplastin time (APTT) and prothrombin time (PT) showed chitosan as a strong anticoagulant. The results of this study showed possibility of using D. singhalensis pen as a non-conventional source of natural antioxidants and anticoagulant which can be incorporated in functional food formulations.

Sulfation of β-chitosan and evaluation of biological activity from gladius of Sepioteuthis lessoniana.

β-Chitosan extracted from the gladius of Sepioteuthis lessoniana was sulfated with chlorosufonic acid. The structural features of sulfated chitosan were analyzed by NMR spectroscopy. The elemental composition was analyzed using elemental analyzer. The molecular weight of sulfated chitosan estimated through viscometry was calculated as 12.47 × 10(4) Da. The water solubility of sulfated chitosan was found to be 81%. The sulfated chitosan was able to scavenge the DPPH, superoxide and hydroxyl radicals and the inhibitory concentration (IC50) of those free radicals was found to be 4, 0.428 and 0.473 mg/ml respectively. Sulfated chitosan also showed reducing and chelating property. The IC50 value of reducing and chelating ability was found to be 0.316 and 5.64 mg/ml respectively. The anticoagulant activity was determined for human plasma with respect to activated partial thromboplastin time and prothrombin time and it was 7.13 IU and 1.26 IU, respectively.