Muthuvel Arumugam

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

Abstract Objective To evaluate the in vitro antioxidant activity of Sargassum wightii ( S. wightii ) and Ulva 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.

Studies on bioprospecting potential of a gastropod mollusc Cantharus tranquebaricus (Gmelin, 1791)

OBJECTIVE To study the biological activities of the tissue extract of Cantharus tranquebaricus (C. tranquebaricus). METHODS Crude extract of gastropod was tested for inhibition of bacterial growth. Antibacterial assay was carried out by disc diffusion method and the activity was measured accordingly based on the inhibition zone around the disc impregnated with gastropod extract. Molecular weight of the extract was determined by using SDS-PAGE. Plasma coagulation, Fibrin plate assay and substrate SDS-PAGE were used to determine the effect of sample on plasma coagulation, fibrin (ogen) olytic and proteolytic activity. RESULTS The maximum inhibition zone (10 mm) was observed against Vibrio cholera (V. cholera) and minimum inhibition zone (2 mm) was noticed against Proteus mirablis (P. mirablis). The molecular weight was determined as 47-106 kDa. The tissue extract shows proteolytic activity above 48 kDa. SDS-PAGE analysis of fibrinogen after incubation with the tissue extract showed fibrinogenolytic activity. In plasma coagulation assay C. tranquebaricus tissue extract showed procoagulant property and it coagulated chicken plasma within 150 s, while control took 5 min to clot. The 9 HU hemolytic units were found against chicken blood and also exhibit high level of brine shrimp lethality. CONCLUSIONS This study suggests that C. tranquebaricus could be used as potential source for isolating bioactive compounds, since it is explored first time and found with promising results.

Isolation and Characterization of Hyaluronic Acid from Marine Organisms

Hyaluronic acid (HA) being a viscous slippery substance is a multifunctional glue with immense therapeutic applications such as ophthalmic surgery, orthopedic surgery and rheumatology, drug delivery systems, pulmonary pathology, joint pathologies, and tissue engineering. Although HA has been isolated from terrestrial origin (human umbilical cord, rooster comb, bacterial sources, etc.) so far, the increasing interest on this polysaccharide significantly aroused the alternative search from marine sources since it is at the preliminary level. Enthrallingly, marine environments are considered more biologically diverse than terrestrial environments. Although numerous methods have been described for the extraction and purification of HA, the hitch on the isolation methods which greatly influences the yield as well as the molecular weight of the polymer still exists. Adaptation of suitable method is essential in this venture. Stimulated by the developed technology, to sketch the steps involved in isolation and analytical techniques for characterization of this polymer, a brief report on the concerned approach has been reviewed.

Isolation and Structural Elucidation of Antioxidant Peptides from Oyster (Saccostrea cucullata) Protein Hydrolysate

Protein derived from the oyster (Saccostrea cucullata) was hydrolyzed using protease from Bacillus cereus SU12 for isolation of antioxidant peptides. The oyster hydrolysate exhibited a strong antioxidant potential in DPPH (85.7±0.37%) followed by Hydrogen peroxide radical scavenging activity (81.6±0.3%), Hydroxyl radical-scavenging activity (79.32±0.6%), Reducing power assay (2.63±0.2 OD at 700nm). Due to the high antioxidant potential, hydrolysate was fractionated in Sephadex G-25 gel filtration chromatography. The active peptide fraction was further purified by UPLC-MS. Totally 7 antioxidant peptides were collected. Among 7 peptides (SCAP 1-7), 3 peptides (SCAP 1, 3 and 7) had highest scavenging ability on DPPH radicals. The amino acid sequence and molecular mass of purified antioxidant peptides (SCAP1, SCAP3 and SCAP7) were determined by Q-TOF ESI mass spectroscopy and structures of the peptides were Leu-Ala-Asn-Ala-Lys (MW=515.29Da), Pro-Ser-Leu-Val-Gly-Arg-Pro-Pro-Val-Gly-Lys-Leu-Thr-Leu (MW=1432.89Da) and Val-Lys-Val-Leu-Leu-Glu-His-Pro-Val-Leu (MW=1145.75Da), respectively. The unique amino acid composition and sequence in the peptides might play an important role in expression of their antioxidant activity. The results of this study suggest that oyster protein hydrolysate is good source of natural antioxidants.

Antiproliferative activity of marine stingray Dasyatis sephen venom on human cervical carcinoma cell line

BackgroundVenoms comprise mixtures of numerous bioactive compounds that have a wide range of pharmacologic actions. Toxins from venomous animals have attracted the attention of researchers because of their affinity for primary sites responsible for lethality and their efficacy at extremely low concentrations. The venoms of marine stingrays have not been extensively studied and limited data is available on them. The present study aims to evaluate the antiproliferative and biochemical properties of the venom obtained from a species of marine stingray (Dasyatis sephen) on human cervical cancer cell line HeLa.MethodsThe antiproliferative effect of D. sephen venom was determined by MTT assay, and the oxidative stress was determined by lipid peroxidation method along with assessment of changes in the enzymatic and non-enzymatic antioxidant status. We observed intracellular reactive oxygen species (ROS) levels by DCFH-DA method, mitochondrial membrane potential alterations by rhodamine 123 staining and apoptotic morphological changes by acridine orange/ethidium bromide dual staining method.ResultsD. sephen venom enhances lipid peroxidative markers such as thiobarbituric acid reactive substance, conjugated diene, and lipid hydroperoxide in HeLa cell lines. Stingray venom enhances the ROS levels, which is evidenced by the increased 2–7-diacetyl dichlorofluorescein fluorescence. Further, D. sephen venom treatment altered the mitochondrial membrane potential in HeLa cells. Additionally, we observed increased apoptotic morphological changes in D. sephen venom-treated groups.ConclusionsDasyatis sephen venom exhibits potent antiproliferative effect on HeLa cell line and upon further purification it could be a promising antiproliferative agent.

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

OBJECTIVE To evaluate the antiangiogenic potential of twenty two marine invertebrate species of Phylum Mollusca from south east coast of India. METHODS 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. RESULTS 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. CONCLUSIONS The significant antiangiogenic activity evinced by the extract of Telescopium telescopium merits further investigation for ocular neovascular diseases.

Purification and characterization of protease from Bacillus cereus SU12 isolated from oyster Saccostrea cucullata

Protease-producing bacterium Bacillus cereus SU12 was isolated from oyster Saccostrea cucullata . Fifteen strains of bacteria were isolated from oyster S. cucullata and screened for secretion of protease on casein agar plates. Among them, SU12 isolate was selected due to its high enzyme production capacity and was identified as B. cereus SU12 on the basis of its morphological, biochemical and 16S rDNA properties. Media and cultivation conditions were studied to optimize bacterial growth and protease production which includes different carbon and nitrogen sources, in addition to different factors such as incubation time, pH, temperature, NaCl concentrations. At pH 7, temperature 40°C and 2.5% NaCl concentration, carbon source such as starch and beef extract as nitrogen source, the protease activity was maximum. Extracellular protease was isolated, purified to 8.73 fold by diethyl aminoethyl (DEAE) ion-exchange chromatography and its specific activity was determined to be 886.56 U/mg and the sodium dodecyl sulfate poly-acrylamide gel electrophoresis (SDS-PAGE) showed a single band for the purified enzyme, with an apparent molecular weight of 66 kDa. These findings suggest that the scope for the use of B. cereus SU12 strain as suited organism for the industrial production of the extracellular protease enzyme. Keywords: Protease, Bacillus cereus SU12, Oyster, diethyl aminoethyl (DEAE) ion-exchange chromatography, optimization. African Journal of Biotechnology Vol. 12(40), pp. 5897-5908

Antioxidant Properties of Protein Hydrolysate Obtained from Oyster Saccostrea cucullata (Born, 1778)

The antioxidant activities of enzymatically hydrolyzed (protease from Bacillus cereus SU12) oyster (Saccostrea cucullata) protein were studied. The hydrolysate exhibited a strong antioxidant potential in 1, 1-diphenyl-2-picrylhydrazyl (DPPH, 85.7 ± 0.37%), followed by hydrogen peroxide radical scavenging activity (81.6 ± 0.3%), hydroxyl radical scavenging activity (79.32 ± 0.6%), and reducing power assay (2.63 ± 0.2 OD at 700 nm) at a concentration of 1 mg/mL. Due to the high antioxidant potential, the hydrolysate was purified in Sephadex G-25 gel filtration chromatography. The active peptide fraction was identified by DPPH and reducing power assay. The amino acid content of the purified active peptide fraction was analyzed by high performance liquid chromatography. The active fraction contained a good quantity of both essential and nonessential amino acids. The present study revealed that oyster (S. cucullata) protein hydrolysate is a potential source for natural antioxidants.

Biological Activities of Heparan Sulfate

Heparan sulfate was isolated from two bivalve mollusks such as Tridacna maxima and Perna viridis. The isolated heparin was quantified in crude as well as purified samples and they were estimated as 2.72 and 2.2g/kg (crude) and 260 and 248 mg/g (purified) in T. maxima and P. viridis, respectively. Both the bivalves showed the anticoagulant activity of the crude and purified sample as 20,128 USP units/kg and 7.4 USP units/mg, 39,000 USP units/kg and 75 USP units/mg, 9460 USP units/kg and 4.3 USP units/mg, and 13,392 USP units/kg and 54 USP units/mg correspondingly in T. maxima and P. viridis. The antiproliferative activity that was studied with pulmonary artery smooth muscle cells using RPMI media reported that the result is in a dose-dependent manner. Among the two clams, P. viridis showed more antiproliferative activity than that of T. maxima.

Evaluation of astaxanthin incorporated collagen film developed from the outer skin waste of squid Doryteuthis singhalensis for wound healing and tissue regenerative applications

The present investigation was aimed to evaluate in vivo wound healing activity of astaxanthin incorporated collagen hydrogel film biomaterials extracted from the outer skin waste of squid Doryteuthis singhalensis, to releases antibiotic, delivering potentialities of excisional and incisional wound model in Wistar rats. These results suggested that the astaxanthin incorporated collagen film (ACF) and gentamicin incorporated collagen film (GCF) exhibited excellent wound healing activity (71%) in both full thickness excision and linear incision in rats. The in-vitro antioxidant abilities of extracted astaxanthin exhibited strongly significant 1,1‑diphenyl‑2‑picrylhydrazyl (DPPH) radical scavenging activity. In addition, tensile strength, epithelialization, hydroxyproline content and protein content in ACF and GCF treated groups were significantly increased. Histopathological assessment revealed an increase in collagen content, fibroblasts, granulation, thickness of scar formation, effective neovascularization and faster epithelialization within the short duration after the treatment of ACF and GCF compared to the control groups. The structure of prepared ACF and GCF biomaterials were characterized by SEM, EDS, and XRD. The in vivo biological study of the collagen-based film releases the antibiotic substance. The composite of collagen based biomaterials displays a promising biocompatibility through the dermal wound healing process as well as an evidence of biodegradability. Thus, the marine-derived biomaterials gave a substantial pledge for the development of biodegradable materials in drug delivery and soft tissue regeneration process.