Kalpa W. Samarakoon

Purification and Determination of Two Novel Antioxidant Peptides from Flounder Fish (paralichthys olivaceus) Using Digestive Proteases

We investigated the effects of bioactive-peptides from hydrolysates of flounder fish muscle (FFM) on antioxidant activity. The hydrolysates were prepared by enzymatic reactions of FFM using eight commercial proteases such as papain, pepsin, trypsin, neutrase, alcalase, kojizyme, protamex, and α-chymotrypsin. The α-chymotrypsin hydrolysate showed the strongest antioxidant activity among the eight enzymatic hydrolysates. Further separation of the α-chymotrypsin hydrolysate was performed by ultrafiltration, gel filtration, and reverse-phase high performance liquid chromatography. Consequently, two novel peptides with high antioxidant activity were purified, and their amino acid sequences were determined (Val-Cys-Ser-Val [VCSV] and Cys-Ala-Ala-Pro [CAAP], respectively). The two peptides showed good scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical (IC(50) values, 111.32 and 26.89 μM, respectively) and high cytoprotective activities against 2,2-azobis-(2-amidino-propane) dihydrochloride (AAPH) without cytotoxicity and scavenged total reactive oxygen species in Vero cells. In particular, apoptotic bodies produced by AAPH dose-dependently decreased following treatment with the CAAP peptide. These results revealed firstly the two peptides with strong antioxidative effects from FFM.

In vitro and in vivo antioxidant activities of polysaccharide purified from aloe vera (Aloe barbadensis) gel

The in vitro and in vivo antioxidant potentials of a polysaccharide isolated from aloe vera gel were investigated. Enzymatic extracts were prepared from aloe vera gel by using ten digestive enzymes including five carbohydrases and five proteases. Among them, the highest yield was obtained with the Viscozyme extract and the same extract showed the best radical scavenging activity. An active polysaccharide was purified from the Viscozyme extract using ethanol-added separation and anion exchange chromatography. Purified aloe vera polysaccharide (APS) strongly scavenged radicals including DPPH, hydroxyl and alkyl radicals. In addition, APS showed a protective effect against AAPH-induced oxidative stress and cell death in Vero cells as well as in the in vivo zebrafish model. In this study, it is proved that both the in vitro and in vivo antioxidant potentials of APS could be further utilized in relevant industrial applications.

Protective effect of a marine polyphenol, dieckol against carbon tetrachloride-induced acute liver damage in mouse

In this study, the hepatoprotective effect of dieckol on carbon tetrachloride (CCl4) induced hepatic damages in ICR mice liver was investigated. Mice were randomly divided into 4 groups such as saline treated (negative control), CCl4 treated (positive control), CCl4+dieckol (5mg/kg mouse) and CCl4+dieckol (25mg/kg mouse), respectively. The body weights and survival rates of mice, followed by dieckol treatments were significantly increased compared to the positive control. The level of GOT, GPT and MDA in the serum of the dieckol treated groups were reduced dose dependently than the control, significantly. The antioxidant enzymes including CAT, and GSH-px levels were increased significantly compared to the positive control. However, no significant differences were observed on hepatic histophathological analysis in dieckol treated groups dose dependently. Down-regulation of Bax and up-regulation of Bcl-xl protein expressions were observed in liver tissues of the dieckol administered groups. These results suggested that, dieckol can be developed as a therapeutic agent for liver disease by oxidative stress.

Preparative isolation of sargachromanol E from Sargassum siliquastrum by centrifugal partition chromatography and its anti-inflammatory activity

Centrifugal partition chromatography (CPC) can be used to isolate various bioactive compounds from natural materials by one-step. We confirmed antioxidative compounds existed in chloroform (CHCl3) fraction of Sargassum siliquastrum using online-HPLC. Fractions (A, B, C, D and E) were separated from the CHCl3 fraction by preparative CPC (n-hexane:ethyl acetate:methanol:water, 5:5:7:3, v/v). In this study, we proved that the isolated compounds exhibit anti-inflammatory activities using lipopolysaccharide (LPS) stimulated RAW 264.7 macrophages. The fraction A which exhibited the strongest inhibitory effect on nitric oxide (NO) production level, was confirmed as sargachromanol E by LC-MS-ESI, (1)H NMR and (13)C NMR data. The sargachromanol E significantly reduced the inflammatory response in LPS induced macrophages, decreasing LPS-induced transcription factor of pro-inflammatory cyclooxygenase-2, NO synthase, phosphate P38, phosphate ERK1/2, LPS-stimulated tumor-necrosis factor alpha, interleukin-1 beta and prostaglandin E2 release. In conclusion, it was suggested that sargachromanol E inhibited inflammation in LPS induced RAW 264.7 cells via MAPK pathway.

The Growth, Innate Immunity and Protection against H 2 O 2 -Induced Oxidative Damage of a Chitosan-Coated Diet in the Olive Flounder Paralichthys olivaceus

We demonstrate enhanced growth, innate immunity and protection against hydrogen peroxide (H2O2)-induced protein oxidation and cellular DNA damage in olive flounder Paralichthys olivaceus fed a chitosan-coated moist pallet (MP) diet. A chitosanbased biopolymer coated MP as the experimental diet and a non-coated MP (control) was fed to olive flounder fish. Growth, including the average weight gain (g/fish), weight gain (%) and feed intake (g) of the fish group fed a chitosan-coated MP diet increased significantly. The survival rate was reported as 100% throughout the experimental period. Immunological parameters indicated higher mucus lysozyme activity and significantly higher fish skin mucus total protein content was observed in fish fed the chitosan-coated MP diet compared to the control. A blood plasma analysis revealed attenuation of cellular DNA and protein oxidative damage caused by H2O2-induced oxidative stress in the fish fed the chitosan-coated MP diet compared to the control group. Moreover, blood serum biochemical analysis revealed health-promoting effects, including significantly higher hemoglobin and total cholesterol levels in the fish fed the chitosan-coated MP diet compared to the control group. In conclusion, growth, in nate immunity and protection against oxidative stresses were improved by feeding of the chitosan-coated MP diet to olive flounder reared in aquaculture.

Purification of antioxidative peptide from peptic hydrolysates of Mideodeok (Styela clava) flesh tissue

In this study, an antioxidative peptide was obtained by hydrolyzation of mideodeok (Styela clava) flesh tissue with various proteases and purified through gel filtration chromatography and reverse phage-HPLC (RPHPLC), and then antioxidant activity was investigated using electron spin resonance (ESR) spectrometer. Among the enzymatic hydrolysates, the peptic hydrolysate exhibited the highest antioxidant activity, and a strong antioxidant peptide was purified from the hydrolysate. The peptide sequence, Leu-Trp-His-Thr-His (692.2 Da), was identified by quardruple time-of-flight electrospray ionization (QTOF ESI)-MS. This antioxidative peptide strongly scavenged peroxyl radical with the IC50 value of 39.4 μM.

A fucoidan fraction purified from Chnoospora minima; a potential inhibitor of LPS-induced inflammatory responses

Fucoidans are an interesting group of bioactive sulfated polysaccharides abundant in brown seaweeds. The current study highlights the enrichment and extraction of fucoidan from Chnoospora minima by means of enzyme-assistant extraction using Celluclast and evaluation of its anti-inflammatory potential through in vitro and in vivo studies. The purified C. minima fucoidan (F2,4) inhibited the nitrous oxide (NO) production (IC50=27.82±0.88μg/ml) and expression of PGE2 through the subsequent downregulation of iNOS and COX-2 expression in lipopolysaccharide (LPS) stimulated RAW 264.7 macrophages. F2,4 downregulated TNF-α, IL1-β, and IL-6 in RAW 264.7 macrophages in a dose-dependent manner and suppressed NO and ROS production in LPS stimulated zebrafish embryos while exerting a protective effect against the cell damage caused by LPS. Polysaccharide structural characterization was performed using FTIR, HPAE-PAD analysis of the monosaccharide content and NMR spectroscopy. Current findings confirm the potential anti-inflammatory activity of fucoidan purified from C. minima and elaborate its potential application as a functional ingredient in consumer products.

Antibacterial effect of citrus press-cakes dried by high speed and far-infrared radiation drying methods

In this study, the antibacterial effect was evaluated to determine the benefits of high speed drying (HSD) and far-infrared radiation drying (FIR) compared to the freeze drying (FD) method. Citrus press-cakes (CPCs) are released as a by-product in the citrus processing industry. Previous studies have shown that the HSD and FIR drying methods are much more economical for drying time and mass drying than those of FD, even though FD is the most qualified drying method. The disk diffusion assay was conducted, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined with methanol extracts of the dried CPCs against 11 fish and five food-related pathogenic bacteria. The disk diffusion results indicated that the CPCs dried by HSD, FIR, and FD prevented growth of all tested bacteria almost identically. The MIC and MBC results showed a range from 0.5-8.0 mg/mL and 1.0-16.0 mg/mL respectively. Scanning electron microscopy indicated that the extracts changed the morphology of the bacteria cell wall, leading to destruction. These results suggest that CPCs dried by HSD and FIR showed strong antibacterial activity against pathogenic bacteria and are more useful drying methods than that of the classic FD method in CPCs utilization.

Future Prospects and Health Benefits of Functional Ingredients from Marine Bio-resources: A review

The marine ecosystem represents a vast and dynamic array of bio-resources attributed with itshuge diversity and considered as potential untapped reservoirs for the development of functional foods for future health markets. Basically, marine microorganisms, sponges, algae, invertebrates such as crustaceans and mollusks along with marine fish species can be considered as marine bio-resources, which can be utilized to obtain different health benefits for humans, directly or after processing. Most of the bio-molecular components, such as lipids and proteins from these marine bio-resources, which can be extracted in large scale using the modern and advanced biotechnological approaches, are suitable drug candidates for the pharmaceutical industry as well as functional food ingredients for the food industry. Moreover, the furtherance of high throughput molecular biological techniques has already been incorporated with identification, mining and extraction of molecular components from marine bio-resources. In this review, potential marine bio-resources with respect to their extractable bio-molecules were described in details, while explaining the present and prospective methods of identification and extraction, which are integrated with advanced techniques in modern biotechnology. In addition, this provides an overview of future trends in marine biotechnology.

Marine-Derived Pharmaceuticals and Future Prospects

Over the last decades, the ocean has been identified as a sustained source for the requirements of human beings. The marine environment has an enormous biodiversity and is a source with huge potential for scientific applications. Among the potentials, the pharmaceutical perspective has been identified as having an important and substantial role for future therapeutic uses. Marine-derived secondary metabolites have become a promising source for the design and development of drugs. Therefore, in this chapter, we describe the recent findings of marine derived-secondary metabolites, including halogenated terpenes, steroids and sterols, and polyphenols, along with their therapeutic potentials. Marine proteins and lipids are also targeted to speculate on their role in human health. Moreover, molecular biology approaches and future trends in pharmaceuticals with a view of current drug developments will also be discussed.