Inhibitory effect of chitooligosaccharides on matrix metalloproteinase-9 in human fibrosarcoma cells (HT1080)

Antimicrobial and anticarcinogenic activity of bioactive peptides derived from abalone viscera (Haliotis fulgens and Haliotis corrugata)

Bioactive peptides have been studied in several sources due to their valuable potential in the pharmaceutical and food industries. Abalone viscera, which are normally discarded as byproducts, are a rich source of protein. Thus, the aim of this study was to explore the potential bioactivity of peptides derived from abalone viscera (Haliotis fulgens and Haliotis corrugata) after hydrolysis with a commercial mixture of enzymes. The hydrolysates obtained were fractionated using gel filtration chromatography. The resulting hydrolysate fractions were investigated for their antimicrobial and cytotoxic activities, including the expression of gelatinases mmp-2 and mmp-9 in human prostate cancer cell lines (PC3). Results showed antimicrobial activity for protein fractions of H. corrugata against Proteus mirabilis and Pseudomona aeuroginosa (66.2-116.25 kDa), Bacillus subtilis (6.5-21.5 kDa), and Aspergillus niger (97.4-116.25 kDa), while H. fulgens peptide fractions (200-31 kDa) displayed activity against six bacterial strains, and fractions from 116.25 to 21.5 kDa had effects on the fungus A. niger, Alternaria alternata, and Aspergillus flavus. Additionally, protein fractions displayed cytotoxic activity, inhibiting 30.4-53.8% of PC3 cellular growth. Selected fractions decreased the PMA-induced and not-induced expressions of mmp-2 and mmp-9 in PC3 cells. Abalone viscera, as byproducts, can be used as a potential source of antimicrobial and anticancer peptides.

Self-assembled chitosan derived microparticles inhibit tumor angiogenesis and induce apoptosis in Ehrlich-ascites-tumor bearing mice

Self-assembled microparticles from chitosan (SAMC) was prepared by depolymerization induced by potassium persulfate. Particle size distribution data showed averaged around 5 μm size and SEM indicated the sequential formation of "RBC" shaped particles. Soluble SAMC consists of 'deacetylated' residues as revealed by ¹³C NMR. SAMC showed antitumor efficacy in human breast cancer cell lines through mitigation in cell proliferation, colony formation and cell migration. Anti-tumor and anti-angiogenic properties of SAMC was found in vivo Ehrlich ascites tumor (EAT) bearing mice model resulting in tumor growth inhibition (EAT control, 17.4 ml; SAMC treated, 6.8 ml) and improved survival potency (15 days). Moreover, the decrease in ascites VEGF secretion (EAT control, 1354 ng; SAMC treated, 351 ng) accompanied with reduction in neovessel formation. Apoptosis induction by SAMC was confirmed by DNA fragmentation, caspase activities and fluorescence staining methods respectively. SAMC may be a safe candidate for anti-tumor dietary supplement production in food industry.

The impact of chitooligosaccharides and their derivatives on the in vitro and in vivo antitumor activity: A comprehensive review

Chitooligosaccharides (COS) are the degraded products of chitin or chitosan. COS is water-soluble, non-cytotoxic to organisms, readily absorbed through the intestine, and eliminated primarily through the kidneys. COS possess a wide range of biological activities, including immunomodulation, cholesterol-lowering, and antitumor activity. Although work on COS goes back at least forty years, several aspects remain unclear. This review narrates the recent developments in COS antitumor activities, while paying considerable attention to the impacts of physicochemical properties (such as molecular weight and degrees of deacetylation) and chemical modifications both in vitro and in vivo. COS derivatives not only improve some physicochemical properties, but also expand the range of applications in drug and gene delivery. COS (itself or as a drug carrier) can inhibit tumor cell proliferation and metastasis, which might be attributed to its ability to stimulate the immune response along with its anti-angiogenic activity. Further, an attempt has been made to report limitations and future research. The potential health benefits of COS and its derivatives against cancer may offer a new insight on their applications in food and medical fields.

Cloning and Characterization of a New Chitosanase From a Deep-Sea Bacterium Serratia sp. QD07

Chitosanase is a significant chitosan-degrading enzyme involved in industrial applications, which forms chitooligosaccharides (COS) as reaction products that are known to have various biological activities. In this study, the gene csnS was cloned from a deep-sea bacterium Serratia sp. QD07, as well as over-expressed in Escherichia coli, which is a new chitosanase encoding gene. The recombinant strain was cultured in a 5 L fermenter, which yielded 324 U/mL chitosanases. After purification, CsnS is a cold-adapted enzyme with the highest activity at 60°C, showing 37.5% of the maximal activity at 0°C and 42.6% of the maximal activity at 10°C. It exhibited optimum activity at pH 5.8 and was stable at a pH range of 3.4–8.8. Additionally, CsnS exhibited an endo-type cleavage pattern and hydrolyzed chitosan polymers to yield disaccharides and trisaccharides as the primary reaction products. These results make CsnS a potential candidate for the industrial manufacture of COS.

Impacts of chitosan oligosaccharide (COS) on angiogenic activities

It has been proved that chitosan oligosaccharide (COS) has a more favorable therapeutic applications such as wound healing and anti-tumor treatment, and can affect angiogenesis. For better understanding the effect of COS on angiogenic activities at cellular level, COS with different concentration and degree of polymerization (DP) were used to culture human umbilical vein endothelial cells (HUVECs) in this work. Cell proliferation activity, cell morphology, cell migration and angiogenesis associated factor expression of HUVECs were evaluated. The results indicated that COS at a high concentration of 400 μg/mL (COS(400)) and DP of 6 (Chitinhexaose Hydrochloride, COS6) had inhibitory effect on angiogenic activities of HUVECs. Specifically, COS(400) and COS6 inhibited cell proliferation activity, cell migration, and vascular endothelial cell growth factor (VEGF) expression of HUVECs. While COS at a low concentration (<400 μg/mL) and suitable polymerization degrees (DP < 6) had little significant effect on cell proliferation, migration, and VEGF expression of HUVECs, showing dose-dependent effect. These findings provided insight for the potential use of COS, for broadening its future applications in biomedical fields and functional materials area. It also helped guide the design and synthesis of chitosan-based materials as an angiogenesis inhibitor for anti-angiogenic therapy.

In situ synthesis of Fe3O4 nanoparticles coated by chito-oligosaccharides: physico-chemical characterizations and cytotoxicity evaluation for biomedical applications

Fe₃O₄ nanoparticles coated with chito-oligosaccharides (COS) were prepared in situ by a simple co-precipitation method through a mixing of iron ions (Fe³⁺ and Fe²⁺) and COS aqueous solutions followed by precipitation with ammonia. The impact of COS with different degree of polymerization (DP 10, 24 and 45) and degree of N-acetylation (DA) ∼ 24% and 50% (exhibiting high solubility) on the synthesis and physical properties of the coated magnetic nanoparticles was evaluated. Several advantages were found when the magnetic nanoparticles were prepared in the presence of the studied COS, such as: preparation of functionalized magnetic nanoparticles with narrower size distributions and, consequently, higher saturation magnetization (an increase of up to 22%); and an expressive increasing in the concentration of COS-coated magnetic nanoparticles (up to twice) in the cell viability test in comparison with pure Fe₃O₄ nanoparticles. Furthermore, among the analyzed samples, the magnetic nanoparticles coated by COS with DA ∼ 50% present a higher cytocompatibility. Our results allow envisioning various biomedical applications, valorizing the use of coated-magnetic nanoparticles for magnetic-field assisted drug delivery, enzyme or cell immobilization, or as a marker for specific cell tracking, among others.

Downregulation of CD147 by chitooligosaccharide inhibits MMP-2 expression and suppresses the metastatic potential of human gastric cancer

Metastasis is considered to be the major cause of mortality in patients with cancer, and gastric cancer is a highly metastatic cancer. In the present study, the anti-metastatic activity of chitooligosaccharide (COS) in human gastric cancer cells and its underlying mechanism were investigated. It was found that COS significantly inhibited SGC-7901 cell proliferation and metastasis in a dose-dependent manner, as observed by MTT, wound-healing and Transwell assays. Quantitative real-time polymerase chain reaction and western blot analysis indicated that COS could decrease the expression of cluster of differentiation 147 (CD147) and subsequently reduce matrix metalloproteinase-2 (MMP-2) expression. A clear dose-dependent inhibition of MMP-2 activity was also observed in SGC-7901 cells following treatment with COS in gelatin zymography experiments. Furthermore, overexpression of CD147 (when transfected with pEGFP-C1 plasmid) in SGC-7901 cells partially protected against COS-induced inhibition of MMP-2. The results of the present study demonstrated the potential of COS in suppressing gastric cancer metastasis, and that the CD147/MMP-2 pathway may be involved as the key mechanism of its anti-metastatic effect.

Caffeic acid-conjugated chitosan derivatives and their anti-tumor activity

In this study, we synthesized caffeic acid (CFA)-conjugated chitosan (ChitoCFA) as an anti-cancer compound. CFA was conjugated to the amine groups of chitosan (ChitoCFA) and its chemical composition was confirmed using (1)H nuclear magnetic resonance spectra, which indicates that specific peaks of CFA was observed at ChitoCFA conjugates. The anti-cancer effects of CFA and ChitoCFA were studied using CT26 colorectal carcinoma cells. In this cytotoxicity study, CFA and ChitoCFA revealed a dose-dependent decrease of cell viability while chitosan had lower cytotoxicity against tumor cells. CFA and ChitoCFA also proved an anti-proliferative effect against tumor cells. In comparison with CFA, ChitoCFA may accelerate an apoptosis of tumor cells. Furthermore, ChitoCFA demonstrated good anti-invasive efficacy at Matrigel(®) invasion assay against tumor cells. We suggest that ChitoCFA is a promising candidate as an anti-cancer compound.

Inhibition of angiogenesis by chitooligosaccharides with specific degrees of acetylation and polymerization

Chitooligosaccharides (CHOS) inhibit angiogenesis and may be used in the treatment of cancer tumors. We have studied the effect of the fraction of acetylation (FA) and the degree of polymerization (DP) on CHOS anti-angiogenic activity. We tested enzymatically produced CHOS-mixtures with FA0.15, FA0.3 and FA0.6, and DP≤12 in initial experiments with chorioallantoic membranes. All of the samples reduced the formation of new blood vessels, CHOS with FA0.3 giving the best effect. Single-DP fractions from the FA0.3 sample purified by size-exclusion chromatography (DP3-DP12) were then tested for inhibition of migration of human endothelial cells, which is an important element of the angiogenesis process. All of the fractions inhibited migration, meaning that, within the DP area tested in this study, FA is more important than DP for the effect. Generally, the results reveal that DP3-DP12 CHOS have considerable potential as anti-angiogenic compounds.

β-secretase inhibitory activity of phenolic acid conjugated chitooligosaccharides

Eight kinds of phenolic acid conjugated chitooligosaccharides (COSs) were synthesized using hydroxyl benzoic acid and hydroxyl cinnamic acid. These phenolic acid conjugated-COSs with different substitution groups, including p-hydroxyl, 3,4-dihydroxyl, 3-methoxyl-4-hydroxyl and 3,5-dimethoxyl-4-hydroxy groups, were evaluated for their inhibitory activities against β-site amyloid precursor protein (APP)-cleaving enzyme (BACE) and inhibited BACE with a ratio of 50.8%, 74.8%, 62.1%, 64.8% and 42.6%, respectively at the concentration of 1,000 μg/mL. BACE is a critical component to reduce the levels of Aβ amyloid peptide in Alzheimer's disease (AD) which is based on the amyloid cascade theory in the brain, as this protease initiates the first step in Aβ production. Among them, Caffeic acid conjugated-COS (CFA-COS) was further analysed to determine mode of inhibition of BACE and it showed non-competitive inhibition. Hence in this study, we suggest that CFA-COS derivatives have potential to be used as novel BACE inhibitors to reduce the risk of AD.

Antimetastatic activity of pinosylvin, a natural stilbenoid, is associated with the suppression of matrix metalloproteinases

Metastasis is a major cause of death in cancer patients. Our previous studies showed that pinosylvin, a naturally occurring trans-stilbenoid mainly found in Pinus species, exhibited a potential cancer chemopreventive activity and also inhibited the growth of various human cancer cell lines via the regulation of cell cycle progression. In this study, we further evaluated the potential antimetastatic activity of pinosylvin in in vitro and in vivo models. Pinosylvin suppressed the expression of matrix metalloproteinase (MMP)-2, MMP-9 and membrane type 1-MMP in cultured human fibrosarcoma HT1080 cells. We also found that pinosylvin inhibited the migration of HT1080 cells in colony dispersion and wound healing assay systems. In in vivo spontaneous pulmonary metastasis model employing intravenously injected CT26 mouse colon cancer cells in Balb/c mice, pinosylvin (10 mg/kg body weight, intraperitoneal administration) significantly inhibited the formation of tumor nodules and tumor weight in lung tissues. The analysis of tumor in lung tissues indicated that the antimetastatic effect of pinosylvin coincided with the down-regulation of MMP-9 and cyclooxygenase-2 expression, and phosphorylation of ERK1/2 and Akt. These data suggest that pinosylvin might be an effective inhibitor of tumor cell metastasis via modulation of MMPs.

Biocompatibility and Alkaline Phosphatase Activity of Phosphorylated Chitooligosaccharides on the Osteosarcoma MG63 Cell Line

Phosphorylated chitooligosaccharides (P-COS) were prepared using a H3PO4, P2O5, Et3PO4 and hexanol solvent system. The P-COS were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Thermo gravimetric-Differential Thermal Analyzer (TG-DTA), 13C NMR, 31P NMR, X-ray diffraction analysis, solubility studies, biocompatibility and Alkaline Phosphatase Activity (ALP). The results reveal that phosphorylation occurred at the C3 and C6 position of OH groups and the C2 position of NH2 group. FT-IR confirmed no decomposition in pyranose ring in P-COS even with heating and treatment in acidic conditions. The amorphous nature of P-COS was confirmed by X-ray diffraction analysis. Further, the biocompatibility and alkaline phosphatase activity of P-COS were checked against the osteosarcoma MG63 cell line at different concentrations and no cytotoxicity was observed. After 12 h and 24 h of incubation, the ALP activity of P-COS was higher compared with the control group. These results suggest that P-COS is a biocompatible material and in future P-COS could open up a number of promising pharmaceutical and clinical applications to mankind.

Marine antitumor drugs: status, shortfalls and strategies

Cancer is considered as one of the deadliest diseases in the medical field. Apart from the preventive therapies, it is important to find a curative measure which holds no loopholes and acts accurately and precisely to curb cancer. Over the past few decades, there have been advances in this field and there are many antitumor compounds available on the market, which are of natural as well as synthetic origin. Marine chemotherapy is well recognized nowadays and profound development has been achieved by researchers to deal with different molecular pathways of tumors. However, the marine environment has been less explored for the production of safe and novel antitumor compounds. The reason is a number of shortfalls in this field. Though ample reviews cover the importance and applications of various anticancerous compounds from marine natural products, in the present review, we have tried to bring the current status of antitumor research based on marine inhibitors of cancer signaling pathways. In addition, focus has been placed on the shortfalls and probable strategies in the arena of marine antitumor drug discovery.

Neuroprotective properties of chitosan and its derivatives

Neuronal cells are extremely vulnerable and have a limited capacity for self-repair in response to injury. For those reasons, there is obvious interest in limiting neuronal damage. Mechanisms and strategies used in order to protect against neuronal injury, apoptosis, dysfunction, and degeneration in the central nervous system are recognized as neuroprotection. Neuroprotection could be achieved through several classes of natural and synthetic neuroprotective agents. However, considering the side effects of synthetic neuroprotective agents, the search for natural neuroprotective agents has received great attention. Recently, an increasing number of studies have identified neuroprotective properties of chitosan and its derivatives; however, there are some significant challenges that must be overcome for the success of this approach. Hence, the objective of this review is to discuss neuroprotective properties of chitosan and its derivatives.

Anti-photoaging and photoprotective compounds derived from marine organisms

Marine organisms form a prominent component of the oceanic population, which significantly contribute in the production of cosmeceutical and pharmaceutical molecules with biologically efficient moieties. In addition to the molecules of various biological activities like anti-bacterial, anti-cancerous, anti-inflammatory and anti-oxidative etc., these organisms also produce potential photoprotective or anti-photoaging agents, which are attracting present day researchers. Continuous exposure to UV irradiation (both UV-A and UV-B) leads to the skin cancer and other photoaging complications, which are typically mediated by the reactive oxygen species (ROS), generated in the oxidative pathways. Many of the anti-oxidative and anti-photoaging compounds have been identified previously, which work efficiently against photodamage of the skin. Recently, marine originated photoprotective or anti-photoaging behavior was observed in the methanol extracts of Corallina pilulifera (CPM). These extracts were found to exert potent antioxidant activity and protective effect on UV-A-induced oxidative stress in human dermal fibroblast (HDF) cells by protecting DNA and also by inhibiting matrix metalloproteinases (MMPs), a key component in photoaging of the skin due to exposure to UV-A. The present review depicts various other photoprotective compounds from algae and other marine sources for further elaborative research and their probable use in cosmeceutical and pharmaceutical industries.

Matrix metalloproteinase inhibitors (MMPIs) from marine natural products: the current situation and future prospects

Matrix metalloproteinases (MMPs) are a family of more than twenty five secreted and membrane-bound zinc-endopeptidases which can degrade extracellular matrix (ECM) components. They also play important roles in a variety of biological and pathological processes. Matrix metalloproteinase inhibitors (MMPIs) have been identified as potential therapeutic candidates for metastasis, arthritis, chronic inflammation and wrinkle formation. Up to present, more than 20,000 new compounds have been isolated from marine organisms, where considerable numbers of these naturally occurring derivatives are developed as potential candidates for pharmaceutical application. Eventhough the quantity of marine derived MMPIs is less when compare with the MMPIs derived from terrestrial materials, huge potential for bioactivity of these marine derived MMPIs has lead to large number of researches. Saccharoids, flavonoids and polyphones, fatty acids are the most important groups of MMPIs derived from marine natural products. In this review we focus on the progress of MMPIs from marine natural products.

Matrix metalloproteinase inhibitors (MMPIs) from marine natural products: the current situation and future prospects

Matrix metalloproteinases (MMPs) are a family of more than twenty five secreted and membrane-bound zinc-endopeptidases which can degrade extracellular matrix (ECM) components. They also play important roles in a variety of biological and pathological processes. Matrix metalloproteinase inhibitors (MMPIs) have been identified as potential therapeutic candidates for metastasis, arthritis, chronic inflammation and wrinkle formation. Up to present, more than 20,000 new compounds have been isolated from marine organisms, where considerable numbers of these naturally occurring derivatives are developed as potential candidates for pharmaceutical application. Eventhough the quantity of marine derived MMPIs is less when compare with the MMPIs derived from terrestrial materials, huge potential for bioactivity of these marine derived MMPIs has lead to large number of researches. Saccharoids, flavonoids and polyphones, fatty acids are the most important groups of MMPIs derived from marine natural products. In this review we focus on the progress of MMPIs from marine natural products.