Advances in anti-cancer effects and underlying mechanisms of marine algae polysaccharides.

Cancer is a leading cause of death in both developing and developed countries. With the increase in the average global life expectancy, it has become a major health problem and burden for most public healthcare systems worldwide. Due to the fewer side effects of natural compounds than of chemotherapeutic drugs, increasing scientific attention is being focused on the development of anti-cancer drugs derived from natural sources. Marine algae are an interesting source of functional compounds with diverse health-promoting activities. Among these compounds, polysaccharides have attracted considerable interest for many years because of their excellent anti-cancer abilities. They improve the efficacy of conventional chemotherapeutic drugs with relatively low toxicity to normal human cells. However, there are few reviews summarising the unique anti-cancer effects and underlying mechanisms of marine algae polysaccharides (MAPs). Thus, the current review focuses on updating the advances in the discovery and evaluation of MAPs with anti-cancer properties and the elucidation of their mechanisms of action, including the signalling pathways involved. This review aims to provide a deeper understanding of the anti-cancer functions of the natural compounds derived from medicinal marine algae and thereby offer a new perspective on cancer prevention and therapy with high effectiveness and safety.

Restitution of epithelial cells during intestinal mucosal wound healing: The effect of a polysaccharide from the sclerotium of Lignosus rhinocerotis (Cooke) Ryvarden.

ETHNOPHARMACOLOGICAL RELEVANCE: Lignosus rhinocerotis (Cooke) Ryvarden cultivar TM02, also known as tiger's milk mushroom, is regarded as important folk medicine in Malaysia, while is used for the treatment of liver cancer, chronic hepatitis, gastric ulcer in traditional Chinese medicine. However, there is no compilation of scientific evidence that its protection for gastric, and no attempts have been made to understand how polysaccharides in Lignosus rhinocerotis might promote intestinal mucosal wound healing. AIM OF THE STUDY: This study aimed to investigate the effect and mechanism of ß-glucan prepared from L. rhinocerotis using an enzymatic method on epithelial restitution during intestinal mucosal damage. MATERIALS AND METHODS: Based on FT-IR, MALDI-TOF-MS, HPSEC-MALLS-RID, and AFM, the structure of polysaccharides from L. rhinocerotis was analysed. In addition, polysaccharides were used to test for wound healing activity in IEC-6 cells by measuring cell migration, proliferation, and expression of cell division control protein 42, Rac-1, RhoA, and Par-3. RESULTS: ß-glucan was extracted using enzyme-assisted extraction, and a yield of approximately 8.5 ± 0.8% was obtained from the dried biomass. The ß-glucan extracted by enzyme-assisted extraction (EAE) of polysaccharides was composed entirely of D-glucose with a total carbohydrate content of 95.5 ± 3.2%. The results of HPLC, FTIR, and MALDI-TOF-MS analyses revealed EAEP to be confirmed as ß-glucan. The molecular weight of prepared ß-glucan was found to be 5.315 × 104 g/mol by HPSEC-MALLS-RID. Furthermore, mucosal wound healing studies showed that the treatment of IEC-6 with a ß-glucan concentration of 200 µg/mL promoted cell migration and proliferation, and it enhanced the protein expression of cell division control protein 42, Rac-1, RhoA, and Par-3. CONCLUSIONS: The present study reveals that the prepared ß-glucan accelerates intestinal epithelial cell proliferation and migration via activation of Rho-dependent pathway. Hence, ß-glucan can be employed as a prospective therapeutic agent for the treatment of diseases associated with gastrointestinal mucosal damage, such as peptic ulcers and inflammatory bowel disease.

Physicochemical properties and potential beneficial effects of porphyran from Porphyra haitanensis on intestinal epithelial cells.

This study examined the beneficial effects of porphyran from Porphyra haitanensis (PHP) on intestinal epithelial cells, in terms of cell proliferation and migration and elucidated the potential molecular mechanism of action of PHP. Purified PHP is a homogenous polysaccharide with a molecular weight of 2.01 × 105 Da, intrinsic viscosity [η] of 463.76 mL/g, and radius of gyration of 61.2 nm. When the intestinal epithelial wound healing activity of PHP was investigated in vitro using the IEC-6 cell line (intestinal epithelial cells-6), it was found that PHP could promote cell migration and proliferation. PHP enhanced the protein expression of cell division control protein 42, paxillin, and focal adhesion kinase, which suggest that PHP might modulate the expression of these proteins to improve intestinal epithelial healing. Thus, this study indicated that PHP could serve as a potential source of functional food constituents for intestinal epithelial protection and restoration.

Anti-cancer effects of Porphyra haitanensis polysaccharides on human colon cancer cells via cell cycle arrest and apoptosis without causing adverse effects in vitro.

In this study, the anticancer effects of Porphyra haitanensis polysaccharides (PHPs) on human colon cancer cells and non-cancerous cells were evaluated. PHP was extracted by an ultrasonic/microwave-assisted method, and three fractions of polysaccharides (PHP-F1, PHP-F2 and PHP-F3) were obtained through a DEAE-52 cellulose ion-exchange column. The results of the cytotoxicity test showed that all of the PHP fractions had inhibitory effects on the growth of colon cancer cells HT-29, LoVo and SW-480, but no toxic effects on the normal human cells HaCaT. The fractions PHP-F2 and PHP-F3 had the most significant cytotoxicity on HT-29 cells. Studies on intracellular reactive oxygen species (ROS) levels, cell apoptosis, the apoptosis index (using Hoechst 33342 staining) and analysis of cell cycle arrest using flow cytometry revealed that the fractions PHP-F2 and PHP-F3 could apparently induce oxidative stress and apoptosis in HT-29 cells and cause cell G0-G1 phase arrest. These findings suggest that polysaccharides from P. haitanensis have anticancer effects on human colon cancer cells and therefore might be regarded as new candidates for the prevention and treatment of colon cancers.

Polysaccharides from Gracilaria lemaneiformis promote the HaCaT keratinocytes wound healing by polarised and directional cell migration.

In this study, we evaluated the wound healing activity of polysaccharides fractions from Gracilaria lemaneiformis. Three purified fractions, namely, GLP-1, GLP-2 and GLP-3 were obtained from anion-exchange chromatography and were evaluated for their cell proliferation activity. Among the three fractions, the fraction GLP-2 promoted cell proliferation at a concentration of 100 µg/mL. Further, chemical and structural analysis of GLP-2 revealed it to be a homogenous and repeating structure of alternating 4-linked 3,6-anhydro-α-L-galactopyranosyl and 3-linked ß-d-galactopyranosyl units with sulfate residues. Further, we analysed the wound healing activities of the fraction GLP-2 and its underlying mechanisms. The results showed that GLP-2 promotes cell proliferation and migration through activation of PI3 K/aPKC signaling during human keratinocytes wound healing. Based on the findings in this study, we concluded that the wound healing activities of the GLP-2 fraction can provide the scientific basis for the development of G. lemaneiformis polysaccharides based product for wound management.

Physicochemical characterization and antioxidant activity of sulphated polysaccharides derived from Porphyra haitanensis.

This study was designed to fully characterize Porphyra haitanensis polysaccharides, and to evaluate their antioxidant activity. The polysaccharides primarily contained galactose and 3,6-anhydrogalactose in a molar ratio of 1.2:1.0, respectively and sulfate content about 3.8%. The molecular weight of polysaccharides is 2.5 × 105 Da. Scanning electron microscopy and atomic force microscopy of the polysaccharides pointed towards an irregular network with more or less hexagonal and a few rectangular pores. The chemical structure was confirmed through Fourier transform infrared spectroscopy, and 1D and 2D nuclear magnetic resonance structural characterization wherein â†’ 4-3,6-anhydro-α-L-galactopyranose-(1 â†’ 3)-ß-D-galactopyranose segments. The extracted polysaccharides revealed relatively high 2, 2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity (53.16% at 2 mg/mL), moderate 2,2-diphenyl-1-picrylhydrazyl radical scavenging efficacy (34.63% at 2 mg/mL), and low hydroxyl radical scavenging potential (23.80% at 2 mg/mL). Further purification of these polysaccharides, hence, is advised for their potential role as antioxidants in the food, pharmaceutical and cosmeceutical industry.

Physicochemical characterization of Gracilaria chouae sulfated polysaccharides and their antioxidant potential.

A complete absence of the physicochemical characterization of Gracilaria chouae polysaccharides (GCP) and its corresponding bioactivities urged the need for this study. It was found that GCP is a heteropolysaccharide which exists in linear random coil conformation. It contained a sulfate content of 7.9% in addition to 52.63% total sugar content and 9.62% galacturonic acid. Galactose and 3,6-anhydrogalactose were found in a molar ratio of 1.0:0.6. Its setting and melting points were determined as 41.3 and 71.7 °C, respectively, which makes it a suitable candidate for industrial processing where further heating is required and/or where the end-product needs to have extended shelf life in hot climate. GCP demonstrated 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis and hydroxyl radical scavenging activity (36.86, 27.42 and 19.07% at 3 mg·ml-1). Moreover, the results also suggested its potential use as a prebiotic due to its perceived high fermentability.

Oligosaccharides Derived from Red Seaweed: Production, Properties, and Potential Health and Cosmetic Applications.

Because of their potential use as functional ingredients in human nutrition, oligosaccharides derived from natural sources are receiving paramount consideration. Red seaweed, a proven rich source of agar and carrageenan, is one of the most abundantly present sources of such oligosaccharides. Agaro-oligosaccharides (AOS) and carrageenan-oligosaccharides (COS) are produced from agar and carrageenan, respectively, through chemical and enzymatic hydrolyses. Enzymatic hydrolysis of agar and carrageenan into oligosaccharides is preferred in industrial production because of certain problems associated with chemical hydrolysis, including the release of high amounts of monosaccharides and undesirable toxic products, such as furfural. AOS and COS possess many biological activities, including prebiotic, immuno-modulatory, anti-oxidant, and anti-tumor activities. These activities are related to their chemical structure, molecular weight, degree of polymerization, and the flexibility of the glycosidic linkages. Therefore, the structure⁻function relationship and the mechanisms occurring during the specific biological applications of AOS and COS are discussed herein. Moreover, the chromatographic separation, purification, and characterization of AOS and COS are also part of this review. This piece of writing strives to create a new perspective on the potential applications of AOS and COS in the functional food and pharmaceutical industry.