GFS, a preparation of Tasmanian Undaria pinnatifida is associated with healing and inhibition of reactivation of Herpes

Sulfated Galactofucans: An Outstanding Class of Fucoidans with Promising Bioactivities

Fucoidans encompass versatile and heterogeneous sulfated biopolysaccharides of marine origin, specifically brown algae and marine invertebrates. Their chemistry and bioactivities have been extensively investigated in the last few decades. The reported studies revealed diverse chemical skeletons in which l-fucose is the main sugar monomer. However, other sugars, i.e., galactose, mannose, etc., have been identified to be interspersed, forming several heteropolymers, including galactofucans/fucogalactans (G-fucoidans). Particularly, sulfated galactofucans are associated with rich chemistry contributing to more promising bioactivities than fucans and other marine polysaccharides. The previous reports in the last 20 years showed that G-fucoidans derived from Undaria pinnatifida were the most studied; 21 bioactivities were investigated, especially antitumor and antiviral activities, and unique biomedical applications compared to other marine polysaccharides were demonstrated. Hence, the current article specifically reviews the biogenic sources, chemistry, and outstanding bioactivities of G-fucoidans providing the opportunity to discover novel drug candidates.

Recent research advances in polysaccharides from Undaria pinnatifida: Isolation, structures, bioactivities, and applications

Undaria pinnatifida, one of the most widespread seafood consumed in China and many other nations, has been traditionally utilized as an effective therapeutically active substance for edema, phlegm elimination and diuresis, and detumescence for more than 2000 years. Numerous studies have found that polysaccharides of U. pinnatifida play an indispensable role in the nutritional and medicinal value. The water extraction and alcohol precipitation method are the most used method. More than 40 U. pinnatifida polysaccharides (UPPs) were successfully isolated and purified from U. pinnatifida, whereas only few of them were well characterized. Pharmacological studies have shown that UPPs have high-order structural features and multiple biological activities, including anti-tumor, antidiabetic, immunomodulatory, antiviral, anti-inflammatory, antioxidant, anticoagulating, antithrombosis, antihypertension, antibacterial, and renoprotection. In addition, the structural characteristics of UPPs are closely related to their biological activity. In this review, the extraction and purification methods, structural characteristics, biological activities, clinical settings, toxicities, structure-activity relationships and industrial application of UPPs are comprehensively summarized. The structural characteristics and biological activities as well as the underlying molecular mechanisms of UPPs were also outlined. Furthermore, the clinical settings and structure-activity functions of UPPs were highlighted. Some research perspectives and challenges in the study of UPPs were also proposed.

Brown Seaweed Food Supplementation: Effects on Allergy and Inflammation and Its Consequences

Multiple health benefits have been ascribed to brown seaweeds that are used traditionally as dietary component mostly in Asia. This systematic review summarizes information on the impact of brown seaweeds or components on inflammation, and inflammation-related pathologies, such as allergies, diabetes mellitus and obesity. We focus on oral supplementation thus intending the use of brown seaweeds as food additives. Despite the great diversity of experimental systems in which distinct species and compounds were tested for their effects on inflammation and immunity, a remarkably homogeneous picture arises. The predominant effects of consumption of brown seaweeds or compounds can be classified into three categories: (1) inhibition of reactive oxygen species, known to be important drivers of inflammation; (2) regulation, i.e., in most cases inhibition of proinflammatory NF-κB signaling; (3) modulation of adaptive immune responses, in particular by interfering with T-helper cell polarization. Over the last decades, several inflammation-related diseases have increased substantially. These include allergies and autoimmune diseases as well as morbidities associated with lifestyle and aging. In this light, further development of brown seaweeds and seaweed compounds as functional foods and nutriceuticals might contribute to combat these challenges.

Algae as an attractive source for cosmetics to counter environmental stress

In recent times, a considerable amount of evidence has come to light regarding the effect that air pollution has on skin conditions. The human skin is the chief protection we have against environmental harm, whether biological, chemical, or physical. The stress from these environmental factors, along with internal influences, can be a cause of skin aging and enlarged pores, thinner skin, skin laxity, wrinkles, fine lines, dryness, and a more fragile dermal layer. This knowledge has led to greater demand for skin cosmetics and a requirement for natural raw ingredients with a high degree of safety and efficiency in combating skin complications. Recent developments in green technology have made the employment of naturally occurring bioactive compounds more popular, and novel extraction methods have ensured that the use of these compounds has greater compatibility with sustainable development principles. Thus, there is a demand for investigations into efficient non-harmful naturally occurring raw ingredients; compounds derived from algae could be beneficial in this area. Algae, both macroalgae and microalgae, consists of waterborne photosynthetic organisms that are potentially valuable as they have a range of bioactive compounds in their composition. Several beneficial metabolites can be obtained from algae, such as antioxidants, carotenoids, mycosporine-like amino acids (MAA), pigments, polysaccharides, and scytonemin. Various algae strains are now widely employed in skincare products for various purposes, such as a moisturizer, anti-wrinkle agent, texture-enhancing agents, or sunscreen. This research considers the environmental stresses on human skin and how they may be mitigated using cosmetics created using algae; special attention will be paid to external factors, both generally and specifically (amongst them light exposure and pollutants).

A Review of Antiviral and Antioxidant Activity of Bioactive Metabolite of Macroalgae within an Optimized Extraction Method

Non-conventional extraction of bioactive metabolites could provide sustainable alternative techniques to preserve the potency of antioxidants and antiviral compounds extracted from macro-algae. In this paper, we first reviewed the antioxidant and antiviral potential of the active metabolites that exist in the three known macro-algae classes; Phaeophyceae, Rhodophyceae, and Chlorophyceae, and a comparison between their activities is discussed. Secondly, a review of conventional and non-conventional extraction methods is undertaken. The review then focused on identifying the optimal extraction method of sulphated polysaccharide from macro-algae that exhibits both antiviral and antioxidant activity. The review finds that species belonging to the Phaeophyceae and Rhodophceae classes are primarily potent against herpes simplex virus, followed by human immunodeficiency virus and influenza virus. At the same time, species belonging to Chlorophyceae class are recorded by most of the scholars to have antiviral activity against herpes simplex virus 1. Additionally, all three macro-algae classes exhibit antioxidant activity, the potency of which is a factor of the molecular structure of the bioactive metabolite as well as the extraction method applied.

Antiherpetic Effect of Topical Formulations Containing Sulfated Polysaccharide from Adenanthera pavonina

Adenanthera pavonina is a native tree of Africa and Asia, introduced in Brazil for reforestation and wood industry. Several pharmacological activities have described scientifically, including antiviral activity. This study evaluated the antiviral effect of sulfated polysaccharide of Adenanthera pavonina (SPAp) against acyclovir (ACV)-resistant (AR-29) and sensitive (KOS) herpes simplex virus strains. The 50% cytotoxic concentration (CC50) was determined by MTT method and the 50% inhibitory concentration (IC50) was evaluated by plaque reduction assay. The in vivo SPAp antiviral activity was performed in Balb/c mice infected by skin scarification and treated with topical 0.5% (w/w) SPAp formulations. SPAp showed a CC50 of 47.81 μg/mL and the IC50 were 0.49 μg/mL (SI = 97.5) and 0.54 μg/mL (SI = 88.5) for the strains KOS and AR-29, respectively. Our results demonstrated that mice treated with SPAp presented a delay in the development and progression of skin lesions compared with the control group.

Undaria pinnatifida a Rich Marine Reservoir of Nutritional and Pharmacological Potential: Insights into Growth Signaling and Apoptosis Mechanisms in Cancer

Seaweeds are an important part of diet consumed in a different part of the world such as New Zealand, Ireland, Wales, and Asian countries including Korea, China, and Japan. In addition, seaweed is nutritious sources possessing health improving effects and therapeutic potential. Recently, one of the widely eaten seaweed species Undaria pinnatifida (U. pinnatifida) has got much attention because of its pharmacological properties for the prevention of various ailments, including cancer, inflammation, and other diseases. It is rich in all essential amino acids, physiologically significant fatty acids, vitamins, minerals, and has a variety of bioactive constituents which include fucoidan, carotenoids, and fucoxanthin. The present study reviews the nutritional aspects, key bioactivities specifically focusing on anticancer potential along with apoptosis and growth signaling mechanisms of U. pinnatifida or its constituents. It exhibited anticancer effects both in vitro and in vivo studies in a variety of experimental models. Due to a variety of pharmacological properties of U. pinnatifida can not only fulfilling nutritional necessities, but it can be used for treating, curing and preventing cancer.

[Antiviral action and pathogenetic targets for seaweed sulfated polysaccharides in herpesvirus infections]

The review summarizes results of studies of effects of sulfated polysaccharides from seaweed on herpesviruses and the course of herpesvirus infections. Importance of this problem is determined by the prevalence of herpesviruses that can persist in the human body and demonstrate a high degree of immune mimicry and resistance to antiviral agents. A wide range of physiological action of sulfated polysaccharides, receptor agonists of innate and adaptive immune cells, which possess potent antiviral, antioxidant and anti-inflammatory activities, open the possibility of their use for creation of new generation pharmacological substances and agents with associated activity for the treatment of herpesvirus infections.

Electrochemical behaviour at a liquid-organogel microinterface array of fucoidan extracted from algae

The electrochemical behaviour of fucoidan, a sulfated polysaccharide, was investigated, leading to a detection strategy by adsorptive stripping voltammetry.

Fucoidan and cancer: a multifunctional molecule with anti-tumor potential

There is a wide variety of cancer types yet, all share some common cellular and molecular behaviors. Most of the chemotherapeutic agents used in cancer treatment are designed to target common deregulated mechanisms within cancer cells. Many healthy tissues are also affected by the cytotoxic effects of these chemical agents. Fucoidan, a natural component of brown seaweed, has anti-cancer activity against various cancer types by targeting key apoptotic molecules. It also has beneficial effects as it can protect against toxicity associated with chemotherapeutic agents and radiation. Thus the synergistic effect of fucoidan with current anti-cancer agents is of considerable interest. This review discusses the mechanisms by which fucoidan retards tumor development, eradicates tumor cells and synergizes with anti-cancer chemotherapeutic agents. Challenges to the development of fucoidan as an anti-cancer agent will also be discussed.

Tuning polyelectrolyte multilayer structure by exploiting natural variation in fucoidan chemistry

Fucoidan is a sulfated polysaccharide that is extracted primarily from seaweed. The polymer contains a natural variation in chemistry based upon the species of seaweed from which it is extracted. We have used two different fucoidans from two different seaweed species (Fucus vesiculosus - FV; and Undaria pinnatifida - UP) as polyanions for the formation of polysaccharide-based polyelectrolyte multilayers (PEMs), to determine if the chemistry of different fucoidans can be chosen to fine-tune the structure of the polymer film. Partially acetylated chitosan was chosen as the polycation for the work, and the presented data illustrate the effect of secondary hydrogen bonding interactions on PEM build-up and properties. Ellipsometry and quartz crystal microbalance with dissipation monitoring (QCM-D) measurements performed during film build-up enabled detailed measurements of layer thickness, adsorbed mass, and the dynamics of the multilayer formation process. High quality atomic force microscopy (AFM) images revealed the differences in morphology of the PEMs formed from the two fucoidans, and allowed for a more direct layer thickness measurement. X-ray photoelectron spectroscopy (XPS) confirmed the chemistry of the films, and an indication of the altered interactions between chitosan and fucoidan with variation in fucoidan type, but also with layer number. Distinct differences were observed between multilayers formed with the two fucoidans, with those constructed using UP having thinner, denser, less hydrated layers than those constructed using FV. These differences are discussed in the context of their varied chemistry, primarily their difference in molecular weight and degree of acetylation.

Supplementation of elderly Japanese men and women with fucoidan from seaweed increases immune responses to seasonal influenza vaccination

The elderly are known to have an inadequate immune response to influenza vaccine. Mekabu fucoidan (MF), a sulfated polysaccharide extracted from seaweed, was previously shown to have an immunomodulatory effect. We therefore investigated antibody production after influenza vaccination in elderly Japanese men and women with and without oral MF intake. A randomized, placebo-controlled, double-blind study was conducted with 70 volunteers >60 y of age. They were randomly assigned to 1 of 2 groups, consuming either MF (300 mg/d) or placebo for 4 wk, and then given a trivalent seasonal influenza vaccine. Serum was sampled at 5 and 20 wk after vaccination to measure the hemagglutination inhibition titer and natural killer cell activity. The MF group had higher antibody titers against all 3 strains contained in the seasonal influenza virus vaccine than the placebo group. Titers against the B/Brisbane/60/2008 (B) strain increased substantially more in the MF group than in the placebo group over the product consumption period. The immune response against B antigen met the European Union Licensure criteria regarding the geometric mean titer ratio in the MF group (2.4), but not in the placebo group (1.7). In the MF group, natural killer cell activity tended to increase from baseline 9 wk after MF intake (P = 0.08). However, in the placebo group no substantial increase was noted at 9 wk, and the activity decreased substantially from 9 to 24 wk. In the immunocompromised elderly, MF intake increased antibody production after vaccination, possibly preventing influenza epidemics.

Bioactive activities of natural products against herpesvirus infection

More than 90% of adults have been infected with at least one human herpesvirus, which establish long-term latent infection for the life of the host. While anti-viral drugs exist that limit herpesvirus replication, many of these are ineffective against latent infection. Moreover, drug-resistant strains of herpesvirus emerge following chemotherapeutic treatment. For example, resistance to acyclovir and related nucleoside analogues can occur when mutations arise in either HSV thymidine kinase or DNA polymerases. Thus, there exists an unmet medical need to develop new anti-herpesvirus agents with different mechanisms of action. In this Review, we discuss the promise of anti-herpetic substances derived from natural products including extracts and pure compounds from potential herbal medicines. One example is Glycyrrhizic acid isolated from licorice that shows promising antiviral activity towards human gammaherpesviruses. Secondly, we discuss anti-herpetic mechanisms utilized by several natural products in molecular level. While nucleoside analogues inhibit replicating herpesviruses in lytic replication, some natural products can disrupt the herpesvirus latent infection in the host cell. In addition, natural products can stimulate immune responses against herpesviral infection. These findings suggest that natural products could be one of the best choices for development of new treatments for latent herpesvirus infection, and may provide synergistic anti-viral activity when supplemented with nucleoside analogues. Therefore, it is important to identify which natural products are more efficacious anti-herpetic agents, and to understand the molecular mechanism in detail for further advance in the anti-viral therapies.

In vivo anti-herpes simplex virus activity of a sulfated derivative of Agaricus brasiliensis mycelial polysaccharide

Agaricus brasiliensis (syn. A. subrufescens), a basidiomycete fungus native to the Atlantic forest in Brazil, contains cell walls rich in glucomannan polysaccharides. The β-(1 → 2)-gluco-β-(1 → 3)-mannan was isolated from A. brasiliensis mycelium, chemically modified by sulfation, and named MI-S. MI-S has multiple mechanisms of action, including inhibition of herpes simplex virus (HSV) attachment, entry, and cell-to-cell spread (F. T. G. S. Cardozo, C. M. Camelini, A. Mascarello, M. J. Rossi, R. J. Nunes, C. R. Barardi, M. M. de Mendonça, and C. M. O. Simões, Antiviral Res. 92:108-114, 2011). The antiherpetic efficacy of MI-S was assessed in murine ocular, cutaneous, and genital infection models of HSV. Groups of 10 mice were infected with HSV-1 (strain KOS) or HSV-2 (strain 333). MI-S was given either topically or by oral gavage under various pre- and posttreatment regimens, and the severity of disease and viral titers in ocular and vaginal samples were determined. No toxicity was observed in the uninfected groups treated with MI-S. The topical and oral treatments with MI-S were not effective in reducing ocular disease. Topical application of MI-S on skin lesions was also not effective, but cutaneously infected mice treated orally with MI-S had significantly reduced disease scores (P < 0.05) after day 9, suggesting that healing was accelerated. Vaginal administration of MI-S 20 min before viral challenge reduced the mean disease scores on days 5 to 9 (P < 0.05), viral titers on day 1 (P < 0.05), and mortality (P < 0.0001) in comparison to the control groups (untreated and vehicle treated). These results show that MI-S may be useful as an oral agent to reduce the severity of HSV cutaneous and mucosal lesions and, more importantly, as a microbicide to block sexual transmission of HSV-2 genital infections.

Dietary algae and HIV/AIDS: proof of concept clinical data

Dietary algae have been reported to decrease HIV viral fusion/entry and replication and increase immune response, suggesting that regular consumption of algae by people in Japan, Korea, and Chad could be an important factor in their relatively low HIV/AIDS rates. Five antiretroviral-naïve people with HIV (three females, two males; five African Americans) living in Columbia SC participated in the phase I study of acute toxicity. Subjects were randomly assigned to 5 g day(-1) brown seaweed (Undaria pinnatifida), Spirulina (Arthrospira platensis), or a combination of both. Endpoints included HIV viral load, complete blood count (CBC), metabolic and lipid panel, and quality of life questionnaire data. When no short-term toxicities were observed, six additional subjects (four females, two males; five African Americans, one Latina) were recruited to further evaluate short- and long-term toxicities (phase II). No adverse effects were observed for the 11 subjects in the phase I trial, and quality of life indicators improved at 3 weeks. No significant changes were observed in CBC, metabolic or lipid panel analyses. CD4 cells (milliliters) and HIV-1 viral load remained stable over the first 3-month phase II study period. One subject continued in the study for 13 months and had clinically significant improvement in CD4 (>100 cells mL(-1)) and decreased HIV viral load of 0.5 log(10). Our pilot data suggest that Undaria, Spirulina, and a combination of both were nontoxic and over time may improve clinical endpoints of HIV/AIDS.

Therapies from fucoidan; multifunctional marine polymers

Published research on fucoidans increased three fold between 2000 and 2010. These algal derived marine carbohydrate polymers present numerous valuable bioactivities. This review discusses the role for fucoidan in the control of acute and chronic inflammation via selectin blockade, enzyme inhibition and inhibiting the complement cascade. The recent data on toxicology and uptake of fucoidan is detailed together with a discussion on the comparative activities of fractions of fucoidan from different sources. Recent in vivo, in vitro and clinical research related to diverse clinical needs is discussed. Targets include osteoarthritis, kidney and liver disease, neglected infectious diseases, hemopoietic stem cell modulation, protection from radiation damage and treatments for snake envenomation. In recent years, the production of well characterized reproducible fucoidan fractions on a commercial scale has become possible making therapies from fucoidan a realizable goal.

Potential application of marine algae as antiviral agents in medicinal foods

Viral diseases, caused by pathogenic virus infections, are still the leading cause of death in humans worldwide. Although many antiviral agents have been developed and are used for treatment of infectious diseases, emergence of drug resistance, side effects, and the necessity for extensive clinical use are the main reasons for failure of antiviral therapy. Therefore, the development of new antiviral agents with diverse kinds of antiviral actions is required. The search for new antiviral agents focuses on not only synthetic compounds but also natural products such as plants, insects, animal organs, and their components. Recently, a great deal of interest has been expressed regarding marine algae as potential antiviral agents. This contribution focuses on antiherpes virus therapeutic agents derived from marine algae which are considered as novel functional ingredients in antiherpes virus therapy.

Toxicological evaluation of fucoidan from Cladosiphon okamuranus

Fucoidans are sulfated polysaccharides extracted from brown seaweeds. They have a wide spectrum of activity in biological systems. Besides their well-known anticoagulant and anti-thrombotic activity, fucoidans modulate inflammation, possess antiproliferative and anti-adhesive effects on cells, protect cells from viral infection, and interfere with mammalian fertilization. Fucoidans are now used as raw material for development of drugs and are also widely used as a health-promoting food component. However, studies on the toxicity of fucoidans from different brown algae are limited. The present study examined the acute toxicity of varying levels of fucoidan extracted from Okinawa mozuku, a brown alga (Cladosiphon okamuranus), in Wistar rats after oral administration. No significant toxicological changes were induced by fucoidan at a dose of 600 mg/kg of body weight/day. However, with concentrations at and above 1,200 mg/kg of body weight/day, clotting time was significantly prolonged. No other signs of toxicity were observed.

Defensive effects of a fucoidan from brown alga Undaria pinnatifida against herpes simplex virus infection

Fucoidan, a sulfated polysaccharide isolated from an edible brown alga Undaria pinnatifida, was previously shown to be a potent inhibitor of the in vitro replication of herpes simplex virus type 1 (HSV-1). HSV-1 is a member of herpes viruses that cause infections ranging from trivial mucosal ulcers to life-threatening disorders in immunocompromised hosts. In the in vivo conditions, the replication of HSV-1 is controlled under the immunoresponse coordinated by both the innate and adaptive immune systems. In the present study, the effects of the fucoidan were examined on in vivo viral replication and the host's immune defense system. Oral administration of the fucoidan protected mice from infection with HSV-1 as judged from the survival rate and lesion scores. Phagocytic activity of macrophages and B cell blastogenesis in vitro were significantly stimulated by the fucoidan, while no significant change in the release of NO(2)(-) by macrophages was observed. In in vivo studies, oral administration of the fucoidan produced the augmentation of NK activity in HSV-1-infected mice immunosuppressed by 5-fluorouracil treatment. CTL activity in HSV-1-infected mice was also enhanced by oral administration of the fucoidan. The production of neutralizing antibodies in the mice inoculated with HSV-1 was significantly promoted during the oral administration of the fucoidan for 3 weeks. These results suggested that oral intake of the fucoidan might take the protective effects through direct inhibition of viral replication and stimulation of both innate and adaptive immune defense functions.

Efficacy and safety of a new-class hemostatic drug candidate, AV513, in dogs with hemophilia A

AV513 is a select fucoidan, a sulfated polysaccharide of botanical origin. It inhibits tissue factor pathway inhibitor (TFPI) activity and accelerates clotting of human hemophilia A and B plasma. In prior work, subcutaneous administration of AV513 to mice with hemophilia A improved hemostasis. The current studies were designed to evaluate potential efficacy and safety in dogs with hemophilia A (hemophilia A dogs) with minimally increased hemostasis after adenoassociated viral-FVIII gene transfer and in treatment-naive severe hemophilia A dogs. AV513 administered subcutaneously to low-FVIII dogs for multiple weeks improved hemostasis as exhibited in thromboelastography (TEG) and cuticle bleeding time (CBT) tests. Moreover, AV513 administered orally to AAV-FVIII dogs and treatment-naive severe hemophilia A dogs for a multiweek dose-escalating period yielded correction to normal ranges in both TEG and CBT end points at 5 to 15 mg/kg and 15 to 20 mg/kg dose levels, respectively. In all 3 separate studies, throughout their duration, AV513 was well tolerated by the dogs without any adverse events. Additional pharmacologic characterization of AV513 included intravenous pharmacokinetic analysis in rats. In summary, the combination of safety and efficacy in 2 global tests of hemostasis in the hemophilia A dog model indicate that further evaluation of AV513 as a hemostatic agent in hemophilia A patients is warranted.

The effect of Fucus vesiculosus, an edible brown seaweed, upon menstrual cycle length and hormonal status in three pre-menopausal women: a case report

BACKGROUND

Rates of estrogen-dependent cancers are among the highest in Western countries and lower in the East. These variations may be attributable to differences in dietary exposures such as higher seaweed consumption among Asian populations. The edible brown kelp, Fucus vesiculosus (bladderwrack), as well as other brown kelp species, lower plasma cholesterol levels. Since cholesterol is a precursor to sex hormone biosynthesis, kelp consumption may alter circulating sex hormone levels and menstrual cycling patterns. In particular, dietary kelp may be beneficial to women with or at high risk for estrogen-dependent diseases. To test this, bladderwrack was administered to three pre-menopausal women with abnormal menstrual cycling patterns and/or menstrual-related disease histories.

CASE PRESENTATION

Intake of bladderwrack was associated with significant increases in menstrual cycle lengths, ranging from an increase of 5.5 to 14 days. In addition, hormone measurements ascertained for one woman revealed significant anti-estrogenic and progestagenic effects following kelp administration. Mean baseline 17beta-estradiol levels were reduced from 626 +/- 91 to 164 +/- 30 pg/ml (P = 0.04) following 700 mg/d, which decreased further to 92.5.0 +/- 3.5pg/ml (P = 0.03) with the 1.4 g/d dose. Mean baseline progesterone levels rose from 0.58 +/- 0.14 to 8.4 +/- 2.6 ng/ml with the 700 mg/d dose (P = 0.1), which increased further to 16.8 +/- 0.7 ng/ml with the 1.4 g/d dose (P = 0.002).

CONCLUSIONS

These pilot data suggest that dietary bladderwrack may prolong the length of the menstrual cycle and exert anti-estrogenic effects in pre-menopausal women. Further, these studies also suggest that seaweed may be another important dietary component apart from soy that is responsible for the reduced risk of estrogen-related cancers observed in Japanese populations. However, these studies will need to be performed in well-controlled clinical trials to confirm these preliminary findings.

Antiviral activity of Undaria pinnatifida against herpes simplex virus

The major component of an aqueous extract of the seaweed Undaria pinnati fi da has been identified previously as a galactofucan (GFS), a sulfated polysaccharide. The galactofucan was partially purified and the material tested in this study is 75% pure galactofucan sulfate. GFS was evaluated for antiviral activity against 32 clinical strains of herpes simplex virus (HSV): 14 strains of HSV-1 and 18 strains of HSV-2. Twelve strains (four HSV-1 and eight HSV-2) were resistant to acyclovir (ACV-R) and 20 strains (10 HSV-1 and 10 HSV-2) were susceptible to ACV (ACV-S). The median IC(50) of GFS for the 14 strains of HSV-1 was 32 micro g/mL. The median IC(50) of GFS for the 18 strains of HSV-2 was 0.5 micro g/mL. GFS is significantly more active against clinical strains of HSV-2 than HSV-1, p < 0.001. The mode of action of the GFS was shown to be the inhibition of viral binding and entry into the host cell. The cytotoxicity of GFS was >4.0 mg/mL in the neutral red dye uptake assay indicating that GFS is non-toxic in this assay.