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Mushroom medicine
Objective: To evaluate the biopotential activity of secondary metabolites from marine sponge
Dendrilla nigra (D. nigra) collected from the Gulf of Mannar. Objective: Soxhlet extraction
method was used to extract the secondary metabolites and various assays were carried out.
Results: D. nigra showed potent antibacterial, antioxidant, anti-inflammatory and anticancer
activities and it was also subjected for brine shrimp lethality and cytotoxicity assays. The
secondary metabolites were characterized by gas chromatography-mass spectrometry (GC-MS)
analysis. Conclusions: Based on the present study, it can be inferred that the bioassay guided
fractionation and purification of D. nigra may come up with potent bioactive drug.
During the course of evolution, animals encountered the harmful effects of fungi, which are strong pathogens. Therefore, they have developed powerful mechanisms to protect themselves against these fungal invaders. β-Glucans are glucose polymers of a linear β(1,3)-glucan backbone with β(1,6)-linked side chains. The immunostimulatory and antitumor activities of β-glucans have been reported; however, their mechanisms have only begun to be elucidated. Fungal and particulate β-glucans, despite their large size, can be taken up by the M cells of Peyer's patches, and interact with macrophages or dendritic cells (DCs) and activate systemic immune responses to overcome the fungal infection. The sampled β-glucans function as pathogen-associated molecular patterns (PAMPs) and are recognized by pattern recognition receptors (PRRs) on innate immune cells. Dectin-1 receptor systems have been incorporated as the PRRs of β-glucans in the innate immune cells of higher animal systems, which function on the front line against fungal infection, and have been exploited in cancer treatments to enhance systemic immune function. Dectin-1 on macrophages and DCs performs dual functions: internalization of β-glucan-containing particles and transmittance of its signals into the nucleus. This review will depict in detail how the physicochemical nature of β-glucan contributes to its immunostimulating effect in hosts and the potential uses of β-glucan by elucidating the dectin-1 signal transduction pathway. The elucidation of β-glucan and its signaling pathway will undoubtedly open a new research area on its potential therapeutic applications, including as immunostimulants for antifungal and anti-cancer regimens.
Present interest of consumers to a large extent concerns food that can be used in prevention
of many diet-dependent diseases, whereas the interest of food industry is directed at the
search for new ingredients of pro-health influence. The knowledge of functional properties
of preparations containg β-glucans might be used to shape proper quality of food products
for special purposes.
β-Glucan is a valuable functional ingredient and various extraction techniques are available
for its extraction. Choice of an appropriate extraction technique is important as it may affect
the quality, structure, rheological properties, molecular weight, and other functional
properties of the extracted β-glucan. These properties lead to the use of β-glucan into
various food systems and have important implications in human health.
Diet supplementation with β-glucans from spent brewer’s yeast and preparation of dried
spent brewer’s yeast contributed to advantageous lowering of cholesterol concentration in
blood and lowering lipid concentration in liver. The results described above allow for the
formulation of the following conclusions:
1. β-glucan preparations obtained from spent brewer’s yeast and dried spent brewer’s
yeast show efficient biological activity, connected with the improvement of blood lipid
profile and liver of experimental animals.
2. Spent brewer’s yeast show a similar pro-health influence to β-glucans isolated from
them, therefore, they can be a valuable and much cheaper diet suplement, correcting
blood lipid metabolism disturbed by atherogenic diet.
3. β-glucan preparations from spent brewer’s yeast (CMG and HP) given in higher doses
(100 mg/kg of body mass daily), efficiently protect liver against excessive fat layering.
Results obtained in the experiment described above with various yeast preparations are
valuable, since they point out that β-glucans obtained from a new source, i.e. spent brewer’s
yeast have a hypocholesterolemic effect, similarly to other glucans described in literature.
Moreover, it has been shown that each of examined β-glucans isolated from spent brewer’s yeast was as efficient. Final effect correcting lipid metabolism, particularly various fractions
of lipids, was more connected with the dose, rather than physic-chemical properties.
Health advantages contributing to significant cholesterol reduction in blood obtained in
experiments on animals, might constitute the basis for assuming that similar influence will
be observed in case of a human body. Therefore, it would be recommended to supplement
human diet with β-glucans, particularly for people whose diet is abundant in fat and
cholesterol. Spent brewer’s yeast constituting a serious problem for brewing plants (waste
material), can be used successfully as a valuable source of beta glucans, which can be used
as diet supplements or as food additives, e.g. in yoghurts, breakfast desserts or snacks.
Currently conducted research is the continuation of a presented experiment. It shows that
atherogenic diet supplementation with beta-glucans or spent brewer’s yeast contributed to
simultaneous obtaining more advantageous content of testine microflara in relation to
control group, connected with the increased number of lactid acid bacteria Bifidobacterium
and Lactobacillus and limited growth frequency of disadvantageous yeast fungi Candida
albicans. Conducted research on functional properties and biological experiment proves the
complexity of β-glucan and other fibre preparation influence on experimental animals.
Non-prescriptional use of medicinal herbs among cancer patients is common around the world. The alleged anti-cancer effects of most herbal extracts are mainly based on studies derived from in vitro or in vivo animal experiments. The current information suggests that these herbal extracts exert their biological effect either through cytotoxic or immunomodulatory mechanisms. One of the active compounds responsible for the immune effects of herbal products is in the form of complex polysaccharides known as beta-glucans. beta-glucans are ubiquitously found in both bacterial or fungal cell walls and have been implicated in the initiation of anti-microbial immune response. Based on in vitro studies, beta-glucans act on several immune receptors including Dectin-1, complement receptor (CR3) and TLR-2/6 and trigger a group of immune cells including macrophages, neutrophils, monocytes, natural killer cells and dendritic cells. As a consequence, both innate and adaptive response can be modulated by beta-glucans and they can also enhance opsonic and non-opsonic phagocytosis. In animal studies, after oral administration, the specific backbone 1-->3 linear beta-glycosidic chain of beta-glucans cannot be digested. Most beta-glucans enter the proximal small intestine and some are captured by the macrophages. They are internalized and fragmented within the cells, then transported by the macrophages to the marrow and endothelial reticular system. The small beta-glucans fragments are eventually released by the macrophages and taken up by other immune cells leading to various immune responses. However, beta-glucans of different sizes and branching patterns may have significantly variable immune potency. Careful selection of appropriate beta-glucans is essential if we wish to investigate the effects of beta-glucans clinically. So far, no good quality clinical trial data is available on assessing the effectiveness of purified beta-glucans among cancer patients. Future effort should direct at performing well-designed clinical trials to verify the actual clinical efficacy of beta-glucans or beta-glucans containing compounds.
Continuously improving the developmental process and the efficacy of oral vaccines is essential in the fight against intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery system and their adjuvant characteristics. GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8 and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells. Additionally, adoptive transfer experiments showed proliferating ovalbumin (OVA)-specific CD4(+) T cells mainly in the spleens of GP-OVA-fed mice. Furthermore, we detected a significantly increased IL-17 and a trend towards increased IFN-γ production in the spleen of GP-OVA-fed mice upon antigen restimulation. Oral administration of GP-OVA induced increased OVA-specific IgA, secretory-IgA (S-IgA) and secretory component (SC) production in intestinal fluids. Our data show that GP vehicles are able to deliver OVA via an oral route allowing efficient antigen presentation alongside adaptive immune activation, resulting in a Th17-biased response and the production of OVA-specific IgA, secretory-IgA and secretory component antibodies.
(1→3)-β-d-Glucans that have β-d-glucopyranosyl units attached by (1→6) linkages as single unit branches enhance the immune system systemically. This enhancement results in antitumor, antibacterial, antiviral, anticoagulatory and wound healing activities. The (1→3)-β-d-glucan backbone is essential. The most active polymers have degrees of branching (DB) between 0.20 and 0.33. Data suggest both that triple helical structures formed from high molecular weight polymers are possibly important for immunopotentiating activity and that activity is independent of any specific ordered structure. Other data indicate that it is the distribution of the branch units along the backbone chain that is responsible for activity. There are data that indicate both that β-d-glucopyranosyl units are required for immunopotentiating activity and that the specific nature of the substituent is unimportant. There are also data that indicate both that the more water-soluble polymers are more active (up to a certain degree of substitution (DS) or DB) and that some insoluble aggregates are more stimulatory than the soluble polymers. The best conclusion at this time is that the immunopotentiating activity of (1→3)-β-d-glucans depends on a helical conformation and on the presence of hydrophilic groups located on the outside surface of the helix. Immunopotentiation effected by binding of a (1→3)-β-glucan molecule or particle probably includes activation of cytotoxic macrophages, helper T cells, and NK cells, promotion of T cell differentiation, and activation of the alternative complement pathway.
Beta-glucans are recognized by the innate immune system. This recognition plays important roles in host defense and presents specific opportunities for clinical modulation of the host immune response. Neutrophils, macrophages, and dendritic cells among others express several receptors capable of recognizing beta-glucan in its various forms. This review explores what is currently known about beta-glucan recognition and how this recognition stimulates immune responses. Special emphasis is placed on Dectin-1, as we know the most about how this key beta-glucan receptor translates recognition into intracellular signaling, stimulates cellular responses, and participates in orchestrating the adaptive immune response.
The Iceman and his Natural EnvironmentThe Man in the Ice Ethnomycological remarks on the Iceman's fungi Rice PJ et al Oral Delivery and Gastrointestinal Absorption of Soluble Glucans Stimulate Increased Resistance to
- U Peintner
Peintner U &Pöder R 2000, The Iceman and his Natural
Environment,The Man in the Ice Volume 4, 2000, p 143150, Ethnomycological remarks on the Iceman's fungi
Rice PJ et al 2005, Oral Delivery and Gastrointestinal Absorption of
Soluble Glucans Stimulate Increased Resistance to Infectious
Challenge J Pharmacol Exper Ther. 314(3): 1079-1086