Omnia SanaSymptom → Plant Sources
Oyster mushroom (Pleurotus ostreatus) and Cold & flu: evidence and sources
inferred from immunomodulator action
For educational purposes only, not medical advice. Always consult a qualified practitioner before using medicinal plants, especially alongside prescribed medication, during pregnancy, or for a serious condition.
Prolonged and high-intensity exercise affects immune function and leads to an increased risk of upper respiratory tract infections (URTIs) in endurance athletes. The increased incidence of URTI symptoms may negatively affect athletic performance. Various nutritional supplements have been tested in the last decade for their ability to prevent developing of URTIs or reduce their incidence. One of the most promising nutritional supplements is β-glucan, a well-known immunomodulator with positive effects on functioning of immunocompetent cells. However, β-glucans are a diverse group of molecules that vary in macromolecular structure, solubility, viscosity, molecular weight and biological activity. This fact is supported by results from recent human clinical studies where β-glucans of different origin and properties differed in ability to prevent or reduce incidence of URTIs in athletes. It has been found that pleuran, a unique insoluble β-glucan isolated from mushroom Pleurotus ostreatus, significantly reduced the incidence of URTI symptoms in athletes. In addition, it was able to increase the number of circulating natural killer cells and to prevent reduction of natural killer cell activity. Contrarily, soluble oat β-glucan supplementation did not alter URTI incidence in endurance athletes. This difference suggests that the immunomodulatory capacity of β-glucans is strongly dependent on solubility and structural factors such as backbone structure and degree of branching. This review refers to using pleuran as a natural supplement that is able to protect endurance athletes against development of URTI.
1 source supporting Oyster mushroom for Cold & flu. Includes scientific publications, books, monographs and traditional-use references.
Mechanistic basis
This use is associated with the plant's immunomodulator / immune support action. Further evidence for that pharmacology:
In the wide field of nutraceuticals, the effects of mushrooms on immunity, cancer and including autoimmunity have been proposed for centuries but in recent years a growing interest has led scientists to elucidate which specific compounds have bioactive properties and through which mechanisms. Glucans and specific proteins are responsible for most of the biological effects of mushrooms, particularly in terms of immunomodulatory and anti-tumor results. Proteins with bioactive effects include lectins, fungal immunomodulatory proteins (FIPs), ribosome inactivating proteins (RIPs), ribonucleases, laccases, among others. At the present status of knowledge, numerous studies have been performed on cell lines and murine models while only a few clinical trials have been conducted. As in most cases of dietary components, the multitude of variables implicated in the final effect and an inadequate standardization are expected to affect the observed differences, thus making the available evidence insufficient to justify the treatment of human diseases with mushrooms extracts. We will herein provide a comprehensive review and critically discussion the biochemical changes induced by different mushroom compounds as observed in in vitro studies, particularly on macrophages, dendritic cells, T cells, and NK cells, compared to in vivo and human studies. Additional effects are represented by lipids which constitute a minor part of mushrooms but may have a role in reducing serum cholesterol levels or phenols acting as antioxidant and reducing agents. Human studies provide a minority of available data, as well illustrated by a placebo-controlled study of athletes treated with β-glucan from Pleurotus ostreatus. Variables influencing study outcomes include different mushrooms strains, growing conditions, developmental stage, part of mushroom used, extraction method, and storage conditions. We foresee that future rigorous research will be needed to determine the potential of mushroom compounds for human health to reproduce the effects of some compounds such as lentinan which a metaanalysis demonstrated to increase the efficacy of chemotherapy in the treatment of lung cancer and in the improvement of the patients quality of life.
Mushrooms are consumed for their nutrients and therapeutic bioactive compounds and are used medicinally in Chinese and Japanese medicine traditions since time immemorial. Members of the genus Pleurotus form a heterogeneous group of edible species with outstanding nutritional profiles rich in fiber, vitamins (thiamine, riboflavin, ascorbic acid, ergosterine, and niacin), micro and macro-elements (phosphorus and iron), and carbohydrates. Pleurotus is one of the most diversified medicinal and edible mushrooms related to the composition of chemical structures such as polysaccharides, glycoproteins, and secondary metabolites such as alkaloids and betalains. The cultivation of Pleurotus spp. on lignocellulosic wastes represents one of the most economically and cost-effective organic recycling processes, especially for the utilization of different feasible and cheap recyclable residues. Also, several Pleurotus spp. have the ability to remove phenolic compounds from wastewater with the action of phenoloxidase activity. Here, we have reviewed the chemistry of such polysaccharides and their reported biological activities, namely, anti-inflammatory, immunomodulatory, anti-diabetic, anti-tumor, antioxidant, etc. The mechanism of action and effects of novel polysaccharides extracted from various species of Pleurotus have been studied. The current study will be beneficial for guiding future research projects on the above concept and investigating more deeply the health of human beings. PRACTICAL APPLICATIONS: Mushrooms are one of the most delicious foods around the globe and have many medicinal properties for decades. Various Pleurotus species have been in focus in recent years because of their palatability and medicinal importance too. It contains many bioactive compounds among which polysaccharides are valued to a great extent. Many biological activities are exerted by polysaccharides derived from the Pleurotus spp., namely, anti-tumor, antioxidant, and many more. They are responsible for significant physiological responses in animals, animal-alternative in vitro models, and humans. Their important physicochemical characteristics benefit their use in the food industry as well. So, the biological activities of these Pleurotus spp. polysaccharides will provide an insight to develop Pleurotus spp. as functional foods, because of their nutritional value and presence of bioactive components.
In this work, aqueous extracts from six different Pleurotus species were obtained and their yield, gross composition, β-glucan content, monosaccharide profile, thermal stability, molecular weight distribution, and FT-IR were analyzed before and after purification through ethanol precipitation of the carbohydrate-rich fractions. The bioactivity (anti-inflammatory and immunomodulatory activity) of the various fractions obtained was also analyzed in three different cell cultures and compared with a lentinan control. The trend observed after purification of the aqueous fractions was an increase in the concentration of polysaccharides (especially β-glucans), a decrease in ash, glucosamine and protein content and the elimination of low molecular weight (Mw) compounds, thus leaving in the purified samples high Mw populations with increased thermal stability. Interestingly, all these purified fractions displayed immunomodulatory capacity when tested in THP-1 macrophages and most of them also showed significant activity in HEK-hTLR4 cells, highlighting the bioactivity observed for Pleurotus ostreatus (both the extracts obtained from the whole mushroom and from the stipes). This specific species was richer in heteropolysaccharides, having moderate β-glucan content and being enriched upon purification in a high Mw fraction with good thermal stability.
Aim: To evaluate the effect of pleuran (β-glucan from Pleurotus ostreatus ) administration on the immune profile of patients with endocrine-dependent breast cancer (clinical stages I-II) in clinical and imaging remission. Methodology: Antitumor cellular immunity (CD19 + , CD3 + , CD4 + and CD8 + T lymphocytes and natural killer cells) of 195 patients (49 in the pleuran group and 146 in the control group) was measured by flow cytometry. Results: We observed a significant increase in the absolute number of CD3 + , CD19 + , CD4 + and CD8 + T lymphocytes in the pleuran group compared with the control group. Conclusion: Our results suggest potential benefit of continuous pleuran administration on immune rehabilitation of cellular antitumor immunity and better prognosis in breast cancer patients in remission.