Submerged culture mycelium and broth of Grifola frondosa improve glycemic responses in diabetic rats

Anti-diabetic effects of Grifola frondosa bioactive compound and its related molecular signaling pathways in palmitate-induced C2C12 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Grifola frondosa (GF), a high value medicinal mushroom, is popularly consumed as traditional medicines and health foods in China and Japan. It is a herbal medicine traditionally used for treating inflammation, cancer and diabetes.

AIM OF THE STUDY

This study aimed to examine the anti-diabetic effects of a GF bioactive compound ergosterol peroxide (EPO), and its mechanism(s) of action in palmitate (PA)-induced C2C12 cells.

MATERIALS AND METHODS

EPO was isolated and purified from GF fruiting bodies, and used to test for anti-diabetic activity in PA-induced murine C2C12 skeletal muscle cells through measuring glucose uptake, intracellular ROS production, and expressions of MAPKs, IRS-1, PI3K, Akt and GLUT-4 proteins.

RESULTS

EPO significantly up-regulated glucose absorption and increased cell growth. At 5 μM, EPO significantly enhanced glucose uptake and decreased ROS formation, as well as up-regulated the expression of IRS-1, p-IRS-1, PI3K, Akt, p-Akt, and GLUT-4 proteins in PA-induced cells, while their p-JNK and p-p38 expression were down-regulated. GLUT-4 siRNA treatment effectively down-regulated the EPO-induced absorption of glucose and inhibited the expression of GLUT-4.

CONCLUSION

These results suggest that the anti-diabetic effect of GF was from its bioactive compound EPO through the inhibition of ROS production, up-regulation of glucose absorption, and modulation of PI3K/Akt, MAPKs and GLUT-4 signaling transduction pathways.

Chinese herbal medicines in the treatment of IBD and colorectal cancer: a review

OPINION STATEMENT

Inflammatory bowel diseases (IBD) are a group of chronic inflammatory gastrointestinal (GI) disorders, mainly represented by Crohn's disease and ulcerative colitis. Although the etiology of IBD is not fully understood, there is substantial evidence that immunologic, genetic, and environmental factors are the main contributors in IBD pathogenesis. Conventional therapies for IBD include anti-inflammatory and immunosuppressive drugs, such as 5-aminosalicylic acid, corticosteroids, antibiotics, and biologicals, such as anti-TNFα antibodies. However, because of low efficacy and high risk of side effects, there is a clear need for the development of novel and efficient pharmacologic strategies in IBD treatment. Among various complementary and alternative medicine (CAM) approaches, which are used for the treatment of gastrointestinal (GI) disorders, traditional Chinese medicine (TCM) is one of the most developed and diversified. TCM encompasses methods and therapies that emerged over centuries and is based mostly on ethnic wisdom and observations transmitted from generation to generation. In the recent years, the efficacy of TCM as treatment of IBD has been extensively characterized in preclinical and clinical studies, which resulted in a significant number of research reports. Moreover, the popularity of TCM among patients with IBD has rapidly increased not only in Asia, but also in the Western hemisphere.

Hypoglycemic effects of Grifola frondosa (Maitake) polysaccharides F2 and F3 through improvement of insulin resistance in diabetic rats

This study demonstrated the hypoglycemic effects of Grifola frondosa polysaccharides F2 and F3 through insulin sensitivity improvement in diabetic rats.

Inhibitory potential of Grifola frondosa bioactive fractions on α-amylase and α-glucosidase for management of hyperglycemia

This study examined the inhibitory effects of Grifola frondosa (GF), a medicinal mushroom popularly consumed in traditional medicine and health food, on digestive enzymes related to type 2 diabetes; chemical profiles and inhibitory kinetics of its bioactive fractions were also analyzed. Results showed that all GF extracts showed weak anti-α-amylase activity; however, strong anti-α-glucosidase activity was noted on GF n-hexane extract (GF-H). Further fractionation confirmed that compared with acarbose (a commercial α-glucosidase inhibitor), the nonpolar fraction of GF possessed a stronger anti-α-glucosidase activity but a weaker anti-α-amylase activity. These activities were not derived from ergosterol and ergosterol peroxide, two major compounds of this fraction. The inhibitory kinetics of GF-H on α-glucosidase was competitive inhibition. GF-H was as good as acarbose in inhibiting the starch digestion in vitro. Oleic acid and linoleic acid could be the major active constituents that have contributed to the potency of GF in inhibiting α-glucosidase activity.

Nutritional supplements and their effect on glucose control

As diabetes mellitus (DM) continues to be a growing health concern, many people have been turning to natural health products (NHPs) in order to manage this condition, adjunctive to, or even in place of conventional therapies. In order to keep up with this trend, research focussing on the efficacy and mechanisms behind the most common NHPs has been growing amongst the scientific community. The purpose of this chapter is to search and compile scientific literature focussing on the most commonly used NHPs in diabetes treatment, so to educate health professionals on the efficacy, safety and dosage of these products. From our findings, it is apparent that there are promising results from many studies on the potential benefit of NHPs in the treatment of diabetes. Nonetheless, many of the herbs and single nutraceuticals still require further studies in order to confirm safety, dosage and potential interactions with standard conventional therapies. Soluble fibre, alpha lipoic acid, milk thistle, prickly pear cactus and pycnogenol appear to be the most beneficial in the treatment of diabetes.

[Biotechnological cultivation of edible macrofungi: an alternative for obtaining nutraceutics]

Macromycetes have been part of the human culture for thousand years, and have been reported as food in the most important civilizations in history. Many nutraceutical properties of macromycetes have been described, such as anti-cancer, anti-tumour, cholesterol lowering, antiviral, antibacterial, or immunomodulatory, among others. Given that production of mushrooms by traditional cultivation and extraction of bioactive metabolites is very difficult in some cases, biotechnology is essential for the development of profitable and productive techniques for obtaining these metabolites. It is the development of this technology, and the ease in which it enables the use of its variables that has allowed mycelium to be cultivated in liquid medium of macrofungi, with a significant reduction in time and an increased production of metabolites. This increased production has led to the study of compounds that have medicinal, nutriceutical and quasi-farmaceutical potential, in the exhausted media and the mycelium. The aim of this review is to provide an overview of the use of liquid-state fermentation as a technological tool for obtaining edible fungi, and the study of these and their metabolites, by describing the different cultivation conditions used in recent years, as well as the results obtained. The relevance of Agaricus, Flammulina, Grifola, Pleurotus and Lentinula genera, will also be discussed, with emphasis on the last one, since Shiitake has been always considered as the ultimate medicinal mushroom.