Production of the bioactive compound eritadenine by submerged cultivation of shiitake (Lentinus edodes) mycelia

Enhancing Eritadenine Production in Submerged Cultures of Shiitake (Lentinula edodes Berk. Pegler) Using Blue LED Light and Activated Charcoal. Revealing Eritadenine's Novel In Vitro Bioherbicidal Activity Against Chrysanthemum morifolium

Eritadenine from shiitake mushroom is a secondary metabolite with hypocholesterolemic, hypotensive and antiparasitic properties, thus promising for pharmaceutical and agricultural applications. Eritadenine is obtained from submerged mycelial cultures of shiitake, but the actual yields remain unsatisfactory to explore potential applications or industrial-scale production. In this study, green and blue LED lights were tested to increase yields of eritadenine in submerged cultures of shiitake. Notably, blue LEDs increased yields by 13-14 times, reaching 165.7 mg/L, compared to darkness (11.2 mg/L) and green light (12.1 mg/L) (p < 0.05, Tukey test). Nitrogen sources yeast extract (YE) and peptone (at 2 g/L) increased eritadenine production. YE promoted 22.6 mg/L, while peptone 18.3 mg/L. The recovery of eritadenine was evaluated using amberlite and activated charcoal (AC) adsorption isotherms. AC demonstrated the highest adsorption rate, with 75 mg of eritadenine per gram of AC, according to the Freundlich isotherm. The desorption rate reached 93.95% at pH 10. The extract obtained from submerged cultures had eritadenine content of 63.31%, corresponding to 87.86% of recovery, according to HPLC analysis. Furthermore, the novel bioherbicidal potential of eritadenine was tested on in vitro Chrysanthemum morifolium plants. The cultures extract containing eritadenine had a detrimental impact on plant development, generating mortality of 100% at 3%, 0.5%, and 0.25%. Moreover, pure eritadenine exhibited a phytotoxic effect similar than glyphosate on leaves, stems and roots. These findings highlight the significant bioherbicidal properties of eritadenine. Further studies are needed to understand the biosynthetic pathway of eritadenine and its bioherbicidal properties on weeds and illicit crops.

Increasing the production of the bioactive compounds in medicinal mushrooms: an omics perspective

Macroscopic fungi, mainly higher basidiomycetes and some ascomycetes, are considered medicinal mushrooms and have long been used in different areas due to their pharmaceutically/nutritionally valuable bioactive compounds. However, the low production of these bioactive metabolites considerably limits the utilization of medicinal mushrooms both in commerce and clinical trials. As a result, many attempts, ranging from conventional methods to novel approaches, have been made to improve their production. The novel strategies include conducting omics investigations, constructing genome-scale metabolic models, and metabolic engineering. So far, genomics and the combined use of different omics studies are the most utilized omics analyses in medicinal mushroom research (both with 31% contribution), while metabolomics (with 4% contribution) is the least. This article is the first attempt for reviewing omics investigations in medicinal mushrooms with the ultimate aim of bioactive compound overproduction. In this regard, the role of these studies and systems biology in elucidating biosynthetic pathways of bioactive compounds and their contribution to metabolic engineering will be highlighted. Also, limitations of omics investigations and strategies for overcoming them will be provided in order to facilitate the overproduction of valuable bioactive metabolites in these valuable organisms.

The Health and Clinical Benefits of Medicinal Fungi

The human uses of mushrooms and cultured mycelium products for nutrition and medicine are detailed and supported by available human studies, which in many cases are clinical trials published in peer-reviewed journals. The major medically active immunomodulating compounds in the cell walls-chitin, beta-glucans, and glycoproteins, as well as lower weight molecules-nitrogen-containing compounds, phenolics, and terpenes-are discussed in relation to their current clinical uses. The nutritional content and foods derived from mushrooms, particularly related to their medical benefits, are discussed. High-quality major nutrients such as the high amounts of complete protein and prebiotic fibers found in edible and medicinal fungi and their products are presented. Mushrooms contain the highest amount of valuable medicinal fiber, while dried fruiting bodies of some fungi have up to 80% prebiotic fiber. These fibers are particularly complex and are not broken down in the upper gut, so they can diversify the microbiome and increase the most beneficial species, leading to better immune regulation and increasing normalizing levels of crucial neurotransmitters like serotonin and dopamine. Since the growth of medicinal mushroom products is expanding rapidly worldwide, attention is placed on reviewing important aspects of mushroom and mycelium cultivation and quality issues relating to adulteration, substitution, and purity and for maximizing medicinal potency. Common questions surrounding medicinal mushroom products in the marketplace, particularly the healing potential of fungal mycelium compared with fruiting bodies, extraction methods, and the use of fillers in products, are all explored, and many points are supported by the literature.

Molecular identification of Shiitake [Lentinula edodes Berk (Pegler)] and production of secondary metabolites with biotechnological potential

The Shitake mushroom (Lentinula edodes) is the second most-consumed mushroom in the world; in Colombia, it is cultivated and commercialized on a small scale in some supermarkets. Little is known about the precedence, nutritional and medicinal properties of Shiitake produced in Colombia. In this study, four shiitake isolates were grown in Colombia (LEUCO1, LEUCO2, LEUCO3, and LEUCO4) were sequenced in their ITS genes and evaluated for the production of three medicinal metabolites, eritadenine, ergotioneine and β-glucans (1,3-1, 6), using submerged culture. Genetic analysis revealed that all the isolates were close and related to the Japanese strain Cr62. LEUCO1 and LEUCO2 showed a distance of 0.000, as well as LEUCO3 and LEUCO4. All four isolates produced erythadenin in a range of 26.3-8.6 mg / L, with the best performance of LEUCO1 at 26.3 mg / L (p <0.05). Ergotioneine was produced with similar statistical yields in all the isolates with an average of 0.7 mg / g of dry weight biomass (DW). Β-glucans (1.3-1.6) were produced with yields of 5.6 - 3.8% of DW biomass, with the best values ​​for LEUCO2 and the lowest for LEUCO4 (p <0.05). In conclusion, we identified low genetic diversity in the four isolates, corresponding to two haplotypes with minimal genetic difference between them, related to the Japanese strain Cr62, indicating that Colombian farmers cultivate almost the same strains of shitake. Secondary metabolites, eritadenine, β-glucans and ergotioneine were found in promising yields useful for the pharmaceutical and food industries. More studies should be conducted to improve the yield of shitake metabolites through new growing conditions for industrial production and to find metabolic pathways and related genes.

Effect of traditional and modern culinary processing, bioaccessibility, biosafety and bioavailability of eritadenine, a hypocholesterolemic compound from edible mushrooms

Eritadenine is a hypocholesterolemic compound that is found in several mushroom species such as Lentinula edodes, Marasmius oreades, and Amanita caesarea (1.4, 0.7 and 0.6 mg per g dry weight, respectively). It was synthesized during all developmental stages, being present in higher concentrations in the skin of shiitake fruiting bodies. When subjected to traditional cooking, grilling followed by frying were more adequate methodologies than boiling or microwaving to maintain its levels. Modern culinary processes such as texturization (with agar-agar) and spherification (with alginate) also interfered with its release. Grilling and gelling using gelatin enhanced eritadenine's bioaccessibility in an in vitro digestion model. An animal model (where male and female rats were administered 21 and 10 mg per kg animal per day of eritadenine) indicated that intake of the compound was safe under these concentrations; it reached the liver and reduced the atherogenic index (TC/HDL) in rat sera. Thus, it might be used to design a functional food.

Antiproliferative protein from the culture supernatant of Lentinula edodes C91-3 mycelia

We purified and isolated a novel protein (LFP(91-3)A2) with antitumor effect from Lentinula edodes C(91-3) liquid mycelial culture supernatant. LFP(91-3)A2 was purified by (NH4)2SO4 precipitation, ion-exchange chromatography (DEAE-cellulose) and gel filtration chromatography (Sephacryl S-200HR). SDS-PAGE and MALDI-TOF/MS analysis Mascot search showed LFP(91-3)A2 is a new protein with apparent molecular weight of 26 kDa. The effect on tumor cell proliferation was assessed by using MTT assay in vitro, and the LFP(91-3)A2 reduced tumor cell growth obviously in a dose dependent manner (5-15 μg/mL) (p < 0.05), while it exhibited no toxic effect on normal chick embryo fibroblasts. The antiproliferative mechanism of LFP(91-3)A2 was found to be associated with inducing cell apoptosis by flow cytometry analysis and transmission electron microscopy. The LFP(91-3)A2 is a novel protein from Lentinula edodes with tumor-suppressive activity via inducing apoptosis of tumor cells without toxicity on normal cells and may be beneficial to natural products in clinical treatment.

Antihypertensive effect of 3,3,5,5-tetramethyl-4-piperidone, a new compound extracted from Marasmius androsaceus

AIM OF THE STUDY

To evaluate the antihypertensive effect of 3,3,5,5-tetramethyl-4-piperidone (TMP), a new compound extracted from Marasmius androsaceus. Besides, the hemodynamic profiles and pertinent mechanism of the compound were explored.

MATERIALS AND METHODS

Acute and chronic antihypertensive effects of TMP were examined in spontaneous hypertensive rats (SHRs) and reno-hypertensive rats (two kidneys one clip model, 2K1C). Anesthetized dogs were used to evaluate the hemodynamic effects of TMP. Moreover, the cat nictitating membrane response was used to test the ganglionic blocking property of TMP.

RESULTS

TMP (2.5, 5 and 10mg/kg, p.o.) notably reduced the blood pressure of SHR in 30 min. Two-week administration of TMP (2.5, 5 and 10mg/kg, p.o.) also decreased the blood pressure of 2K1C rats. TMP (30 mg/kg, i.v.) abolished the response of the nictitating membrane induced by preganglionic stimulation. The results of hemodynamic study in anesthetized dogs showed that, except for the reduction in blood pressure and left ventricular work, no other changes were detected. The results of heart rate variability analysis indicated an intact sympathetic-vagal balance after TMP treatment.

CONCLUSIONS

TMP is a new antihypertensive compound, and the effect is partially related to ganglionic blocking.