Antioxidant property of edible mushrooms collected from Ethiopia

Pleurotus albidus Modulates Mitochondrial Metabolism Disrupted by Hyperglycaemia in EA.hy926 Endothelial Cells

Hyperglycaemia exacerbates the production of reactive oxygen species (ROS), contributing to the multiple complications associated with diabetes. Mitochondrial dysfunction is also known to be associated with diabetes. Therefore, the aim of this work was to study the effect of Pleurotus albidus extract on the mitochondrial dysfunction induced by hyperglycaemia in EA.hy926 endothelial cells. The results showed that P. albidus treatment prevented the increase in the activity of complex I of the electron transport chain and minimized the ROS production induced by hyperglycaemia. In addition, the extract minimized oxidative damage to lipids and proteins, caused an imbalance in the antioxidant enzyme activities of superoxide dismutase and catalase, and decreased the nitric oxide levels induced by hyperglycaemia. These data contribute to our understanding of the mitochondrial disorder induced by hyperglycaemia as well as establishing the conditions required to minimize these alterations.

Ergothioneine production using Methylobacterium species, yeast, and fungi

Ergothioneine (EGT) is a sulfur-containing, anti-oxidative amino acid derived from histidine. EGT is synthesized in bacteria and fungi but not in animals and plants, and is now recognized as important for human health. Its cost-effective fermentative production has not been elucidated due to the lack of information for productive microorganisms. In this study, we doubled the gene copy for EGT synthesis and deleted the histidine ammonia-lyase gene in a potent EGT-producing methylotrophic bacterium Methylobacterium aquaticum strain 22A, and optimized its culture conditions, resulting in increased EGT production of 7.0 mg EGT/g dry cell weight and 100 μg EGT/5 mL/7 days. In addition, through screening we found EGT-producing eukaryotic strains of Aureobasidium pullulans and Rhodotorula mucilaginosa, which can produce 1.0 and 3.2 mg EGT/g dry cell weight, 70 and 120 μg EGT/5 mL/7 days, respectively. This study proposes practical uses of potent EGT-producing recombinant Methylobacterium species and non-recombinant yeast and fungal strains.

Indigenous Ethiopian okra (Abelmoschus esculentus) mucilage: A novel ingredient with functional and antioxidant properties

Functional and antioxidant properties of mucilage extracted from the pods of eight okra accessions grown in Benishangul-Gumuz region, Western Ethiopia, were evaluated. This study had shown that the mucilage contents of the pods of eight okra accessions ranged from 1.25 to 3.45 g/100 g. Functional properties of the mucilage of okra pods varied significantly (p < .05) and had respective ranges of bulk density of 0.58-0.64 g/ml; water absorption capacity of 2.45-4.60 ml/g; oil absorption capacity of 0.02-3.64 ml/g; emulsifying capacity of 42.22%-74.45%; emulsion stability of 42.22%-74.45%; foaming capacity of 50.51%-62.50%, and foam stability of 36.04%-54.35%. Total phenolic and flavonoid contents of the mucilage of the pods of okra accessions ranged from 4.66 to 49.93 mg GAE/g and 8.18-18.72 mg CE/g, respectively. The effective concentration (EC 50) values (mg/ml) of mucilage of okra pods varied from 3.15 to 6.60 and 1.10 to 1.85 for DPPH scavenging and metal-chelating activity, respectively. The study revealed that the mucilage of the pods of okra accessions was found to exhibit good functional properties and can offer a great potential in various food systems. Particularly, mucilage of the pods from OPA#5 and OPA#7 had desirable water and oil absorption capacities, whereas the mucilage of accession OPA#1 and OPA#6 had high emulsifying and foaming properties. The results also demonstrated that okra pod mucilage had potential sources of natural antioxidant.

Wild Mushrooms: A Potential Source of Nutritional and Antioxidant Attributes with Acceptable Toxicity

This paper describes in detail proximate composition, nutritional profile, phytochemical constituents, antioxidant activities, antimicrobial potential, and antihemolytic activity (towards human erythrocytes) of various fractions of wild Ganoderma lucidum. Proximate analysis established that wild G. lucidum comprises about 87.02±5.45% of moisture, and the remaining part is a rich source of proteins (8.59±0.37%), crude fiber (54.21±1.2%), and carbohydrate (35.16%) with smaller fat content (3.33 %). Similarly, phytochemical screening revealed the presence of flavonoids (217.51±0.30 mg/g), ascorbic acid (116±7.32 mg/g), phenolics (360.72±34.07 mg/g), β-carotenes (0.42±0.04 μg/g), and lycopene (0.05±0.00 μg/g). Extracts of wild G. lucidum in various solvents provided first line protection against Escherichia coli and Pasteurella multocida in the order of ethyl acetate> ethanol> methanol> n-hexane> water. Furthermore, aqueous and methanolic extracts of wild G. lucidum were found to be safe towards human erythrocytes. Overall, wild mushroom (G. lucidum) was found to be a good source of dietary supplements, antimicrobial and antioxidant agents in the pursuance of its commercial utilization in food and pharmaceutical industries.

Assessment of the antimicrobial, antioxidant and cytotoxic activities of the wild edible mushroom Agaricus lanipes (F.H. Møller & Jul. Schäff.) Hlaváček

The present investigation was undertaken to evaluate the antimicrobial and antioxidant activities of the wild edible mushroom Agaricus lanipes, and also to investigate its cytotoxicity and potential and possible apoptotic effect against the A549 lung cancer cell line in in vitro conditions. Total antioxidant capacity, total phenolic content, total oxidant status, total antioxidant status, lipid hydroperoxides, and total free -SH levels of A. lanipes were found to be 4.55 mg T/g, 14.6 mg GA equivalent/g, 3.10 mg H2O2 equivalent/g, 2.25 mg H2O2 equivalent/g, and 1.90 µmol/g, respectively. The methanolic extract of A. lanipes had relatively strong antimicrobial activity against seven tested microorganism strains. It also had high anti-proliferative potency and strong pro-apoptotic effects, and this mushroom used as a daily nutrient could be a source for new drug developments and treatment in cancer therapies, and could be a guide for studies in this area.

Purification and Structural Characterization of a Novel Water-Soluble Neutral Polysaccharide from Cantharellus cibarius and Its Immunostimulating Activity in RAW264.7 Cells

Polysaccharide is one of the important active ingredients of Cantharellus cibarius. The aims of this work were to analyze preliminary characterization and to investigate immunostimulating activity of a novel water-soluble neutral polysaccharide named JP1, which was purified from the fruiting body of Cantharellus cibarius using DEAE-FF chromatography and Sephadex G-100 chromatography. The characteristics of JP1 were determined by HPGPC, FT-IR spectra, gas chromatography, and Congo Red Method. Immunostimulating activity of JP1 was investigated in RAW264.7 cells. Results indicated that JP1 consisted of L-Arabinose, D-Mannose, D-Glucose, and D-Galactose in a molar ratio of 1 : 1.06 : 1.95 : 1.17 with a molecular weight of 336 kDa. JP1 is nontoxic to RAW264.7 cells at this concentration range (62.5–1000 μg/mL). Furthermore, JP1 can promote mouse peritoneal macrophages to secrete NO and enhance the secretion of macrophages’ cytokines IL-6 in RAW264.7 cells. These results suggested that JP1 could have potential immunostimulating activity applications as medicine or functional food.

Phenolic Compounds, Antioxidant Activity and Lipid Profile of Huitlacoche Mushroom (Ustilago maydis) Produced in Several Maize Genotypes at Different Stages of Development

Huitlacoche mushroom (composed by the fruiting bodies growing on the maize ears from the basidiomycete Ustilago maydis) is a culinary delicacy with a great economic and nutraceutical value. In this work, phenolic content, antioxidant activity, ergosterol and fatty acids profile from huitlacoche produced in 15 creole and in one hybrid maize genotypes, and harvested at different stages of development were determined. The hybrid crop was studied in raw and cooked samples. Total phenolic content ranged from 415.6 to 921.8.0 mg gallic acid equivalents per 100 g of flour. Samples exhibited attractive antioxidant activities: 75 % of antiradical activity on average by DPPH methodology, and ORAC values up to 7661.3 μmol Trolox equivalents /100  g. Important quantities of ferulic acid, quercetin, ergosterol, linoleic and oleic acids were observed. Stage of development and cooking process had an effect on evaluated compounds, sometimes negative and sometimes positive. Results suggest that huitlacoche is an attractive food source of phenolics with excellent antioxidant potential and interesting lipidic compounds.

Mushroom varieties found in the Himalayan regions of India: Antioxidant, antimicrobial, and antiproliferative activities

This study evaluates the antioxidant, antimicrobial, and antiproliferative activities of mushroom varieties (Agaricus bisporus, Pleurotus ostreatus, and Coprinus atramentarius) found in the Himalayan regions of Jammu and Kashmir, India. All three mushroom varieties exhibited antioxidant activity. A. bisporus showed the highest diphenyl-2-picrylhydrazyl inhibition activity (87.88±5.6%), C. atramentarius showed the highest reducing power (0.49±0.01) and metal chelating ability (48.57± 0.38%), and P. ostreatus contained the highest phenolic (5.25±0.14 mg gallic acid equivalent per gram) and flavonoid content (64.39±0.73 μg rutin equivalent per gram). C. atramentarius showed maximum antibacterial activity against all the pathogenic strains and the highest zone of inhibition was against S. typhi (7.45±0.5 mm). P. ostreatus exhibited the highest cell proliferation inhibition against Colo-205 and MCF-7 cancer cell lines. The structural analysis by Fourier transform infrared spectroscopy indicated the presence of β-configuration in carbohydrates, phenolic compounds, and protein, which impart nutraceutical properties to mushrooms.

Chemical Composition and Inhibitory Effect of Lentinula edodes Ethanolic Extract on Experimentally Induced Atopic Dermatitis in Vitro and in Vivo

The ethanolic extract of Lentinula edodes was partially analyzed and then characterized for its efficacy in treating atopic dermatitis. Polyphenols were determined to be the major antioxidant component in the extract (6.12 mg/g), followed by flavonoids (1.76 mg/g), β-carotene (28.75 μg/g), and lycopene (5.25 μg/g). An atopic dermatitis (AD) model was established and epidermal and dermal ear thickness, mast cell infiltration, and serum immunoglobulin levels were measured after oral administration of the L. edodes extract for 4 weeks. L. edodes extract decreased Dermatophagoides farinae extract (DFE) and 4-dinitrochlorobenzene (DNCB)-induced expression of several inflammatory cytokines in the ears, cervical lymph nodes, and splenocytes. Consequently, L. edodes extract may have therapeutic potential in the treatment of AD attributable to its immunomodulatory effects.

Effect of lactic acid fermentation on antioxidant properties and phenolic acid contents of oyster (Pleurotus ostreatus) and chanterelle (Cantharellus cibarius) mushrooms

Fruiting bodies of Pleurotus ostreatus (oyster) and Cantharellus cibarius (chanterelle) mushrooms underwent acid fermentation using 3 strains of lactic acid bacteria (LAB) as starter cultures. Polyphenol contents, antioxidant activities, and phenolic acid contents in fresh, blanched, and fermented mushrooms were investigated. Fruiting bodies of oyster mushrooms exhibited higher total phenolic contents than chanterelle mushrooms. Blanching caused a decrease in polyphenol contents and antioxidant activities in both mushroom types. No important differences were observed in total phenolic compound contents (measured using Folin-Ciocalteau reagent) in mushrooms using different LAB strains. Lactobacillus plantarum was the most useful microorganism for lactic acid fermentation of fruiting bodies for reduction of the pH value. The highest concentrations of single phenolic acids: gallic, homogentisic, and ferulic acids were present in mushrooms fermented using L. plantarum.

Effect of conventional milling on the nutritional value and antioxidant capacity of wheat types common in Ethiopia and a recovery attempt with bran supplementation in bread

The effect of wheat flour refined milling on nutritional and antioxidant quality of hard and soft grown in Ethiopia was evaluated. Bread was prepared with the supplementation of the white wheat flour with different levels (0%, 10%, 20%, and 25%) of wheat bran. Whole (100% extraction) and white wheat (68% extraction) flours were analyzed for proximates, minerals, and antioxidants. Results indicated that at a low extraction rate (68%), the protein, fat, fiber, ash, iron, zinc, phosphorous, and antioxidant contents of the samples significantly (P < 0.05) decreased by milling. The TPC (total phenolic content) of the white wheat flours, which ranged from 3.34 to 3.49 mg GAE (gallic acid equivalent)/g, was significantly (P < 0.005) lower than those of the whole wheat flours, whose TPC ranged from 7.66 to 8.20 GAE/g). At 50 mg/mL, the DPPH (2‐diphenyl‐1‐picrylhydrazyl) scavenging effect of the wheat extracts decreased in the order of soft whole, hard whole, soft white, and hard white wheat flour, which was 90.39, 89.89, 75.80, and 57.57%, respectively. Moreover, the proximate and mineral contents of the bran‐supplemented breads increased significantly (P < 0.05) with the bran level of the bread, and the highest values (protein, 12.0 g/100 g; fat, 2.6 g/100 g; fiber, 2.5 g/100 g; ash, 3.3 g/100 g; iron, 4.8 mg/100 g and zinc, 2.33 mg/100 g) were found in 25% bran supplemented bread. The sensory evaluation of bread showed that all the supplementation levels had a mean score above 4 for all preferences on a 7‐ point hedonic scale. The results indicated that refined milling at 68% extraction significantly reduces the nutritional and antioxidant activity of the wheat flours. Bread of good nutritional and sensory qualities can be produced from 10% and 20% bran supplementations.

Production of ergothioneine by Methylobacterium species

Metabolomic analysis revealed that Methylobacterium cells accumulate a large amount of ergothioneine (EGT), which is a sulfur-containing, non-proteinogenic, antioxidative amino acid derived from histidine. EGT biosynthesis and its role in methylotrophy and physiology for plant surface-symbiotic Methylobacterium species were investigated in this study. Almost all Methylobacterium type strains can synthesize EGT. We selected one of the most productive strains (M. aquaticum strain 22A isolated from a moss), and investigated the feasibility of fermentative EGT production through optimization of the culture condition. Methanol as a carbon source served as the best substrate for production. The productivity reached up to 1000 μg/100 ml culture (1200 μg/g wet weight cells, 6.3 mg/g dry weight) in 38 days. Next, we identified the genes (egtBD) responsible for EGT synthesis, and generated a deletion mutant defective in EGT production. Compared to the wild type, the mutant showed better growth on methanol and on the plant surface as well as severe susceptibility to heat treatment and irradiation of ultraviolet (UV) and sunlight. These results suggested that EGT is not involved in methylotrophy, but is involved in their phyllospheric lifestyle fitness of the genus in natural conditions.

Two Ganoderma species: profiling of phenolic compounds by HPLC-DAD, antioxidant, antimicrobial and inhibitory activities on key enzymes linked to diabetes mellitus, Alzheimer's disease and skin disorders

This work reports the antioxidant, antimicrobial, and inhibitory effects of methanol and water extracts from Ganoderma applanatum (GAM: methanol extract and GAW: water extract) and G. resinaceum (GRM: methanol extract and GRW: water extract) against cholinesterase, tyrosinase, α-amylase and α-glucosidase. The total phenolics, flavonoids contents, and HPLC profile of phenolic components present in the extracts, were also determined. Antioxidant activities were investigated by using different assays, including DPPH, ABTS, FRAP, CUPRAC, phosphomolybdenum and metal chelating assays. Antimicrobial activity of the tested Ganoderma extracts was also studied by the broth microdilution method. Generally, the highest antioxidant (59.24 mg TEs per g extract for DPPH, 41.32 mg TEs per g extract for ABTS, 41.35 mg TEs per g extract for CUPRAC, 49.68 mg TEs per g extract for FRAP, 130.57 mg AAEs per g extract for phosphomolybdenum and 26.92 mg EDTAEs per g extract) and enzyme inhibitory effects (1.47 mg GALAEs per g extract for AChE, 1.51 mg GALAEs per g extract for BChE, 13.40 mg KAEs per g extract for tyrosinase, 1.13 mmol ACEs per g extract for α-amylase and 2.20 mmol ACEs per g extract for α-glucosidase) were observed in GRM, which had the highest concentrations of phenolics (37.32 mg GAEs g(-1) extract). Again, Ganoderma extracts possess weak antibacterial and antifungal activities. Apigenin and protocatechuic acid were determined as the main components in GRM (1761 μg per g extract) and GAM (165 μg per g extract), respectively. The results suggest that the Ganoderma species may be considered as a candidate for preparing new food supplements and can represent a good model for the development of new drug formulations.