Immunomodulatory activities of polysaccharides isolated from Amauroderma rugosum (Blume and T. Nees) Torrend and their structural characterization.

Amauroderma rugosum (Blume and T. Nees) Torrend is a traditionally well-known mushroom that is used for the treatment of cancer. In order to evaluate the pharmacological activities of A. rugosum polysaccharides, the mushroom powder was subjected to hot water extraction and pure polysaccharides (ARPs) were isolated by gel-filtration method. Three important APRs called ARP-1, ARP-2 and ARP-5 were identified with average molecular weights of 1494, 450, and 7 kDa respectively. Their antioxidant abilities were estimated by examining free radical scavenging potential against 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid radical (ABTS●+), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH●), and hydroxyl radical. Immunomodulatory potentials of these ARPs were determined using murine macrophage cells. These polysaccharides exhibited high antioxidant abilities and stimulated mouse macrophages leading to the generation of tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Excellent activities were displayed by ARP-1 and APR-2. Gas chromatography and spectroscopic (FT-IR and NMR) methods were employed in order to carry out their structural characterisation. The two high molecular weight ARPs (ARP-1 and ARP-2) displayed ß-(1 â†’ 3)-D-glucan backbone structure with branching of ß-(1 â†’ 6)-d-glucopyranosyl. These observations suggest high potential of ARPs for immunotherapeutic applications.

Structural Characterization and In-Vitro Antioxidant and Immunomodulatory Activities of Polysaccharide Fractions Isolated from Artemisia annua L.

Arimisia annua L. is an important anticancer herb used in traditional Chinese medicine. The molecular basis underpinning the anticancer activity is complex and not fully understood, but the herbal polysaccharides, broadly recognised as having immunomodulatory, antioxidant and anticancer activities, are potential key active agents. To examine the functions of polysaccharides from A. annua, their immunomodulatory and antioxidant potentials were evaluated, as well as their structural characterization. The water-soluble polysaccharides (AAPs) were fractionated using size-exclusion chromatography to obtain three dominant fractions, AAP-1, AAP-2 and AAP-3, having molecular masses centered around 1684, 455 and 5.8kDa, respectively. The antioxidant potentials of the isolated polysaccharides were evaluated by measuring radical scavenging activities against DPPH● (2,2-diphenyl-1-picrylhydrazyl radical), ABTS●+ (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid radical ion), and the OH● (hydroxyl radical). AAP-1 displayed high antioxidant activities against these radicals, which were 68%, 73% and 78%, respectively. AAP-2 displayed lower scavenging activities than the other two fractions. Immunostimulatory activities of AAPs were measured using mouse macrophages. The three polysaccharide fractions displayed significant antioxidant activities and stimulated the production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). AAP-1 showed significant immunostimulatory activity (16-fold increase in the production of IL-6 compared to the control and 13-fold increase in the production of TNF-α) with low toxicity (>60% cell viability at 125 µg/mL concentration). Preliminary structural characterization of the AAPs was carried out using gas chromatography (GC) and FTIR techniques. The results indicate that AAP-1 and AAP-2 are pyranose-containing polysaccharides with ß-linkages, and AAP-3 is a ß-fructofuranoside. The results suggest that these polysaccharides are potential candidates for immunotherapy and cancer treatment.

Yellow lupin (Lupinus luteus L.) polysaccharides: Antioxidant, immunomodulatory and prebiotic activities and their structural characterisation.

Yellow lupin polysaccharides (YLP-1, YLP-2 and YLP-3) were isolated from the whole seeds of Lupinus luteus L. Their antioxidant activities were evaluated by ABTS+ and hydroxyl radical scavenging, and Fe2+ chelating assays. Immunostimulatory activities were measured by their ability to activate macrophages to produce TNF-α and NO. Four strains of probiotic bacteria were used to measure their prebiotic activities. YLP-2 with largest galactose content displayed the best activity amongst the three isolated polysaccharides. NMR and FT-IR spectroscopic methods have revealed that YLPs contain galactans and galactomannans which are linked with ß-(1,4) glycosidic bond in the main chain. The side chain Galp unit of galactomannan is connected to the main chain Manp by α-(1,6) linkage. The results presented in this paper strongly suggest that YLPs display significant antioxidant, immunostimulatory and prebiotic activities and hence hold great potential as nutraceutical and functional agents.

Ageratum conyzoides L. inhibits 5-alpha-reductase gene expression in human prostate cells and reduces symptoms of benign prostatic hypertrophy in otherwise healthy men in a double blind randomized placebo controlled clinical study.

A double-blind, randomized, placebo-controlled clinical trial assessed the efficacy and safety of Ageratum conyzoides in treating benign prostatic hypertrophy (BPH). In this study, 109 men with medically diagnosed BPH, aged 41-76 years, were administered the investigational product, A. conyzoides extract at a dose of 250 mg/d or placebo, q.d. for 12 weeks. The primary outcome measures were the International Prostate Symptom Score (IPSS), daily urinary frequency and safety evaluations. The secondary outcome measures were testosterone, dihydrotestosterone, oestradiol, sex hormone binding globulin (SHBG), Dehydroepiandrosterone sulfate (DHEA-S) and cortisol levels, and prostate specific antigen (PSA), lipids, blood glucose, the Aging Male's Symptom (AMS) Score and sexual function assessed by Derogatis Interview for Sexual Functioning-Self Report (DISF-SR). The effect of A. conyzoides L extract on gene expression of 5-alpha-reductase in human prostate cells was also investigated to elucidate a potential mechanism of action. The clinical study, showed a significant reduction in total IPSS score (p < 0.01) and day- and night-time urinary frequency (P < 0.01) over time after treatment with A. conyzoides. Steroid hormones, SHBG, PSA levels, lipids, and blood glucose remained within healthy reference range in both groups. There were no changes in AMS or DISF-SR in either group. Gene arrays demonstrated that A. conyzoides extract was effective in reducing the expression of mRNA coding for 5-alpha-reductase types 2 and 1 in human prostate epithelial cells. The overall results indicate that A. conyzoides may be an effective treatment for reducing symptoms of BPH in healthy men, in part, through inhibition of 5-alpha-reductase enzyme activity. © 2017 BioFactors, 43(6):789-800, 2017.

Antioxidant Capacities of Hot Water Extracts and Endopolysaccharides of Selected Chinese Medicinal Fruits.

Fruits are a rich source of antioxidants and traditional Chinese fruits have been studied for their chemopreventive and chemotherapeutic properties against cancers and other diseases. The total phenol and flavonoid contents of eleven Chinese fruits extracts were determined. Total phenolic and flavonoid contents were estimated by both the Folin-Ciocalteau and aluminium chloride methods. The antioxidant activities were evaluated by four assays: a biological assay using Saccharomyces cerevisiae, DPPH radical scavenging activity, chelating ability for ferrous ions and ferric reducing antioxidant power (FRAP). The phenols and flavonoids contents of the hot water extracts were in the range of 17.7 to 94.7 mg/g and 12.3 to 295.4 mg/g, whereas the endopolysaccharides lie in the range of 4.5 to 77.4 mg/g and 22.7 to 230.0 mg/g. Significant amounts of phenols and flavonoids were present in the majority of the fruit extracts and showed strong antioxidant activities. The antioxidant properties of the fruit extracts of Crataegus pinnatifida, Illicium verum, Ligustrum lucidum, Momordica grosvenori and Psoralea corylifolia as determined by the DPPH and FRAP methods, were significant compared to other fruit extracts. In the present study, we found that significant amounts of phenolic and flavonoid compounds were present in these fruit extracts and may contribute to in vitro antioxidant activities.

Immunomodulatory activities of polysaccharides isolated from Taxillus chinensis and Uncaria rhyncophylla.

Taxillus chinensis and Uncaria rhyncophylla are the herbs used in traditional Chinese anticancer formulations. During the past decade, research on plant polysaccharides has gained importance due to their therapeutic value and minimum side effects. In this study, hot water extraction method was employed to isolate polysaccharides from the stems of T. chinensis and stems with hooks of U. rhyncophylla. Size-exclusion chromatography was then used for further fractionation. Separated fractions from T. chinensis were designated as TCP-1, TCP-2 and TCP-3 and those from U. rhyncophylla were termed UC-1 and UC-2. Their sugar compositions were estimated using gas chromatography that revealed the presence fructose, glucose, xylose, arbinose, and rhamnose. Amino acid analysis of these fractions has indicated that they are protein-bound polysaccharides. The antioxidant activities were investigated using DPPH and yeast assays. The ability of these polysaccharide fractions to stimulate mouse macrophages was measured using Griess reagent and ELISA test. The results revealed that some of the isolated fractions (TCP-2, TCP-3, UC-1 and UC-2) displayed significant antioxidant activities and were also found to be effective immunomodulators in a concentration-dependent manner. Outcomes of this research strongly indicate that U. rhyncophylla and T. chinensis have therapeutic potential to be used for the treatment of cancer.

Antioxidant and immunomodulating activities of exo-and endopolysaccharide fractions from submerged mycelia cultures of culinary-medicinal mushrooms.

A number of mushrooms are known to possess pharmacological activities. In this study, the phenolic and flavonoid contents of extracts of exo- and endopolysaccharide fractions obtained from submerged mycelia cultures of 7 edible or medicinal mushroom species, as well as their antioxidant and immunomodulatory properties, were evaluated. The exo- and endopolysaccharide yields were 0.576-1.950 and 0.438-0.933 g/L, respectively. The sugar and protein contents of these fractions were analyzed and contained predominantly sugars (52.3-87.6%). The exo- and endopolysaccharide fractions contained appreciable amounts of phenolics and flavonoids. The highest flavonoid contents were found in Cryptosporus volvatus (349.6 mg/g), followed by Cordyceps militaris (312.6 mg/g). The antioxidant activities were evaluated by 4 assays: biological assay using Saccharomyces cerevisiae, DPPH radical scavenging activity, chelating ability for ferrous ions and ferric reducing antioxidant power. The mycelia polysaccharide fractions had more ferric reducing antioxidant power than other antioxidant activities. Both exo- and endo polysaccharides of C. volvatus inhibited production of the T lymphocyte Th1 cytokines interferon (IFN)-γ and interleukin (IL)-2, the Th2 cytokines IL-4 and IL-5, and macrophage enzyme activity. Although those from C. militaris had similar inhibitory effects on cytokine production, the exopolysaccharides stimulated macrophage enzyme activity. The other exopolysaccharides (Pleurotus citrinopileatus, P. australis, and P. pulmonarius) inhibited IFN-γ and IL-5 production, but they had varying effects on IL-2 and IL-4 production. Only 3 exopolysaccharides (P. pulmonarius, Tremella mesenterica, and Cordyceps sinensis) also stimulated macrophage enzyme activity to the same extent as lipopolysaccharides. All of them reduced IL-5 production, but those from T. mesenterica also inhibited IFN-γ, IL-2, and IL-4 production. Thus the polysaccharide fractions from the mushrooms studied have antioxidant activities and general immunomodulating effects in vitro.

Antioxidant and anti-inflammatory activities of selected medicinal plants and fungi containing phenolic and flavonoid compounds.

BACKGROUND: This study aims to determine the relationship between the antioxidant and anti-inflammatory activities of the thirteen herbs and two fungi extracts, and their total phenolic and flavonoid contents. METHODS: Antioxidant activities were evaluated by four assays: an antioxidant activity assay using Saccharomyces cerevisiae, a DPPH ((2, 2-diphenyl-1-picrylhydrazyl) assay to assess free radical scavenging, an assay assessing ferrous ions or iron (II) chelating ability, and a ferric reducing antioxidant power (FRAP) assay. Total phenolic and flavonoid contents were determined using the Folin-Ciocalteu and aluminium chloride methods, respectively. Anti-inflammatory activities were determined by measuring the inhibition of nitric oxide and TNF-α production in lipopolysaccharide- and interferon-γ-activated J774A.1 macrophages. Their cytotoxicities against macrophages were determined by MTT assay. RESULTS: A positive linear correlation between antioxidant activities and the total phenolic and flavonoid content of the plant extracts was found. The plant extracts with high phenolic and flavonoid content also exhibited significant anti-inflammatory activity with good cell viability. CONCLUSION: The selected herbs could be a rich source of antioxidants and free radical scavenging compounds. The levels of phenolic and flavonoid compounds were correlated with the antioxidant and anti-inflammatory activities of the extracts from the herbs.

Antioxidant and anti-inflammatory activities of selected Chinese medicinal plants and their relation with antioxidant content.

BACKGROUND: The main aim of this study is to evaluate the antioxidant and anti-inflammatory properties of forty four traditional Chinese medicinal herbal extracts and to examine these activities in relation to their antioxidant content. METHODS: The antioxidant activities were investigated using DPPH radical scavenging method and yeast model. The anti-inflammatory properties of the herbal extracts were evaluated by measuring their ability to inhibit the production of nitric oxide and TNF-α in RAW 264.7 macrophages activated by LPS and IFN- γ, respectively. The cytotoxic effects of the herbal extracts were determined by Alomar Blue assay by measuring cell viability. In order to understand the variation of antioxidant activities of herbal extracts with their antioxidant contents, the total phenolics, total flavonoids and trace metal (Mg, Mn, Cu, Zn, Se and Mo) quantities were estimated and a correlation analysis was carried out. RESULTS: Results of this study show that significant levels of phenolics, flavonoids and trace metal contents were found in Ligustrum lucidum, Paeonia suffuticosa, Salvia miltiorrhiza, Sanguisorba officinalis, Spatholobus suberectus, Tussilago farfara and Uncaria rhyncophylla, which correlated well with their antioxidant and anti-inflammatory activities. Some of the plants displayed high antioxidant and anti-inflammatory activities but contained low levels of phenolics and flavonoids. Interestingly, these plants contained significant levels of trace metals (such as Zn, Mg and Se) which are likely to be responsible for their activities. CONCLUSIONS: The results indicate that the phenolics, flavonoids and trace metals play an important role in the antioxidant activities of medicinal plants. Many of the plants studied here have been identified as potential sources of new antioxidant compounds.

Antioxidant and immunomodulatory activities of polysaccharides from the roots of Sanguisorba officinalis.

The roots of Sanguisorba officinalis are used in traditional Chinese medicine for the treatment of diseases such as inflammation and internal haemorrhage. Several scientific investigations involving extraction and pharmacological studies of terpenoids and triterpenoid glycosides from this herb have been carried out. However, little is known regarding the immunomodulatory and antioxidant properties of polysaccharides from S. officinalis. Hence the polysaccharides from this herb have been investigated here. The hot water extract of S. officinalis has been fractionated using size-exclusion chromatography to obtain four polysaccharide fractions designated as SOP-1, SOP-2, SOP-3 and SOP-4. The range of molecular masses of these fractions were from 280 Da to 2000 kDa, and their sugar compositions consisted mainly of fructose, glucose, xylose, arabinose, and rhamnose. The antioxidant activities of the crude polysaccharide fractions were evaluated in a biological assay using Saccharomyces cerevisiae, whereas the radical scavenging activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Analysis of the immunomodulatory activities of these polysaccharide fractions were measured by using mouse macrophages. Most of the polysaccharide fractions have stimulated the production of nitric oxide and tumour necrosis factor-α (TNF-α), and also displayed antioxidant activities. These results suggest that the roots of S. officinalis are likely to have therapeutic value for the treatment of cancer.

Macrophage immunomodulating and antitumor activities of polysaccharides isolated from Agaricus bisporus white button mushrooms.

Agaricus bisporus white button mushroom (WBM) is widely consumed in most countries for its culinary properties. Recently, its dietary intake has been shown to protect against breast cancer. Mushroom polysaccharides are known for their immunomodulating and antitumor properties; however, little is known regarding the properties of A. bisporus polysaccharides. Using size-exclusion chromatography to fractionate the crude extract of A. bisporus, two polysaccharide fractions (designated as ABP-1 and ABP-2) were obtained. The estimated molecular masses of ABP-1 and ABP-2 were 2,000 kDa and 40-70 kDa, respectively, and their sugar compositions consisted mainly of glucose, mannose, xylose, and fructose. Analysis of the effects of the polysaccharides on murine macrophages demonstrated that both fractions stimulated the production of nitric oxide, interleukin-6, and tumor necrosis factor-α. Modulation of macrophage function by A. bisporus polysaccharides was mediated in part through activation of nuclear factor-κB with the production p50/105 heterodimers. Both ABP-1 and ABP-2 had the ability to inhibit the growth of human breast cancer MCF-7 cells but had little effect on the growth of human colon, prostate, gastric cancer, and murine Sarcoma 180 cells as assessed by a tetrazolium dye [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]-based assay. However, when murine Sarcoma 180 cells exposed to ABP-1 or ABP-2 were implanted subcutaneously into mice, a reduction in tumor growth was observed compared with that observed in control mice. Taken together, our data provide a molecular basis to explain in part the reported beneficial therapeutic effects of A. bisporus WBM intake and suggest that macrophages likely contribute to the antitumor effects of Agaricus polysaccharides.

Dietary intake of Agaricus bisporus white button mushroom accelerates salivary immunoglobulin A secretion in healthy volunteers.

OBJECTIVE: Secretory immunoglobulin A (SIgA) acts as the first line of adaptive humoral immune defense at mucosal surfaces. A lack of SIgA or the inability to produce antigen-specific SIgA can lead to an increased risk of infections. Dietary intake may improve mucosal immunity by accelerating SIgA secretion. This study investigated the effect of dietary intake of Agaricus bisporus white button mushroom (WBM) on salivary IgA (sIgA) secretion in healthy subjects. METHODS: Twenty-four healthy volunteers were randomly assigned to a normal daily diet (control group) or a normal diet with WBM. The subjects in the active group (n = 12, 41.4 ± 11.3 y old) consumed 100 g of blanched WBM daily with their normal diet for 1 wk, whereas those in the control group consumed their normal diet (n = 12, 43.5 ± 12.5 y old) without WBM. Saliva was collected before and after commencement of the study and every week thereafter for 3 wk. Saliva flow rate, sIgA concentration, and osmolality were determined and the sIgA:osmolality ratio and the sIgA secretion rate were calculated. RESULTS: There was no significant difference between pre- and postdietary mushroom intakes for all indices in the control group (P > 0.05). In contrast, the mean sIgA secretion rate increased significantly at weeks 1 and 2 by 53% and 56%, respectively, compared with that at week 0 (P < 0.0005) in the WBM intake group and then returned to a baseline level at week 3. Changes in sIgA secretion rate over the intervention period were greater in the WBM group than in the control group without WBM. In both groups, no significant changes in osmolality and saliva IgG were noted. There was, however, a significant increase in the sIgA:osmolality ratio (P < 0.0012), confirming the postdietary WBM-induced sIgA increase. CONCLUSION: The dietary intake of A. bisporus WBM significantly accelerates sIgA secretion, thereby indicating its potential health benefits for improving mucosal immunity.

Antioxidant and anti-inflammatory activities of selected medicinal plants containing phenolic and flavonoid compounds.

The antioxidant, anti-inflammatory, and cytotoxic activities of water and ethanol extracts of 14 Chinese medicinal plants were investigated and also their total phenolics and flavonoid contents measured. The antioxidant activity was evaluated in a biological assay using Saccharomyces cerevisiae , whereas the radical scavenging activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Total phenolics and flavonoid contents were estimated by Folin-Ciocalteu and aluminum chloride methods, respectively. The anti-inflammatory activities of the plant extracts were determined by measuring the inhibition of production of nitric oxide (NO) and TNF-α in LPS and IFN-γ activated RAW 264.7 macrophages. Their cytotoxic activities against macrophages were determined by Alamar Blue assay. Four plants, namely, Scutellaria baicalensis , Taxillus chinensis , Rheum officinale , and Sophora japonica , showed significant antioxidant activity in both yeast model and also free radical scavenging methods. The ethanol extract of S. japonica showed highest levels of phenolics and flavonoids (91.33 GAE mg/g and 151.86 QE mg/g, respectively). A positive linear correlation between antioxidant activity and the total phenolics and flavonoid contents indicates that these compounds are likely to be the main antioxidants contributing to the observed activities. Five plant extracts (S. baicalensis, T. chinensis, S. japonica, Mahonia fortunei , and Sophora flavescens ) exhibited significant anti-inflammatory activity by in vitro inhibition of the production of NO and TNF-α with low IC(50) values. These findings suggest that some of the medicinal herbs studied in this paper are good sources of antioxidants.

White button mushroom (Agaricus bisporus) lowers blood glucose and cholesterol levels in diabetic and hypercholesterolemic rats.

Agaricus bisporus (white button mushroom; WBM) contains high levels of dietary fibers and antioxidants including vitamin C, D, and B(12); folates; and polyphenols that may provide beneficial effects on cardiovascular and diabetic diseases. The objective of this study was to examine the hypothesis that intake of the fruiting bodies of WBM regulates anticholesterolemic and antiglycemic responses in rats fed a hypercholesterolemic diet (0.5% cholesterol; 14% fat) and rats with type 2 diabetes induced by injection of streptozotocin (STZ) (50 mg/kg body weight), respectively. The STZ-induced diabetic male Sprague-Dawley rats fed the Agaricus bisporus powder (ABP; 200 mg/kg of body weight) for 3 weeks had significantly reduced plasma glucose and triglyceride (TG) concentrations (24.7% and 39.1%, respectively), liver enzyme activities, alanine aminotransferase and aspartate aminotransferase (11.7% and 15.7%, respectively), and liver weight gain (P < .05). In hypercholesterolemic rats, oral feeding of ABP for 4 weeks resulted in a significant decrease in plasma total cholesterol (TC) and low-density lipoprotein (LDL) (22.8% and 33.1%, respectively) (P < .05). A similar significant decrease in hepatic cholesterol and TG concentrations was observed (36.2% and 20.8%, respectively) (P < .05). Decrease in TC, LDL, and TG concentrations was accompanied by a significant increase in plasma high-density lipoprotein concentrations. It was concluded that A bisporus mushroom had both hypoglycemic and hypolipidemic activity in rats.

Vitamin B12 is the active corrinoid produced in cultivated white button mushrooms (Agaricus bisporus).

Analysis of vitamin B(12) in freshly harvested white button mushrooms ( Agaricus bisporus ) from five farms was performed by affinity chromatography and HPLC-ESI-MS techniques. The vitamin B(12) concentrations obtained varied from farm to farm, with higher concentrations of vitamin B(12) detected in outer peel than in cap, stalk, or flesh, suggesting that the vitamin B(12) is probably bacteria-derived. High concentrations of vitamin B(12) were also detected in the flush mushrooms including cups and flats. HPLC and mass spectrometry showed vitamin B(12) retention time and mass spectra identical to those of the standard vitamin B(12) and those of food products including beef, beef liver, salmon, egg, and milk but not of the pseudovitamin B(12), an inactive corrinoid in humans. The results suggest that the consumer may benefit from the consumption of mushroom to increase intake of this vitamin in the diet.

Vitamin D2 formation and bioavailability from Agaricus bisporus button mushrooms treated with ultraviolet irradiation.

Agaricus bisporus mushrooms contain an abundance of ergosterol, which on exposure to UV irradiation is converted to vitamin D2. The present study evaluated the effects UV-C irradiation on vitamin D2 formation and its bioavailability in rats. Fresh button mushrooms were exposed to UV-C irradiation at mean intensities of 0.403, 0.316, and 0.256 mW/cm(2) from respective distances of 30, 40, and 50 cm for periods ranging from 2.5 to 60 min. Vitamin D2 and ergosterol were measured by HPLC-MS/MS. The stability and retention of vitamin D2 were assessed including the extent of discoloration during storage at 4 degrees C or at room temperature. Exposure to UV-C irradiation at 0.403 mW/cm(2) intensity from 30 cm distance resulted in a time-dependent increase in vitamin D2 concentrations that was significantly higher than those produced at intensities of 0.316 and 0.256 mW/cm(2) from distances of 40 and 50 cm, respectively. Furthermore, the concentrations of vitamin D2 produced after exposure to UV-C irradiation doses of 0.125 and 0.25 J/cm(2) for, 2.5, 5, and 10 min were 6.6, 15.6, and 23.1 microg/g solids, equivalent to 40.6, 95.4, and 141 microg/serving, respectively. The data showed a high rate of conversion from ergosterol to vitamin D2 at short treatment time, which is required by the mushroom industry. The stability of vitamin D2 remained unchanged during storage at 4 degrees C and at room temperature over 8 days (P = 0.36), indicating no degradation of vitamin D2. By visual assessment or using a chromometer, no significant discoloration of irradiated mushrooms, as measured by the degree of "whiteness", was observed when stored at 4 degrees C compared to that observed with mushrooms stored at room temperature over an 8 day period (P < 0.007). Vitamin D2 was well absorbed and metabolized as evidenced by the serum response of 25-hydroxyvitamin D in rats fed the irradiated mushrooms. Taken together, the data suggest that commercial production of button mushrooms enriched with vitamin D2 for improving consumer health may be practical.