The hypocholesterolemic action of eritadenine in the rat

"Eritadenine as a regulator of anxiety Disorders: An experimental and docking Approach"

Uncertainty persists regarding the specific chemical causal factors and their corresponding behavioral effects in anxiety disorders. Commonly employed first-line treatments for anxiety target G protein-coupled receptors (GPCRs), including inhibitors of monoaminergic systems. Alternatively, emerging natural bioactive strategies offer potential for mitigating adverse effects. Recent investigations have implicated adenosine in anxiety-triggering mechanisms, while eritadenine, an adenosine analog derived from Shiitake mushroom, has displayed promising attributes. This study explores eritadenine's potential as a bioactive substance for anxiety disorders in mice, employing behavioral tests, pentobarbital-sleep induction, and molecular docking. Behavioral test results reveal a pronounced anxiolytic and sedative-hypnotic pharmacological effect of eritadenine. Our findings suggest that eritadenine may modulate locomotor functions mediated by adenosine receptors, with a stronger affinity for binding to A2AAR over A1AR, thus eliciting these effects.

Emerging Role of Edible Exosomes-Like Nanoparticles (ELNs) as Hepatoprotective Agents

Liver diseases are responsible for over 2 million deaths each year and the number is rapidly increasing. There is a strong link between edibles, gut microbiota, liver fat and the liver damage. There are very limited therapeutic options for treatment specifically for Alcoholic liver disease (ALD) and Non-Alcoholic liver disease (NAFLD). Recently, identified Edible Exosomes-like nanoparticles (ELNs) are plant derived membrane bound particles, released by microvesicular bodies for cellular communication and regulate immune responses against many pathogens. Many studies have identified their role as hepatoprotective agent as they carry bioactive material as cargoes which are transferred to recipient cells and affect various biological functions in liver. They are also known to carry specific miRNA, which increases the copy number of beneficial bacteria and the production of lactic acid metabolites in gut and hence restrains from liver injury through portal vein. Few in-vitro studies also have been reported about the anti-inflammatory, anti-oxidant and detoxification properties of ELNs which again protects the liver. The properties such as small size, biocompatibility, stability, low toxicity and non-immunogenicity make ELNs as a better therapeutic option. But, till now, studies on the effect of ELNs as therapeutics are still at its infancy yet promising. Here we discuss about the isolation, characterization, their role in maintaining the gut microbiome and liver homeostasis. Also, we give an outline about the latest advances in ELNs modifications, its biological effects, limitations and we propose the future prospective of ELNs as therapeutics.

Protective Role of Shiitake Mushroom-Derived Exosome-Like Nanoparticles in D-Galactosamine and Lipopolysaccharide-Induced Acute Liver Injury in Mice

Fulminant hepatic failure (FHF) is a rare, life-threatening liver disease with a poor prognosis. Administration of D-galactosamine (GalN) and lipopolysaccharide (LPS) triggers acute liver injury in mice, simulating many clinical features of FHF in humans; therefore, this disease model is often used to investigate potential therapeutic interventions to treat FHF. Recently, suppression of the nucleotide-binding domain and leucine-rich repeat related (NLR) family, pyrin domain containing 3 (NLRP3) inflammasome, was shown to alleviate the severity of GalN/LPS-induced liver damage in mice. Therefore, the goal of this study was to find dietary exosome-like nanoparticles (ELNs) with therapeutic potential in curbing FHF by suppressing the NLRP3 inflammasome. Seven commonly consumed mushrooms were used to extract ELNs. These mushrooms were found to contain ELNs composed of RNAs, proteins, and lipids. Among these mushroom-derived ELNs, only shiitake mushroom-derived ELNs (S-ELNs) substantially inhibited NLRP3 inflammasome activation by preventing inflammasome formation in primary macrophages. S-ELNs also suppressed the secretion of interleukin (IL)-6, as well as both protein and mRNA levels of the Il1b gene. Remarkably, pre-treatment with S-ELNs protected mice from GalN/LPS-induced acute liver injury. Therefore, S-ELNs, identified as potent new inhibitors of the NLRP3 inflammasome, represent a promising class of agents with the potential to combat FHF.

Effects of Shiitake Intake on Serum Lipids in Rats Fed Different High-Oil or High-Fat Diets

Shiitake (Lentinula edodes) extract, eritadenine, has been shown to reduce cholesterol levels, and its hypocholesterolemic actions are involved in the metabolism of methionine. However, the mechanisms by which eritadenine affects cholesterol metabolism in animals fed a high-fat diet containing different sources of lipids have not yet been elucidated in detail. This study was conducted to investigate the effects of shiitake supplementation on serum lipid concentrations in rats fed a diet including a high amount of a plant oil (HO [high oil] and HOS [high oil with shiitake] groups), animal fat (HF [high fat] and HFS [high fat with shiitake] groups), or MCT- (medium-chain triglyceride-) rich plant oil (HM [high MCT] and HMS [high MCT with shiitake] groups). Rats in the HOS, HFS, and HMS groups were fed shiitake. When rats were fed a diet containing shiitake, serum triglyceride, cholesterol levels, and LCAT (lecithin-cholesterol acyltransferase) activities were lower in rats given MCT-rich plant oil than in those that consumed lard. The lipid type in the diet with shiitake also affected serum cholesterol levels and LCAT activities. The diet containing MCT-rich plant oil showed the greatest rates of decrease in all serum lipid profiles and LCAT activities. These results suggest that shiitake and MCT-rich plant oil work together to reduce lipid profiles and LCAT activity in serum.

A high-dose Shiitake mushroom increases hepatic accumulation of triacylglycerol in rats fed a high-fat diet: underlying mechanism

Shiitake mushroom have been shown to have health benefits including lowering plasma lipids and preventing body weight gain. However, their underlying mechanisms are largely unknown. The study aim was to assess the potential underlying mechanism of Shiitake mushrooms in lowering plasma triacylglycerol (TAG) in rats fed a high fat diet (HFD). Forty Wistar rats were divided into control group were given HFD and treatment group were fed HFD, enriched with Shiitake mushroom powder at a low dose (LD-M): 0.7%, medium dose (MD-M): 2%, or high dose (HD-M): 6% (wt:wt) for six weeks. Diets were isocaloric containing ~50% energy from fat. After six weeks' dietary intervention, the rats were sacrificed, and blood and tissue samples were collected. The HD-M group showed a significantly higher ratio of liver weight to 100 g body weight (p < 0.05), a more severe hepatic steatosis marker, such as hepatocyte ballooning (p < 0.0001), and more liver triacylglycerol content than LD-M and MD-M (p < 0.05). HD-M also showed a significantly decreased ratio of phosphatidylcholine (PC) to phosphatidylethanolamine (PE) compared to HFD (p < 0.05), however, there were no differences compared to HD-M and MD-M. Our results also showed a positive association between the dosage, liver TAG, and liver ballooning histology. A negative association was found between the mushroom dosage and the ratio of liver PC to PE. This study showed the mechanism of how high-dose Shiitake mushroom (HD-M) prevents obesity by increasing TAG accumulation in the liver, rather than adipose tissue.

Differential effects of shiitake- and white button mushroom-supplemented diets on hepatic steatosis in C57BL/6 mice

Shiitake mushrooms (SMs) have been used in Asia for treatment and/or prevention of chronic diseases and hypercholesterolemia. Previously, we observed a diet supplemented with 5% SM resulted in a twofold increase in plasma IL-6 levels in DBA arthritic mice. An elevation in plasma IL-6 has also been implicated in the pathogenesis fatty liver disease. Thus, the aim of this study was to investigate the effect of SM supplemented-diet on hepatic steatosis. In study 1, eight-week old female C57BL/6 mice were randomly assigned to the following groups for 6 weeks: the AIN-93 diet; 5% SM, and 5% white button mushroom (WBM) supplemented diets (12/group). In study 2, mice were fed either the AIN-93 diet or SM (20/group). After 6 weeks, 13 mice fed SM diet were given the AIN93 diet for 8 or 15 days. Unlike other groups, all mice fed the SM diet developed fatty liver (mean histopathology score 4.5 vs <1 in the other groups; p<0.001) without fibrosis and inflammation. Fifteen days post withdrawal of SM completely normalized liver histology. To the best of our knowledge, this is the first report that chronic consumption of SM is associated with the development of fatty liver. The mechanism by which SM causes hepatic steatosis warrants further investigation.

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

Fruit bodies and mycelia of shiitake mushroom ( Lentinus edodes) have been shown to contain the cholesterol-reducing compound eritadenine, 2( R),3( R)-dihydroxy-4-(9-adenyl)butyric acid. In the search for a production method for eritadenine, shiitake mycelia were investigated in the present study. The mycelia were cultivated both in shake flasks and in bioreactors, to investigate the effects of pH, stirring rate, and reactor type on the production and distribution of eritadenine. Both the biomass and the culture broth were examined for their eritadenine content. In the shake flasks, the final concentration of eritadenine was 1.76 mg/L and eritadenine was equally distributed between the mycelia and the growth media. In the bioreactors, the shiitake mycelia were found to contain eritadenine in relatively low levels, whereas the majority, 90.6-98.9%, was detected in the growth media. Applying a stirring rate of 250 rpm during bioreactor cultivation resulted in the highest eritadenine concentrations: 10.23 mg/L when the pH was uncontrolled and 9.59 mg/L when the pH was controlled at 5.7. Reducing the stirring rate to 50 rpm resulted in a decreased eritadenine concentration, both at pH 5.7 (5.25 mg/L) and when pH was not controlled (5.50 mg/L). The mycelia in the shake flask cultures appeared as macroscopic aggregates, whereas mycelia cultivated in bioreactors grew more as freely dispersed filaments. This study demonstrates for the first time the extra- and intracellular distribution of eritadenine produced by shiitake mycelial culture and the influence of reactor conditions on the mycelial morphology and eritadenine concentrations.

Eritadenine-induced alterations of plasma lipoprotein lipid concentrations and phosphatidylcholine molecular species profile in rats fed cholesterol-free and cholesterol-enriched diets

The effects of dietary eritadenine on the concentration of plasma lipoprotein lipids and the molecular species profile of plasma lipoprotein phosphatidylcholine (PC) were investigated in rats fed cholesterol-free and cholesterol-enriched diets to obtain insights into the relationship between the changes in PC molecular species profile and the hypocholesterolemic action of eritadenine. The effect of eritadenine on the secretion rate of very low density lipoprotein (VLDL) from the liver was also estimated. Rats were fed the control or eritadenine-supplemented (50 mg/kg) diets with or without exogenous cholesterol for 14 d. Eritadenine supplementation significantly decreased the cholesterol of major plasma lipoproteins, high density lipoprotein and VLDL, in rats fed cholesterol-free and cholesterol-enriched diets, respectively. The ratio of PC to phosphatidylethanolamine, delta6-desaturase activity, and the ratio of arachidonic acid to linoleic acid in liver microsomes were markedly decreased by eritadenine irrespective of the presence or absence of exogenous cholesterol. Dietary eritadenine increased the proportion of 16:0-18:2 molecular species with a decrease in 18:0-20:4 in plasma lipoprotein PC in both rats fed cholesterol-free and cholesterol-enriched diets. Eritadenine did not depress the secretion rate of VLDL in rats fed a cholesterol-free diet containing a high level of choline. The results indicate that dietary eritadenine elicits its hypocholesterolemic action with modulations of the fatty acid and molecular species profiles of PC irrespective of the presence or absence of exogenous cholesterol. The eritadenine-induced alteration of PC molecular species profile is discussed in relation to the hypocholesterolemic action of eritadenine.

Dietary eritadenine and ethanolamine depress fatty acid desaturase activities by increasing liver microsomal phosphatidylethanolamine in rats

The effects of eritadenine, a constituent of the Lentinus edodes mushroom, and ethanolamine, the base constituent of phosphatidylethanolamine (PE), on fatty acid desaturase activities and lipid profiles were investigated comparatively in rats. Rats were fed a control diet or a diet supplemented with either eritadenine (0.05 g/kg) or ethanolamine (8 g/kg) for 14 d. Eritadenine and ethanolamine had marked hypocholesterolemic effects. The concentration of liver microsomal PE was significantly increased and the ratio of phosphatidylcholine (PC) to PE was significantly decreased by both eritadenine and ethanolamine. These changes in phospholipid profile were also observed in the mitochondria and plasma membranes in the liver. The activities of the Delta5-, Delta6- and Delta9-desaturases in liver microsomes were significantly decreased by eritadenine and ethanolamine; there was a significant correlation between the activity of Delta5- or Delta6-desaturase and the proportion of PE in the total phospholipids or the PC/PE ratio. Reflecting decreased Delta5- and Delta6-desaturase activities, the 20:4(n-6)/18:2(n-6) ratio was significantly decreased by eritadenine and ethanolamine in PC of the liver microsomes, mitochondria and plasma membranes. Although the 20:4(n-6)/18:2(n-6) ratio of liver microsomal PE was also significantly decreased by eritadenine and ethanolamine, the fatty acid composition of phosphatidylinositol and phosphatidylserine was less affected by these compounds. Eritadenine and ethanolamine increased the proportion of 16:0-18:2 and decreased the proportion of 18:0-20:4 in liver PC. The results suggest that dietary eritadenine and ethanolamine might lead to decreases in desaturase activities and changes in fatty acid and molecular species composition of PC through an increase in liver microsomal PE.

Correlation of suppressed linoleic acid metabolism with the hypocholesterolemic action of eritadenine in rats

The dose-dependent effects of dietary eritadenine on the metabolism of linoleic acid and on the plasma cholesterol concentration were investigated to clarify the mechanism of the hypocholesterolemic action of eritadenine in rats. Rats were fed control or eritadenine-supplemented (2 to 20 mg/kg) diets for 14 d. Eritadenine supplementation significantly decreased both the plasma cholesterol concentration and the 20:4n-6/18:2n-6 ratio of liver microsomal and plasma phosphatidylcholine (PC) in a dose-dependent manner. Eritadenine was also found to decrease the activity of delta 6 desaturase in liver microsomes; there was significant correlation between the delta 6-desaturase activity and the 20:4n-6/18:2n-6 ratio in the PC of liver microsomes (r = 0.989, P < 0.001) or plasma (r = 0.986, P < 0.001). Certain plasma PC molecular species, as represented by 16:0-18.2, were increased by eritadenine in a dose-dependent manner, and certain plasma PC molecular species, as represented by 18:0-20:4, were conversely decreased by eritadenine. There was a significant correlation between the plasma total cholesterol concentration and the proportion of the sum of plasma PC molecular species which contain 18:1 or 18:2 in the sn-2 position. These results support the idea that the suppression of linoleic acid metabolism by eritadenine might be associated with the hypocholesterolemic action of eritadenine.

Dietary eritadenine modifies plasma phosphatidylcholine molecular species profile in rats fed different types of fat

The effect of dietary eritadenine on plasma phosphatidylcholine (PC) molecular species composition was investigated in relation to its hypocholesterolemic action in rats fed different types of fats (olive oil, corn oil and linseed oil; 100 g/kg diet). Eritadenine supplementation (50 mg/kg diet) significantly decreased the plasma total cholesterol concentration, irrespective of dietary fat sources, and without change in the order of plasma cholesterol concentration among the fat groups (corn oil > olive oil > linseed oil). Eritadenine significantly decreased the ratio of phosphatidylcholine (PC) to phosphatidylethanolamine (PE) in liver microsomes of all the fat groups, while the PC:PE ratio was unaffected by dietary fat type. The fatty acid and molecular species composition of plasma PC was affected either directly or indirectly by the fatty acid composition of dietary fats. The proportion of linoleic acid and linoleic acid-containing molecular species (16:0-18:2 and 18:0-18:2) in plasma PC was the highest in rats fed linseed oil, despite the fact that linoleic acid concentration of linseed oil was only 1/3 that of corn oil. Eritadenine supplementation significantly increased the proportion of linoleic acid and linoleic acid-containing molecular species, especially 16:0-18:2, in plasma PC, irrespective of dietary fat source. Altered plasma PC molecular species composition, as represented by an increase in 16:0-18:2 PC, might contribute to the hypocholesterolemic action of eritadenine.

Dietary eritadenine-induced alteration of molecular species composition of phospholipids in rats

The effect of dietary eritadenine, a hypocholesterolemic compound found in the mushroom Lentinus edodes, on the fatty acid and molecular species profiles of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) in the plasma and liver microsomes was investigated in relation to the hypocholesterolemic action of the compound in rats. Animals were fed the control or eritadenine-supplemented (50 mg/kg diet) diet for 14 d. Eritadenine supplementation significantly decreased the plasma concentrations of cholesterol and phospholipids, but not triglycerides. The PC/PE ratio of liver microsomes, but not plasma, was also markedly decreased by eritadenine. Eritadenine supplementation was found to increase the proportion of 18:2n-6 and, inversely, to decrease the proportion of 20:4n-6 and 22:5n-6 in plasma PC and liver microsomal PC and PE, indicating that eritadenine depressed the metabolism of linoleic acid. The effect of eritadenine on the profile of n-3 fatty acids was dissimilar in PC and PE. These changes in fatty acid composition were selectively reflected in the molecular species composition of both PC and PE; the extent of increase in 16:0-18:2 molecular species or decrease in 18:0-20:4 molecular species was apparently greater than that of other molecular species containing 18:2 or 20:4 in the sn-2 position. These results suggest that, in addition to the decrease in liver microsomal PC/PE ratio, the alteration of plasma PC molecular species composition might also participate in the hypocholesterolemic action of eritadenine.

Influence of water and ethanol extracts of the oyster mushroom (Pleurotus ostreatus) on serum and liver lipids of the Syrian hamsters

Extracts from the dried and ground fungus were prepared with water and with 30%, 60% and 85% ethanol, and thickened in vacuum. The whole fungus and extracts were added to the hyperlipidemic diet in amounts equivalent to 3% of the whole fungus. After 6 weeks the whole fungus, its water as well as 30% and 60% ethanol extracts have significantly reduced the contents of cholesterol (C) and triacylglycerols (TG) in the serum. The C and TG contents of the liver were reduced by 34-48% (in the case of TG insignificantly when applying the water and 60% ethanol extracts). The 85% ethanol extracts reduced the C and TG levels in both serum and liver statistically insignificantly by 18-22%. The reduction of serum C by addition of the whole fungus and its water and 30% ethanol extract was decisively affected by the reduction in the C contents in the very low density fraction of lipoproteins.

Broad-spectrum antiviral activity of adenosine analogues

In recent years certain aliphatic and carbocyclic adenosine analogues have been developed which are of potential clinical importance as antiviral agents. This includes (S)-9-(2,3-dihydroxypropyl)adenine [(S)-DHPA] and carbocyclic 3-deazaadenosine (C-c3Ado). (S)-DHPA and C-c3Ado are remarkably similar in their antiviral spectrum in that they are particularly active against (-) RNA viruses such as measles, para-influenza, respiratory syncytial virus, rabies virus, vesicular stomatitis virus and (+/-)RNA viruses such as reo- and rotavirus, whereas (+)RNA viruses such as polio, coxsackie and (+/-)DNA viruses such as herpes simplex are only minimally affected or not inhibited at all. In contrast with (S)-DHPA and C-c3Ado which are quite selective in their antiviral action, other adenosine analogues, i.e., 3-deazaadenosine and 7-deazaadenosine (tubercidin), exhibit little, if any, selectivity as antiviral agents. Also, tubercidin has a broader activity spectrum, encompassing (+)RNA viruses as well as herpes simplex in addition to the (-)RNA viruses. Considering the high antiviral potency of tubercidin, attempts have been undertaken to increase its selectivity, i.e., by chemical substitutions at C-5 of the pyrrolo(2,3-d)pyrimidine ring. These attempts have been partially successful.

Hypocholesterolaemia in the rat after p-chlorophenoxyisobutyric acid (CPIB) administration as a synthetic triglyceride, 1,3-dipalmitoyl 2(p-chlorophenoxyisobutyroyl)-rac-glycerol

A synthetic triglyceride analogue, 1,3-dipalmitoyl 2(p-chlorophenoxyisobutyroyl)-rac-glycerol, was fed to rats and its effect compared to that of clofibrate. Both compounds significantly lowered plasma cholesterol concentration and the decreases essentially paralleled each other, even when the dose of drug or the period of administration was varied. No consistent effect was noted on the plasma triglyceride concentration. The results suggest that synthetic lipids are potentially suitable carriers for the oral administration of pharmacologically active agents.

High volume screening procedures for hypobetalipoproteinemic activity in rats

We describe high volume screening tests for hypobetalipoproteinemic agents in which compounds are administered orally to cholesterol-cholic acid fed (hypercholesterolemic( or normally fed weanling rats for 4 days. In these tests total serum cholesterol levels and heparin precipitating lipoproteins (HPL) are determined by automated analyses interfaced with a computer which eliminates all manual data reduction and provides necessary reports. The hypercholesterolemic rat test detects compounds which specifically reduce HPL (beta and pre beta lipoproteins) causing a decrease in the HPL: cholesterol ratio. Such activity is called hypobetalipoproteinemia. This activity is exhibited by bicyclo (2.2.2)-octyloxyaniline (U-26328) but not by any of the familiar hypocholesterolemic agents including clofibrats, lifibrats, nicotinic acid, probucol, triparanol, lentysine, D-throxine or the estrogens estrone and diethylstilbestrol.

Cycloalkanones V: synthesis, distribution, and effects on triglyceride metabolism

The 14-C-labeled 2,8-dibenzylcyclooctanone was synthesized to study its absorption, distribution, and excretion in rats. Maximum drug absorption from the GI tract occurred between 12 and 14 hr after administration. The major organs possessed maximum amounts of the drug in 1 hr, with the liver concentrating the most with 6.56% 14-C and the muscle mass reaching a maximum of 41% 14-C after 14 hr. The drug remained in the GI tract over the first 6 hr and was associated with the lipid and glycogen fractions. Eighty-seven percent was eliminated in the feces after 72 hr. 2,8-Dibenzylcyclooctanone caused a significant reduction in vitro of dihydroxyacetone phosphatase acyltransferase and sn-glycerol-3-phosphate acyltransferase, which is the proposed mechanism for the observed in vivo reduction of hepatic, intestinal, and serum triglycerides and total glycerolipids. In vivo administration of the drug resulted in a depression of liver acid phosphatidyl phosphatase, acid phosphatase and lipase, and adipose lipase. The drug increased the rates of excretion of exogenous cholesterol, palmitic acid, and progesterone.