Ganoderic Acid Research Articles

Ganoderic Acid A-Mediated Modulation of Microglial Polarization is Involved in Depressive-Like Behaviors and Neuroinflammation in a Rat Model of Post-Stroke Depression

BackgroundPost-stroke depression (PSD) is a common complication after stroke. Ganoderic acid A (GAA), one of the main bioactive Ganoderma triterpenoids, exerts preventive and therapeutic effects in many diseases. However, the function of GAA in PSD has not been well studied.MethodsPSD model was established via stimulating rats with chronic unpredictable mild stress stimulations (CUMS) after middle cerebral artery occlusion (MCAO). Rats were treated with GAA before CUMS. Depressive-like behaviors were investigated by body weight alteration, open field test (OFT), and sucrose preference test (SPT). Neuronal damage was evaluated by hematoxylin and eosin (HE) staining and Western blotting. Inflammation was detected by enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Microglial polarization was analyzed via qRT-PCR and Western blotting. The extracellular signal-regulated kinase (ERK)/cAMP-response element-binding protein (CREB) pathway was analyzed by Western blotting, and inactivated by the inhibitor PD98059 (PD).ResultsGAA attenuated PSD-induced depressive-like behaviors in rats. GAA mitigated PSD-induced neuronal damage and reduced BDNF and NGF levels in the cerebral hippocampus. GAA weakened PSD-induced inflammatory response in the cerebral hippocampus. GAA prevented pro-inflammatory (M1) polarization and promoted anti-inflammatory (M2) polarization, as indicated by decreased iNOS and CD86 levels and increased Arg-1 and CD206 levels. GAA restored the PSD-induced inactivation of the ERK/CREB pathway. GAA regulated M1/M2 microglial polarization by activating the ERK/CREB pathway.ConclusionGAA alleviated the depressive-like behaviors and brain inflammation in PSD rats, indicating its potential for PSD therapy.

Ganoderic acid A inhibits ox-LDL-induced THP-1-derived macrophage inflammation and lipid deposition via Notch1/PPARγ/CD36 signaling.

Atherosclerosis (AS), a chronic inflammatory disease, is a major contributor to deaths worldwide. Ganoderic acid A (GAA) has been widely applied for various diseases due to its excellent anti-inflammatory properties. To investigate the underlying mechanism of GAA inhibition of inflammation and lipid deposition in human monocyte (THP-1) cells. The Cell Counting Kit-8 (CCK-8) assay was used to assess the potential effect of GAA on the viability of THP-1 cells. The release of inflammatory cytokines and oxidative stress was measured using enzyme-linked immunosorbent assay (ELISA) and the corresponding kit, respectively. The levels of lipid deposition and total cholesterol (TC) were also evaluated. Next, the scavenger receptors and proteins in Notch1/PPARă/CD36 signaling were measured with western blot. As Notch1 was overexpressed in the THP-1 cells induced by oxidized low-density lipoprotein (ox-LDL), the above assays were performed again to confirm the underlying mechanism. Ganoderic acid A suppressed ox-LDL-induced inflammation and oxidative stress in THP-1 cells. At the same time, it inhibited the TC level and lipid deposition. The effects of GAA on alleviating inflammation, oxidative stress and lipid accumulation were relieved after the overexpression of Notch1 in the treated cells, and the effects of GAA on alleviating inflammation, oxidative stress and lipid accumulation were diminished. The PPARă activator also weakened the effects of GAA on relieving inflammation, oxidative stress and lipid accumulation in ox-LDL-induced THP-1 cells. Ganoderic acid A inhibits ox-LDL-induced macrophage inflammation and lipid deposition in THP-1 cells through Notch1/PPARă/CD36 signaling, which may provide theoretical guidance for the clinical applications of GAA in AS treatment.

Postharvest Drying Techniques Regulate Secondary Metabolites and Anti-Neuroinflammatory Activities of Ganoderma lucidum.

Ganoderma lucidum extract is a potent traditional remedy for curing various ailments. Drying is the most important postharvest step during the processing of Ganoderma lucidum. The drying process mainly involves heat (36 h at 60 °C) and freeze-drying (36 h at −80 °C). We investigated the effects of different postharvest drying protocols on the metabolites profiling of Ganoderma lucidum using GC-MS, followed by an investigation of the anti-neuroinflammatory potential in LPS-treated BV2 microglial cells. A total of 109 primary metabolites were detected from heat and freeze-dried samples. Primary metabolite profiling showed higher levels of amino acids (17.4%) and monosaccharides (8.8%) in the heat-dried extracts, whereas high levels of organic acids (64.1%) were present in the freeze-dried samples. The enzymatic activity, such as ATP-citrate synthase, pyruvate kinase, glyceraldehyde-3-phosphatase dehydrogenase, glutamine synthase, fructose-bisphosphate aldolase, and D-3-phosphoglycerate dehydrogenase, related to the reverse tricarboxylic acid cycle were significantly high in the heat-dried samples. We also observed a decreased phosphorylation level of the MAP kinase (Erk1/2, p38, and JNK) and NF-κB subunit p65 in the heat-dried samples of the BV2 microglia cells. The current study suggests that heat drying improves the production of ganoderic acids by the upregulation of TCA-related pathways, which, in turn, gives a significant reduction in the inflammatory response of LPS-induced BV2 cells. This may be attributed to the inhibition of NF-κB and MAP kinase signaling pathways in cells treated with heat-dried extracts.

Probiotic fermentation of Ganoderma lucidum fruiting body extracts promoted its immunostimulatory activity in mice with dexamethasone-induced immunosuppression

Ganoderma lucidum is a legendary traditional Chinese medicine with various bioactivities. This study was conducted (a) to explore the in vitro fermentation of the water extracts of G. lucidum fruiting body with Lactobacillus acidophilus and Bifidobacterium breve and (b) to investigate the effect of fermentation broth (GLFB) on dexamethasone (DEX)-induced immunosuppressed mice. Our results demonstrated that probiotic fermentation of G. lucidum fruiting body extracts underwent structural changing of major ganoderic acid components, such as ganoderic acid A (GA) into GC2, and this fermentation process involves changing of several metabolic pathways in the probiotic strains. GLFB could significantly improve the immunity, intestinal integrity, and gut microbiota dysbiosis in DEX-treated mice, and the immunostimulatory activity of GLFB was found closely related to its direct regulation on the expansion of CD4+ T cells in Peyer’s patches of mice. These data implied that probiotic fermentation of G. lucidum fruiting body extracts promoted its immunostimulatory activity via biotransformation of components such as GA. This research provides a theoretical support for the development and application of G. lucidum fermentation by probiotics.

Nano lipidic carriers for codelivery of sorafenib and ganoderic acid for enhanced synergistic antitumor efficacy against hepatocellular carcinoma

The current study focuses on the development and evaluation of nano lipidic carriers (NLCs) for codelivery of sorafenib (SRF) and ganoderic acid (GA) therapy in order to treat hepatocellular carcinoma (HCC). The dual drug-loaded NLCs were prepared by hot microemulsion technique, where SRF and GA as the drugs, Precirol ATO5, Capmul PG8 as the lipids, while Solutol HS15 and ethanol was used as surfactant and cosolvents. The optimized drug-loaded NLCs were extensively characterized through in vitro and in vivo studies. The optimized formulation had particle size 29.28 nm, entrapment efficiency 93.1%, and loading capacity 14.21%. In vitro drug release studies revealed>64% of the drug was released in the first 6 h. The enzymatic stability analysis revealed stable nature of NLCs in various gastric pH, while accelerated stability analysis at 25◦C/60% RH indicated the insignificant effect of studied condition on particle size, entrapment efficiency, and loading capacity of NLCs. The cytotoxicity performed on HepG2 cells indicated higher cytotoxicity of SRF and GA-loaded NLCs as compared to the free drugs (p < 0.05). Furthermore, the optimized formulation suppressed the development of hepatic nodules in the Wistar rats and significantly reduced the levels of hepatic enzymes and nonhepatic elements against DEN intoxication. The SRF and GA-loaded NLCs also showed a significant effect in suppressing the tumor growth and inflammatory cytokines in the experimental study. Further, histopathology study of rats treated SRF and GA-loaded NLCs and DEN showed absence of necrosis, apoptosis, and disorganized hepatic parenchyma, etc. over other treated groups of rats. Overall, the dual drug-loaded NLCs outperformed over the plain drugs in terms of chemoprotection, implying superior therapeutic action and most significantly eliminating the hepatic toxicity induced by DEN in Wistar rat model.

Heat stress promotes the conversion of putrescine to spermidine and plays an important role in regulating ganoderic acid biosynthesis in Ganoderma lucidum.

Heat stress (HS) is inescapable environmental stress that can induce the production of ganoderic acids (GAs) in Ganoderma lucidum. Our previous studies found that putrescine (Put) played an inhibitory role in GAs biosynthesis, which appeared to be inconsistent with the upregulated transcription of the Put biosynthetic gene GlOdc under HS. To uncover the mechanism underlying this phenomenon, two spermidine (Spd) biosynthetic genes, GlSpds1 and GlSpds2, were identified and upregulated under HS. Put and Spd increased by 94% and 160% under HS, respectively, suggesting that HS induces polyamine biosynthesis and promotes the conversion of Put to Spd. By using GlSpds knockdown mutants, it is confirmed that Spd played a stimulatory role in GAs biosynthesis. In GlOdc-kd mutants, Put decreased by 62-67%, Spd decreased by approximately 34%, and GAs increased by 15-22% but sharply increased by 75-89% after supplementation with Spd. In GlSpds-kd mutants, Put increased by 31-41%, Spd decreased by approximately 63%, and GAs decreased by 24-32% and were restored to slightly higher levels than a wild type after supplementation with Spd. This result suggested that Spd, rather than Put, is a crucial factor that leads to the accumulation of GAs under HS. Spd plays a more predominant and stimulative role than Put under HS, possibly because the absolute content of Spd is 10 times greater than that of Put. GABA and H2O2, two major catabolites of Spd, had little effect on GAs biosynthesis. This study provides new insight into the mechanism by which environmental stimuli regulate secondary metabolism via polyamines in fungi. KEY POINTS: • HS induces polyamine biosynthesis and promotes the conversion of Put to Spd in G. lucidum. • Put and Spd played the inhibitory and stimulatory roles in regulating GAs biosynthesis, respectively. • The stimulatory role of Spd was more predominant than the inhibitory role of Put in GAs biosynthesis.

Ganoderic Acid A Alleviates OVA-Induced Asthma in Mice

The aim of this study is to investigate the effects of ganoderic acid A (GAA) on OVA-induced asthma in mice. Mouse asthma model was established by ovalbumin (OVA) in vitro. Diff-Quik staining was used to observe the total numbers of cells and the number of classification cells in each group, and HE staining was used to observe lung inflammation in lung tissue sections. ELISA was used to detect the effect of GAA on the levels of interleukin-4 (IL-4), IL-5, and IL-13 in serum and lung tissue. The expression levels of TLR/NF-κB were detected by Western blot. Immunohistochemistry was used to observe the expression changes of TLR4 and P-P65. Compared with the normal group, the inflammatory cell count, IL-4, IL-5, and IL-13 expression in the model group increased, and TLR/NF-kB signal protein expression increased. Compared with the model group, in GAA group, the number of inflammatory cells, the expression of IL-4, IL-5, and IL-13 decreased, and the expression of TLR/NF-kB signaling protein decreased. GAA regulated lung inflammation in asthmatic mice by inhibiting TLR/NF-kB signaling pathway.

Ganoderic Acid A Promotes Amyloid-β Clearance (In Vitro) and Ameliorates Cognitive Deficiency in Alzheimer's Disease (Mouse Model) through Autophagy Induced by Activating Axl.

Alzheimer’s disease (AD) is thought to be caused by amyloid-β (Aβ) accumulation in the central nervous system due to deficient clearance. The aim of the present study was to investigate the effect of ganoderic acid A (GAA) on Aβ clearance in microglia and its anti-AD activity. Aβ degradation in BV2 microglial cells was determined using an intracellular Aβ clearance assay. GAA stimulated autophagosome formation via the Axl receptor tyrosine kinase (Axl)/RAC/CDC42-activated kinase 1 (Pak1) pathway was determined by Western blot analyses, and fluorescence-labeled Aβ42 was localized in lysosomes in confocal laser microscopy images. The in vivo anti-AD activity of GAA was evaluated by object recognition and Morris water maze (MWM) tests in an AD mouse model following intracerebroventricular injection of aggregated Aβ42. The autophagy level in the hippocampus was assayed by immunohistochemical assessment against microtubule-associated proteins 1A/1B light-chain 3B (LC3B). Intracellular Aβ42 levels were significantly reduced by GAA treatment in microglial cells. Additionally, GAA activated autophagy according to increased LC3B-II levels, with this increased autophagy stimulated by upregulating Axl and Pak1 phosphorylation. The effect of eliminating Aβ by GAA through autophagy was reversed by R428, an Axl inhibitor, or IPA-3, a Pak1 inhibitor. Consistent with the cell-based assay, GAA ameliorated cognitive deficiency and reduced Aβ42 levels in an AD mouse model. Furthermore, LC3B expression in the hippocampus was up-regulated by GAA treatment, with these GAA-specific effects abolished by R428. GAA promoted Aβ clearance by enhancing autophagy via the Axl/Pak1 signaling pathway in microglial cells and ameliorated cognitive deficiency in an AD mouse model.

Anti-oxidant, anti-inflammatory and anti-fibrosis effects of ganoderic acid A on carbon tetrachloride induced nephrotoxicity by regulating the Trx/TrxR and JAK/ROCK pathway

Ganoderic acid A (GAA), one of the major triterpenoid components extracted from Ganoderma mushroom has been shown to possess numerous important pharmacological activities. The present study was aimed to investigate the mechanisms of GAA on carbon tetrachloride (CCl4)-induced kidney inflammation, fibrosis and oxidative stress in mice. The male mice were treated with 25 and 50 mg/mg GAA after stimulated with CCl4. Our results showed that GAA improved renal damage by decreasing the serum levels of creatinine, urea, uric acid and alleviating kidney fibrosis. GAA ameliorated CCl4-induced indices of inflammation. GAA suppressed oxidative stress by regulating the glutathione antioxidant system and the thioredoxin antioxidant system. GAA increased the activations of thioredoxin reductase (TrxR), Trx, GSH, SOD, GPx. Furthermore, GAA supplementation inhibited the JAK and STAT3 pathway. GAA inhibited the activations of RhoA, ROCK, NF-κB, TGF-β and Smad3. Thus, this study demonstrated that GAA possesses immune-protective properties through regulating the Trx/TrxR, JAK2/STAT3 and RhoA/ROCK pathways.

Computer Aided Drug Screening for Lung Infection

Lung infections are the leading cause of morbidity and mortality worldwide. Most causes of infection are not treatable. In children less than 5 years of age, they are the cause of death. Most infections are caused by viruses and bacteria. We present a dockingscreening using a quantum mechanical scoring of a library built from approved drugs and competent that apiin, baicalein, boswellic acid, eugenol, ganoderic acid, quercetin, vasicine, with proteins with PDB id’s 1VQQ, 3N26, 7K40, 5EG7 could display antiviral activity against lung infection. Clearly, these compounds should be further evaluated and clinical trials to confirm their actual activity against the disease

Ganoderic acid T improves the radiosensitivity of HeLa cells via converting apoptosis to necroptosis.

The use of natural substances derived from traditional Chinese medicine and natural plants as safe radiosensitizing adjuvants is a new trend for cancer radiotherapy. Ganoderma lucidum has been used as a traditional Chinese medicine with a history of more than 2000 years. Ganoderic acid T (GAT) is a typical triterpene of G. lucidum, which has strong cytotoxicity to cancer cells, but whether it has radiation sensitization effect has not been explored. In this work, we treated the HeLa cells with different concentrations of GAT before exposure to gamma-ray radiation and investigated its influence on the radiosensitivity. The cell viability, apoptosis rate, necoptosis rate, intracellular ATP level, cell cycle, the amount of H2AX and 53BP1, reactive oxygen species, and mitochondrial membrane potential were examined. Apoptotic, necroptotic, and autophagic biomarker proteins, including caspase 8, cytochrome c, caspase 3, RIPK, MLKL, P62, and LC3, were analyzed. As a result, we confirmed that with treatment of GAT, the gamma-ray radiation induced both apoptosis and necroptosis in HeLa cells, and with increase of GAT, the percentage ratio of necroptosis was increased. The involved pathways and mechanisms were also explored and discussed.

PADI4 mediates autophagy and participates in the role of ganoderic acid A monomers in delaying the senescence of Alzheimer's cells through the Akt/mTOR pathway.

The effects of PADI4 and GAA on the senescence of Alzheimer's cells were explored in the present work. HT22 cells were treated with Aβ25-35 to establish an Alzheimer's model and were then treated with different concentrations of GAA and transfected with a siPADI4 lentiviral vector. GAA could reverse the effects of Aβ25-35 on inhibiting cell viability and promoting apoptosis and senescence. siPADI4 reduced Aβ25-35-induced cell viability and upregulated Aβ25-35-induced cell apoptosis and senescence, as well as partially reversed the effect of GAA on cells, and these results were confirmed by detecting the expressions of senescence- and apoptosis-related proteins. In addition, siPADI4 was found to promote the phosphorylation of Akt and mTOR, which was partially reversed by GAA. In conclusion, PADI4 mediates autophagy and participates in the role of GAA monomers in delaying the senescence of Alzheimer's cells through the Akt/mTOR pathway.

GCN4 Regulates Secondary Metabolism through Activation of Antioxidant Gene Expression under Nitrogen Limitation Conditions in Ganoderma lucidum.

Nitrogen limitation has been widely reported to affect the growth and development of fungi, and the transcription factor GCN4 (general control nonderepressible 4) is involved in nitrogen restriction. Here, we found that nitrogen limitation highly induced the expression of GCN4 and promoted the synthesis of ganoderic acid (GA), an important secondary metabolite in Ganoderma lucidum. The activated GCN4 is involved in regulating GA biosynthesis. In addition, the accumulation of reactive oxygen species (ROS) also affects the synthesis of GA under nitrogen restrictions. The silencing of the gcn4 gene led to further accumulation of ROS and increased the content of GA. Further studies found that GCN4 activated the transcription of antioxidant enzyme biosynthesis genes gr, gst2, and cat3 (encoding glutathione reductase, glutathione S-transferase, and catalase, respectively) through direct binding to the promoter of these genes to reduce the ROS accumulation. In conclusion, our study found that GCN4 directly interacts with the ROS signaling pathway to negatively regulate GA biosynthesis under nitrogen-limiting conditions. This provides an essential insight into the understanding of GCN4 transcriptional regulation of the ROS signaling pathway and enriches the knowledge of nitrogen regulation mechanisms in fungal secondary metabolism of G. lucidum.IMPORTANCE Nitrogen has been widely reported to regulate secondary metabolism in fungi. Our study assessed the specific nitrogen regulatory mechanisms in Ganoderma lucidum. We found that GCN4 directly interacts with the ROS signaling pathway to negatively regulate GA biosynthesis under nitrogen-limiting conditions. Our research highlights a novel insight that GCN4, the nitrogen utilization regulator, participates in secondary metabolism through ROS signal regulation. In addition, this also provides a theoretical foundation for exploring the regulation of other physiological processes by GCN4 through ROS in fungi.

Potential of waste reduction of agro-biomasses through Reishi medicinal mushroom (Ganoderma lucidum) production using different substrates and techniques

One of the most important priorities in the medicinal mushrooms cultivation is the selection and preparation of the substrate, which depends on factors such as price and easy access to different lignocellulosic compounds. In order to investigate the effect of mixed and non-mixed agro-waste substrates on some vegetative, reproductive, nutritional and medicinal properties of two Iranian and Chinese strains of Ganoderma lucidum, the factorial experiment was conducted as a completely randomized design with three replications. The experimental substrates of different poplar wood chip (PWC), wheat bran (WB), soybean meal (SM), date palm leaf (DPL) and olive oil extraction waste (OOEW) were used. They were enriched with chemical supplements (ammonium nitrate, manganese sulfate and Nano manganese oxide) using two cultivation techniques (open bag door and Polika-Cotton) for fruiting body production.The results showed that various substrates significantly affect dry weight, moisture content quantity, vegetative and fruit yield, total ganoderic acids content, total polysaccharide value and mineral elements amount (nitrogen, potassium and calcium) in fruiting body. The highest amount of N content in the fruiting body of both Iranian and Chinese strains (5.88 and 6.25 mg/100 g dry matter) was dedicated to the combined PWC + SM (70:30) substrate enriched with Nano manganese oxide supplement and Polika-Cotton method. The highest total fresh of Iranian and Chinese strains weight (109.60 and 127.66 g, respectively) obtained in the combined PWC + WB (70:30) substrate enriched with manganese sulfate. The highest amount of total ganoderic acids in fruiting organs in both strains (0.52 and 0.42 μg/mg dry matter) is achieved using a combined PWC + SM (70:30) enriched with manganese sulfate.

In situ effervescence reaction-assisted mechanochemical extraction of ganoderic acids from Ganoderma lucidum

The aim of this work was to develop a simple, green and low-consumption method for the extraction of ganoderic acids. An in situ effervescence reaction-assisted mechanochemical extraction method was proposed, and the effects of independent variations in terms of sodium bicarbonate concentration, milling time, and liquid/solid ratio (mL/g) were investigated by means of a response surface methodology (RSM) Box-Behnken design (BBD). The highest yields of ganoderic acids were achieved by grinding a Ganoderma lucidum sample with sodium bicarbonate (372.60 mg/g) and citric acid for 0.87 min with a water to material ratio of 10.58 mL. The linear calibration ranges were from 0.01–5 μg/mL for the six analytes and had good linearity with a correlation coefficient of determination higher than 0.9991. In addition, the obtained LODs of the six target analytes were 1.46 − 2.97 ng/mL, and the LOQs calculated as ten times the signal-to-noise ratio were 4.88 − 9.90 ng/mL. The proposed method was successfully applied to the Ganoderma lucidum samples.

Biofabrication of gold nanoparticles using Ganoderma lucidum and their cytotoxicity against human colon cancer cell line (HT-29)

Ganoderma lucidum (G. lucidum) is a medicinal mushroom, which is rich in flavonoids as well as polyphenols and contains triterpenes, ganoderic acid. Thus, this research examined the biosynthesis of gold nanoparticles (GNPs) using G. lucidum fruit body and their cytotoxicity, cell morphology and apoptosis detection against HT-29 colon cancer cell line. The study results revealed the occurrence of GNPs, as evidenced by ultraviolet–visible spectroscopy (UV–vis spectroscopy; 520 nm). The X-ray diffraction results show that the synthesized Au-NPs are crystalline. According to field-emission scanning electron microscope, transmission electron microscopy and atomic force microscope, the synthesized GNPS exhibited shapes such as spherical, oval and irregular in shape and the size ranges in between 1 and 100 nm. G. lucidum biofabricated GNPs showed inhibited HT-29 colon cancer cell line with an efficacy IC50 of 84.58 µg ml–1. The results indicated that the apoptotic effects were increased on cells based on the dose-dependent concentration of GNPs.

Long-Term Administration of Triterpenoids From Ganoderma lucidum Mitigates Age-Associated Brain Physiological Decline via Regulating Sphingolipid Metabolism and Enhancing Autophagy in Mice.

With the advent of the aging society, how to grow old healthily has become an important issue for the whole of society. Effective intervention strategies for healthy aging are most desired, due to the complexity and diversity of genetic information, it is a pressing concern to find a single drug or treatment to improve longevity. In this study, long-term administration of triterpenoids of Ganoderma lucidum (TGL) can mitigate brain physiological decline in normal aging mice. In addition, the age-associated pathological features, including cataract formation, hair loss, and skin relaxation, brown adipose tissue accumulation, the β-galactosidase staining degree of kidney, the iron death of spleen, and liver functions exhibit improvement. We used the APP/PS1 mice and 3 × Tg-AD mice model of Alzheimer’s Disease (AD) to further verify the improvement of brain function by TGL and found that Ganoderic acid A might be the effective constituent of TGL for anti-aging of the brain in the 3 × Tg-AD mice. A potential mechanism of action may involve the regulation of sphingolipid metabolism, prolonging of telomere length, and enhance autophagy, which allows for the removal of pathological metabolites.

Impact of oxygen supply on production of a novel ganoderic acid in Saccharomyces cerevisiae fermentation

A novel bioactive ganoderic acid, 3, 28-dihydroxy-lanosta-8, 24-dien-26-oic-acid (DHLDOA), was recently biosynthesized using a heterologous host Saccharomyces cerevisiae by our group, but its low fermentation titer was an obstacle to large-scale application. In this study, the positive effect of oxygen supply on DHLDOA production by the yeast fermentation in shake-flask was revealed. The highest cell mass with an OD600 value of 27.92 was obtained at initial KLa of 15.6 h−1, and the highest DHLDOA titer of 8.79 mg/L was obtained at initial KLa of 12.6 h−1, which was 1.64- and 1.77-fold that at 4.2 and 15.6 h−1, respectively. Slightly higher pyruvate accumulation, lower citrate level, and adequate precursor pools of DHLDOA anabolism were found to be associated with higher DHLDOA production at initial KLa of 12.6 h−1, in which relatively higher CYP5150L8 and CYP5139G1 activities were also observed. Taken together, the results indicated that oxygen supply caused the global changes of the yeast metabolism, including the DHLDOA biosynthesis. This work will be helpful to further improvement of DHLDOA production by the yeast fermentation.

One-Pot Bi-Enzymatic Cascade Synthesis of Novel Ganoderma Triterpenoid Saponins

Ganoderma lucidum is a medicinal fungus whose numerous triterpenoids are its main bioactive constituents. Although hundreds of Ganoderma triterpenoids have been identified, Ganoderma triterpenoid glycosides, also named triterpenoid saponins, have been rarely found. Ganoderic acid A (GAA), a major Ganoderma triterpenoid, was synthetically cascaded to form GAA-15-O-β-glucopyranoside (GAA-15-G) by glycosyltransferase (BtGT_16345) from Bacillus thuringiensis GA A07 and subsequently biotransformed into a series of GAA glucosides by cyclodextrin glucanotransferase (Toruzyme® 3.0 L) from Thermoanaerobacter sp. The optimal reaction conditions for the second-step biotransformation of GAA-15-G were found to be 20% of maltose; pH 5; 60 °C. A series of GAA glucosides (GAA-G2, GAA-G3, and GAA-G4) could be purified with preparative high-performance liquid chromatography (HPLC) and identified by mass and nucleic magnetic resonance (NMR) spectral analysis. The major product, GAA-15-O-[α-glucopyranosyl-(1→4)-β-glucopyranoside] (GAA-G2), showed over 4554-fold higher aqueous solubility than GAA. The present study demonstrated that multiple Ganoderma triterpenoid saponins could be produced by sequential actions of BtGT_16345 and Toruzyme®, and the synthetic strategy that we proposed might be applied to many other Ganoderma triterpenoids to produce numerous novel Ganoderma triterpenoid saponins in the future.

Ganoderic acid alleviates chemotherapy-induced fatigue in mice bearing colon tumor.

Chemotherapy-related fatigue (CRF) is increasingly being recognized as one of the severe symptoms in patients undergoing chemotherapy, which not only largely reduces the quality of life in patients, but also diminishes their physical and social function. At present, there is no effective drug for preventing and treating CRF. Ganoderic acid (GA), isolated from traditional Chinese medicine Ganoderma lucidum, has shown a variety of pharmacological activities such as anti-tumor, anti-inflammation, immunoregulation, etc. In this study, we investigated whether GA possessed anti-fatigue activity against CRF. CT26 tumor-bearing mice were treated with 5-fluorouracil (5-FU, 30 mg/kg) and GA (50 mg/kg) alone or in combination for 18 days. Peripheral and central fatigue-related behaviors, energy metabolism and inflammatory factors were assessed. We demonstrated that co-administration of GA ameliorated 5-FU-induced peripheral muscle fatigue-like behavior via improving muscle quality and mitochondria function, increasing glycogen content and ATP production, reducing lactic acid content and LDH activity, and inhibiting p-AMPK, IL-6 and TNF-α expression in skeletal muscle. Co-administration of GA also retarded the 5-FU-induced central fatigue-like behavior accompanied by down-regulating the expression of IL-6, iNOS and COX2 in the hippocampus through inhibiting TLR4/Myd88/NF-κB pathway. These results suggest that GA could attenuate 5-FU-induced peripheral and central fatigue in tumor-bearing mice, which provides evidence for GA as a potential drug for treatment of CRF in clinic.