Quality control of Cordyceps sinensis, a valued traditional Chinese medicine

Comparative study of the composition of cultivated, naturally grown Cordyceps sinensis, and stiff worms across different sampling years

Natural Cordyceps sinensis, which is a valuable anti-tumor, immunomodulatory, and antiviral agent in Asia, has been overexploited in recent years. Therefore, it is important for cultivated C. sinensis to be recognized in the market. In this research, the main components of entirely cultivated, naturally grown C. sinensis, and stiff worms across different sampling years were detected and compared by HPLC-MS and UV spectrometry. The results indicated that the mean levels of adenosine and cordycepin were significantly higher, whereas the mean levels of mannitol and polysaccharides were remarkably lower in the cultivated type than in the natural type. No distinct difference in the average soluble protein content was observed. The composition of the stiff worms was similar to that of the natural herb, except that the total soluble protein content was higher, and that of mannitol was lower. In addition, the ultraviolet absorption spectroscopy of the three types showed high similarity at 260 nm. This research indicates that the main nutritional composition of cultivated and natural C. sinensis is identical and that cultivated type can be used as an effective substitute.

Structural Characterization and Chain Conformation of Water-Soluble β-Glucan from Wild Cordyceps sinensis

Water-soluble β-d-glucan was obtained from wild Cordyceps sinensis by alkali solution and ethanol precipitation. The structure characteristics were determined using high-performance anion-exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD), methylation combined with gas chromatography-mass spectrometry, and one-/two-dimensional nuclear magnetic resonance spectroscopy. Results showed that β-d-glucan had a structure of every seven (1→3)-β-d-Glcp backbone residues with two (1→6)-β-d-Glcp branches. Additionally, conformation properties in different solvents were investigated by static light scattering, dynamic light scattering, and HPSEC with multiple detectors. It was found that β-d-glucan in 0.5 M NaOH had a narrow unimodal distribution of hydrodynamic radius displaying a spherical coil conformation, whereas it formed severe aggregation in dimethyl sulfoxide. In 0.1 M NaNO₃, β-d-glucan mainly existed as a rod-like conformation corresponding to a helical structure together with small aggregates (10%). This work added more information to the understanding of C. sinensis polysaccharides.

A novel nucleoside rescue metabolic pathway may be responsible for therapeutic effect of orally administered cordycepin

Although adenosine and its analogues have been assessed in the past as potential drug candidates due to the important role of adenosine in physiology, only little is known about their absorption following oral administration. In this work, we have studied the oral absorption and disposition pathways of cordycepin, an adenosine analogue. In vitro biopharmaceutical properties and in vivo oral absorption and disposition of cordycepin were assessed in rats. Despite the fact that numerous studies showed efficacy following oral dosing of cordycepin, we found that intact cordycepin was not absorbed following oral administration to rats. However, 3′-deoxyinosine, a metabolite of cordycepin previously considered to be inactive, was absorbed into the systemic blood circulation. Further investigation was performed to study the conversion of 3′-deoxyinosine to cordycepin 5′-triphosphate in vitro using macrophage-like RAW264.7 cells. It demonstrated that cordycepin 5′-triphosphate, the active metabolite of cordycepin, can be formed not only from cordycepin, but also from 3′-deoxyinosine. The novel nucleoside rescue metabolic pathway proposed in this study could be responsible for therapeutic effects of adenosine and other analogues of adenosine following oral administration. These findings may have importance in understanding the physiology and pathophysiology associated with adenosine, as well as drug discovery and development utilising adenosine analogues.

Simultaneous Quantification of Adenosine and Deoxyadenosine Isomers in Foods with High Sensitivity

Simultaneous quantification of adenosine and deoxyadenosine isomers, including 2'-deoxyadenosine (dA) and 3'-deoxyadenosine (cordycepin, COR) is a challenge because they are very similar in chemical structure. In some previous studies on food ingredients, adenine and dA might be mistakenly detected as COR that has been shown to have multiple health benefits. In this work, we developed a novel HPLC method with fluorescence detction (HPLC-FD) to simultaneously quantify COR, adenosine and dA. Pre-column derivatization with chloroacetaldehyde (CAA) was deployed. The proposed method has a limit of detection at the nM level for COR and adenosine, and is far more sensitive than the methods previously deveopled for COR determination. Using the present method, caterpillar fungi were analyzed as model food samples. The analysis revealed that COR was present in cordyceps militaris and cordyceps flowers in a concentration range from 0.314 to 0.735 mg/g, but not in cordyceps sinensis (C. sinensis), a natural and the priciest caterpillar fungus. These results suggest that the profile of active ingredients in C. sinensis has been wrongly claimed for many years. This finding was also supported by the results from further HPLC-MS/MS analyses.

Genome-wide analysis of DNA methylation in subcultured Cordyceps militaris

The entomopathogenic mushroom Cordyceps militaris is a storehouse of various medicinal compounds and pharmacological effects. However, the high frequency of strain degeneration during subculture and preservation severely limits the large-scale production of C. militaris. DNA methylation is an important epigenomic modification involved in gene regulation. In this study, we used bisulfite sequencing for DNA methylation profiling of wild-type and mutant C. militaris. The differentially methylated regions (DMRs) of the two types were analyzed using Gene Ontology (GO) clustering and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. DNA methylation levels of the wild-type and mutant-type C. militaris were 0.48% and 0.56%, respectively. Methylation appeared at CHH dinucleotides in 58.62% and 58.20% of all methylated cytosine sites in the wild and mutant types, respectively. In all, 188 DMRs were identified from the wild and mutant types. Most of the DMRs ranged from 200 to 350 bp in length. KEGG pathways of the expression of DMR-related genes, which are involved in pyruvate metabolism, glycerophospholipid metabolism, DNA replication, and N-glycan biosynthesis. This contributes to the knowledge and understanding of the possible mechanisms of C. militaris strain degeneration.

Extract of Paecilomyces hepiali mycelia induces lipolysis through PKA-mediated phosphorylation of hormone-sensitive lipase and ERK-mediated downregulation of perilipin in 3T3-L1 adipocytes

Background

Cordyceps sinensis has been used for centuries in China as one of the most valued herbal medicine and tonic food. Paecilomyces hepiali, a fungal strain isolated from natural C. sinensis, has been used widely as a substitute of C. sinensis in medicine and health food. P. hepiali has been reported to have various pharmaceutical benefits, including triglyceride-lowing activity. However, its effects on triglyceride metabolism in adipocytes remain unknown. The purpose of the present study was to evaluate the effect of P. hepiali mycelia on adipocyte lipolysis and to clarify the underlying mechanisms.

Methods

The fully differentiated 3T3-L1 adipocytes were treated with methanol extract of Paecilomyces hepiali mycelia (PHME). Contents of glycerol released into the culture medium and intracellular triglyceride were measured as indices of lipolysis using glycerol assay kit and Oil red O staining, respectively. Then, effects of PHME on the main lipases or kinases involved in lipolysis regulation were investigated. Protein expression of adipose triglyceride lipase (ATGL) and perilipin, as well as phosphorylation of hormone-sensitive lipase (HSL), AMP-activated protein kinase (AMPK), and mitogen-activated protein kinases (MAPKs) were determined by western blotting. Moreover, nucleosides, important constituents of PHME, were analyzed using high performance liquid chromatography (HPLC).

Results

Treatment with PHME led to a significant increase in glycerol release thereby reduced intracellular triglyceride accumulation in fully differentiated adipocytes. PHME upregulated protein kinase (PK) A-mediated phosphorylation of HSL at serine residues of 563 and 660. Meanwhile, PHME treatment also upregulated phosphorylation of extracellular signal-regulated kinase (ERK), and downregulated the protein level of perilipin. Pretreatment with the PKA inhibitor, H89, blunted the PHME-induced lipolysis and the phosphorylation of HSL (Ser 563 and 660). Moreover, pretreatment with ERK inhibitor, PD98059, weakened the PHME-caused glycerol release and downregulation of perilipin expression. HPLC analysis indicated there were adenosine, cordycepin, uridine and vernine in PHME.

Conclusions

Our results showed that PHME significantly induced lipolysis in 3T3-L1 adipocytes, which is mainly mediated by activation of HSL through PKA pathway and by downregulation of perilipin through activation of ERK pathway.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2389-0) contains supplementary material, which is available to authorized users.

Nucleosides isolated from Ophiocordyceps sinensis inhibit cigarette smoke extract-induced inflammation via the SIRT1-nuclear factor-κB/p65 pathway in RAW264.7 macrophages and in COPD mice

Background

Ophiocordyceps sinensis (C. sinensis) extracts have been found to have a therapeutic effect on patients with chronic obstructive pulmonary disease (COPD). Silent information regulator 1 (SIRT1) plays an important role in the regulation of inflammatory mediators and correlates with lung function and COPD exacerbations. The objective of this work was to explore the anti-inflammatory effect and preliminary pathways of nucleosides from cultured C. sinensis on RAW264.7 macrophages and COPD mice.

Materials and methods

The nucleosides were extracted from cultured C. sinensis powder and further purified by macroporous resin D101 and glucan G10 columns. Inflammation and oxidative stress models in RAW264.7 macrophages and in mice were established by injection of cigarette smoke extract (CSE). We then examined how the isolated nucleosides regulated the production of the associated inflammatory mediators in vitro and in vivo by enzyme-linked immunosorbent assay, reverse transcription polymerase chain reaction, and Western blot.

Results

The nucleosides inhibited inflammatory mediator expression of tumor necrosis factor-α, interleukin-6, interleukin-1β, and nitric oxide in both the CSE-stimulated RAW264.7 macrophages and mice. Moreover, the nucleosides elevated SIRT1 activation and suppressed nuclear factor-κB (NF-κB)/p65 activation in vitro and in vivo. Nucleoside treatment significantly decreased the levels of the inflammatory mediators in the bronchoalveolar lavage fluid (BALF) and serum of the CSE-induced mice. The nucleosides also altered the recruitment of inflammatory cells in BALF and improved characteristic features of the lungs in the CSE-induced mice.

Conclusion

These results show that the nucleosides suppressed COPD inflammation through the SIRT1–NF-κB/p65 pathway, suggesting that the nucleosides may be partly responsible for the therapeutic effects of cultured C. sinensis on COPD patients.

Multiuse of Bar-HRM for Ophiocordyceps sinensis identification and authentication

Bar-HRM is a hybrid method which combines DNA barcoding and High Resolution Melting analysis. It has proven to be a fast, cost-effective and reliable molecular approach for species identification and authentication. Here, three aspects of the use of Bar-HRM are focused on. First, Bar-HRM is used to discriminate between closely related Ophiocordyceps species. Second, identification of an unknown powder that is claimed to be Ophiocordyceps species using Bar-HRM. Third, authenticating the O. sinensis products sold on the market by the Bar-HRM. Results from HRM analyses with ITS primers shows that the two Ophiocordyceps species (Ophiocordyceps sinensis and Ophiocordyceps militaris) were easily differentiated. Also, an unknown sample was able to be identified in less time compared with using DNA barcoding alone. In addition, the substitution or adulteration of O. sinensis products sold on market was detected via Bar-HRM. The substitution or adulteration of inferior Ophiocordyceps species, particularly O. militaris in high price O. sinensis products has been a concern throughout Asia. Based on our results, the Bar-HRM was again proved to be a promising tool for species identification and authentication.

Optimization of protein extraction and two-dimensional gel electrophoresis profiles for the identification of Cordyceps sinensis and other similar species

Given that Chinese materia medica (CMM) is expensive and rare, people take tremendous risk to adulterate and falsify Cordyceps sinensis with counterfeit species with similar morphological features. It is thus essential to develop new methods to identify the authenticity of Cordyceps sinensis. It is hypothesized in this study that Cordyceps sinensis possesses certain protein biomarkers distinct from its counterfeits, which can be identified by proteomic technologies for authentication purposes. This is the first study that aims to optimize the conditions for extracting proteins from Cordyceps sinensis, a hybrid of fungal-animal CMM, and to compare the two-dimensional gel electrophoresis (2-DE) profiles between different Cordyceps species. Two different protein extraction buffer systems, namely, phenol/sodium dodecyl sulfate (SDS) buffer or lysis buffer, were evaluated, where the preparation using lysis buffer yielded better protein content. The results also showed that extraction with lysis buffer without pre- or post-washing of samples was the most effective protocol, with over 220% of protein yield and 819 protein spots detected on a 2-DE gel. Moreover, the results demonstrated that Cordyceps sinensis possesses protein biomarkers distinct from its counterfeits, and these biomarkers are not source- or origin-dependent, strongly supporting the feasibility of using identified biomarkers as indicators for authentication of Cordyceps species. The findings of this study warrant further investigations on the structural identification of protein biomarkers of Cordyceps species.

Establishment of a PCR Assay for the Detection and Discrimination of Authentic Cordyceps and Adulterant Species in Food and Herbal Medicines

Accurate detection and differentiation of adulterants in food ingredients and herbal medicines are crucial for the safety and basic quality control of these products. Ophiocordyceps sinensis is described as the only fungal source for the authentic medicinal ingredient used in the herbal medicine "Cordyceps", and two other fungal species, Cordyceps militaris and Isaria tenuipes, are the authentic fungal sources for food ingredients in Korea. However, substitution of these three species, and adulteration of herbal material and dietary supplements originating from Cordyceps pruinosa or Isaria cicadae, seriously affects the safety and reduces the therapeutic efficacy of these products. Distinguishing between these species based on their morphological features is very difficult, especially in commercially processed products. In this study, we employed DNA barcode-based species-specific sequence characterized amplified region (SCAR) markers to discriminate authentic herbal Cordyceps medicines and Cordyceps-derived dietary supplements from related but inauthentic species. The reliable authentication tool exploited the internal transcribed spacer (ITS) region of a nuclear ribosomal RNA gene (nrDNA). We used comparative nrDNA-ITS sequence analysis of the five fungal species to design two sets of SCAR markers. Furthermore, we used a set of species-specific SCAR markers to establish a real-time polymerase chain reaction (PCR) assay for the detection of species, contamination, and degree of adulteration. We confirmed the discriminability and reproducibility of the SCAR marker analysis and the real-time PCR assay using commercially processed food ingredients and herbal medicines. The developed SCAR markers may be used to efficiently differentiate authentic material from their related adulterants on a species level. The ITS-based SCAR markers and the real-time PCR assay constitute a useful genetic tool for preventing the adulteration of Cordyceps and Cordyceps-related dietary supplements.

Bioaccessibility and risk assessment of heavy metals, and analysis of arsenic speciation in Cordyceps sinensis

Background

Cordyceps sinensis (C. sinensis) is a famous and precious Traditional Chinese Medicine (TCM), while frequent reports of heavy metals, especially arsenic, exceeding standards in C. sinensis in recent years have raised concerns of its safety. Therefore, it is urgent for a research on heavy metals (Cu, Pb, As, Cd, Hg) in C. sinensis, of its bioaccessibility, dietary exposure estimation, arsenic speciation analysis and health risks assessment to human body.

Methods

Three 30 g batches of mixed wild growth C. sinensis samples were collected from Qinghai Province and each batch were divided into three parts: the whole C. sinensis, the stroma and the caterpillar body. The in vitro gastrointestinal method was used to evaluate the bioaccessibility of the heavy metals in the samples. The arsenic speciation analysis in the in vitro gastrointestinal solutions and dilute nitric acid extracted solutions were conducted using high performance liquid chromatography–inductively coupled plasma mass (HPLC–ICP-MS) method. Finally, the target hazard quotient (THQ) developed by the US EPA (1989) was used to assess the health risks of heavy metals in C. sinensis.

Results

The contents of Cu, Pb, Cd and Hg in the stroma were higher than those in the caterpillar body. In contrast, As was mainly found in the caterpillar body. In the whole C. sinensis, the average bio-accessibilities of Cu, Pb, As, Hg and Cd were 41.29, 40.11, 64.46, 18.91, and 81.14%, respectively. While in the caterpillar body, the corresponding bio-accessibilities values were 48.26, 42.92, 66.15, 12.86, 87.07%, respectively, and were 38.30, 30.53, 30.18, 7.46, and 82.30%, respectively in the stroma part. Different arsenic speciations of arsenite [As(III)], arsenate [As(V)] and trace amounts of methylarsonic acid [MMA] were detected. Of the total As, 8.69% was in inorganic form, which was also the major form of dissolved As. Among the extracted inorganic species, the concentrations of As(III) and As(V) were 0.56 ± 0.16 and 0.29 ± 0.06 mg kg⁻¹, respectively. In the gastrointestinal solutions, only As(III) and As(V) could be detected; the sum content of the two species was 2.00–2.73%. The bioaccessibility target hazard quotient (BTHQ) values for Cu, Pb, As, Cd and Hg in C. sinensis were 0.0041, 0.0040, 0.5334, 0.0020 and 0.0005, respectively, all less than 1.

Conclusion

None of the five heavy metals in C. sinensis can be 100% absorbed by human body. The content of arsenic in C. sinensis is high, but the strong toxic inorganic arsenic accounted for only 8.69%. The heavy metals in C. sinensis presented no obvious risks to human health in a reasonable taking way.

Electronic supplementary material

The online version of this article (10.1186/s13020-018-0196-7) contains supplementary material, which is available to authorized users.

Identification of Ophiocordyceps sinensis and Its Artificially Cultured Ophiocordyceps Mycelia by Ultra-Performance Liquid Chromatography/Orbitrap Fusion Mass Spectrometry and Chemometrics

Since the cost of Ophiocordyceps sinensis, an important fungal drug used in Chinese medicine, has increased dramatically, and the counterfeits may have adverse health effects, a rapid and precise marker using the peptide mass spectrometry identification system could significantly enhance the regulatory capacity. In this study, we determined the marker peptides in the digested mixtures of fungal proteins in wild O. sinensis fruiting bodies and various commercially available mycelium fermented powders using ultra-performance liquid chromatography/Orbitrap Fusion mass spectrometry coupled with chemometrics. The results indicated the following marker peptides: TLLEAIDSIEPPK (m/z 713.39) was identified in the wild O. sinensis fruiting body, AVLSDAITLVR (m/z 579.34) was detected in the fermented O. sinensis mycelium powder, FAELLEK (m/z 849.47) was found in the fermented Ophiocordyceps mycelium powder, LESVVTSFTK (m/z 555.80) was discovered in the artificial Ophiocordyceps mycelium powder, and VPSSAVLR (m/z 414.75) was observed in O. mortierella mycelium powder. In order to verify the specificity and applicability of the method, the five marker peptides were synthesized and tested on all samples. All in all, to the best of our knowledge, this is the first time that mass spectrometry has been employed to detect the marker peptides of O.sinensis and its related products.

HPLC-ICP-MS speciation analysis and risk assessment of arsenic in Cordyceps sinensis

BACKGROUND

Cordyceps sinensis, one of the most valued traditional herbal medicines in China, contains high amount of arsenic. Considering the adverse health effects of arsenic, this is of particular concern. The aim of this study was to determine and analyze arsenic speciation in C. sinensis, and to measure the associated human health risks.

METHODS

We used microwave extraction and high-performance liquid chromatography coupled with inductively coupled plasma mass spectrometry to determine and analyze the arsenic content in C. sinensis, and measured the associated human health risks according to the hazard index (HI), lifetime cancer risk (CR), and target hazard quotient (THQ).

RESULTS

The main arsenic speciation in C. sinensis were not the four organic arsenic compounds, including dimethyl arsenic, monomethyl arsenic, arsenobetaine, and arsenocholine, but comprised inorganic arsenic and other unknown risk arsenic compounds. HI scores indicated that the risk of C. sinensis was acceptable. CR results suggested that the cancer risk was greater than the acceptable lifetime risk of 10-5, even at low exposure levels. THQ results indicated that at the exposure level < 2.0 months/year, the arsenic was not likely to harm human health during a lifetime; however, if the exposure rate was > 3.0 months/year, the systemic effects of the arsenic in C. sinensis was of great concern.

CONCLUSION

The arsenic in C. sinensis might not be free of risks. The suggested C. sinensis consumption rate of 2.0 months/year provided important insights into the ways by which to minimize potential health risks. Our study not only played the role of "cast a brick to attract jade" by which to analyze arsenic speciation in C. sinensis but also offered a promising strategy of risk assessment for harmful residues in traditional herbal medicines.

Investigation of the neuroprotective effects of Lycium barbarum water extract in apoptotic cells and Alzheimer's disease mice

Alzheimer's disease (AD) affects people worldwide and is caused by chronic and progressive damage to the central nervous system. Lycium barbarum (LB), a renowned functional food and medicinal plant in Southeast Asia, may possess protective effects against nerve injury. The present study aimed to investigate the neuroprotective effects of LB water extract in a differentiated (D)PC12 cellular apoptosis model induced by L-glutamic acid (L-Glu), and a mouse model of AD, induced by the combination of AlCl₃ and D-galactose. LB markedly increased DPC12 cell survival against L-Glu induced damage by increasing cell viability, reducing the apoptosis rate and G1 phase arrest, suppressing intracellular reactive oxygen species accumulation, blocking Ca²⁺ overload and preventing mitochondrial membrane potential depolarization. LB additionally normalized the expression levels of apoptosis regulator Bcl-2, apoptosis regulator BAX, and cleaved caspase-3, −8 and −9 in L-Glu exposed cells. In the AD mouse model, LB increased the amount of horizontal and vertical movement in the autonomic activity test, improved endurance time in the rotarod test and decreased escape latency time in the Morris water maze test. Additionally, the levels of acetylcholine and choline acetyltransferase were significantly increased in the serum and hypothalamus in the LB-treated AD mice. These data suggested that LB may exert neuroprotective effects and may aid in preventing neurodegenerative disease.

Enhancement of Nucleoside Production in Hirsutella sinensis Based on Biosynthetic Pathway Analysis

To enhance nucleoside production in Hirsutella sinensis, the biosynthetic pathways of purine and pyrimidine nucleosides were constructed and verified. The differential expression analysis showed that purine nucleoside phosphorylase, inosine monophosphate dehydrogenase, and guanosine monophosphate synthase genes involved in purine nucleotide biosynthesis were significantly upregulated 16.56-fold, 8-fold, and 5.43-fold, respectively. Moreover, dihydroorotate dehydrogenase, uridine nucleosidase, uridine/cytidine monophosphate kinase, and inosine triphosphate pyrophosphatase genes participating in pyrimidine nucleoside biosynthesis were upregulated 4.53-fold, 10.63-fold, 4.26-fold, and 5.98-fold, respectively. To enhance the nucleoside production, precursors for synthesis of nucleosides were added based on the analysis of biosynthetic pathways. Uridine and cytidine contents, respectively, reached 5.04 mg/g and 3.54 mg/g when adding 2 mg/mL of ribose, resulting in an increase of 28.6% and 296% compared with the control, respectively. Meanwhile, uridine and cytidine contents, respectively, reached 10.83 mg/g 2.12 mg/g when adding 0.3 mg/mL of uracil, leading to an increase of 176.3% and 137.1%, respectively. This report indicated that fermentation regulation was an effective way to enhance the nucleoside production in H. sinensis based on biosynthetic pathway analysis.

Determination and comparative analysis of 13 nucleosides and nucleobases in natural fruiting body of Ophiocordyceps sinensis and its substitutes

Nucleosides and nucleobases are one of the most important indicators of quality control. A sensitive and reliable high performance liquid chromatography-ultraviolet method was applied to analyse 13 nucleosides and nucleobases simultaneously in 15 batches of nine Ophiocordyceps species and its allies in China. Principal component analysis (PCA) and cluster analysis were conducted by SPSS 22.0 software (IBM Corp., Armonk, NY, USA). The 15 samples of Cordyceps were differentiated successfully based on their nucleoside and nucleobase content. Total nucleosides content in mycelium was significantly higher than that in the natural fruiting bodies of Ophiocordyceps sinensis (NFOS). Five nucleosides or nucleobases - adenine (A), guanosine (Gu), uracil (U), uridine (Ur) and guanine (G) - were the major components contributed to the total variance according to PCA. The profiles of the 13 tested nucleosides and nucleobases (including adenosine, cytidine, guanosine, inosine, thymidine, uridine, cordycepin, adenine, cytosine, guanine, thymine, uracil and hypoxanthine) can discriminate different samples and can be candidate indicators applied for the quality control of Ophiocordyceps and its allies.

Transcriptome-wide analysis reveals the progress of Cordyceps militaris subculture degeneration

BACKGROUND

The entomopathogenic mushroom Cordyceps militaris is an important medicinal and food resource owing to its various medicinal components and pharmacological effects. However, the high frequency of strain degeneration during subculture seriously restricts the large-scale production of C. militaris, and the mechanism underlying strain degeneration remains unclear. In this study, we artificially cultured C. militaris for six generations and compared changes during fruiting body growth. The transcriptome of six generations of C. militaris strains were sequenced with the Illumine Hiseq4000.

RESULTS

The subcultured C. militaris strains degenerated beginning at the third generation, with incomplete fruiting body growth beginning at the fourth generation. Over 9,015 unigenes and 731 new genes were identified. In addition, 35,323 alternative splicing (AS) events were detected in all samples, and more AS events occurred in the second, fourth and sixth generations. Compared with the first generation, the third generation (degenerated strain) included 2,498 differentially expressed genes (DEGs) including 1,729 up-regulated and 769 down-regulated genes. This number was higher than the number of DEGs in the second (1,892 DEGs), fourth (2,006 DEGs), fifth (2,273 DEGs) and sixth (2,188 DEGs) generations. Validation of RNA-seq by qRT-PCR showed that the expression patterns of 51 DEGs were in accordance with the transcriptome data.

CONCLUSION

Our results suggest that the mechanism of C. militaris strain degeneration is associated with gene involved in toxin biosynthesis, energy metabolism, and DNA methylation and chromosome remodeling.

GC-MS Profiling of Volatile Components in Different Fermentation Products of Cordyceps Sinensis Mycelia

The fermentation products of Cordyceps sinensis (C. sinensis) mycelia are sustainable substitutes for natural C. sinensis. However, the volatile compositions of the commercial products are still unclear. In this paper, we have developed a simultaneous distillation-extraction (SDE) and gas chromatography-mass spectrometry (GC-MS) method for the profiling of volatile components in five fermentation products. A total of 64, 39, 56, 52, and 44 components were identified in the essential oils of Jinshuibao capsule (JSBC), Bailing capsule (BLC), Zhiling capsule (ZLC), Ningxinbao capsule (NXBC), and Xinganbao capsule (XGBC), respectively. 5,6-Dihydro-6-pentyl-2H-pyran-2-one (massoia lactone) was first discovered as the dominant component in JSBC volatiles. Fatty acids including palmitic acid (C16:0) and linoleic acid (C18:2) were also found to be major volatile compositions of the fermentation products. The multivariate partial least squares-discriminant analysis (PLS-DA) showed a clear discrimination among the different commercial products as well as the counterfeits. This study may provide further chemical evidences for the quality evaluation of the fermentation products of C. sinensis mycelia.

Cordycepin induces apoptotic cell death of human brain cancer through the modulation of autophagy

Brain cancer, in particular neuroblastoma and glioblastoma, is a global challenge to human health. Cordycepin, extracted from Cordyceps ssp., has been revealed as a strong anticancer agent through several ways; however, the mechanism, by which cordycepin counteracts brain cancers, is still poorly understood. In this study, the underlying mechanisms of cordycepin against human brain cancer cells were explored. SH-SY5Y and U251 cells were being a model to represent human neuroblastoma and glioblastoma, respectively. Here, it was found that cordycepin inhibited cell growth, and induced apoptosis in a dose-dependent manner in both SH-SY5Y and U-251 cell lines. The expression of pro-apoptotic genes, including P53, BAX, Caspase-3, and Caspase-9, were upregulated, whereas the expression of anti-apoptotic gene, BCL-2, was suppressed. Besides, cordycepin induced the generation of reactive oxygen species (ROS) along with the suppression of antioxidant genes, including GPX, SOD, and Catalase. Importantly, cordycepin was shown to involve in the activation of autophagy, which was evidenced by the increment of LC3I/II. The combination of cordycepin with chloroquine, an autophagy inhibitor, further inhibited the growth, and enhanced the death of brain cancer cells. Altogether, this finding suggested that cordycepin induced apoptosis of human brain cancer cells through mitochondrial-mediated intrinsic pathway and the modulation of autophagy. Therefore, cordycepin could be a promising candidate for the development of anticancer drugs targeting human brain cancers.

Determination of the Main Nucleosides and Nucleobases in Natural and Cultured Ophiocordyceps xuefengensis

Ophiocordyceps xuefengensis, a recently described species of Ophiocordycepsthat is associated with the larvae of Phassusnodus (Hepialidae) in the living root or trunk of the medicinal plant Clerodendrumcyrtophyllum, isthe largest known Cordycepsspecies and is recognized as a desirable alternative for natural Ophiocordycepssinensis. This study investigated the main nucleosides and nucleobases in natural and cultured Ophiocordycepsxuefengensis. The contents of the nucleosides and nucleobases in the natural and cultured samples were determined by reverse phase HPLC. The highest concentration of adenosine was found in the natural fruit body and the cultured stroma, with almost no adenosine in the cadaver of Phassusnodus. The contents of adenine, guanosine, uridine and uracil in the cultured mycelium were significantly higher than those in the natural sample. Inosine was only detected in the natural samples. Thymidine and 2-deoxyadenosine were only found in the cadaver of Phassusnodus. Cordycepin was not detected in the five samples examined. These results suggested that the cultured mycelium and cultured stroma of Ophiocordycepsxuefengensis might be a promising substitute for natural O. xuefengensis.

Beauveria bassiana: a new N6-(2-hydroxyethyl)-adenosine-producing fungus

N6-(2-Hydroxyethyl)-adenosine (HEA), which was the first calcium antagonist derived from biological sources, has been intensively investigated because of its ability to inhibit tumour cell proliferation, restrain inflammation, protect kidneys and function as a sedative and insecticide. Up to now, the production of HEA has been detected only in a few species such as Cordyceps pruinosa, C. militaris and Isaria tenuipes. Here, we found a new HEA-producing fungus, which was identified as Beauveria bassiana based on morphological and phylogenetic characteristics. The HEA production was verified by reversed-phase high-performance liquid chromatography/mass spectrometry in this fungus. Moreover, HEA was also detected in the mycelia of two other B. bassiana strains from different origins, but not in the culture medium of all tested B. bassiana strains. The maximum production of HEA (0.8483 ± 0.0439 mg/g mycelia dry weight) was achieved on day 7. The fungal biomass and kinetics of HEA production exhibited similar trends over the duration of the culture period. This is the first report describing HEA production in B. bassiana, which suggests that this fungal strain may have new applications as a source of HEA.

Metabolomic profile and nucleoside composition of Cordyceps nidus sp. nov. (Cordycipitaceae): A new source of active compounds

Cordyceps sensu lato is a genus of arthropod-pathogenic fungi, which have been used traditionally as medicinal in Asia. Within the genus, Ophiocordyceps sinensis is the most coveted and expensive species in China. Nevertheless, harvesting wild specimens has become a challenge given that natural populations of the fungus are decreasing and because large-scale culture of it has not yet been achieved. The worldwide demand for products derived from cultivable fungal species with medicinal properties has increased recently. In this study, we propose a new species, Cordyceps nidus, which parasitizes underground nests of trapdoor spiders. This species is phylogenetically related to Cordyceps militaris, Cordyceps pruinosa, and a sibling species of Cordyceps caloceroides. It is found in tropical rainforests from Bolivia, Brazil, Colombia and Ecuador. We also investigated the medicinal potential of this fungus based on its biochemical properties when grown on four different culture media. The metabolic profile particularly that of nucleosides, in polar and non-polar extracts was determined by UPLC, and then correlated to their antimicrobial activity and total phenolic content. The metabolome showed a high and significant dependency on the substrate used for fungal growth. The mass intensities of nucleosides and derivative compounds were higher in natural culture media in comparison to artificial culture media. Among these compounds, cordycepin was the predominant, showing the potential use of this species as an alternative to O. sinensis. Furthermore, methanol fractions showed antimicrobial activity against gram-positive bacteria, and less than 3.00 mg of gallic acid equivalents per g of dried extract were obtained when assessing its total phenolic content by modified Folin-Ciocalteu method. The presence of polyphenols opens the possibility of further exploring the antioxidant capacity and the conditions that may enhance this characteristic. The metabolic composition and biochemical activity indicate potential use of C. nidus in pharmaceutical applications.

Paecilomyces tenuipes extract prevents depression-like behaviors in chronic unpredictable mild stress-induced rat model via modulation of neurotransmitters

The medicinal fungus Paecilomyces tenuipes exhibits a variety of pharmacological effects, including antidepressive effects. The chronic unpredictable mild stress (CUMS)‑induced rat model has served an important role in studies involving antidepressants screening. The aim of the present study was to evaluate the antidepressant‑like activity of P. tenuipes N45 aqueous extract (PTNE) in a CUMS‑induced rat model of behavioral despair depression. Following 4 weeks of PTNE treatment, behavioral tests were conducted to investigate the antidepressant‑like activities, and the levels of neurotransmitters and hormones in blood and hypothalamus were measured. The results demonstrated that PTNE treatment significantly increased movement in the forced running test, whereas the immobility time was reduced in the hotplate test and the forced swim test in depression‑model rats. PTNE treatment was able to normalize the levels of hormones and neurotransmitters in serum and hypothalamus of CUMS rats. The data demonstrated that PTNE treatment may be a potential pharmaceutical agent in treatment‑resistant depression, and the effects of PTNE may be partly mediated through normalizing the levels of neurotransmitters.

Analysis of Cordyceps by multi-column liquid chromatography

Cordyceps is a famous traditional Chinese medicine (TCM) that has been used in China for hundreds of years. In the present study a multi-column liquid chromatography (MC-LC) system was developed for the qualitative analysis of macromolecules and micromolecules in Cordyceps. The MC-LC system includes a size exclusion pre-column, a size exclusion column (SEC) and a reversed phase column (RP) which were controlled by column-switching valves. The sample was separated by the size exclusion pre-column into two fractions (macromolecules and micromolecules). These fractions were further separated on SEC and RP columns, respectively. A diode array detector (DAD) and a mass spectrometer (MS) were used to detect the components. This MC-LC method was utilized for analysis of Cordyceps samples. Two macromolecular peaks and 15 micromolecular peaks were found in Cordyceps, and 11 of the micromolecular peaks were identified as adenosine-5'-monophosphate (AMP), phenylalanine, uridine, hypoxanthine, inosine, guanine, guanosine, deoxyadenosine-5'-monophosphate (dAMP), adenosine, adenine and cordycepin (or its isomer). This method is useful for quality control of Cordyceps.

Comparison of structural features and antioxidant activity of polysaccharides from natural and cultured Cordyceps sinensis

Four polysaccharides (named as P1, P2, and P3 from three natural Cordyceps sinensis and P4 from cultured C. sinensis) were obtained by hot-water extraction and ethanol precipitation and their structural characteristics as well as antioxidant potentials were compared. Results revealed that the backbone of P1, P2, and P3 comprised α-1,4-glucose, with a branching point mainly at position 6 and terminating at glucose. On the other hand, the structure of P4 was highly complex, mainly comprising glucose, galactose, and mannose, with 1,4-glucose and 1,4-galactose as the main chain. For in vitro antioxidant assays, all the four polysaccharides showed similar scavenging capacity against DPPH and hydroxyl radicals, whereas P1 had a relatively low ferric reducing ability, possibly related to a combination of factors such as the phenolic compounds and amino acids that conjugated in polysaccharides.

Identification of Chinese medicinal fungus Cordyceps sinensis by depth-profiling mid-infrared photoacoustic spectroscopy

With increased demand for Cordyceps sinensis it needs rapid methods to meet the challenge of identification raised in quality control. In this study Cordyceps sinensis from four typical natural habitats in China was characterized by depth-profiling Fourier transform infrared photoacoustic spectroscopy. Results demonstrated that Cordyceps sinensis samples resulted in typical photoacoustic spectral appearance, but heterogeneity was sensed in the whole sample; due to the heterogeneity Cordyceps sinensis was represented by spectra of four groups including head, body, tail and leaf under a moving mirror velocity of 0.30cms^-1. The spectra of the four groups were used as input of a probabilistic neural network (PNN) to identify the source of Cordyceps sinensis, and all the samples were correctly identified by the PNN model. Therefore, depth-profiling Fourier transform infrared photoacoustic spectroscopy provides novel and unique technique to identify Cordyceps sinensis, which shows great potential in quality control of Cordyceps sinensis.

Entomopathogenicity and Biological Attributes of Himalayan Treasured Fungus Ophiocordyceps sinensis (Yarsagumba)

Members of the entomophagous fungi are considered very crucial in the fungal domain relative to their natural phenomenon and economic perspectives; however, inadequate knowledge of their mechanisms of interaction keeps them lagging behind in parallel studies of fungi associated with agro-ecology, forest pathology and medical biology. Ophiocordyceps sinensis (syn. Cordyceps sinensis), an intricate fungus-caterpillar complex after it parasitizes the larva of the moth, is a highly prized medicinal fungus known widely for ages due to its peculiar biochemical assets. Recent technological innovations have significantly contributed a great deal to profiling the variable clinical importance of this fungus and other related fungi with similar medicinal potential. However, a detailed mechanism behind fungal pathogenicity and fungal-insect interactions seems rather ambiguous and is poorly justified, demanding special attention. The goal of the present review is to divulge an update on the published data and provides promising insights on different biological events that have remained underemphasized in previous reviews on fungal biology with relation to life-history trade-offs, host specialization and selection pressures. The infection of larvae by a fungus is not a unique event in Cordyceps; hence, other fungal species are also reviewed for effective comparison. Conceivably, the rationale and approaches behind the inheritance of pharmacological abilities acquired and stored within the insect framework at a time when they are completely hijacked and consumed by fungal parasites, and the molecular mechanisms involved therein, are clearly documented.

Profiling metals in Cordyceps sinensis by using inductively coupled plasma mass spectrometry

Cordyceps sinensis (C. sinensis) is a natural product that has diverse nutritional and medicinal values. Since the availability of natural C. sinensis becomes limited its authentication and quality control is of high significance. Herein we report on profiling of metals in C. sinensis by using inductively coupled plasma mass spectrometry (ICP-MS). The analysis reveals that C. sinensis contains a wide array of essential elements, including P, Mg, Zn, Cu, Fe, etc. Toxic metals detected are Cd, Pb, and As. In all five samples analyzed Pb contents are below 2.0 ppm. Arsenic level in C. sinensis caterpillar is significantly higher than that in its mycelium and varies from 3.0 to 32 ppm likely due to soil contamination. It's for the first time demonstrated in this work that clustering analysis on the proposed metal profiles consisting of 24 elements is very useful to identify "abnormal" C. sinensis samples, thus adding another dimension to the effective means for authentication and quality assessment of this highly demanded previous natural product.

Isolation, Culture and Characterization of Hirsutella sinensis Mycelium from Caterpillar Fungus Fruiting Body

The caterpillar fungus Ophiocordyceps sinensis (previously called Cordyceps sinensis) has been used for centuries in Asia as a tonic to improve health and longevity. Recent studies show that O. sinensis produces a wide range of biological effects on cells, laboratory animals and humans, including anti-fatigue, anti-infection, anti-inflammatory, antioxidant, and anti-tumor activities. In view of the rarity of O. sinensis fruiting bodies in nature, cultivation of its anamorph mycelium represents a useful alternative for large-scale production. However, O. sinensis fruiting bodies harvested in nature harbor several fungal contaminants, a phenomenon that led to the isolation and characterization of a large number of incorrect mycelium strains. We report here the isolation of a mycelium from a fruiting body of O. sinensis and we identify the isolate as O. sinensis’ anamorph (also called Hirsutella sinensis) based on multi-locus sequence typing of several fungal genes (ITS, nrSSU, nrLSU, RPB1, RPB2, MCM7, β-tubulin, TEF-1α, and ATP6). The main characteristics of the isolated mycelium, including its optimal growth at low temperature (16°C) and its biochemical composition, are similar to that of O. sinensis fruiting bodies, indicating that the mycelium strain characterized here may be used as a substitute for the rare and expensive O. sinensis fruiting bodies found in nature.

Cordyceps militaris fruit body extract ameliorates membranous glomerulonephritis by attenuating oxidative stress and renal inflammation via the NF-κB pathway

Membranous glomerulonephritis (MGN) is a common pathogenesis of nephritic syndrome in adult patients. Nuclear factor kappa B (NF-κB) serves as the main transcription factor for the inflammatory response mediated nephropathy. Cordyceps militaris, containing various pharmacological components, has been used as a kind of crude drug and folk tonic food for improving immunity and reducing inflammation. The current study aims to investigate the renoprotective activity of Cordyceps militaris aqueous extract (CM) in the cationic bovine serum albumin (C-BSA)-induced rat model of membranous glomerulonephritis. Significant renal dysfunction was observed in MGN rats; comparatively, 4-week CM administration strongly decreased the levels of 24 h urine protein, total cholesterol, triglyceride, blood urea nitrogen and serum creatinine, and increased the levels of serum albumin and total serum protein. Strikingly, recovery of the kidney histological architecture was noted in CM-treated MGN rats. A significant improvement in the glutathione peroxidase and superoxide dismutase levels, and a reduced malondialdehyde concentration were observed in the serum and kidney of CM-treated rats. Altered levels of inflammatory cytokines including interleukins, monocyte chemoattractant protein-1, intercellular adhesion molecule 1, vascular adhesion molecule 1, tumor necrosis factor-α, 6-keto-prostaglandin F1α, and nuclear transcriptional factor subunit NF-κB p65 reverted to normal levels upon treatment with CM. The present data suggest that CM protects rats against membranous glomerulonephritis via the normalization of NF-κB activity, thereby inhibiting oxidative damage and reducing inflammatory cytokine levels, which further provide experimental evidence in support of the clinical use of CM as an effective renoprotective agent.

Cordyceps collected from Bhutan, an appropriate alternative of Cordyceps sinensis

Natural Cordyceps collected in Bhutan has been widely used as natural Cordyceps sinensis, an official species of Cordyceps used as Chinese medicines, around the world in recent years. However, whether Cordyceps from Bhutan could be really used as natural C. sinensis remains unknown. Therefore, DNA sequence, bioactive components including nucleosides and polysaccharides in twelve batches of Cordyceps from Bhutan were firstly investigated, and compared with natural C. sinensis. Results showed that the fungus of Cordyceps from Bhutan was C. sinensis and the host insect belonged to Hepialidae sp. In addition, nucleosides and their bases such as guanine, guanosine, hypoxanthine, uridine, inosine, thymidine, adenine, and adenosine, as well as compositional monosaccharides, partial acid or enzymatic hydrolysates, molecular weights and contents of polysaccharides in Cordyceps from Bhutan were all similar to those of natural C. sinensis. All data suggest that Cordyceps from Bhutan is a rational alternative of natural C. sinensis, which is beneficial for the improvement of their performance in health and medicinal food areas.

Bioactive peptides derived from traditional Chinese medicine and traditional Chinese food: A review

There is an urgent treat of numerous chronic diseases including heart disease, stroke, cancer, chronic respiratory diseases and diabetes, which have a significant influence on the health of people worldwide. In addition to numerous preventive and therapeutic drug treatments, important advances have been achieved in the identification of bioactive peptides that may contribute to long-term health. Although bioactive peptides with various biological activities received unprecedented attention, as a new source of bioactive peptides, the significant role of bioactive peptides from traditional Chinese medicine and traditional Chinese food has not fully appreciated compared to other bioactive components. Hence, identification and bioactivity assessment of these peptides could benefit the pharmaceutical and food industry. Furthermore, the functional properties of bioactive peptides help to demystify drug properties and health benefits of traditional Chinese medicine and traditional Chinese food. This paper reviews the generation and biofunctional properties of various bioactive peptides derived from traditional Chinese medicine and traditional Chinese food. Mechanisms of digestion, bioavailability of bioactive peptides and interactions between traditional Chinese medicine and traditional Chinese food are also summarized in this review.

Cordyceps militaris induces tumor cell death via the caspase‑dependent mitochondrial pathway in HepG2 and MCF‑7 cells

Cordyceps militaris (CM), an entomopathogenic fungus belonging to the class ascomycetes, possesses various pharmacological activities, including cytotoxic effects, on various types of human tumor cells. The present study investigated the anti-hepatocellular carcinoma (HCC) and anti-breast cancer effects of CM in in vitro and in vivo models. CM aqueous extract reduced cell viability, suppressed cell proliferation, inhibited cell migration ability, caused the over-release of lactate dehydrogenase, induced mitochondrial dysfunction and enhanced apoptotic rates in MCF-7 and HepG2 cells. The expression levels of cleaved poly (ADP ribose) polymerase and caspase-3, biomarkers of apoptosis, were increased following treatment with CM aqueous extract for 24 h. Furthermore, in the MCF-7 and HepG2 cells, enhanced levels of B cell-associated X protein and cleaved caspase-8 were observed in the CM-treated cells. Finally, the antitumor activities of CM in HCC and breast cancer were also confirmed in MCF-7- and HepG2-xengraft nude mice models. Collectively, the data obtained in the present study suggested that the cytotoxic effects of CM aqueous extract on HCC and breast cancer are associated with the caspase-dependent mitochondrial pathway.

Anti-inflammatory Cerebrosides from Cultivated Cordyceps militaris

Cordyceps militaris (bei-chong-chaw, northern worm grass) is a precious and edible entomopathogenic fungus, which is widely used in traditional Chinese medicine (TCM) as a general booster for the nervous system, metabolism, and immunity. Saccharides, nucleosides, mannitol, and sterols were isolated from this fungus. The biological activity of C. militaris was attributed to the saccharide and nucleoside contents. In this study, the aqueous methanolic fraction of C. militaris fruiting bodies exhibited a significant anti-inflammatory activity. Bioactivity-guided fractionation of the active fraction led to the isolation of eight compounds, including one new and two known cerebrosides (ceramide derivatives), two nucleosides, and three sterols. Cordycerebroside A (1), the new cerebroside, along with soyacerebroside I (2) and glucocerebroside (3) inhibited the accumulation of pro-inflammatory iNOS protein and reduced the expression of COX-2 protein in LPS-stimulated RAW264.7 macrophages. This is the first study on the isolation of cerebrosides with anti-inflammatory activity from this TCM.

Fast Simultaneous Determination of 13 Nucleosides and Nucleobases in Cordyceps sinensis by UHPLC-ESI-MS/MS

A reliable ultra-high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (UHPLC–ESI–MS/MS) method for the fast simultaneous determination of 13 nucleosides and nucleobases in Cordyceps sinensis (C. sinensis) with 2-chloroadenosine as internal standard was developed and validated. Samples were ultrasonically extracted in an ice bath thrice, and the optimum analyte separation was performed on an ACQUITY UPLC^TM HSS C18 column (100 mm × 2.1 mm, 1.8 μm) with gradient elution. All targeted analytes were separated in 5.5 min. Furthermore, all calibration curves showed good linear regression (r > 0.9970) within the test ranges, and the limits of quantitation and detection of the 13 analytes were less than 150 and 75 ng/mL, respectively. The relative standard deviations (RSDs) of intra- and inter-day precisions were <6.23%. Recoveries of the quantified analytes ranged within 85.3%–117.3%, with RSD < 6.18%. The developed UHPLC–ESI–MS/MS method was successfully applied to determine nucleosides and nucleobases in 11 batches of C. sinensis samples from different regions in China. The range for the total content in the analyzed samples was 1329–2057 µg/g.