Determination of nucleosides in Cordyceps sinensis and Ganoderma lucidum by high performance liquid chromatography method

Diverse meroterpenoids with α-glucosidase inhibitory activity from Ganoderma cochlear

Three new meroterpenoids, cochlearins J-L (1-3) and three known meroterpenoids (4-6) were isolated from the fruiting bodies of Ganoderma cochlear. NMR (¹H and ¹³C NMR, ¹H - ¹H COSY, HSQC, HMBC and ROESY), and HRESIMS were employed for the structure elucidation of new compounds. The stereostructures of 1-3 were confirmed by calculated ECD and optical rotation methods. Furthermore, compounds (+)-1, (-)-1, (+)-2, (-)-2, (+)-3, (-)-3, and 4-6 were evaluated for their α-glucosidase inhibitory activity. The results showed that compounds (+)-1, (-)-1 and (+)-2 exhibited stronger inhibition against α-glucosidase with IC₅₀ values of 24.18 ± 1.98, 26.49 ± 3.20 and 29.68 ± 2.73 μM, respectively, compared to the positive control ursolic acid (49.65 ± 2.21 μM). The molecular docking experiments reveal that (+)-2 and (-)-2 had different binding mode with α-glucosidase, leading to their different inhibition.

Neuroprotective effects of Hericium erinaceus (Bull.: Fr.) Pers. against high-dose corticosterone-induced oxidative stress in PC-12 cells

BACKGROUND

Hericium erinaceus is a culinary and medicinal mushroom in Traditional Chinese Medicines. It has numerous pharmacological effects including immunomodulatory, anti-tumour, anti-microbial, anti-aging and stimulation of nerve growth factor (NGF) synthesis, but little is known about its potential role in negating the detrimental effects of oxidative stress in depression. The present study investigated the neuroprotective effects of H. erinaceus standardised aqueous extract (HESAE) against high-dose corticosterone-induced oxidative stress in rat pheochromocytoma (PC-12) cells, a cellular model mimicking depression.

METHODS

PC-12 cells was pre-treated with HESAE for 48 h followed by 400 μM corticosterone for 24 h to induce oxidative stress. Cells in complete medium without any treatment or pre-treated with 3.125 μg/mL desipramine served as the negative and positive controls, respectively. The cell viability, lactate dehydrogenase (LDH) release, endogenous antioxidant enzyme activities, aconitase activity, mitochondrial membrane potentials (MMPs), intracellular reactive oxygen species (ROS) levels and number of apoptotic nuclei were quantified. In addition, HESAE ethanol extract was separated into fractions by chromatographic methods prior to spectroscopic analysis.

RESULTS

We observed that PC-12 cells treated with high-dose corticosterone at 400 μM had decreased cell viability, reduced endogenous antioxidant enzyme activities, disrupted mitochondrial function, and increased oxidative stress and apoptosis. However, pre-treatment with HESAE ranging from 0.25 to 1 mg/mL had increased cell viability, decreased LDH release, enhanced endogenous antioxidant enzyme activities, restored MMP, attenuated intracellular ROS and protected from ROS-mediated apoptosis. The neuroprotective effects could be attributed to significant amounts of adenosine and herierin III isolated from HESAE.

CONCLUSIONS

HESAE demonstrated neuroprotective effects against high-dose corticosterone-induced oxidative stress in an in vitro model mimicking depression. HESAE could be a potential dietary supplement to treat depression.

Evidence for Effective Inhibitory Actions on Hyperpolarization-Activated Cation Current Caused by Ganoderma Triterpenoids, the Main Active Constitutents of Ganoderma Spores

The triterpenoid fraction of Ganoderma (Ganoderma triterpenoids, GTs) has been increasingly demonstrated to provide effective antioxidant, neuroprotective or cardioprotective activities. However, whether GTs is capable of perturbing the transmembrane ionic currents existing in electrically excitable cells is not thoroughly investigated. In this study, an attempt was made to study whether GTs could modify hyperpolarization-activated cation currents (I_h) in pituitary tumor (GH₃) cells and in HL-1 atrial cardiomyocytes. In whole-cell current recordings, the addition of GTs produced a dose-dependent reduction in the amplitude of I_h in GH₃ cells with an IC₅₀ value of 11.7 µg/mL, in combination with a lengthening in activation time constant of the current. GTs (10 µg/mL) also caused a conceivable shift in the steady-state activation curve of I_h along the voltage axis to a more negative potential by approximately 11 mV. Subsequent addition of neither 8-cyclopentyl-1,3-dipropylxanthine nor 8-(p-sulfophenyl)theophylline, still in the presence of GTs, could attenuate GTs-mediated inhibition of I_h. In current-clamp voltage recordings, GTs diminished the firing frequency of spontaneous action potentials in GH₃ cells, and it also decreased the amplitude of sag potential in response to hyperpolarizing current stimuli. In murine HL-1 cardiomyocytes, the GTs addition also suppressed the amplitude of I_h effectively. In DPCPX (1 µM)-treated HL-1 cells, the inhibitory effect of GTs on I_h remained efficacious. Collectively, the inhibition of I_h caused by GTs is independent of its possible binding to adenosine receptors and it might have profound influence in electrical behaviors of different types of electrically excitable cells (e.g., pituitary and heart cells) if similar in vitro or in vivo findings occur.

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.

Analysis of the High-Performance Liquid Chromatography Fingerprints and Quantitative Analysis of Multicomponents by Single Marker of Products of Fermented Cordyceps sinensis

Fermented Cordyceps sinensis, the succedaneum of Cordyceps sinensis which is extracted and separated from Cordyceps sinensis by artificial fermentation, is commonly used in eastern Asia in clinical treatments due to its health benefit. In this paper, a new strategy for differentiating and comprehensively evaluating the quality of products of fermented Cordyceps sinensis has been established, based on high-performance liquid chromatography (HPLC) fingerprint analysis combined with similar analysis (SA), hierarchical cluster analysis (HCA), and the quantitative analysis of multicomponents by single marker (QAMS). Ten common peaks were collected and analysed using SA, HCA, and QAMS. These methods indicated that 30 fermented Cordyceps sinensis samples could be categorized into two groups by HCA. Five peaks were identified as uracil, uridine, adenine, guanosine, and adenosine, and according to the results from the diode array detector, which can be used to confirm peak purity, the purities of these compounds were greater than 990. Adenosine was chosen as the internal reference substance. The relative correction factors (RCF) between adenosine and the other four nucleosides were calculated and investigated using the QAMS method. Meanwhile, the accuracy of the QAMS method was confirmed by comparing the results of that method with those of an external standard method with cosines of the angles between the groups. No significant difference between the two methods was observed. In conclusion, the method established herein was efficient, successful in identifying the products of fermented Cordyceps sinensis, and scientifically valid to be applicable in the systematic quality control of fermented Cordyceps sinensis products.