Antioxidant and Cytotoxic Effects and Identification of Ophiocordyceps sinensis Bioactive Proteins Using Shotgun Proteomic Analysis.

RESEARCH BACKGROUND: Ophiocordyceps sinensis, a highly valued medicinal fungus, is close to extinction due to overexploitation. Successful cultivation of O. sinensis fruiting body (OCS02®) shows that the cultivar has a promising nutritional value and numerous bioactive compounds. Antioxidant and antiproliferative properties and biologically active proteins of the OCS02® are investigated for possible development into nutraceuticals. EXPERIMENTAL APPROACH: The chemical composition of the OCS02® cold water extract was determined, and the antioxidant activities were examined using ferric reducing, DPPH• and O2 •- scavenging assays. Tetrazolium dye (MTT) cytotoxic assay was performed to assess the antiproliferative activity of the extract. Bioactive proteins in the active fraction of the extract were identified using liquid chromatography (LC) and tandem-mass spectrometry (MS/MS). RESULTS AND CONCLUSIONS: The OCS02® extract exhibited strong O2 •- scavenging (expressed as Trolox equivalents (18.4±1.1) mol/g) and potent cytotoxic activities against adenocarcinomic human alveolar basal epithelial (A549) cells (IC50=(58.2±6.8) µg/mL). High molecular mass polysaccharides, proteins and protein-polysaccharide complexes could have contributed to the antioxidant and cytotoxic selectivity of the OCS02®. LC-MS/MS analysis identified several potential cytotoxic proteases and an oxalate decarboxylase protein which may exhibit protection effects on kidneys. NOVELTY AND SCIENTIFIC CONTRIBUTIONS: The findings demonstrate the potential of OCS02® to be developed into functional food due to its promising superoxide anion radical scavenging capacity, cytotoxic effect and presence of biopharmaceutically active proteins.

Immunomodulatory Properties of Water-Soluble Polysaccharides Extracted from the Fruiting Body of Chinese Caterpillar Mushroom, Ophiocordyceps sinensis Cultivar OCS02® (Ascomycetes).

Ophiocordyceps sinensis (=Cordyceps sinensis) has been known for its various medicinal properties, in particular immunomodulatory activities associated with its polysaccharides. In this study, the fruiting body of O. sinensis cultivar OCS02® was investigated for its chemical composition and monosaccharide profile. Cold water extract (CWE) obtained from this fruiting body was fractionated by molecular weight (MW) into high (HMW), medium (MMW), and low (LMW) fractions. Polysaccharides in the extract and fractions were identified as heteroglycans containing mostly glucose and mannose with small amounts of galactose, fucose, arabinose, and xylose. The immunomodulatory potential of these heteroglycans was evaluated by induction of cytokine/chemokine secretion using murine macrophage RAW 264.7. All treatments showed significant modulation of IL-6, IL-9, MIP-2, and TIMP-1, especially for CWE, HMW, and MMW, which might be due to their high ratios of glucose and the presence of protein. Further investigation on the structure-function relationship of these fruiting body polysaccharide fractions is needed to delineate the underlying mechanism of their immunomodulatory effect both in vitro and in vivo.

The Immunomodulating Properties of Tiger Milk Medicinal Mushroom, Lignosus rhinocerus TM02® Cultivar (Agaricomycetes) and Its Associated Carbohydrate Composition.

Natural compounds found in Lignosus rhinocerus like polysaccharides and polysaccharide-protein complexes have the capabilities to modulate the immune system. It possesses antitumor and anti-inflammatory properties and is commonly used in Southeast Asia and Southern China to alleviate illness. To investigate its immunomodulating properties, composition of polysaccharides and the expression of cytokines/chemokines from L. rhinocerus (TM02®) cultivar treated RAW 264.7 were explored. It was revealed, CWE contains linear polysaccharides with 1,4-linkages and rhinoprolycan fraction (HMW & MMW) possesses 1,4-Glcp and 1,6-Glcp backbone and branched chain (1,3,6-Glcp, 1,4,6-Glcp, 1,3,6-Glcp, 1,2,4,6-Glcp). Cytokines profile showed upregulation from CWE (IL-5: 12.078 ± 1.225), HMW (IL-6: 7.297 ± 0.338; TIMP-1: 3.358 ± 0.200), MMW (IL-5: 15.412 ± 5.823; TIMP-1: 1.747 ± 0.053), and LMW (MIP-2: 3.495 ± 0.416; TIMP-1: 7.573 ± 0.088) and possible involvement of NF-κB and MAPK signaling pathway. Further in vivo studies are needed to fully understand the immunomodulatory effects of TM02®.

Leptin and soluble leptin receptor in association with gestational diabetes: a prospective case-control study.

PURPOSE: To assess the association of serum leptin and its receptor (SLeptinR) with the risk of gestational diabetes mellitus (GDM) and to evaluate the longitudinal circulation of these peptides in pregnancy. METHODS: This study consisted of 53 subjects diagnosed with GDM and 43 normal glucose tolerance (NGT) pregnant women. Serum leptin and SLeptinR were measured at 24-28 weeks, prior and after delivery, and post-puerperium. RESULTS: Lower levels of leptin and SLeptinR were observed in GDM compared to NGT. Leptin [OR 0.97 (95% CI 0.94-1.0)] and SLeptinR [OR 0.86 (95% CI 0.79-0.93]) were inversely associated with GDM. Participants in the lowest tertile for leptin and SLeptinR had a 2.8-fold (95% CI 1.0-7.6) and a 5.7-fold (95% CI 1.9-17.3) higher risk of developing GDM compared with the highest tertile, respectively. These relationships were attenuated after adjustment for covariates. In both the groups, peak leptin was observed at 24-28 weeks, decreasing continuously during pregnancy (p > 0.05) and after delivery (p < 0.017). SLeptinR level increased (p < 0.001) during pregnancy and decreased (p < 0.005) after delivery in GDM, however, levels remained the same in NGT. In GDM, leptin and SLeptinR was positively and inversely correlated with BMI and HOMA-IR at 24-28 weeks and post-puerperium, respectively. The cord levels of both leptin and SLeptinR were lower than maternal levels. There were no significant differences in serum cord leptin and SLeptinR levels between the groups. CONCLUSION: Leptin and SLeptinR are independently and inversely associated with GDM. Lower levels of these peptides may play an important role in the pathophysiology of GDM and pre-diabetic state in post-puerperium.

Subversion of immunoproteasome subunit expression in dengue virus serotype 2-infected HepG2 cells.

INTRODUCTION:: Infection with all serotypes of dengue virus (DV) results in augmented antigen presentation by MHC class I molecules. However, the upregulation of immunoproteasome subunits only results from infection with two serotypes. This study aims to elucidate changes in the expression of immunoproteasome subunits resulting from infection with DV, particularly DV serotype 2 (DV2). METHODS:: HepG2 cells were grown in various culture milieu. Total cellular RNA and proteins were extracted and quantified. RESULTS:: Results demonstrated sequestration of immunoproteasome subunits LMP2 and LMP7 in DV2-infected cells. CONCLUSIONS:: This study provides insights into the mechanisms underlying immune evasion by DV.

Subversion of immunoproteasome subunit expression in dengue virus serotype 2-infected HepG2 cells

Abstract: INTRODUCTION: Infection with all serotypes of dengue virus (DV) results in augmented antigen presentation by MHC class I molecules. However, the upregulation of immunoproteasome subunits only results from infection with two serotypes. This study aims to elucidate changes in the expression of immunoproteasome subunits resulting from infection with DV, particularly DV serotype 2 (DV2). METHODS: HepG2 cells were grown in various culture milieu. Total cellular RNA and proteins were extracted and quantified. RESULTS: Results demonstrated sequestration of immunoproteasome subunits LMP2 and LMP7 in DV2-infected cells. CONCLUSIONS: This study provides insights into the mechanisms underlying immune evasion by DV.