Effects of Ganoderma lucidum on obstructive jaundice-induced oxidative stress

Ganoderma lucidum: Novel Insight into Hepatoprotective Potential with Mechanisms of Action

Ganoderma lucidum (G. lucidum) has been widely used for its health benefits as an edible and traditional medicinal mushroom for thousands of years in Asian countries. It is currently used as a nutraceutical and functional food owing to its major bioactive compounds, polysaccharides and triterpenoids. G. lucidum exhibits a broad range of hepatoprotective impacts in various liver disorders, such as hepatic cancer, nonalcoholic fatty liver disease (NAFLD), alcohol-induced liver disease, hepatitis B, hepatic fibrosis, and liver injury induced by carbon tetrachloride (CCl4) and α-amanitin. G. lucidum protects the liver through a broad range of mechanisms that include the modulation of liver Phase I and II enzymes, the suppression of β-glucuronidase, antifibrotic and antiviral actions, the regulation of the production of nitric oxide (NO), the maintenance of hepatocellular calcium homeostasis, immunomodulatory activity, and scavenging free radicals. G. lucidum could signify an encouraging approach for the management of various chronic hepatopathies, and its potential mechanisms make it a distinctive agent when used alone or with other drugs and applied as a functional food, nutraceutical supplement, or adjuvant to modern medicine. This review summarizes the hepatoprotective properties of G. lucidum with its various mechanisms of action on different liver ailments. Biologically active substances derived from G. lucidum are still being studied for their potential benefits in treating different liver ailments.

The Pharmacological Rationales and Molecular Mechanisms of Ganoderma lucidum Polysaccharides for the Therapeutic Applications of Multiple Diseases

As a versatile Chinese herb, Ganoderma lucidum (Leyss. ex Fr.) Karst (G. lucidum) has been applied to treat multiple diseases in clinics and improve the quality of life of patients. Among all of its extracts, the main bioactive components are G. lucidum polysaccharides (GLPs), which possess many therapeutic effects, such as antitumor, immunoregulatory, anti-oxidant, antidiabetic, antibacterial, and antifungal effects and neuroprotection activities. This review briefly summarized the recent studies of the pharmacological rationales of GLPs and their underlying molecular signaling transmission mechanisms in treating diseases. Until now, the clear mechanisms of GLPs for treating diseases have not been reported. In this review, we used the keywords of "Ganoderma lucidum polysaccharides" and "tumor" to search in PubMed (years of 1992-2020), then screened and obtained 160 targets of antitumor activities in the literatures. The network pharmacology and mechanism framework were employed in this study as powerful approaches to systematically analyze the complicated potential antitumor mechanisms and targets of GLPs in cancer. We then found that there are 69 targets and 21 network pathways in "Pathways in cancer". Besides, we summarized the effects of GLPs and the models and methods used in the research of GLPs. In conclusion, GLPs have been studied extensively, but more in-depth research is still needed to determine the exact mechanisms and pathways. Therefore, this review might provide new insights into the vital targets and pathways for researchers to study the pharmacological mechanisms of GLPs for the treatment of diseases.

Resveratrol Protects Oxidative Stress-Induced Intestinal Epithelial Barrier Dysfunction by Upregulating Heme Oxygenase-1 Expression

BACKGROUND/AIM

Obstructive jaundice (OJ) is frequently complicated by infections and has been associated with increased bacterial translocation, intestinal epithelial hyperpermeability, and oxidative stress, but the mechanism remains unclear. The potential effect of resveratrol (Res) on modifying intestinal epithelial dysfunction was evaluated both in vitro and in vivo.

METHODS

Caco-2 cells (in vitro) and male Wistar rats (n = 60; in vivo) were used to evaluate the role of Res on intestinal epithelial dysfunction. Hydrogen peroxide was used to induce oxidative stress in the Caco-2 cells. In bile duct-ligated group, OJ was successfully established on Day 7 after bile duct ligation, whereas sham-operated and vehicle-treated rats served as controls. Western blot and RT-qPCR were performed to analyze TJ proteins expression in epithelium isolated from rat intestine.

RESULTS

Intestinal hyperpermeability was associated with decreased expression and phosphorylation of occludin and zonula occluden (ZO-1), but increased oxidation in Caco-2 cells and the intestinal epithelium. Res treatment increased the epithelial expression and phosphorylation of occludin and ZO-1 in a concentration-dependent manner. Moreover, Res which protected Caco-2 cells from H2O2-induced oxidative damage clearly reduced malondialdehyde level and intracellular reactive oxygen species accumulation, but increased the expression levels of superoxide dismutase and heme oxygenase-1 (HO-1). Further studies showed that Res also inhibited H2O2-induced protein kinase C activity and p38 phosphorylation. Interestingly, these effects of Res were abolished by the HO-1 inhibitor zinc protoporphyrin or knockdown of HO-1 by siRNA.

CONCLUSIONS

Res protected gut barrier function possibly by initiating HO-1-dependent signaling which is essential for common expression of key tight junction proteins. It also provides a rationale to develop Res clinical applications of intestinal disorders.

Therapeutic mechanisms of single Chinese medicine herb or their extracts for extrahepatic obstructive jaundice

Obstructive jaundice (OJ) is classified as extrahepatic OJ or intrahepatic OJ. Extrahepatic OJ is attributed to a variety of intricate etiological factors. Research has begun with Chinese medicine (CM), which can be used as an adjunctive therapy for extrahepatic OJ. Particular attention has been paid to the therapeutic effects and their mechanisms of single CM herb and relevant extracts. The roles of single CM or their extracts during adjunctive therapy for extrahepatic OJ have been described briefly. This review focuses on the effects and their mechanisms of relevant herbal medicines.

Structural characterization and antioxidative activity of low-molecular-weights beta-1,3-glucan from the residue of extracted Ganoderma lucidum fruiting bodies

The major cell wall constituent of Ganoderma lucidum (G. lucidum) is β-1,3-glucan. This study examined the polysaccharide from the residues of alkaline-extracted fruiting bodies using high-performance anion-exchange chromatography (HPAEC), and it employed nuclear magnetic resonance (NMR) and mass spectrometry (MS) to confirm the structures. We have successfully isolated low-molecular-weight β-1,3-glucan (LMG), in high yields, from the waste residue of extracted fruiting bodies of G. lucidum. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay evaluated the capability of LMG to suppress H₂O₂-induced cell death in RAW264.7 cells, identifying that LMG protected cells from H₂O₂-induced damage. LMG treatment decreased H₂O₂-induced intracellular reactive oxygen species (ROS) production. LMG also influenced sphingomyelinase (SMase) activity, stimulated by cell death to induce ceramide formation, and then increase cell ROS production. Estimation of the activities of neutral and acid SMases in vitro showed that LMG suppressed the activities of both neutral and acid SMases in a concentration-dependent manner. These results suggest that LMG, a water-soluble β-1,3-glucan recycled from extracted residue of G. lucidum, possesses antioxidant capability against H₂O₂-induced cell death by attenuating intracellular ROS and inhibiting SMase activity.

Evaluation of rat models of acute and chronic obstructive jaundice

AIM: To develop rat models of acute and chronic obstructive jaundice and to evaluate the extent to which they mimic features of clinical diseases.

METHODS: Ninety Sprague-Dawley rats were randomly and equally divided into three groups: acute obstructive jaundice group, chronic obstructive jaundice group, and control group. Each group was further divided into five subgroups for testing at different time points. Liver function was determined and the diameter of the common bile duct was measured under a microscope at weeks 1, 2, 3, 4, and 5 after model induction. Pathological changes in liver tissue were also observed by microscope. Choledochoduodenostomy was performed at week 4.

RESULTS: Jaundice progressively worsened in rats with acute obstructive jaundice, and TBIL increased from 84.86 μmol/L ± 49.09 μmol/L at week 1 to 749.38 μmol/L ± 38.99 μmol/L at week 4. Meanwhile, the diameter of the common bile duct diameter increased from 0.35 cm ± 0.15 cm to 1.50 cm ± 0.30 cm, and obvious degeneration, necrosis and hyperplasia of liver cells were observed. Jaundice was obviously improved after choledochoduodenostomy (TBIL: 153.93 μmol/L ± 57.36 μmol/L; diameter of the common bile duct: 0.40 cm ± 0.20 cm). Jaundice was mild in rats with chronic obstructive jaundice, and TBIL decreased from 42.43 μmol/L ± 23.56 μmol/L at week 1 to 36.52 μmol/L ± 16.28 μmol/L at week 4. Meanwhile, the diameter of the common bile duct increased from 0.20 cm ± 0.15 cm to 0.30 cm ± 0.10 cm, and obvious degeneration and hyperplasia of liver cells were noted. Jaundice slowly subsided after choledochoduodenostomy (TBIL: 32.15 μmol/L ± 13.20 μmol/L; diameter of the common bile duct: 0.15 cm ± 0.10 cm). Total bilirubin and the diameter of the common bile duct differed significantly at different time points between rats with acute and chronic obstructive jaundice (both P < 0.05).

CONCLUSION: Rat models of acute and chronic obstructive jaundice have been successfully established. There were significantly different manifestations between rats with chronic and acute obstructive jaundice.