Ganoderma lucidum ameliorates the diabetic nephropathy via down-regulatory effect on TGFβ-1 and TLR-4/NFκB signalling pathways

Potentials of Natural Antioxidants in Reducing Inflammation and Oxidative Stress in Chronic Kidney Disease

Chronic kidney disease (CKD) presents a substantial global public health challenge, with high morbidity and mortality. CKD patients often experience dyslipidaemia and poor glycaemic control, further exacerbating inflammation and oxidative stress in the kidney. If left untreated, these metabolic symptoms can progress to end-stage renal disease, necessitating long-term dialysis or kidney transplantation. Alleviating inflammation responses has become the standard approach in CKD management. Medications such as statins, metformin, and GLP-1 agonists, initially developed for treating metabolic dysregulation, demonstrate promising renal therapeutic benefits. The rising popularity of herbal remedies and supplements, perceived as natural antioxidants, has spurred investigations into their potential efficacy. Notably, lactoferrin, Boerhaavia diffusa, Amauroderma rugosum, and Ganoderma lucidum are known for their anti-inflammatory and antioxidant properties and may support kidney function preservation. However, the mechanisms underlying the effectiveness of Western medications and herbal remedies in alleviating inflammation and oxidative stress occurring in renal dysfunction are not completely known. This review aims to provide a comprehensive overview of CKD treatment strategies and renal function preservation and critically discusses the existing literature's limitations whilst offering insight into the potential antioxidant effects of these interventions. This could provide a useful guide for future clinical trials and facilitate the development of effective treatment strategies for kidney functions.

Ganoderma lucidum: Multifaceted mechanisms to combat diabetes through polysaccharides and triterpenoids: A comprehensive review

Diabetes is a chronic metabolic disorder. Diabetes complications can affect many organs and systems in the body. Ganoderma lucidum (G. lucidum) contains various compounds that have been studied for their potential antidiabetic effects, including polysaccharides, triterpenoids (ganoderic acids, ganoderol B), proteoglycans, and G. lucidum extracts. G. lucidum polysaccharides (GLPs) and triterpenoids have been shown to act through distinct mechanisms, such as improving glucose metabolism, modulating the mitogen-activated protein kinase (MAPK) system, inhibiting the nuclear factor-kappa B (NF-κB) pathway, and protecting the pancreatic beta cells. While GLPs exhibit a significant role in controlling diabetic nephropathy and other associated complications. This review states the G. lucidum antidiabetic mechanisms of action and potential biologically active compounds that contribute to diabetes management and associated complications. To make G. lucidum an appropriate replacement for the treatment of diabetes with fewer side effects, more study is required to completely comprehend the number of physiologically active compounds present in it as well as the underlying cellular mechanisms that influence their effects on diabetes.

Inhibition of intrarenal PRR-RAS pathway by Ganoderma lucidum polysaccharide peptides in proteinuric nephropathy

Excessive proteinuria leads to renal dysfunction and damage. Ganoderma lucidum polysaccharide peptide (GL-PP) and Ganoderma lucidum polysaccharide peptide 2 (GL-PP2) are biologically active compounds extracted from Ganoderma lucidum. GL-PP has a relative molecular weight of 37,121 with 76.39 % polysaccharides and 16.35 % polypeptides, while GL-PP2 has a relative molecular weight of 31,130, composed of 64.14 % polysaccharides and 17.73 % polypeptides. The xylose: mannose: glucose monosaccharide ratios in GL-PP and GL-PP2 were 4.83:1:7.03 and 2.35:1:9.38, respectively. In this study, we investigated the protective effects of GL-PP and GL-PP2 on proteinuria-induced renal dysfunction and damage using rat and cell models. Both compounds reduced kidney injury, proteinuria, and inhibited the (pro)renin receptor (PRR)-renin-angiotensin system (RAS) pathway, inflammatory cell infiltration, oxidative stress, and fibrosis. GL-PP2 showed stronger inhibition of cyclooxygenase-2 and inducible nitric oxide synthase proteins compared to GL-PP. In cell models, both compounds displayed anti-inflammatory properties and improved cellular viability by inhibiting the PRR-RAS pathway. GL-PP2 has higher feasibility and productivity than GL-PP in pharmacology and industrial production. It shows promise in treating proteinuria-induced renal disease with superior anti-inflammatory effects and economic, safe industrial application prospects. Further research is needed to compare efficacy, mechanisms, clinical applications, and commercial feasibility of GL-PP and GL-PP2.

The role of toll-like receptors (TLRs) and their therapeutic applications in glomerulonephritis

One of the most important features of innate immunity is the presence of a special group of pattern recognition receptors (PRRs) called toll-like receptors (TLRs), which recognize pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), resulting in a quick and effective immune response to them. Glomerulonephritis (GN) is one of the most important categories of renal disorders characterized by destructive responses of the immune system to the glomerulus. To date, the association of TLRs as important innate immune system members with GN has been one of the topics that attracted the attention of researchers in this field. However, the exact role of these receptors in the immunopathogenesis of GN has not yet been fully discussed. Therefore, this study aims to overview the role of TLRs in GN and the possibility of using them as a potential therapeutic target.

Understanding the lncRNA/miRNA-NFκB regulatory network in Diabetes Mellitus: From function to clinical translation

Diabetes mellitus (DM) and its significant ramifications make out one of the primary reasons behind morbidity worldwide. Noncoding RNAs (ncRNAs), such as microRNAs and long noncoding RNAs, are involved in regulating manifold biological processes, including diabetes initiation and progression. One of the established pathways attributed to DM development is NF-κB signaling. Neurons, β cells, adipocytes, and hepatocytes are among the metabolic tissues where NF-κB is known to produce a range of inflammatory chemokines and cytokines. The direct or indirect role of ncRNAs such as lncRNAs and miRNAs on the NF-κB signaling pathway and DM development has been supported by many studies. As a result, effective diabetes treatment and preventive methods will benefit from a comprehensive examination of the interplay between NF-κB and ncRNAs. Herein, we provide a concise overview of the role of NF-κB-mediated signaling pathways in diabetes mellitus and its consequences. The reciprocal regulation of ncRNAs and the NF-κB signaling pathway in diabetes is then discussed, shedding light on the pathogenesis of the illness and its possible therapeutic interventions.

Effects of a Ganoderma lucidum Proteoglycan on Type 2 Diabetic Rats and the Recovery of Rat Pancreatic Islets

Type 2 diabetes (T2D) results from both insulin resistance and pancreatic β-cell dysfunction. A natural proteoglycan extracted from Ganoderma lucidum, namely, FYGL, has been demonstrated to be capable of ameliorating insulin resistance in previous work. In this work, a T2D rat model induced by streptozocin (STZ) and a high-fat diet was used to investigate the effects of FYGL on pancreatic functions, and the transcriptomics of the rat pancreas was used to investigate the biological processes (BP) and signal pathways influenced by FYGL on the gene basis. Furthermore, the results of transcriptomics were verified both by histopathological analyses and protein expression. The studies showed that FYGL positively regulated T2D-related BP and signaling pathways and recovered the pancreatic function, therefore ameliorating hyperglycemia and hyperlipidemia in vivo. Importantly, the recovery of the pancreatic function suggested a crucial strategy to radically treat T2D.

TLR4/Inflammasomes Cross-Talk and Pyroptosis Contribute to N-Acetyl Cysteine and Chlorogenic Acid Protection against Cisplatin-Induced Nephrotoxicity

Background: Cisplatin (Cp) is an antineoplastic agent with a dose-limiting nephrotoxicity. Cp-induced nephrotoxicity is characterized by the interplay of oxidative stress, inflammation, and apoptosis. Toll-4 receptors (TLR4) and NLPR3 inflammasome are pattern-recognition receptors responsible for activating inflammatory responses and are assigned to play a significant role with gasdermin (GSDMD) in acute kidney injuries. N-acetylcysteine (NAC) and chlorogenic acid (CGA) have documented nephroprotective effects by suppressing oxidative and inflammatory pathways. Therefore, the current study aimed to investigate the contribution of the upregulation of TLR4/inflammasomes/gasdermin signaling to Cp-induced nephrotoxicity and their modulation by NAC or CGA. Methods: A single injection of Cp (7 mg/kg, i.p.) was given to Wistar rats. Rats received either NAC (250 mg/kg, p.o.) and/or CGA (20 mg/kg, p.o.) one week before and after the Cp injection. Results: Cp-induced acute nephrotoxicity was evident by the increased blood urea nitrogen and serum creatinine and histopathological insults. Additionally, nephrotoxicity was associated with increased lipid peroxidation, reduced antioxidants, and elevated levels of inflammatory markers (NF-κB and TNF-α) in the kidney tissues. Moreover, Cp upregulated both TLR4/NLPR3/interleukin-1beta (IL-1β) and caspase-1/GSDMD-signaling pathways, accompanied by an increased Bax/BCL-2 ratio, indicating an inflammatory-mediated apoptosis. Both NAC and/or CGA significantly corrected these changes. Conclusions: This study emphasizes that inhibition of TLR4/NLPR3/IL-1β/GSDMD might be a novel mechanism of the nephroprotective effects of NAC or CGA against Cp-induced nephrotoxicity in rats.

Jiedu Tongluo Baoshen formula enhances podocyte autophagy and reduces proteinuria in diabetic kidney disease by inhibiting PI3K/Akt/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine (TCM) has been applied to diabetic kidney disease (DKD). A large number of animal trials each year focus on TCM for DKD, but the evidence for these preclinical studies is not clear.

AIM OF THE STUDY

The aim of this study was to study the therapeutic effect of Jiedu Tongluo Baoshen formula (JTBF) on DKD proteinuria and renal protection. At the same time, it is verified that JTBF can reduce podocyte injury by enhancing autophagy function, and then achieve the effect of proteinuria.

MATERIALS AND METHODS

We use high performance liquid chromatography to detect and analyze the fingerprint of JTBF to find the chemical composition. Subsequently, we constructed a DKD rat model induced by high-fat diet and streptozocin (HFD + STZ). Urine and blood biochemical automatic analyzer were used to detect 24-h urine protein quantification (24 h-UP) and renal function. The renal pathological changes were observed by H&E and transmission electron microscopy (TEM), and the levels of autophagy-related proteins and mRNA in podocytes were detected by immunohistochemistry, RT-qPCR and Western Blot. The chemical composition of JTBF was screened from traditional Chinese medicine systems pharmacol (TCMSP) and PubChem databases, and the potential targets and associated pathways of JTBF were predicted using kyoto encyclopedia of genes and genomes (KEGG) and protein-protein interaction (PPI) network analysis in network pharmacology, and confirmed in animal experiments and histopathological methods.

RESULTS

We discovered 77 active ingredients of JTBF. Through animal experiments, it was found that JTBF reduced 24 h-UP and promoted the expression of podocin, nephrin, and WT-1 in podocytes, thereby reducing podocyte damage. At the same time, JTBF activates the expression of podocyte autophagy-related proteins (beclin-1, LC3 and P62). Subsequently, through network pharmacology predictions, 208 compounds were obtained from JTBF, and phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) was a potential signal pathway. JTBF was obtained in DKD rat kidney tissue to inhibit the expression of PI3K, Akt and mTOR related proteins.

CONCLUSIONS

JTBF enhance podocyte autophagy to reduce podocyte damage, thereby effectively treating DKD proteinuria and protecting kidney function.

Ganoderma lucidum polysaccharide ameliorated diabetes mellitus-induced erectile dysfunction in rats by regulating fibrosis and the NOS/ERK/JNK pathway

Background

Diabetes mellitus-induced erectile dysfunction (DMED) is a frequent complication of diabetes mellitus (DM), with limited therapy at present. This study aimed to explore the role and mechanism of Ganoderma lucidum polysaccharide (GLP) on DMED.

Methods

DMED was induced in the experimental rats [male 12-week-old Sprague-Dawley (SD) rats] by treatment with streptozotocin (60 mg/kg) and apomorphine (APO). Next, rats in the GLP low dose (GLP-L)/GLP high dose (GLP-H) groups were treated with GLP (100 or 400 mg/kg/d, respectively) for 8 weeks. Subsequently, erectile function was assessed by APO and electrostimulation of the cavernous nerve (CN). Serum or penile testosterone (T), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and cyclic guanosine monophosphate (cGMP) contents were evaluated by enzyme-linked immunosorbent assay (ELISA). The levels of oxidative stress indicators in the corpus cavernosum (CC) were measured by corresponding kits, and histological changes in the CC were observed by hematoxylin-eosin (HE) and Masson staining. Additionally, the apoptosis index, caspase-3, caspase-9, and eNOS expression, and mitochondrial membrane potential (MMP) were also detected. Furthermore, quantitative polymerase chain reaction (qPCR) and western blot assays were conducted to determine the NOS, TGF-β1 mRNA expression, ERK1/2, eNOS, JNK phosphorylation, and arginase II protein expression.

Results

The erectile function test revealed that erectile dysfunction (ED) was alleviated in the DMED rats following treatment with GLP. Moreover, GLP upregulated the T and cGMP content, improved the oxidative stress and histological injuries of CC, and also inhibited the apoptosis and MMP loss of penile tissues in DMED rats. Furthermore, GLP treatment enhanced the mRNA expression of NOS and TGF-β1 and suppressed the phosphorylation of ERK1/2, eNOS, and JNK, as well as the protein expression of arginase II in DMED rats.

Conclusions

GLP ameliorated DMED by repairing the CC pathological damage and upregulating NOS expression and ERK/JNK phosphorylation, indicating that GLP may be a candidate drug for DMED therapy.

TLR9 regulates NLRP3 inflammasome activation via the NF-kB signaling pathway in diabetic nephropathy

BACKGROUND

Toll-like receptors (TLRs) are critical sensors for the conservation of bacterial molecules and play a key role in host defense against pathogens. The effect of TLRs on the maintenance of diabetic nephropathy (DN) and resistance to infection has been investigated; however, the detailed effects of TLR9 on DN development remain elusive.

METHODS

We performed quantitative reverse transcription-polymerase chain reaction and western blotting to detect TLR9 expression levels in the kidneys of experimental mice (db/db) and high-glucose-treated mouse mesangial cell strains (MCs).

RESULTS

TLR9 expression was found to be remarkably upregulated in the kidneys of experimental mice (db/db) and MCs cultivated under hyperglycemic conditions. Moreover, knockdown of TLR9 could restrain NF-kB viability and downregulate the NLRP3 inflammasome in high glucose-treated MCs. TLR9 inhibition also alleviated inflammation and apoptosis, which was reversed by the addition of the NF-κB activator, betulinic acid. Furthermore, depleted TLR9 levels restrained NF-κB viability and NLRP3 expression and reduced kidney inflammation, microalbuminuria discharge, blood sugar level, and glomerular damage in experimental mice (db/db) kidneys. Conclusions These findings offer novel insights into the regulation of TLR9 via the nuclear factor-kB/NOD-, LRR-, and pyrin domain-containing protein 3 inflammasome inflammation pathways in DN progression.

Interaction and Inhibition of a Ganoderma lucidum Proteoglycan on PTP1B Activity for Anti-diabetes

Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of insulin and an effective target for the treatment of type 2 diabetes (T2D). A natural hyperbranched proteoglycan extracted from Ganoderma lucidum, namely, Fudan-Yueyang G. Lucidum (FYGL), was demonstrated capable of inhibiting the activity of PTP1B. Here, to identify the effective active components of FYGL, three different components, the polysaccharide FYGL-1, proteoglycans FYGL-2, and FYGL-3, were isolated from FYGL, and then, the protein moiety of FYGL-3 was further separated, namely, FYGL-3-P. Their abilities to enhance the glucose uptake in cells and inhibit the activity of PTP1B were compared. The inhibitory mechanisms were systematically explored by spectroscopic methods and MD simulations. The results showed that FYGL-3 and FYGL-3-P significantly enhanced the insulin-provoked glucose uptake in insulin-resistant HepG2 cells, detected by the glucose oxidase method. Also, the FYGL-3-P protein moiety in FYGL played an essential role in inhibiting the activity of PTP1B. A strong, enthalpy-driven, and multitargeted interaction by electrostatic forces between PTP1B and FYGL-3-P dramatically inhibited the catalytic activity of PTP1B. These results provided deep insights into the molecular mechanisms of FYGL inhibiting the activity of PTP1B and structurally helped researchers seek natural PTP1B inhibitors.

NADH/NAD+ Redox Imbalance and Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a common and severe complication of diabetes mellitus. If left untreated, DKD can advance to end stage renal disease that requires either dialysis or kidney replacement. While numerous mechanisms underlie the pathogenesis of DKD, oxidative stress driven by NADH/NAD⁺ redox imbalance and mitochondrial dysfunction have been thought to be the major pathophysiological mechanism of DKD. In this review, the pathways that increase NADH generation and those that decrease NAD⁺ levels are overviewed. This is followed by discussion of the consequences of NADH/NAD⁺ redox imbalance including disruption of mitochondrial homeostasis and function. Approaches that can be applied to counteract DKD are then discussed, which include mitochondria-targeted antioxidants and mimetics of superoxide dismutase, caloric restriction, plant/herbal extracts or their isolated compounds. Finally, the review ends by pointing out that future studies are needed to dissect the role of each pathway involved in NADH-NAD⁺ metabolism so that novel strategies to restore NADH/NAD⁺ redox balance in the diabetic kidney could be designed to combat DKD.