The aqueous extract of Lycopus lucidus Turcz ameliorates streptozotocin-induced diabetic renal damage via inhibiting TGF-β1 signaling pathway

Therapeutic Potential and Mechanisms of Rosmarinic Acid and the Extracts of Lamiaceae Plants for the Treatment of Fibrosis of Various Organs

Fibrosis, which causes structural hardening and functional degeneration in various organs, is characterized by the excessive production and accumulation of connective tissue containing collagen, alpha-smooth muscle actin (α-SMA), etc. In traditional medicine, extracts of medicinal plants or herbal prescriptions have been used to treat various fibrotic diseases. The purpose of this narrative review is to discuss the antifibrotic effects of rosmarinic acid (RA) and plant extracts that contain RA, as observed in various experimental models. RA, as well as the extracts of Glechoma hederacea, Melissa officinalis, Elsholtzia ciliata, Lycopus lucidus, Ocimum basilicum, Prunella vulgaris, Salvia rosmarinus (Rosmarinus officinalis), Salvia miltiorrhiza, and Perilla frutescens, have been shown to attenuate fibrosis of the liver, kidneys, heart, lungs, and abdomen in experimental animal models. Their antifibrotic effects were associated with the attenuation of oxidative stress, inflammation, cell activation, epithelial-mesenchymal transition, and fibrogenic gene expression. RA treatment activated peroxisomal proliferator-activated receptor gamma (PPARγ), 5' AMP-activated protein kinase (AMPK), and nuclear factor erythroid 2-related factor 2 (NRF2) while suppressing the transforming growth factor beta (TGF-β) and Wnt signaling pathways. Interestingly, most plants that are reported to contain RA and exhibit antifibrotic activity belong to the family Lamiaceae. This suggests that RA is an active ingredient for the antifibrotic effect of Lamiaceae plants and that these plants are a useful source of RA. In conclusion, accumulating scientific evidence supports the effectiveness of RA and Lamiaceae plant extracts in alleviating fibrosis and maintaining the structural architecture and normal functions of various organs under pathological conditions.

Renal protective effect of ellipticine against streptozotocin induced diabetic nephropathy in rats via suppression of oxidative stress and inflammatory mediator

PURPOSE

Diabetes mellitus is a serious health problem worldwide, and diabetic nephropathy is the complication. The diabetic nephropathy considerably enhances the oxidative stress, glycation, lipid parameters and inflammatory reaction. Ellipticine has potent free radical scavenging and anti-inflammatory effect.

METHODS

In the current study, our objectives were to thoroughly examine the renal protective effects of ellipticine in a rat model of streptozotocin (STZ)-induced diabetic nephropathy (DN) and to elucidate the underlying mechanisms involved. For the induction of diabetic nephropathy, streptozotocin (50 mg/kg) was used, and rats were separated into groups and given varying doses of ellipticine (2.5, 5 and 7.5 mg/kg). The body weight, and renal weight were estimated. The inflammatory cytokines, renal biomarkers, inflammatory antioxidant, and urine parameters were estimated.

RESULTS

Result showed that ellipticine considerably enhanced the body weight and reduced the renal tissue weight. Ellipticine treatment significantly (P < 0.001) repressed the level of blood urea nitrogen, serum creatinine, uric acid, blood glucose and altered the lipid parameters. Ellipticine significantly (P < 0.001) repressed the level of malonaldehyde and boosted the glutathione, catalase, superoxide dismutase, and glutathione peroxidase. Ellipticine treatment significantly (P < 0.001) reduced the inflammatory cytokines and inflammatory mediators.

CONCLUSIONS

Ellipticine could be a renal protective drug via attenuating the inflammatory reaction, fibrosis and oxidative stress in streptozotocin induced rats.

Improvement in the Blood Urea Nitrogen and Serum Creatinine Using New Cultivation of Cordyceps militaris

Background

Chronic kidney disease (CKD) is a critical public health issue with a huge financial burden for both patients and society worldwide. Unfortunately, there are currently no efficacious therapies to prevent or delay the progression of end-stage renal disease (ESRD). Traditional Chinese medicine practices have shown that Cordyceps militaris (C. militaris) mycelia have a variety of pharmacologically useful properties, including antitumor, immunomodulation, and hepatoprotection. However, the effect of mycelial C. militaris on CKD remains unclear.

Methods

Here, we investigated the effects of C. militaris mycelia on mice with CKD using four types of media: HKS, HKS with vitamin A (HKS + A), CM, and CM with vitamin A (CM + A).

Results

The results at day 10 revealed that the levels of blood urea nitrogen (BUN) were significantly lower in the HKS (41%), HKS + A (41%), and CM + A (34%) groups compared with those in the corresponding control groups (nephrectomic mice). The level of serum creatinine in the HKS + A group decreased by 35% at day 10, whereas the levels in the HKS and CM + A groups decreased only by 14% and 13%, respectively, on day 30. Taken together, this is the first report using four new media (HKS, HKS + A, CM, and CM + A medium) for C. militaris mycelia. Each medium of mycelial C. militaris on CKD exhibits specific effect on BUN, serum creatinine, body weight, total protein, and uric acid.

Conclusions

Taken together, this is the first report using four new media (HKS, HKS + A, CM, and CM + A medium) for C. militaris mycelia. Each medium of mycelial C. militaris on CKD exhibits specific effects on BUN, serum creatinine, body weight, total protein, and uric acid. We concluded that treatment with C. militaris mycelia cultured in HKS or CM + A medium could potentially prevent the deterioration of kidney function in mice with CKD.

Potential signaling pathway through which Notch regulates oxidative damage and apoptosis in renal tubular epithelial cells induced by high glucose

Diabetic nephropathy (DN) is one of the most common and serious complications of diabetes mellitus, and glomerular sclerosis and renal tubular interstitial fibrosis are the main pathological features. Current evidence indicates that the Notch pathway can mediate the impairment of renal tubular function and induce angiogenesis and renal interstitial fibrosis. This study was conducted to explore the potential signaling pathway through which Notch regulates oxidative damage and apoptosis in renal tubular epithelial cells induced by high glucose. mRNA and protein expression levels were assessed using real-time PCR and Western blot, respectively. The protein expression levels of Jaggedl, Notchl, pro-caspase-3, Drpl, and PGC-1α were increased by high glucose, but N-[N-(3,5-difluorohenacetyl)-l-alanyl]-S-phenylglycine tert-butyl ester (DAPT; an inhibitor of the Notch signaling pathway) reversed these effects. Furthermore, DAPT reduced the mRNA expression of Jaggedl, Notchl, MnSOD2, Drpl, and PGC-1α in renal tubular epithelial cells induced by high glucose. In conclusion, the Notch signaling pathway may regulate oxidative damage and apoptosis in renal tubular epithelial cells induced by high glucose by regulating mitochondrial dynein and biogenesis genes, which can accelerate renal interstitial fibrosis in DN. The Notch signaling pathway might be a potential therapeutic target for DN, and DAPT might become a potential drug for the treatment of DN.

Involvement of TGF-β and Autophagy Pathways in Pathogenesis of Diabetes: A Comprehensive Review on Biological and Pharmacological Insights

Despite recent advancements in clinical drugs, diabetes treatment still needs further progress. As such, ongoing research has attempted to determine the precise molecular mechanisms of the disorder. Specifically, evidence supports that several signaling pathways play pivotal roles in the development of diabetes. However, the exact molecular mechanisms of diabetes still need to be explored. This study examines exciting new hallmarks for the strict involvement of autophagy and TGF-β signaling pathways in the pathogenesis of diabetes and the design of novel therapeutic strategies. Dysregulated autophagy in pancreatic β cells due to hyperglycemia, oxidative stress, and inflammation is associated with diabetes and accompanied by dysregulated autophagy in insulin target tissues and the progression of diabetic complications. Consequently, several therapeutic agents such as adiponectin, ezetimibe, GABA tea, geniposide, liraglutide, guava extract, and vitamin D were shown to inhibit diabetes and its complications through modulation of the autophagy pathway. Another pathway, TGF-β signaling pathway, appears to play a part in the progression of diabetes, insulin resistance, and autoimmunity in both type 1 and 2 diabetes and complications in diabetes. Subsequently, drugs that target TGF-β signaling, especially naturally derived ones such as resveratrol, puerarin, curcumin, hesperidin, and silymarin, as well as Propolis, Lycopus lucidus, and Momordica charantia extracts, may become promising alternatives to current drugs in diabetes treatment. This review provides keen insights into novel therapeutic strategies for the medical care of diabetes.

The protective effects of lycopus lucidus turcz in diabetic retinopathy and its possible mechanisms

The aim of the present study was to investigate the effect of Lycopus lucidus Turcz (LT) on diabetic retinopathy (DR) and its underlying mechanisms. SD rats and human retinal microvascular endothelial cells (HRECs) were applied for establishment DR model. HE and TUNEL staining were used to evaluate the pathological changes and apoptosis of retinal ganglion cells. Additionally, retinal vessels were detected by immunofluorescence staining with CD31 and VEGF. The function of BRB was observed using Evans blue. Moreover, the oxidative stress, inflammation and angiogenesis associated factors were measured respectively. The expression of p38-MAPK/NF-κB signalling proteins were detected by Western blot. The results demonstrated that pathological changes and retinal optic disc cells apoptosis in retinas of diabetic rats, both of which were reduced in the LT-treated group. And LT treatment attenuated the levels of oxidative stress, inflammation and angiogenesis factors. Importantly, the expression levels of p-p38, p-ERK, p-JNK and NF-κB were decreased. After treatment with TNF-α combined with LT, the levels of inflammatory factors were decreased but higher than the negative control. Taken together, the results suggested that LT treatment is of therapeutic benefit by ameliorating oxidative stress, inflammation and angiogenesis of DR via p38-MAPK/NF-κB signaling pathway.

Protective effect of free phenolics from Lycopus lucidus Turcz. root on carbon tetrachloride-induced liver injury in vivo and in vitro

Protective effect of free phenolics from Lycopus lucidus Turcz. root (FPLR) on CCl₄-induced hepatotoxicity in vivo and in vitro was first evaluated. Oral administration of FPLR (100 mg/kg bw) to mice significantly reduced the CCl₄-induced elevation of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, triacylglycerols, total cholesterol, and total bilirubin. FPLR also increased the hepatic GSH contents and antioxidant enzyme activities of SOD and CAT and decreased the hepatic MDA level. Histopathological examinations further confirmed that the FPLR could protect the liver from CCl₄-induced damage. Further research indicated that FPLR prevented the DNA fragmentation caused by CCl₄ based on TUNEL assay. Moreover, immunohistochemistry staining demonstrated that pretreatment with FPLR significantly inhibited the elevation of hepatic TNF-α, IL-6, IL-8, iNOS, COX-2, and Caspase-3 in CCl₄-treated mice. In vitro experiments showed that FPLR remarkably reduced BRL hepatocyte apoptosis and damage caused by CCl₄ treatment. These findings indicate that FPLR could be developed as a functional food or medication for therapeutic purpose and prevention of hepatic injury.

Natural antioxidants in the treatment and prevention of diabetic nephropathy; a potential approach that warrants clinical trials

Diabetic nephropathy is the major cause of end-stage renal disease and effective and new therapeutic approaches are needed in diabetic nephropathy and chronic kidney diseases. Oxidative stress and inflammatory process are important factors contributing to kidney damage by increasing production of oxidants. KEAP1/Nrf2/ARE pathway regulates the transcription of many antioxidant genes and modulation of the pathway up regulates antioxidants. NFB controls the expression of genes involved in the inflammatory response. Natural substances have antioxidant and anti-inflammatory activities and have an impact on NFB and KEAP1/Nrf2/ARE pathways. The preclinical studies explored the effectiveness of whole herbs, plants or seeds and their active ingredients in established diabetic nephropathy. They ameliorate oxidative stress induced kidney damage, enhance antioxidant system, and decrease inflammatory process and fibrosis; most likely by activating KEAP1/Nrf2/ARE pathway and by deactivating NFB pathway. Whole natural products contain balanced antioxidants that might work synergistically to induce beneficial therapeutic outcome. In this context, more clinical studies involving whole plants or herbal products or mixtures of different herbs and plants and their active ingredients might change our strategies for the management of diabetic nephropathy. The natural products might be useful as preventive interventions and studies are required in this field.

Diosmin Modulates the NF-kB Signal Transduction Pathways and Downregulation of Various Oxidative Stress Markers in Alloxan-Induced Diabetic Nephropathy

Hyperglycaemia-mediated oxidative stress plays an imperative role in the progression of diabetic nephropathy. NF-kB is an important transcription factor in eukaryotes which regulates a diverse array of cellular process, including inflammation, immunological response, apoptosis, growth and development. Increased expression of NF-kB plays a vital role in the pathogenesis of many inflammatory diseases including diabetic nephropathy. Hence, the present study was designed to explore the nephroprotective nature of diosmin by assessing the various biochemical parameters, markers of oxidative stress and proinflammatory cytokine levels in alloxan-induced diabetic Wistar rats. Type 2 diabetes was induced in Wistar rats by single intraperitoneal injection of alloxan (120 mg/kg body weight). Seventy-two hours after the conformation of diabetes (blood glucose level ≥ 250 mg/dl), the rats were segregated into four groups, each group having six animals. Diabetic rats were treated with diosmin at a dose of 50 mg and 100 mg/kg body weight respectively. After the 28th day of treatment, rats were sacrificed, blood serum, plasma and kidney tissue were collected for various biochemical analysis. Inflammatory cytokine levels were measured through ELISA kit. Diosmin treatment produces significant reduction in the blood glucose and plasma insulin level and increases the body weight when compared with diabetic rats. Elevated level of malondialdehyde (MDA) and decrease levels of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and nitric oxide (NO) were significantly restored after 28 days of diosmin treatment. Diosmin treatment group also restores the normal architecture of the kidney tissue which was confirmed by histopathological examination. Moreover, oral administration of diosmin shows a significant normalization in the level of NF-kB, proving its pivotal role in maintaining renal function. The above ameliorative effects were more pronounced with diosmin at a dose of 100 mg/kg body weight. The above results permit us to conclude that treatment with diosmin halts hyperglycaemia-mediated oxidative stress and decline in pro-inflammatory cytokines and thus has beneficial anti-diabetic activity.

Magnolol Attenuates Concanavalin A-induced Hepatic Fibrosis, Inhibits CD4+ T Helper 17 (Th17) Cell Differentiation and Suppresses Hepatic Stellate Cell Activation: Blockade of Smad3/Smad4 Signalling

Magnolol is a pharmacological biphenolic compound extracted from Chinese herb Magnolia officinalis, which displays anti-inflammatory and antioxidant effects. This study was aimed at exploring the potential effect of magnolol on immune-related liver fibrosis. Herein, BALB/c mice were injected with concanavalin A (ConA, 8 mg/kg/week) up to 6 weeks to establish hepatic fibrosis, and magnolol (10, 20, 30 mg/kg/day) was given to these mice orally throughout the whole experiment. We found that magnolol preserved liver function and attenuated liver fibrotic injury in vivo. In response to ConA stimulation, the CD4⁺ T cells preferred to polarizing towards CD4⁺ T helper 17 (Th17) cells in liver. Magnolol was observed to inhibit Th17 cell differentiation in ConA-treated liver in addition to suppressing interleukin (IL)-17A generation. Hepatic stellate cells were activated in fibrotic liver as demonstrated by increased alpha smooth muscle actin (α-SMA) and desmin. More transforming growth factor (TGF)-β1 and activin A were secreted into the serum. Magnolol suppressed this abnormal HSC activation. Furthermore, the phosphorylation of Smad3 in its linker area (Thr179, Ser 204/208/213) was inhibited by magnolol. In vitro, the recombinant IL-17A plus TGF-β1 or activin A induced activation of human LX2 HSCs and promoted their collagen production. Smad3/Smad4 signalling pathway was activated in LX2 cells exposed to the fibrotic stimuli, as illustrated by the up-regulated phospho-Smad3 and the enhanced interaction between Smad3 and Smad4. These alterations were suppressed by magnolol. Collectively, our study reveals a novel antifibrotic effect of magnolol on Th17 cell-mediated fibrosis.

Protective Effects of Luteolin on Lipopolysaccharide-Induced Acute Renal Injury in Mice

Background

Sepsis can cause serious acute kidney injury in bacterium-infected patients, especially in intensive care patients. Luteolin, a bioactive flavonoid, has renal protection and anti-inflammatory effects. This study aimed to investigate the effect and underlying mechanism of luteolin in attenuating lipopolysaccharide (LPS)-induced renal injury.

Material/Methods

ICR mice were treated with LPS (25 mg/kg) with or without luteolin pre-treatment (40 mg/kg for three days). The renal function, histological changes, degree of oxidative stress, and tubular apoptosis in these mice were examined. The effects of luteolin on LPS-induced expression of renal tumor necrosis factor-α (TNF-α), NF-κB, MCP-1, ICAM-1, and cleaved caspase-3 were evaluated.

Results

LPS resulted in rapid renal damage of mice, increased level of blood urea nitrogen (BUN), and serum creatinine (Scr), tubular necrosis, and increased oxidative stress, whereas luteolin pre-treatment could attenuate this renal damage and improve the renal functions significantly. Treatment with LPS increased TNF-α, NF-κB, IL-1β, cleaved caspase-3, MCP-1, and ICAM-1 expression, while these disturbed expressions were reversed by luteolin pre-treatment.

Conclusions

These results indicate that luteolin ameliorates LPS-mediated nephrotoxicity via improving renal oxidant status, decreasing NF-κB activation and inflammatory and apoptosis factors, and then disturbing the expression of apoptosis-related proteins.

Renal Protective Effects of Low Molecular Weight of Inonotus obliquus Polysaccharide (LIOP) on HFD/STZ-Induced Nephropathy in Mice

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in diabetes mellitus. Oxidative stress, insulin resistance and pro-inflammatory cytokines have been shown to play an important role in pathogeneses of renal damage on type 2 diabetes mellitus (DM). Inonotus obliquus (IO) is a white rot fungus that belongs to the family Hymenochaetaceae; it has been used as an edible mushroom and exhibits many biological activities including anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic properties. Especially the water-soluble Inonotus obliquus polysaccharides (IOPs) have been previously reported to significantly inhibit LPS-induced inflammatory cytokines in mice and protect from streptozotocin (STZ)-induced diabetic rats. In order to identify the nephroprotective effects of low molecular weight of IOP fraction (LIOP), from the fruiting bodies of Inonotus obliquus, high-fat diet (HFD) plus STZ-induced type 2-like diabetic nephropathy C57BL/6 mice were investigated in this study. Our data showed that eight weeks of administration of 10–100 kDa, LIOP (300 mg/kg) had progressively increased their sensitivity to glucose (less insulin tolerance), reduced triglyceride levels, elevated the HDL/LDL ratio and decreased urinary albumin/creatinine ratio(ACR) compared to the control group. By pathological and immunohistochemical examinations, it was indicated that LIOP can restore the integrity of the glomerular capsules and increase the numbers of glomerular mesangial cells, associated with decreased expression of TGF-β on renal cortex in mice. Consistently, three days of LIOP (100 μg/mL) incubation also provided protection against STZ + AGEs-induced glucotoxicity in renal tubular cells (LLC-PK1), while the levels of NF-κB and TGF-β expression significantly decreased in a dose-dependent manner. Our findings demonstrate that LIOP treatment could ameliorate glucolipotoxicity-induced renal fibrosis, possibly partly via the inhibition of NF-κB/TGF-β1 signaling pathway in diabetic nephropathy mice.

The effects of the water-extraction of Astragali Radix and Lycopi herba on the Pathway of TGF-smads-UPP in a rat model of Diabetic Nephropathy

Background:

Astragali Radix and Lycopi Herba were widely used in clinical practice for treating the diabetic nephropathy (DN), but their therapeutic mechanisms were not clear.

Objective:

To observe the effects of the water-extraction of Astragali Radix and Lycopi Herba on the signaling pathway of TGF-Smads-UPP in streptozotocin (STZ)-induced DN.

Materials and Methods:

Sprague-Dawley (SD) rats were randomly divided into the normal control (NC) group and the model group. The NC group was fed with a standard diet and the other five diabetic groups received a high-fat diet. After 4 weeks, five diabetic groups were treated with STZ (30mg/kg i.p.). The NC group rats were treated with citrate buffer. Tail random blood glucose (RBG) was measured 72h later using a strip-operated blood glucose sensor and monitored every 2 weeks until drug intervention. Rats with RBG levels less than 16.7mmol/L were excluded from the diabetic groups. At the end of 4 weeks after STZ injection, 24h microalbuminuria was collected and detected. The microalbuminuria was measured by radioimmunoassay (RIA). The blood glucose was tested using a blood glucose meter. The kidney was dissected from each SD rat. Proteins and mRNA of TGF-β1, Smads and Smurf were tested by western-blot and real-time PCR analysis, and 26S proteasome activity was measured by an ELISA kit.

Results:

The water-extraction of Astragali Radix and Lycopi Herba significantly lowered fasting glucose and urine albumin in diabetic rats through inhibition of TGF-β1 mRNA and protein expression in the STZ-induced diabetic rats, and regulation of the Smad3, Smad7, Smurf1, Smurf2 mRNA and protein expression, as well as elevated 26S proteasome activity to play control effect in DN.

Conclusion:

0.9 g/ml water-extraction of Astragali Radix and Lycopi Herba group has significant therapeutic effects on the STZ-induced diabetic rats, and this regulation depends on TGF-Smads-UPP signaling pathway.

Dual role of acetaminophen in promoting hepatoma cell apoptosis and kidney fibroblast proliferation

Acetaminophen (APAP), is a safe analgesic and antipyretic drug at therapeutic dose, and is widely used in the clinic. However, high doses of APAP can induce hepatotoxicity and nephrotoxicity. Most studies have focused on high‑dose APAP‑induced acute liver and kidney injury. So far, few studies have investigated the effects of the therapeutic dose (1/10 of the high dose) or of the low dose (1/100 of the high dose) of APAP on the cells. The aim of this study was to investigate the cellular effects of therapeutic- or low‑dose APAP treatment on hepatoma cells and kidney fibroblasts. As expected, high‑dose APAP treatment inhibited while therapeutic and low‑dose treatment did not inhibit cell survival of kidney tubular epithelial cells. In addition, therapeutic-dose treatment induced an increase in the H2O2 level, activated the caspase‑9/‑3 cascade, and induced cell apoptosis of hepatoma cells. Notably, APAP promoted fibroblast proliferation, even at low doses. This study demonstrates that different cellular effects are exerted upon treatment with different APAP concentrations. Our results indicate that treatment with the therapeutic dose of APAP may exert an antitumor activity on hepatoma, while low‑dose treatment may be harmful for patients with fibrosis, since it may cause proliferation of fibroblasts.