scholarly journals Two New Apotirucallane-Type Triterpenoids from the Pericarp of Toona sinensis and Their Ability to Reduce Oxidative Stress in Rat Glomerular Mesangial Cells Cultured under High-Glucose Conditions

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 801 ◽  
Author(s):  
Di Liu ◽  
Rong-shen Wang ◽  
Lu-lu Xuan ◽  
Xiao-hong Wang ◽  
Wan-zhong Li

Hyperglycemia is a strong risk factor for chronic complications of diabetes. Hyperglycemic conditions foster not only the production of reactive oxygen species (ROS), but also the consumption of antioxidants, leading to oxidative stress and promoting the occurrence and progression of complications. During our continuous search for antioxidant constituents from the pericarp of Toona sinensis (A. Juss.) Roem, we isolated two previously unreported apotirucallane-type triterpenoids, toonasinensin A (1) and toonasinensin B (2), together with five known apotirucallane-type triterpenoids (3–7) and two known cycloartane-type triterpenoids (8–9) from the pericarp. Compounds 8–9 were obtained from T. sinensis for the first time. Their structures were characterized based on interpretation of spectroscopic data (1D, 2D NMR, high-resolution electrospray ionization mass spectra, HR-ESI-MS) and comparison to previous reports. Compounds (2, 4, 6, 7, and 9) were able to inhibit proliferation against rat glomerular mesangial cells (GMCs) cultured under high-glucose conditions within a concentration of 80 μM. Compounds (2, 6, and 7) were tested for antioxidant activity attributable to superoxide dismutase (SOD), malondialdehyde (MDA), and ROS in vitro, and the results showed that compounds (2, 6, and 7) could significantly increase the levels of SOD and reduce the levels of MDA and ROS. The current studies showed that apotirucallane-type triterpenoids (2, 6, and 7) might have the antioxidant effects against diabetic nephropathy.

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Feng ◽  
Junling Gu ◽  
Fang Gou ◽  
Wei Huang ◽  
Chenlin Gao ◽  
...  

While inflammation is considered a central component in the development in diabetic nephropathy, the mechanism remains unclear. The NLRP3 inflammasome acts as both a sensor and a regulator of the inflammatory response. The NLRP3 inflammasome responds to exogenous and endogenous danger signals, resulting in cleavage of procaspase-1 and activation of cytokines IL-1β, IL-18, and IL-33, ultimately triggering an inflammatory cascade reaction. This study observed the expression of NLRP3 inflammasome signaling stimulated by high glucose, lipopolysaccharide, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine in glomerular mesangial cells, aiming to elucidate the mechanism by which the NLRP3 inflammasome signaling pathway may contribute to diabetic nephropathy. We found that the expression of thioredoxin-interacting protein (TXNIP), NLRP3, and IL-1βwas observed by immunohistochemistry in vivo. Simultaneously, the mRNA and protein levels of TXNIP, NLRP3, procaspase-1, and IL-1βwere significantly induced by high glucose concentration and lipopolysaccharide in a dose-dependent and time-dependent manner in vitro. This induction by both high glucose and lipopolysaccharide was significantly inhibited by N-acetyl-L-cysteine. Our results firstly reveal that high glucose and lipopolysaccharide activate ROS/TXNIP/ NLRP3/IL-1βinflammasome signaling in glomerular mesangial cells, suggesting a mechanism by which inflammation may contribute to the development of diabetic nephropathy.


2017 ◽  
Vol 312 (6) ◽  
pp. F1090-F1100 ◽  
Author(s):  
Peiwen Wu ◽  
Yuezhong Ren ◽  
Yuhong Ma ◽  
Yanxia Wang ◽  
Hui Jiang ◽  
...  

Collagen IV (Col IV) is a major component of expanded glomerular extracellular matrix in diabetic nephropathy and Smad1 is a key molecule regulating Col IV expression in mesangial cells (MCs). The present study was conducted to determine if Smad1 pathway and Col IV protein abundance were regulated by store-operated Ca2+ entry (SOCE). In cultured human MCs, pharmacological inhibition of SOCE significantly increased the total amount of Smad1 protein. Activation of SOCE blunted high-glucose-increased Smad1 protein content. Treatment of human MCs with ANG II at 1 µM for 15 min, high glucose for 3 days, or TGF-β1 at 5 ng/ml for 30 min increased the level of phosphorylated Smad1. However, the phosphorylation of Smad1 by those stimuli was significantly attenuated by activation of SOCE. Knocking down Smad1 reduced, but expressing Smad1 increased, the amount of Col IV protein. Furthermore, activation of SOCE significantly attenuated high-glucose-induced Col IV protein production, and blockade of SOCE substantially increased the abundance of Col IV. To further verify those in vitro findings, we downregulated SOCE specifically in MCs in mice using small-interfering RNA (siRNA) against Orai1 (the channel protein mediating SOCE) delivered by the targeted nanoparticle delivery system. Immunohistochemical examinations showed that expression of both Smad1 and Col IV proteins was significantly greater in the glomeruli with positively transfected Orai1 siRNA compared with the glomeruli from the mice without Orai1 siRNA treatment. Taken together, our results indicate that SOCE negatively regulates the Smad1 signaling pathway and inhibits Col IV protein production in MCs.


2019 ◽  
Vol 33 (8) ◽  
pp. 9279-9290 ◽  
Author(s):  
Qi‐Jin Zhu ◽  
Mei Zhu ◽  
Xing‐Xin Xu ◽  
Xiao‐Ming Meng ◽  
Yong‐Gui Wu

2017 ◽  
Vol 45 (07) ◽  
pp. 1441-1457 ◽  
Author(s):  
Lin An ◽  
Mei Zhou ◽  
Faiz M. M. T. Marikar ◽  
Xue-Wen Hu ◽  
Qiu-Yun Miao ◽  
...  

Diabetic nephropathy (DN) is a common cause of chronic kidney disease and end-stage renal disease, which can be triggered by oxidative stress. In this study, we investigated the renoprotective effect of the ethyl acetate extract of Salvia miltiorrhiza (EASM) on DN and examined the underlying molecular mechanism. We observed that EASM treatment attenuated metabolic abnormalities associated with hyperglycemic conditions in the experimental DN model. In streptozotocin (STZ)-induced mice, EASM treatment reduced albuminuria, improved renal function and alleviated the pathological alterations within the glomerulus. To mimic the hyperglycemic conditions in DN patients, we used high glucose (25[Formula: see text]mmol/L) media to stimulate mouse mesangial cells (MMCs), and EASM inhibited high glucose-induced reactive oxygen species. We also observed that EASM enhanced the expression of nuclear factor erythroid-2-related factor 2 (Nrf2), which mediated the anti-oxidant response, and its downstream gene heme oxygenase-1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1) with concomitant decrease of expression of kelch-like ECH-associated protein 1 (keap1) both in vitro and in vivo. Taken together, these results suggest that EASM alleviates the progression of DN and this might be associated with activation of Nrf2.


Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2000
Author(s):  
Mingyeong Kim ◽  
Chiheung Cho ◽  
Changjun Lee ◽  
Bomi Ryu ◽  
Sera Kim ◽  
...  

Advanced glycation end-products (AGEs) such as methylglyoxal (MGO) play a vital role in the pathogenesis of nephropathy, a diabetic complication. In the present study, we evaluated the anti-glycation and renal protective properties of Ishige okamurae extract (IOE) against AGE-induced oxidative stress. HPLC analysis confirmed that bioactive phlorotannins such as diphlorethohydroxycarmalol and ishophloroglucin A are predominantly present in IOE. IOE showed strong anti-glycation activities via inhibition of AGE formation, inhibition of AGE–protein cross-linking, and breaking of AGE–protein cross-links. In addition, in vitro studies using mesangial cells demonstrated that IOE effectively suppressed intracellular reactive oxygen species production, intracellular MGO accumulation, and apoptotic cell death by MGO-induced oxidative stress, in addition to regulating the expression of proteins involved in the receptor for AGEs and nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response elements (ARE) signaling pathways. Therefore, IOE can serve as a natural therapeutic agent for the management of AGE-related nephropathy.


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