BAY 11-7082 ameliorates diabetic nephropathy by attenuating hyperglycemia-mediated oxidative stress and renal inflammation via NF-κB pathway.

Diabetic nephropathy is a serious microvascular complication for patients associated with diabetes mellitus. Recent studies have suggested that NF-κB is the main transcription factor for the inflammatory response mediated progression of diabetic nephropathy. Hence, the present study is hypothesized to explore the renoprotective nature of BAY 11-7082 an IκB phosphorylation inhibitor on Streptozotocin (STZ) induced diabetic nephropathy in Sprague-Dawley (SD) rats. Male SD rats were divided into five groups, group I sham control, group II drug control, group III diabetic control (STZ 50mg/kg), group IV and V are test drug groups to which a single dose of STZ 50mg/kg was injected initially and later received BAY 11-7082 1mg/kg and 3mg/kg, respectively from 5th to 8th week. Eight weeks after STZ injection, diabetic rats exhibited significant renal dysfunction, as evidenced by reduced creatinine clearance, increased blood glucose, urea nitrogen and creatinine, which were reversed to near normal by BAY 11-7082. BAY 11-7082 treated rats showed significant improvement in the decreased enzymatic antioxidant SOD, non-enzymatic antioxidant GSH levels, and elevated lipid peroxidation and nitric oxide levels as observed in the diabetic rats. BAY 11-7082 treatment was found to significantly recover kidney histological architecture in the diabetic rats. Altered levels of inflammatory cytokines like TNF-α, IL-1β, IL-6 and nuclear transcriptional factor subunit NF-κB p65 were reverted to the normal level upon treatment with BAY 11-7082. Our results suggest that by limiting the activation of NF-κB, thereby reducing the expression of inflammatory cytokines and by inhibiting the oxidative damage BAY 11-7082 protect the rats against diabetic nephropathy.

Kolati SR ，Kasala ER ，Bodduluru LN ，Mahareddy JR ，Uppulapu SK ，Gogoi R ，Barua CC ，Lahkar M ... -  《-》

Suppression of NF-κB and NF-κB regulated oxidative stress and neuroinflammation by BAY 11-7082 (IκB phosphorylation inhibitor) in experimental diabetic neuropathy.

Inflammation is an emerging patho-mechanism of diabetes and its complications. NF-κB pathway is one of the central machinery initiating and propagating inflammatory responses. The present study envisaged the involvement of NF-κB inflammatory cascade in the pathophysiology of diabetic neuropathy using BAY 11-7082, an IκB phosphorylation inhibitor. Streptozotocin was used to induce diabetes in Sprauge Dawley rats. BAY 11-7082 (1 & 3 mg/kg) was administered to diabetic rats for 14 days starting from the end of six weeks post diabetic induction. Diabetic rats developed deficits in nerve functions and altered nociceptive parameters and also showed elevated expression of NF-κB (p65), IκB and p-IκB along with increased levels of IL-6 & TNF-α and inducible enzymes (COX-2 and iNOS). Furthermore, there was an increase in oxidative stress and decrease in Nrf2/HO-1 expression. We observed that BAY 11-7082 alleviated abnormal sensory responses and deficits in nerve functions. BAY 11-7082 also ameliorated the increase in expression of NF-κB, IκB and p-IκB. BAY 11-7082 curbed down the levels of IL-6, TNF-α, COX-2 and iNOS in the sciatic nerve. Lowering of lipid peroxidation and improvement in GSH levels was also seen along with increased expression of Nrf2/HO-1. Thus it can be concluded that NF-κB expression and downstream expression of proinflammatory mediators are prominent features of nerve damage leading to inflammation and oxidative stress and BAY 11-7082 was able to ameliorate experimental diabetic neuropathy by modulating neuroinflammation and improving antioxidant defence.

Kumar A ，Negi G ，Sharma SS 《-》

Andrographolide ameliorates diabetic nephropathy by attenuating hyperglycemia-mediated renal oxidative stress and inflammation via Akt/NF-κB pathway.

Diabetic nephropathy (DN) is characterized by proliferation of mesangial cells, mesangial hypertrophy and extracellular matrix (ECM) accumulation. Our recent study found that andrographolide inhibited high glucose-induced mesangial cell proliferation and fibronectin expression through inhibition of AP-1 pathway. However, whether andrographolide has reno-protective roles in DN has not been fully elucidated. Here, we studied the pharmacological effects of andrographolide against the progression of DN and high glucose-induced mesangial dysfunction. Diabetes was induced in C57BL/6 mice by intraperitoneal injection of streptozotocin (STZ). After 1 weeks after STZ injection, normal diet was substituted with a high-fat diet (HFD). Diabetic mice were intraperitoneal injected with andrographolide (2 mg/kg, twice a week). After 8 weeks, functional and histological analyses were carried out. Parallel experiments uncovering the molecular mechanism by which andrographolide prevents from DN was performed in mesangial cells. Andrographolide inhibited the increases in fasting blood glucose, triglyceride, kidney/body weight ratio, blood urea nitrogen, serum creatinine and 24-h albuminuria in diabetic mice. Andrographolide also prevented renal hypertrophy and ECM accumulation. Furthermore, andrographolide markedly attenuated NOX1 expression, ROS production and pro-inflammatory cytokines as well. Additionally, andrographolide inhibited Akt/NF-κB signaling pathway. These results demonstrate that andrographolide is protective against the progression of experimental DN by inhibiting renal oxidative stress, inflammation and fibrosis.

Ji X ，Li C ，Ou Y ，Li N ，Yuan K ，Yang G ，Chen X ，Yang Z ，Liu B ，Cheung WW ，Wang L ，Huang R ，Lan T ... -  《-》

Danshen injection ameliorates STZ-induced diabetic nephropathy in association with suppression of oxidative stress, pro-inflammatory factors and fibrosis.

Diabetic nephropathy (DN) is one of the most frequent complications in diabetes mellitus. This study aimed to explore whether Danshen injection is protective to renal tissue in diabetes. Intraperitoneal injection of streptozotocin (STZ) (60mg/kg) was used to induce diabetes in rats. Some STZ-induced diabetic rats were also intraperitoneally injected with Danshen solution at two different dosages (0.5 or 1ml/kg/day) for 6weeks. Our results showed that serum creatinine (sCr) and blood urea nitrogen were significantly increased in STZ-induced diabetic rats, which was alleviated upon Danshen injection. Danshen injection was also found to ameliorate hypertrophy and dilatation of renal tubule and glomeruli possibly by decreasing the expression of collagen and fibronectin in association with suppression of TGF-β1/Smad pathway. Further investigation revealed that Danshen injection could increase the activity of superoxide dismutase (SOD), and reduce reactive oxygen species (ROS) and malondialdehyde (MDA) levels in STZ-induced diabetic rats, indicating suppression of oxidative stress. In addition, we also found that Danshen injection could suppress IκB/NF-κB signaling pathway and reduce the level of a number of pro-inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in the diabetic renal tissue, indicating suppression of inflammation. In conclusion, our results demonstrated that Danshen injection may rescue STZ-induced diabetic nephropathy, possibly via suppressing the oxidative stress, inflammatory responses and fibrosis progression.

Xu L ，Shen P ，Bi Y ，Chen J ，Xiao Z ，Zhang X ，Wang Z ... -  《-》

Ellagic acid, an NF-κB inhibitor, ameliorates renal function in experimental diabetic nephropathy.

Diabetic nephropathy (DN) is a serious complication confronted by diabetic patients. Available data indicate that the development of DN is linked to inflammation. In this context, nuclear factor-kappa B (NF-κB) has received much attention. Ellagic acid (2,3,7,8-tetrahydroxy-chromeno[5,4,3-cde]chromene-5,10-dione), found abundantly in plant extracts and fruits, possesses numerous medicinal properties. We investigated the nephroprotective effects of oral treatment of ellagic acid in high fat diet/low dose streptozotocin (HFD/STZ)-induced type 2 diabetic Wistar albino rats. Ellagic acid treatment for 16weeks post induction of diabetes significantly attenuated renal dysfunction and oxidative stress. Ellagic acid significantly inhibited the renal NF-кB activation. Moreover, ellagic acid significantly lowered renal pathology and suppressed transforming growth factor-beta (TGF-β) and fibronectin expressions in renal tissues. Ellagic acid also significantly reduced the serum levels of pro-inflammatory cytokines, interleukin-1beta (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α). In cultured rat NRK 52E proximal tubular epithelial cells, ellagic acid treatment inhibited high glucose-induced activation of NF-κB and pro-inflammatory cytokine synthesis. These results suggest that ellagic acid exhibited renal protective effect in diabetic rats partly through antihyperglycemia which was accompanied by attenuation of inflammatory processes via inhibition of NF-κB pathway.

Ahad A ，Ganai AA ，Mujeeb M ，Siddiqui WA ... -  《-》