Vitamin K2 (MK-7) Intercepts Keap-1/Nrf-2/HO-1 Pathway and Hinders Inflammatory/Apoptotic Signaling and Liver Aging in Naturally Aging Rat.

Aging is a naturally occurring physiological process with a deleterious impact on various body organs and humans' well-being. The aging population is increasing worldwide, which imposes the need for the exploration of nutritional options that can intercept the impact of the aging processed on various body organs. Vitamin K2 (VK2) is a fat-soluble vitamin with emerging evidence on its therapeutic merits. In the current study, natural aging induced a significant liver deterioration with a disrupted Keap-1/Nrf-2/HO-1 axis and increased COX-2, iNOS and TNF-α expression and apoptotic and fibrotic changes. VK2 administration, on the other hand, improved the biochemical indices of liver function (total protein, albumin, ALT and AST); the suppressed hepatic expression of Keap-1 and increased the hepatic expression of Nrf-2 with a parallel increase in the hepatic activity of HO-1. Subsequently, the liver content and hepatic expression of TNF-α, COX-2 and iNOS were significantly retracted. In context, the liver content and hepatic expression of the fibrotic biomarkers TGFß and TIMP significantly retracted as well. Moreover, the TUNEL assay confirmed the retraction of liver apoptotic changes. Of notice, electron transmission microscope examination confirmed the preservation of mitochondrial functions and preservation of the ultra-microscopical structures. In conclusion, the VK2-mediated interception of aging-induced Keap-1/Nrf-2/HO-1 signaling suppressed the hepatic contents of inflammatory and fibrotic biomarkers, as well as apoptotic changes with preservation of the hepatic architectural and functional status. VK2 can be presumed to be an effective nutritional supplement to the aging population to spare the liver, amongst other body organs, against aging-induced deleterious injury.

Protective effect of metformin on rat diabetic retinopathy involves suppression of toll-like receptor 4/nuclear factor-k B expression and glutamate excitotoxicity.

Microvascular complications of diabetes mellitus are progressively significant reasons for mortality. Metformin (MET) is considered as the first-line therapy for type 2 diabetes patients, and may be especially beneficial in cases of diabetic retinopathy although the precise mechanisms of MET action are not fully elucidated. The current study was designed to inspect the antioxidant and modulatory actions of MET on DRET in streptozotocin-induced diabetic rats. The effect of MET on the toll-like receptor 4/nuclear factor kappa B (TLR4/NFkB), inflammatory burden and glutamate excitotoxicity was assessed. Twenty-four male rats were assigned to four experimental groups: (1) Vehicle group, (2) Diabetic control: developed diabetes by injection of streptozotocin (60 mg/kg, i.p.). (3&4) Diabetic + MET group: diabetic rats were left for 9 weeks without treatment and then received oral MET 100 and 200 mg/kg for 6 weeks. Retinal samples were utilized in biochemical, histological, immunohistochemical and electron microscopic studies. MET administration significantly decreased retinal level of insulin growth factor and significantly suppressed the diabetic induced increase of malondialdehyde, glutamate, tumor necrosis factor-α and vascular endothelial growth factor (VEGF). Further, MET decreased the retinal mRNA expression of NFkB, tumor necrosis factor-α and TLR4 in diabetic rats. The current findings shed the light on MET's efficacy as an adjuvant therapy to hinder the development of diabetic retinopathy, at least partly, via inhibition of oxidative stress-induced NFkB/TLR4 pathway and suppression of glutamate excitotoxicity.

Renoprotective effect of calycosin in high fat diet-fed/STZ injected rats: Effect on IL-33/ST2 signaling, oxidative stress and fibrosis suppression.

Type 2 diabetes mellitus (T2DM) is a disease with a drastically growing worldwide prevalence. It is usually associated with numerous complications of which; diabetic nephropathy (DN); is a main complication of microvasculature and more seriously, a common cause of end-stage renal disease (ESRD). Unfortunately, both the lack of a definitive remedy alongside the economic and the social burden on DN patients enforces considerable impetus for developing alternative therapies. IL-33 is a newly discovered member of the IL-1 cytokine family. IL33/ST2 signaling plays a crucial role in acute and chronic kidney diseases. Calycosin is an isoflavone with reported IL33 signaling inhibitory activity. The present study aimed to investigate if calycosin possess renal protective effect in high-fat diet/STZ-induced T2DM model and to clarify the potential underlying mechanisms. HFD-STZ control rats showed functional and structural renal damage confirmed by increased serum creatinine, blood urea nitrogen and albuminuria associated with marked renal glomerulosclerosis and interstitial fibrosis. Initiation of inflammation, oxidative stress, and fibrosis was evident as depicted by elevated renal levels of IL33/ST2 mRNA as well as increased renal NF-κBp65, TNF-α, IL-1ß, MDA, and TGF-ß contents with suppressed Nrf2 and TAC. Calycosin treatment markedly improved the aforementioned makers of renal injury and dysfunction, modulated IL33/ST2 signaling, inflammatory cytokines, oxidative stress and fibrotic processes. This was accompanied by improvement of T2DM-induced renal ultramicroscopic and histopathological alterations.

Sulforaphane protects against sodium valproate-induced acute liver injury.

Drug-induced hepatotoxicity is one of the most commonly encountered obstacles in the field of medical practice. Sodium valproate (VPA) is among many drugs with reported hepatotoxic effects. Sulforaphane (SFN) is a thiol compound found in wide abundance in cruciferous plants that has numerous reported therapeutic efficacies. The current investigation sheds light on the potential hepatoprotective effect of SFN against VPA-induced liver injury in rats. Twice daily VPA (700 mg/kg, i.p.) for 7 days induced significant biochemical alterations and hepatic histopathological damage. SFN (0.5 mg/kg, orally) for 7 days significantly boosted liver function biomarkers; it reduced serum alanine transaminase, aspartate aminotransferase, and alkaline phosphatase, and restored serum albumin concentration in a significant manner. Meanwhile, SFN significantly mitigated VPA-induced histopathological alterations. To highlight the mechanisms implicated in the observed hepatoprotective action, hepatic malondialdehyde and tumour necrosis factor α content significantly declined with concomitant increase in hepatic heme oxygenase-1 content and glutathione concentration with SFN treatment. In conclusion, SFN can significantly ameliorate VPA-induced hepatotoxicity and liver injury primarily by direct association between antioxidant and anti-inflammatory properties.