AMPK-mediated autophagy is involved in the protective effect of canagliflozin in the vitamin D3 plus nicotine calcification model in rats

Vascular calcification (VC) is a major risk factor for cardiovascular events. A mutual interplay between inflammation, oxidative stress, apoptosis, and autophagy is implicated in its development. Herein, we aimed to evaluate the potential protective effects of canagliflozin in a vitamin D3 plus nicotine (VDN) model of VC, and to explore potential mechanisms. VC was induced by VDN in adult male Wistar rats on day one. Then, rats were randomly assigned into three groups to receive canagliflozin (10 mg or 20 mg/kg/day) or its vehicle for 4 weeks. Age-matched normal rats served as a control group. After euthanization, aorta and kidneys were harvested for biochemical and histopathological evaluation of calcification. Aortic markers of oxidative stress, alkaline phosphatase (ALP) activity, runt-related transcription factor (Runx2) and bone morphogenic protein-2 (BMP-2) levels were determined. Additionally, the protein expression of autophagic markers, LC3 and p62, and adenosine monophosphate activated protein kinase (AMPK) were also assessed in aortic homogenates. Canagliflozin dose-dependently improved renal function, enhanced the antioxidant capacity of aortic tissues and reduced calcium deposition in rat aortas and kidneys. Both doses of canagliflozin attenuated ALP and osteogenic markers while augmented the expression of autophagic markers and AMPK. Histopathological examination of aortas and kidneys by H&E and Von Kossa stain further support the beneficial effect of canagliflozin. Canagliflozin could alleviate VDN-induced vascular calcification, in a dose dependent manner, via its antioxidant effect and modulation of autophagy. Further studies are needed to verify whether this effect is a member or a class effect.

Resveratrol protects against Schistosoma mansoni-induced liver fibrosis by targeting the Sirt-1/NF-κB axis

Hepatic schistosomiasis is a prevalent form of chronic liver disease that drastically affects human health. Nevertheless, an antifibrotic drug that could suppress the development of hepatic fibrosis does not exist yet. The current study aimed to evaluate the effect of resveratrol, a natural polyphenol with multiple biological activities, on Schistosoma mansoni (S. mansoni)-induced hepatic fibrosis and delineate the underlying molecular mechanism. Swiss male albino mice were randomly assigned into infected and non-infected groups. Hepatic schistosomiasis infection was induced via exposure to S. mansoni cercariae. 6 weeks later, resveratrol was administrated either as 20 mg/kg/day or 100 mg/kg/day for 4 weeks to two infected groups. Another group received vehicle and served as infected control group. At the end of the study, portal hemodynamic, biochemical, and histopathological evaluation of liver tissues were conducted. Remarkably, resveratrol significantly reduced portal pressure, portal and mesenteric flow in a dose-dependent manner. It improved several key features of hepatic injury as evidenced biochemically by a significant reduction of bilirubin and liver enzymes, and histologically by amelioration of the granulomatous and inflammatory reactions. In line, resveratrol reduced the expression of pro-inflammatory markers; TNF-α, IL-1β and MCP-1 mRNA, together with fibrotic markers; collagen-1, TGF-β1 and α-SMA. Moreover, resveratrol restored SIRT1/NF-κB balance in hepatic tissues which is the main switch-off control for all the fibrotic and inflammatory mechanisms. Taken together, it can be inferred that resveratrol possesses a possible anti-fibrotic effect that can halt the progression of hepatic schistosomiasis via targeting SIRT1/ NF-κB signaling.

Sodium valproate, a histone deacetylase inhibitor, with praziquantel ameliorates Schistosoma mansoni-induced liver fibrosis in mice

AIMS

This study explores the potential antifibrotic effect of sodium valproate (SV), an inhibitor of class I histone deacetylase (HDAC) enzymes, and/or praziquantel (PZQ) on Schistosoma mansoni (S. mansoni)-induced liver fibrosis in mice.

MAIN METHODS

Male Swiss albino mice were divided into nine groups: group I- normal control (NC); group II- uninfected gum mucilage (GM) treated; group III- uninfected PZQ- treated; group IV- uninfected SV-treated; group V- control S. mansoni infected mice; group VI- infected GM-treated; group VII- infected PZQ-treated; group VIII- infected SV-treated; group IX- infected PZQ+SV treated. All SV administrations were 300mg/kg/day orally and administered for five weeks beginning on the 5th week post infection (WPI). All PZQ administrations were 500mg/kg/day orally and administered for 2 consecutive days beginning on the 7th WPI. Serum transforming growth factor-beta 1 (TGF-β1), tumor necrosis factor-alpha (TNF-α), hepatic hydroxyproline (Hyp) content, and liver function tests (AST and ALT) were determined. Specimens of the hepatic tissues were examined histologically.

KEY FINDINGS

Treatment of S. mansoni-infected mice with SV significantly decreased the serum levels of ALT, TGF-β1 and TNF-α, and the liver tissue hydroxyproline content compared with the S. mansoni infected untreated groups. Histologically, treatment with SV revealed regression of the granulomatous inflammatory reaction. Combined treatment with PZQ and SV produces more favorable biochemical results, and aborted granulomatous reaction compared with either drug alone.

SIGNIFICANCE

Sodium valproate is a promising anti-fibrotic agent. It demonstrated an anti-fibrotic effect in early stages of S. mansoni infection through downregulation of profibrogenic cytokines, and collagen deposition.