Fructose 1,6 biphosphate administration to rats prevents metabolic acidosis and oxidative stress induced by deep hypothermia and rewarming

Fructose-1,6-bisphosphate induces generation of reactive oxygen species and activation of p53-dependent cell death in human endometrial cancer cells

Fructose-1,6-bisphosphate (F1,6BP), an intermediate of the glycolytic pathway, has been found to play a promising anticancer effect; nevertheless, the mechanisms involved remain poorly understood. The present study aimed to evaluate the effect and mechanisms of F1,6BP in a human endometrial cancer cell line (Ishikawa). F1,6BP showed an antiproliferative and non-cytotoxic effect on endometrial cancer cells. These effects are related to the increase in reactive oxygen species (ROS) levels and mitochondrial membrane potential (ΔΨm). These harmful stimuli trigger the upregulation of the expression of pro-apoptotic genes (p53 and Bax), leading to the reduction of cell proliferation through inducing programmed cell death by apoptosis. Furthermore, F1,6BP-treated cells had the formation of autophagosomes induced, as well as a decrease in their proliferative capacity after withdrawing the treatment. Our results demonstrate that F1,6BP acts as an anticancer agent through the generation of mitochondrial instability, loss of cell function, and p53-dependent cell death. Thus, F1,6BP proves to be a potential molecule for use in the treatment against endometrial cancer.

A fully integrated new paradigm for lithium's mode of action - lithium utilizes latent cellular fail-safe mechanisms

It is proposed that lithium's therapeutic effects occur indirectly by augmenting a cascade of protective "fail-safe" pathways pre-configured to activate in response to a dangerous low cell [Mg⁺⁺] situation, eg, posttraumatic brain injury, alongside relative cell adenosine triphosphate depletion. Lithium activates cell protection, as it neatly mimics a lowered intracellular [Mg⁺⁺] level.

An alternative pathway through the Fenton reaction for the formation of advanced oxidation protein products, a new class of inflammatory mediators

The accumulation of advanced oxidation protein products (AOPPs) has been linked to several pathological conditions, and their levels are formed during oxidative stress as a result of reactions between plasma proteins and chlorinated oxidants produced by myeloperoxidase (MPO). However, it was suggested that the generation of this mediator of inflammation may also occur via an MPO-independent pathway. The aim of this study was to induce the formation of AOPPs in vitro through Fenton reaction and to investigate whether this generation could be counteracted by N-acetylcysteine (NAC) and fructose-1,6-bisphosphate (FBP). The complete Fenton system increased the AOPPs levels and both NAC and FBP were capable of inhibiting the formation of Fenton reaction-induced AOPPs. These data provide a new hypothesis about another pathway of AOPPs formation, as well as report that NAC and FBP may be good candidates to neutralize pro-inflammatory and pro-oxidant effects of AOPPs in several diseases.

Status of systemic oxidative stress during therapeutic hypothermia in patients with post-cardiac arrest syndrome

Therapeutic hypothermia (TH) is thought to be due to the downregulation of free radical production, although the details of this process remain unclear. Here, we investigate changes in oxidative stress and endogenous biological antioxidant potential during TH in patients with post-cardiac arrest syndrome (PCAS). Nineteen PCAS patients were enrolled in the study. Brain temperature was decreased to the target temperature of 33°C, and it was maintained for 24 h. Patients were rewarmed slowly (0.1°C/h, <1°C/day). The generation of reactive oxygen metabolites (ROMs) was evaluated in plasma samples by d-ROM test. Plasma antioxidant capacity was measured by the biological antioxidant potential (BAP) test. Levels of d-ROMs and BAP levels during the hypothermic stage (33°C) were suppressed significantly compared with pre-TH induction levels (P < 0.05), while both d-ROM and BAP levels increased with rewarming (33-36°C) and were correlated with brain temperature. Clinical monitoring of oxidative stress and antioxidant potential is useful for evaluating the redox state of patients undergoing TH after PCAS. Additional therapy to support the antioxidant potential in the rewarming stage following TH may reduce some of the observed side effects associated with the use of TH.

Fructose-1,6-bisphosphate and N-acetylcysteine attenuate the formation of advanced oxidation protein products, a new class of inflammatory mediators, in vitro

The accumulation of advanced oxidation protein products (AOPP) has been linked to several pathological conditions. Previous studies have identified AOPP as a novel biomarker of oxidative damage to proteins and a novel class of mediator of inflammation. The aim of this study was to determine the effects of fructose-1,6-bisphosphate (FBP) and N-acetylcysteine (NAC) as well as the synergistic effect of both treatments on the formation of AOPP in vitro. For this purpose, we incubated the human serum albumin (HSA) with various hypochlorous acid (HOCl) concentrations to produce albumin-advanced oxidation protein products (HSA-AOPP). Both FBP and NAC were capable of inhibiting the formation of HOCl-induced AOPP in a concentration-dependent manner. The synergistic effect promoted by the association of these drugs showed to be more effective than when tested alone. Thus, both FBP and NAC may be good candidates to mitigate and neutralize pro-inflammatory and pro-oxidant effects of AOPP in several diseases.

Nitric oxide as a mediator of fructose 1,6-bisphosphate protection in galactosamine-induced hepatotoxicity in rats

Fructose 1,6-bisphosphate (F1,6BP) has been widely used as a therapeutic agent for different harmful conditions in a variety of tissues. The hypothesis of the present work was that the increase in nitric oxide production and the prevention of oxidative stress induced by exogenous F1,6BP mediate its protective effect against the hepatotoxic action of GalN. Experimental groups used were sham, F1,6BP (2g/kg bw i.p.), GalN (0.4g/kg bw i.p), l-NAME (10mg/kg bw i.v.), F1,6BP+GalN, l-NAME+GalN and l-NAME+F1,6BP+GalN. Animals were killed after 24h of bolus administration. F1,6BP induced an increase in NO and the redox ratio (GSH/GSSG) in liver. Western blot assays pointed to overexpression of liver eNOS in F1,6BP-treated rats. The hepatic injury induced by GalN increased transaminases in plasma and decreased the reduced/oxidized glutathione ratio in liver. The concomitant administration of F1,6BP reversed this damage, while the addition of l-NAME worsened the liver injury. We provided evidence that this F1,6BP-induced protection may be related to the increase in NO production through the positive modulation of eNOS, and the increase in intracellular reduced glutathione, thus providing a higher reducing capacity.