Crocin protects human erythrocytes from nitrite-induced methemoglobin formation and oxidative damage

Protective effect of rutin against thiram-induced cytotoxicity and oxidative damage in human erythrocytes

Thiram is a fungicide that is used to prevent fungal diseases in seeds and crops and also as an animal repellent. The pro-oxidant activity of thiram is well established. Rutin is a flavonoid glycoside present in many fruits and plants and has several beneficial properties, including antioxidant effects. We have previously shown that thiram causes oxidative damage in human erythrocytes. The present study was designed to evaluate the protective effect of rutin against thiram-induced damage in human erythrocytes. Treatment of erythrocytes with 0.5 mM thiram for 4 h increased the level of oxidative stress markers, decreased antioxidant power and lowered the activity of antioxidant and membrane bound enzymes. It also enhanced the generation of reactive oxygen and nitrogen species (ROS and RNS) and altered the morphology of erythrocytes. However, prior treatment of erythrocytes with rutin (0.5, 1 and 2 mM) for 2 h, followed by 4 h incubation with 0.5 mM thiram, led to a decrease in the level of oxidative stress markers in a rutin concentration-dependent manner. A significant restoration in the antioxidant power and activity of antioxidant enzymes was observed upon the treatment of erythrocytes with 1 and 2 mM rutin. Pre-incubation with rutin lowered the generation of ROS and RNS which will reduce oxidative damage in erythrocytes. The thiram-induced changes in cell morphology and activity of membrane-bound enzymes were also attenuated by rutin. These results suggest that rutin can be used to mitigate thiram-induced oxidative damage in human erythrocytes.

In vitro evaluation of the protective effect of crocin on human erythrocytes

The interactions and the protective effect of the carotenoid crocin (CRO) on human erythrocytes (RBC) and molecular models of its membrane were investigated. The latter consisted of bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representative of phospholipid classes located in the outer and inner monolayers of the RBC membrane, respectively. X-ray diffraction, differential scanning calorimetry (DSC) and electronic paramagnetic resonance spectroscopy (EPR) showed that CRO produced structural perturbations in DMPC bilayers and in isolated unsealed human erythrocyte membranes. On the other hand, scanning electron microscopy (SEM) showed that CRO induced shape changes in the RBC from their normal discoid form to echinocytes. This result indicates that the CRO molecules were mainly localized in the outer monolayer of the RBC membrane. The assessment of the protective capacity of CRO was revealed by the carotenoid inhibition of the morphological alterations caused by hypochlorous acid (HOCl) to RBC.

Para-tertiary butyl catechol induces eryptosis in vitro via oxidative stress and hemoglobin leakage in human erythrocytes

Exposure of human population to industrial chemicals is believed as a significant contributing factor to the outgrowth of occupational diseases especially in developing countries due to improper safety measures and sanitary conditions. Para-tertiary butylcatechol (PTBC) widely employed in petrochemical, thermofax and phototypesetting industries, induces melanocytotoxicity and contact dermatitis leading to occupational leukoderma/vitiligo. Few vitiligo patients were reported for oxidative stress-induced hemolytic anemia and thrombocytopenia, however its impact on blood components is still not clear. Erythrocytes are the major cell population in circulation and play a prominent role in various diseases. In this work, the effect of PTBC on human erythrocytes is evaluated in vitro. PTBC induces oxidative stress-mediated eryptosis (erythrocyte death) causing detrimental changes such as depleted antioxidant levels, altered surface morphology, hemoglobin denaturation and heinz body formation. These findings validate that PTBC could induce toxic effects on human erythrocytes. Exposure of humans to toxic chemicals constitutes an important issue in various industries; one such issue is the exposure of PTBC at work place resulting in a spectrum of dermal complications. Therefore, it is imperative to appraise the long-term toxicities in order to further delineate the mechanisms of resultant disorders associated with PTBC and to establish the therapeutic interventions.

Renal protective effects of thymoquinone against sodium nitrite-induced chronic toxicity in rats: Impact on inflammation and apoptosis

AIMS

Sodium nitrite is a widely used color fixative and preservative. However, it has been reported to exert deleterious toxic effects on various body organs. Moreover, thymoquinone (TQ), the active constituent of Nigella sativa oil is known to possess beneficial antioxidant and anti-inflammatory effects. The present study was conducted to evaluate the potential protective effects of TQ against sodium nitrite-induced renal toxicity.

MAIN METHODS

Male Sprague-Dawley rats were treated with sodium nitrite (80mg/kg, po, daily) in presence or absence of TQ (25 and 50mg/kg, po, daily). Morphological changes in renal sections were assessed by staining with Hematoxylin/Eosin and Periodic acid-Schiff. Renal homogenate was used for measurement of oxidative stress markers (MDA and GSH), inflammatory markers (CRP, TNF-α, IL-6, IL-1β), anti-inflammatory cytokines (IL-10 and IL-4) and apoptotic markers (caspase-3/caspase-8/caspase-9).

KEY FINDINGS

Treatment with sodium nitrite significantly increased markers of renal dysfunction, oxidative stress, inflammation and apoptosis. These effects were markedly attenuated by TQ in dose dependent manner.

SIGNIFICANCE

TQ has a potential protective effect against sodium nitrite-induced renal toxicity. This can be attributed to its ability to dampen oxidative stress, restore the normal balance between pro- and anti-inflammatory cytokines and protect renal tissue form extrinsic and intrinsic apoptosis.