ABSTRACT
Ionizing radiation causes damage to biomolecules in living cells through oxidative stress by excessive generation of reactive oxygen species (ROS) from radiolysis of body water. Blood and its components including the cells are exposed to a significant dose of radiation during irradiation. Grapes (Vitis vinifera L.) contain several bioactive phytochemicals and are rich source of antioxidants. Therefore, we hypothesized that the grape extracts would offer protection against the ionizing radiation-induced damage of the red blood cells (RBCs). To test our hypothesis, in the current study we investigated the radio-protective actions of extract of four different grape (Vitis vinifera) cultivars, namely Flame seedless (Black grapes), Kishmish chorni (Black with reddish brown), Red globe (Red) and Thompson seedless mutant (Sonaka, Green) against the g-irradiation-induced oxidative stress leading to the structural alteration in the RBC membrane in vitro. Freshly drawn blood samples from healthy volunteers itself or mixed with grape extracts from seed, skin or pulp of each cultivar were irradiated at 4 Gy after one hour of treatment. -irradiation for one hour did not change the hematological parameters. The average osmotic fragility (H50) and the maximum rate of hemolysis (dH/dC)max increased after the -irradiation. The confocal microscopic and atomic force microscopic (AFM) studies showed that irradiation induced transformation of RBC from biconcave cells to echinocytes, altered their surface roughness and the vertical distance. The grape extracts did not alter the viability of human erythrocytes. Our results suggested that the grape extract pretreatment ameliorated the ionizing radiation-induced alterations at a dose of 4 Gy in human erythrocytes in vitro. Moreover, protection offered by the seed extract was significantly better than that that of skin or pulp of the same cultivar. Furthermore, the protective action of grape extract depends on its source (seed, skin or pulp) as well on cultivars.
ABSTRACT
The membrane integrity of circulating red blood cells (RBCs) is compromised by the deleterious actions of -radiation in humans. Tea is the most widely consumed popular, inexpensive and non-toxic beverage rich in antioxidants. Here, we explored the radioprotective actions of black tea against the -radiation-induced membrane permeability of human erythrocytes. The phytochemical analysis of tea revealed the total polyphenol content to be 114.89±6.03 mg gallic acid equivalent/g dry wt. and flavonoid content, 34±0.11 mg catechin equivalent/g dry wt. of the extractable solid in the commercially available tea bags. Tea extracts showed potential scavenging of H2O2 and NO, appreciable extent of total antioxidant capacity and effective anti-hemolytic action. Tea extracts (15 µg/mL) significantly ameliorated the -radiation-induced increase of the levels of thiobarbituric acid-reactive substances (TBARS, an index of lipid peroxidation) in the RBC membrane ghosts. Stored blood showed higher levels of K+ ion as compared to the normal blood which was elevated by -radiation. Membrane ATPase was inhibited by the exposure to -radiation. Treatment of RBCs with the tea extracts (15 µg/ml) prior to the exposure of -radiation significantly mitigated these changes in the erythrocyte membranes caused by the lower dose of radiation (4 Gy) as compared to that induced by the higher dose of -radiation.
ABSTRACT
Chronic renal failure (CRF) induces anaemia by shortening the life-span of erythrocytes, due to an increase in oxidative stress, which is considered to be one of the major risk factors in CRF patients undergoing hemodialysis. In the present study, the antioxidant status of the end-staged renal disease (ESRD) patients was investigated. The antihemolytic activity of Boerhaavia diffusa on the erythrocytes of the patients was also studied. Protein, lipid peroxides (LPO), reduced glutathione (GSH) levels and glutathione peroxidase (GPX) and glutathione-S-transferase (GST) activities were measured in the hemolysate from 55 polycystic ESRD patients (Group II) and compared with normal subjects (Group I). The antioxidant status was found to be significantly reduced in the patients as compared to normal healthy volunteers, due to increased oxidative stress. Also, aqueous extract of B. diffusa showed a significant antihemolytic activity on the erythrocytes of the polycystic ESRD patients.