Antioxidant status in haemoglobin E carriers after acute and chronic strenuous exercises.

Haemoglobin E (HbE), an unstable haemoglobin, is highly susceptible to oxidative damages. We examined how acute or chronic physiological challenge induced by exercise affects antioxidant response in HbE carriers. Two independent studies were conducted in individuals with HbE trait and paired normal Hb. In study 1, sedentary participants were tested in a graded maximal exercise and blood samples were collected before, immediately after, and 45 minutes after an acute exercise. Our data showed that erythrocyte glutathione peroxidase (GPx) activity failed to recover in HbE carriers after 45 minutes of rest. In study 2, athletes were trained in a 10-week strenuous training and blood samples were collected before and after training period. We found that athletes with HbE carriers showed a larger increase in plasma GPx activity compared to those with normal Hb. These data suggest that HbE carriers could cope with exercise-induced oxidative stress by adjusting endogenous antioxidant markers.

Anti-oxidant activity of holo- and apo-c-phycocyanin and their protective effects on human erythrocytes.

This study was conducted to investigate the anti-oxidant activity of the recombinant apo-c-phycocyanin (c-PC) ß-subunit compared to native c-PC purified from Spirulina sp. The gene encoding the ß-subunit of c-PC was successfully cloned and expressed in Escherichia coli. The anti-oxidant capacities of recombinant apo-c-PC(ß) and native c-PC were evaluated by measuring their Trolox equivalent antioxidant capacities and examining their protective effects on erythrocytes from normal and homozygous haemoglobin E individuals against peroxyl radicals and hydrogen peroxide. The results demonstrated that the anti-oxidant capacities are native c-PC≫Trolox>recombinant apo-c-PC(ß). Both anti-oxidant proteins can potentially protect erythrocytes from oxidative damage. Expression of c-PC in bacteria reduces the cost and time for protein production, and the recombinant protein could be further developed to obtain a more efficient protein for therapeutic purposes.

Red cell and platelet-derived microparticles are increased in G6PD-deficient subjects.

In response to oxidative stress and during apoptosis, cells often shed microparticles (MPs), submicron elements carrying phosphatidylserine and protein antigens. Glucose-6-phosphate dehydrogenase (G6PD)-deficient cells are extremely sensitive to oxidative damage that may lead to the formation of MPs. To determine whether G6PD deficiency alters membrane phospholipid asymmetry and increases MPs production, we determined the concentrations and cellular origins of MPs in G6PD-deficient individuals using flow cytometry. G6PD-deficient individuals showed an increase in circulating MPs concentrations as compared with G6PD-normal individuals [1051/µL (865-2532/µL) vs. 258/µL (235-575/µL), P < 0.01]. MPs concentrations were significantly increased with the severity of G6PD deficiency. Median MPs concentrations from individuals with severe G6PD deficiency, and individuals with moderate G6PD deficiency were 2567/µL (1216-2532/µL) and 984/µL (685-2107/µL), respectively (P < 0.01). Importantly, G6PD enzymatic activity was significantly correlated with MPs concentrations with r(2) = 0.731. MPs found in G6PD deficiency individuals were largely derived from red blood cells (RBCs) (45%) and platelets (30%). Additionally, Atomic Force Microscopy was used to study the morphology and measures the diameter of MPs found in G6PD-deficient individuals. The mean (SD) width and height of RMPs were 0. 41 (0.18) and 2.04 (0.14) µm, respectively. Together, these results indicate that MP concentration is significantly correlated with G6PD enzymatic activity and is increased in G6PD-deficient as compared with G6PD-normal individuals. Our data also provide an evidence for an alteration in cell membrane associated with a decreased in G6PD activity. However, the significance of MPs in G6PD deficiency needs further clarification.

Multilayer film assembled from charged derivatives of chitosan: physical characteristics and biological responses.

Polyelectrolyte multilayer films were successfully assembled from each of the three charged derivatives of chitosan; N-[(2-hydroxyl-3-trimethylammonium)propyl]chitosan chloride (HTACC), N-succinyl chitosan (SCC) and N-sulfofurfuryl chitosan (SFC), paired with one of the two oppositely charged polyelectrolytes, poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH) on surface-treated poly(ethylene terephthalate) (treated PET) substrates by alternate layer-by-layer adsorption. Surface coverage and wettability of the multilayer films were determined by AFM and water contact angle measurements, respectively. Analysis by quartz crystal balance with dissipation (QCM-D) has suggested that all multilayer films are relatively rigid and have a high water content associated within their structures, accounting for up to 85-90% (w/w) for films having 7-10 layers. In vitro cytocompatibility tests for the fibroblast-like L929 cell line revealed a slight dependency for cell adhesion and proliferation on the outermost layer. The multilayer film containing HTACC exhibited moderate antibacterial activity against E. coli and S. aureus. Bearing negative charges, the multilayer films terminating with SFC and having at least 10 layers were capable of suppressing the adsorption of plasma proteins and platelet adhesion at a comparable level to the multilayer film assembled from heparin, a well-known antithrombogenic polymer.

Effects of tai chi training on antioxidant capacity in pre- and postmenopausal women.

The risk of oxidative stress-related metabolic diseases increases with menopause and physical inactivity. We hypothesized that an 8-week Tai Chi (TC) training program (2 sessions in class; 2 sessions at home; 1-1:15/session) would improve antioxidant capacity and reduce cardiovascular risks in both pre- (n = 8) and postmenopausal (n = 7) sedentary women. Selected measures of physical fitness and blood parameters were analyzed before and after the program. Besides the well-known effects of TC on balance, flexibility, and maximum leg extensor strength, TC (1) increased erythrocyte glutathione peroxidase activity-an aerobic training-responsive antioxidant enzyme-and plasma total antioxidant status and (2) decreased plasma total homocysteine, a cardiovascular risk marker. In addition to being a low-velocity, low-impact, and relatively safe, TC is a suitable physical activity design for pre- and postmenopausal women to increase antioxidant defenses. Investigating breathing effects during TC movements would be an interesting area for further research in diseases prevention.

Genotoxic monitoring and benzene exposure assessment of gasoline station workers in metropolitan Bangkok: sister chromatid exchange (SCE) and urinary trans, trans-muconic acid (t,t-MA).

Early warning of the potential of mutagens or carcinogens caused by benzene exposure that might occur in gasoline station workers can be achieved by examining 2 major biomarkers: sister chromatid exchange (SCE) and trans, trans-muconic acid (t,t-MA), a urinary metabolite of benzene. The main objective of this study was to assess benzene exposure and monitor the genotoxic effect of gasoline station workers in Bangkok, Thailand. Blood and urine samples were collected from 33 gasoline station workers, working in Pathumwan district area, central Bangkok, Thailand, for SCE and t,t-MA analysis, from April to June 2009. Control samples were collected from 30 office workers and students in the same area at the same period. Our results indicated significantly higher frequencies of SCE in gasoline exposed workers were than in controls (p<0.01), independent of gender. Urinary t,t-MA and t,t-MA/creatinine levels of gasoline exposed workers were also significantly higher than the control groups (p<0.05) were significantly higher in women than men workers (p<0.01). Calculated chromosomal damage relative risk (RR) of gasoline station workers was 3.00 (95% CI = 1.81 - 4.98, p<0.001) compared to controls. The gasoline exposed workers had potentially higher risk of chromosomal damage and cancer development because of direct contact to benzene.

Analysis of green pit viper (Trimeresurus alborabris) venom protein by LC/MS-MS.

Green pit viper venom has major effect on the hematological system having a thrombin-like effect. Thus, this study is designed to analyze the composition of Trimeresurus albolabris venom by performing gel filtration and LC/MS-MS. The purified protein was then digested by trypsin, and the tryptic fragments were analyzed by iontrap spectrophotometry. This study found four types of proteins, namely jerdonitin, stejaggregin-A beta chain-1, stejnobin, and stejnihagin-A, as the components of T. albolabris venom. All of these toxins played a greater or lesser role in clot formation or otherwise contributed to cross-reactions in antivenom production.

A correlative study on red blood cell parameters and urine trans, trans-muconic acid in subjects with occupational benzene exposure.

Benzene is of particular concern because of recent research indicating that benzene exposure can result in toxicity. The hematotoxic effect of benzene is mentioned. However, there is little knowledge about the correlation between the biomarker of benzene exposure and changes in red blood cell parameters. Here, the correlation between the urine trans, trans-muconic acid (ttMA) level and red blood cell parameters were studied in 30 Thai subjects at risk. The regression analysis shows no significant correlation between urine ttMA and any studied red cell parameters (Hb, MCV or MCH). Based on our hematologic data, we proposed that only investigation for the urine ttMA might be not sufficient in detection of alteration in red blood cell parameters in the exposed population. Combinations between biomarker and hematological test are recommended.

High sister chromatid exchange among a sample of traffic policemen in Bangkok, Thailand.

There are several volatile substances from the traffic, including benzene, toluene, carbon monoxide, lead and formaldehyde. Most of these substances are considered carcinogens. Police are at occupational risk for toxic fume exposure. This study compared sister chromatid exchange (SCE), a marker for genotoxicity, among a sample of Thai traffic policemen in Bangkok with healthy control subjects. Thirty police officers (all male) and 20 controls were included in this study. The average (mean+/-SD) SCE for policemen and controls were 4.40+/-0.93/cell and 0.24+/-0.12/cell, respectively. A significantly higher SCE among the policemen was observed. Concern for and prevention of toxic substance exposure in traffic police officers should be made a national goal.

Detection of Cryptococcus neoformans in bird excreta.

We evaluated 14 samples of bird excreta from pigeons, parrots, open billed storks and crows obtained from thirteen places in Bangkok and nearby areas between April and July 2004. These bird excreta were examined for Cryptococcus neoformans by direct plating method to inspect their ability to grow at 37 degrees C. Capsule production was examined by Indian ink preparation. They were also tested for urease and phenoloxidase enzymes. Cryptococcus neoformans var neoformans was recovered from pigeon excreta in 9.09%. This implies those having impaired immunity may get this fungus from the environment.

White blood cell sister chromatid exchange among a sample of Thai subjects exposed to toluene, an observation.

There is a particular concern with toluene because some research has indicated that toluene exposure could result in chronic toxicity including mutagenesis and carcinogenesis. This study aimed to determine the rate of sister chromatid exchanges (SCE), a marker for genotoxicity, and its correlation to the classical urine biomarker for toluene exposure, urine hippuric acid, among a sample of Thai exposed subjects. A total of 26 police (all males) were included in this study. The average (mean +/- SD) urine hippuric acid level in these police was 0.8 +/- 0.4 mg/g creatinine. The average (mean +/- SD) SCE level in these police was 4.5 +/- 1.0/cell. The average SCE among the police with high urine hippuric acid levels was non-significantly higher than the average SCE level of those without (P = 0.41). This implies that the cytogenetic response to toluene was not different between the subjects with and without high toluene exposure. High exposure to toluene seems not to be related to high SCE.

The effect of green pit viper (Trimeresurus albolabris) venom on platelet morphology by electron microscopy.

The incidence of venomous snake bites increases every year in Thailand, especially due to green pit viper. After the bite, there is bleeding due to thrombin-like property of the venom. The mean platelet volume has been reported to be decreased in those who have been bitten by this snake. In this study we investigate the effect of green pit viper venom (Trimeresurus albolabris) on platelet volume (MPV), number and morphology of platelets in vitro. The test was carried out by washing platelets in phosphate buffer at pH 7.2 to remove fibrinogen, then the washed platelets were mixed with green pit viper venom. Platelet morphology was examined by scanning electron microscope (SEM). The morphology of platelets was smaller than normal which ranges from 1.1- 1.2 microm. Green pit viper venom can directly effect platelet morphology, decreasing platelet volume.

Preliminary study of the effect of vitamin E supplementation on the antioxidant status of hemoglobin-E carriers.

The antioxidant status of hemoglobin-E carriers was studied pre- and post-treatment with vitamin E for 3 months. Fourteen hemoglobin-E carriers (age = 21.36 +/- 1.08 years, BMI = 18.32 +/- 1.22 kg/m2) were treated with vitamin E 200 I.U. daily for 3 months. Fasting blood samples were collected and analyzed for erythrocyte superoxide dismutase activity, total antioxidant activity, hemoglobin concentration, hematocrit, MCV, Heinz body formation and osmotic fragility test. The blood parameters before and after vitamin E treatment were compared. The results showed that superoxide dismutase activity in the erythrocytes was significantly decreased, while total antioxidant activity in plasma, and the osmotic fragility of the erythrocytes, was significantly increased after vitamin E supplementation. However, hematocrit, MCV, and Heinz body formation did not change significantly. This demonstrated that vitamin E 200 IU could be used as a lipophilic antioxidant in red blood cells and could help increase the level of antioxidant in hemoglobin-E carriers.

Cancer risk for Thai traffic police exposed to traffic benzene vapor.

Benzene exposure is of particular concern because recent research indicates that it can result in chronic toxicity, with an elevated risk of carcinogenesis. Exposure to benzene from automobile exhaust can be an important occupational problem for police. The present study was conducted to estimate risk of Thai traffic police developing cancer due to contact with traffic benzene vapor during daily work. According to the data obtained, the estimated predicted cancer incidence for traffic police is 0.05 case per 70-year period, simply translated as 1.8 cancer cases per 100,000 traffic police per year. This is clearly a cause of concern and annual check up and monitoring for benzene exposure among traffic police should be set up as part of a program for primary prevention of occupation -- related cancer.

Monitoring of urine trans, trans-muconic acid level among smokers and non-smokers.

Smoking has contributed to various neurological, cardiovascular, and pulmonary diseases. According to carcinogens found in cigarette smog, benzene is one of the important carcinogenic compounds. The urinary trans, trans-muconic acid (ttMA) levels among a sample of 10 Thai smokers and 35 Thai non-smokers were investigated, compared and reported. The average urinary ttMA level in smokers and non-smokers were 2.19 +/- 2.32 and 0.24 +/- 0.33 mg/gCr, respectively. A significant higher urinary ttMA level among the smokers was observed (P < 0.05). Since the higher urinary ttMA indicates the higher occult risk for cancer, the usage of urinary ttMA is recommended as a monitoring tool to follow up benzene exposure in the smokers.

Inhibition of Heinz body induction in an in vitro model and total antioxidant activity of medicinal Thai plants.

Herbs have been used for medicinal purposes for centuries and known to possess antioxidant properties that may help to reduce the risk of chronic diseases, cardiovascular disease, and cancer. We screen aqueous extracts from 20 medicinal plants in Thailand that were believed to possess anti-tumor activity, help immune-stimulating property and maintain blood stasis. The antioxidant activities were investigated in two bioassays. Firstly, we demonstrated inhibition of Heinz bodies induction caused by oxidants under in vitro condition. The percentages of Heinz body inhibition activity in plant extracts from Terminalia citrina, Cassia timoriensis, and Derris elliptica were the highest followed by Anamirta cocculus, and Oroxylum indicum respectively. In addition, we investigated total antioxidant activity in plant extracts by improved ABTS radical cation decolorization assay. The total antioxidant activity of the extract from Terminalia citrina was also the highest activity followed by Ficus pubigera, Derris elliptica, Anamirta cocculus, Caesalpinia sappan, and Oroxylum indicum respectively. Our results suggest medicinal Thai plants as valuable sources of antioxidants, which may have a potential anti-carcinogenic activity.

Feasibility of using papaya skin extract for digestion of swamp eel viscera for harvesting infective stage larva of Gnathostoma spp.

In this study, we reported the feasibility of using papaya skin extract (Carica papaya L.) as an alternative to enzyme pepsin in harvesting Gnathostoma spinigerum third-stage larvae. From experimental digestion, we found that the different numbers of recovered larvae between papaya skin extract and pepsin were not statistically significant (p >0.05). When the derived larvae from pepsin and papaya skin extract digestion were cultivated in BME medium for 7 days, the survival rates were not significantly different either (p >0.05). Thus, papaya skin extract might be another choice for recovering Gnathostoma spinigerum third-stage larvae.