Vitamin E protects chondrocytes against hydrogen peroxide-induced oxidative stress in vitro

Objective and design

This study evaluated the effect of an antioxidant, Vitamin E, on cultured chondrocytes against H₂O₂-induced damage in vitro.

Material

Rat chondrocytes isolated from articular cartilage.

Treatment

Chondrocytes were pretreated with either 50 or 100 μM Vitamin E or serum-free medium for 24 h followed by their exposure to 200 μM H₂O₂ for 3 h. Chondrocytes without exposure to H₂O₂ served as control group.

Methods

The effect of Vitamin E pretreatment was evaluated by examining proteoglycan contents, nitrite levels, viability, apoptosis, and senescence of cultured chondrocytes.

Results

Proteoglycan contents increased in groups treated with Vitamin E. Semi-quantitative real-time PCR data also correlated with these results and demonstrated that Vitamin E up-regulated expression of Agc1, Col2a1, and PCNA genes along with down-regulation in the expression of Col1a1 and Casp3 genes. The differentiation index improved after Vitamin E pretreatment. Nitrite levels were reduced with a corresponding increase in cell viability. Reduction in apoptosis and senescence was also observed after Vitamin E pretreatment. Moreover, a dose-dependent effect of Vitamin E was seen. In contrast to 50 μM Vitamin E, 100 μM was more potent in inducing protection of chondrocytes from H₂O₂-induced oxidative damage.

Conclusion

Vitamin E reversed the oxidant-induced alterations in chondrocytes and may be a good option to pretreat chondrocytes before transplantation.     

The Pakistan Risk of Myocardial Infarction Study: a resource for the study of genetic, lifestyle and other determinants of myocardial infarction in South Asia

The burden of coronary heart disease (CHD) is increasing at a greater rate in South Asia than in any other region globally, but there is little direct evidence about its determinants. The Pakistan Risk of Myocardial Infarction Study (PROMIS) is an epidemiological resource to enable reliable study of genetic, lifestyle and other determinants of CHD in South Asia. By March 2009, PROMIS had recruited over 5,000 cases of first-ever confirmed acute myocardial infarction (MI) and over 5,000 matched controls aged 30–80 years. For each participant, information has been recorded on demographic factors, lifestyle, medical and family history, anthropometry, and a 12-lead electrocardiogram. A range of biological samples has been collected and stored, including DNA, plasma, serum and whole blood. During its next stage, the study aims to expand recruitment to achieve a total of about 20,000 cases and about 20,000 controls, and, in subsets of participants, to enrich the resource by collection of monocytes, establishment of lymphoblastoid cell lines, and by resurveying participants. Measurements in progress include profiling of candidate biochemical factors, assay of 45,000 variants in 2,100 candidate genes, and a genomewide association scan of over 650,000 genetic markers. We have established a large epidemiological resource for CHD in South Asia. In parallel with its further expansion and enrichment, the PROMIS resource will be systematically harvested to help identify and evaluate genetic and other determinants of MI in South Asia. Findings from this study should advance scientific understanding and inform regionally appropriate disease prevention and control strategies.     

Application of the can technique and radon gas analyzer for radon exhalation measurements

A passive “can technique” and an active radon gas analyzer with an emanation container were applied for radon exhalation rate measurements from different construction materials, viz. five marble seven ceramic and 100 granite tiles used in Saudi Arabia. The marble and ceramic tiles did not show detectable radon exhalation using the active radon gas analyzer system. However the granite tiles showed relatively high radon exhalations, indicating a relatively high uranium content. A comparison of the radon exhalation rates measured by the two techniques showed a linear correlation coefficient of 0.57. The radon exhalation rates from the granites varied from 0.02 to 6.58 Bq m⁻² h⁻¹ with an average of 1.35±1.40 Bq m⁻² h⁻¹. The geometric mean and the geometric standard deviation of the frequency distribution were found to be 0.80 and 3.1, respectively. The track density found on the nuclear track detectors in the can technique exposed to the granites, having high exhalation rates, varied linearly with exposure time with a linear correlation coefficient of 0.99. This experimental finding agrees with the theoretical prediction. The can technique showed sensitivity to low radon exhalation rates from ceramic, marble and some granite over a period of 2 months, which were not detectable by the active radon gas analyzer system. The reproducibility of data with both measuring techniques was found to be within a 7% deviation.     

Analgesic and anti-inflammatory activities of 11-O-galloylbergenin

Aims of the study

Current study was designed to explore the analgesic and anti-inflammatory effects of a constituent isolated from Mallotus philippinensis, in order to validate its folk use.

Materials and methods

11-O-galloylbergenin was isolated from ethanolic extract of Mallotus philippinensis. Analgesic and anti-inflammatory activities of the test compound were assessed using formalin test and carrageenan-induced paw edema models.

Results

11-O-galloylbergenin showed significant analgesic activity at doses of 20 and 40 mg/kg against formalin test in rats. Similarly, 11-O-galloylbergenin exhibited significant anti-inflammatory activity in carrageenan-induced paw edema model at doses of 10, 20 and 30 mg/kg.

Conclusion

11-O-galloylbergenin has demonstrated its significant potential to be further investigated for its discovery as a new lead compound for management of pain and inflammation.