Effect of the intake of resveratrol, resveratrol phosphate, and catechin-rich grape seed extract on markers of oxidative stress and gene expression in adult obese subjects

BACKGROUND

The preventive effect of resveratrol (RES) on the development of human diseases has been verified by numerous epidemiological studies. Resveratrol triphosphate (RTP) is a stable derivative of RES in which phosphate groups protect the phenolic groups.

AIMS

This study compared the effect of RTP on biochemical and molecular markers of oxidative stress to equimolar doses (0.66 mmol) of RES and catechin-rich grape seed extract (CGSE) in a model of oxidative and metabolic stress associated with obesity in humans.

METHODS

Thirty-two obese subjects (BMI between 30 and 40) were enrolled. They all received 1 capsule of placebo/day for 28 days before being randomly devised into three arms receiving 1 capsule/day of RES, CGSE, or RTP during the following consecutive 28 days. Blood samples were collected at baseline, after the end of placebo intake, and after the end of the investigational product intake. Biochemical parameters of oxidative stress and blood expression of 200 redox-related genes were determined at each time point.

RESULTS

RTP and CGSE showed better antioxidant activities compared to RES and induced important modulations of gene expression.

CONCLUSION

The results suggest that RTP and CGSE could contribute to a significant reduction of oxidative stress in obese subjects.

Functionally active macrophage-derived myeloperoxidase in the skin of drug-induced toxic epidermal necrolysis

BACKGROUND

Drug-induced toxic epidermal necrolysis (TEN) probably results from a complex and specific immune cell reaction involving lymphocytes and macrophages.

OBJECTIVE

To assess the functional role of macrophages in TEN.

METHODS

Immunohistochemistry was performed on biopsies from early blisters developed in 9 TEN patients. The amount of extracellular myeloperoxidase (MPO) was measured by ELISA in TEN blister fluid and serum. Controls were blister fluids taken from 9 second-degree burns. In addition, 3-chlorotyrosine (a specific marker of MPO activity) was searched for using liquid mass chromatography both in TEN and burn blister fluids.

RESULTS

Immunohistochemistry revealed numerous CD68+ macrophages in 8/9 TEN patients; 5-20% of these cells and rare CD15+ neutrophils exhibited MPO immunoreactivity, while keratinocytes were negative. The amount of MPO was significantly higher in TEN blister fluid than in TEN serum, suggesting macrophage production of MPO in the skin. In addition, MPO was significantly more abundant in TEN blister fluid than in burn blister fluid. 3-Chlorotyrosine was detected in 7/9 TEN blister fluids, but in only 2/9 burn blister fluids.

DISCUSSION

MPO produced by macrophages was functionally active in most TEN patients, leading to the production of hypochlorous acid, a potent oxidative compound that alters keratinocytes.

Monitoring of cellular responses after vaccination against tetanus toxoid: comparison of the measurement of IFN-gamma production by ELISA, ELISPOT, flow cytometry and real-time PCR

One of the challenges for immunomonitoring in clinical trials is to detect an antigen specific T cell-mediated immune response. In an attempt to define the most suitable assay, tetanus toxoid was used to compare the capacity of 4 different methods to detect cytokine responses, before and after recall vaccination, in peripheral blood mononuclear cells (PBMC) of 14 healthy volunteers. ELISA, ELISPOT, intracytoplasmic detection and real-time RT-PCR were chosen to measure IFN-gamma production before and after vaccination. As far as the detection of memory T cell status (before vaccination) was concerned, we found that ELISPOT was the most sensitive method to discriminate TT-induced from spontaneous responses. On the other hand, intracytoplasmic cytokine detection was the most efficient method to detect the restimulating effect of TT vaccination.

Newborns Develop a Th1-Type Immune Response to Mycobacterium bovis Bacillus Calmette-Guérin Vaccination

Data obtained in animals indicate that neonatal immune responses are biased toward Th2. This could reduce the efficacy of vaccines against viral and mycobacterial diseases. The ability of human newborns to develop a Th1 immune response upon immunization has not been studied. Since the vaccine Mycobacterium bovis bacillus Calmette-Guérin (BCG) triggers a Th1-type response in adults, we investigated whether it induces a similar response in newborns and whether age at vaccination influences immunogenicity. We found that BCG vaccination at birth induces a memory Th1-type response of similar magnitude to that when given later in life. This study demonstrates that human newborns can be immunized against pathogens controlled by a Th1 immune response.

A decreased production of IL12 in vitro is associated with isolation of cytopathic HIV-1 strains in HIV-1-infected patients

The changes in type 1 (IL12, IFN gamma, IL2) and type 2(IL4, IL10) cytokine profiles may be associated with virological parameters of progression of the disease in HIV-1-infected patients. The production of cytokines was studied in LPS + PHA-activated whole-blood culture in HIV-1-infected individuals at different stages of the disease. The association was investigated between IL12p40 and IL12p70 profiles and other cytokines (IFN gamma, IL4, IL10), as well as the isolation of cytopathogenic HIV-1 strains. The phenotype of HIV strains was studied by a micromethod based on P4 cell line, allowing detection of cytopathic effects of HIV-1 isolates (syncytium-induction and cell-killing without syncytium induction). The individual variations in IL12p40 and IL12p70 production were limited in the healthy controls. Low values were observed in HIV-1-infected patients. The production of IL12 (p40 and p70) and the IL12p70/IL4 ratio and the IFN gamma/IL4 ratio were significantly lower in patients with cytopathic isolates compared with patients with noncytopathic isolates, and a correlation was obtained between the values of IL12 (IL12p40 and IL12p70) and those of IFN gamma/IL4 ratio. There was no increase in the secretion of IL4 and IL10 in patients with cytopathic strains compared with other patients. The results indicate a decreased production of type 1 cytokines (IL12, IFN gamma) in the presence of a relatively preserved production of type 2 cytokines (IL4, IL10) in HIV-1-infected patients. In conclusion, the defect of production of IL12 by whole blood is associated with virological correlates of progression of HIV-1 disease.