The protective effects of procyanidin supplementation on PM2.5-induced acute cardiac injury in rats.

OBJECTIVE: Numerous epidemiological and experimental studies have indicated that ambient fine particulate matter (PM2.5) exposure can lead to myocardial injury by inhibiting oxidative stress and apoptosis. The effects of procyanidin (PC) on PM2.5-induced cardiovascular diseases (CVDs) are still unknown. The purpose of this study was to explore the protective effect of PC supplementation on PM2.5-induced oxidative stress and cardiomyocyte apoptosis in rats. METHOD: Rats were treated by gavage with three different PC concentrations (50, 100 and 200 mg/kg) for 21 days prior to exposure to 10 mg/kg PM2.5 suspension liquid by intratracheal instillation every other day for three times. We determined myocardial reactive oxygen species (ROS) and malondialdehyde (MDA) levels. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in the myocardium were measured. The expression levels of apoptosis-related proteins, including p-Akt/Akt, Bcl-2, caspase-3 and Bax, were determined. In addition, histopathological examination was used to evaluate cardiac injury. RESULTS: PM2.5 exposure noticeably elevated the contents of MDA and ROS and decreased the activities of GSH-Px and SOD. PM2.5 exposure inhibited Bcl-2 expression and up-regulated caspase-3 and Bax expression in the myocardium of rats. The anti-apoptosis-related index p-Akt/Akt was reduced. Moreover, pretreatment with PC could attenuate these PM2.5-induced changes. However, remarkable differences in the protective effect of different PC doses did not exist. CONCLUSIONS: The results indicated that PC supplementation could effectively attenuate the oxidative stress and apoptosis induced by PM2.5 in rat myocardial tissue.

Validation of 4 Estimating Methods to Evaluate 24-h Urinary Sodium Excretion: Summer and Winter Seasons for College Students in China.

Twenty-four-hour urine sample collection is regarded as the gold standard for sodium intake evaluation, but the implementation can be difficult. The objective was to validate and evaluate the accuracy and feasibility of estimating sodium intake by four methods. A group of 268 healthy volunteers aged 18-25 years was enrolled in this study. Twenty-four-hour urine samples as well as timed (morning, afternoon, evening, and overnight) urine samples were randomly collected in summer and winter. The sodium intake was estimated by four published methods-Kawasaki, INTERSALT, Tanaka, and Sun's. The consistencies between estimated sodium intake and real measured values of 24-h urinary sodium excretion were compared by Bland-Altman plots in each of the methods. The 24-h urinary sodium analysis result indicated that average daily sodium intake was 3048.4 ± 1225.9 mg in summer and 3564.7 ± 1369.9 mg in winter. At the population level, the bias (estimated value-measured value) was the least with the INTERSALT method with afternoon (-39.7 mg; 95%CI: -164.7, 85.3 mg) and evening (-43.5 mg; 95%CI: -166.4, 79.5 mg) samples in summer. In winter, the Kawasaki method (162.1 mg; 95%CI: 13.5, 310.7 mg) was superior to others. Estimation of sodium intake using the four methods is affected by the time and temperature. In summer, the INTERSALT method provides the best estimation of the population's mean sodium intake. The Kawasaki method is superior to other methods in winter.

Vascular benefits of vitamin C supplementation against fine particulate air pollution in healthy adults: A double-blind randomised crossover trial.

Evidence on the health benefits of vitamin C supplementation in highly polluted areas has not been evaluated. We aimed to evaluate whether dietary vitamin C supplementation can improve vascular health linked to particulate matter (PM) exposure. A randomised double-blind crossover trial involving 58 health young adults was performed in Shijiazhuang, China in 2018. All subjects were randomly assigned to the vitamin C supplementation group (2000 mg/d) or placebo group for a week alternating with a 2 week washout period. Fifteen circulating biomarkers were measured. Linear mixed-effect model was applied to evaluate the effect of vitamin C supplementation on health outcomes. The average concentrations of PM2.5 and PM10 were 164.91 and 327.05 µg/m3, respectively. Vitamin C supplementation was significantly associated with a 19.47% decrease in interleukin-6 (IL-6), 17.30% decrease in tumour necrosis factor-a (TNF-α), 34.01% decrease in C-reactive protein (CRP), 3.37% decrease in systolic blood pressure (SBP) and 6.03% decrease in pulse pressure (PP). Furthermore, glutathione peroxidase (GSH-Px) was significantly increased by 7.15%. Sex-subgroup analysis showed that vitamin C significantly reduced TNF-α by 27.85% in male participants and significantly increased APOB by 6.28% and GSH-Px by 14.47% only in female participants. This study indicated that vitamin C supplementation may protect vascular vessels against PM exposure among healthy young adults in China.