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<p><b>Background:</b>PM(aerodynamic diameter ≤ 2.5 μm) is a dominant and ubiquitous air pollutant that has become a global concern as PMexposure has been linked to many adverse health effects including cardiovascular and pulmonary diseases. Emerging evidence supports a correlation between increased air PMlevels and skin disorders although reports on the underlying pathophysiological mechanisms are limited. Oxidative stress is the most common mechanism of PM-induced adverse health effects. This study aimed to investigate PM-induced oxidative damage and apoptosis in immortalized human keratinocyte (HaCaT) cells.</p><p><b>Methods:</b>HaCaT cells were exposed to 0, 25, 50, 100, or 200 μg/ml PMfor 24 h. Reactive oxygen species (ROS) generation, lipid peroxidation products, antioxidant activity, DNA damage, apoptotic protein expression, and cell apoptosis were measured.</p><p><b>Results:</b>PMexposure (0-200 μg/ml) for 24 h resulted in increased ROS levels (arbitrary unit: 201.00 ± 19.28, 264.50 ± 17.91, 305.05 ± 19.57, 427.95 ± 18.32, and 436.70 ± 17.77) and malondialdehyde production (0.54 ± 0.05 nmol/mg prot, 0.61 ± 0.06 nmol/mg prot, 0.68 ± 0.05 nmol/mg prot, 0.70 ± 0.05 nmol/mg prot, and 0.76 ± 0.05 nmol/mg prot), diminished superoxide dismutase activity (6.47 ± 0.28 NU/mg prot, 5.97 ± 0.30 NU/mg prot, 5.15 ± 0.42 NU/mg prot, 4.08 ± 0.20 NU/mg prot, and 3.76 ± 0.37 NU/mg prot), and increased DNA damage and apoptosis in a dose-dependent manner in HaCaT cells. Moreover, cytochrome-c, caspase-3, and caspase-9 expression also increased proportionately with PMdosing.</p><p><b>Conclusion:</b>PMmight elicit oxidative stress and mitochondria-dependent apoptosis that likely manifests as skin irritation and damage.</p>
RESUMO
OBJECTIVE: To develop an HPLC method for simultaneous determination of multiple-components in Hedyotis diffusa Willd. METHODS: The HPLC analysis was carried out on a C18 column (4.6 mm×250 mm, 5 μm) by gradient elution with acetoni-trile-water[both containing 0.1‰ (V/V) acetic acid] as mobile phase at a flow rate of 0.8 mL·min-1, the column temperature at 35°C, and the detection wavelength was set at 238 nm. External standard method and quantitative analysis of multi-components by single marker (QAMS) method were adopted for simultaneous determination of six components in Hedyotis diffusa Willd, respectively. RESULTS: The linear ranges for asperulosidic acid, quercetin-3-O-[2-O-(6-O-E-feruloyl)-β -D-glucopyranosyl]-β-D-glucopyrano-side, kaempferol-3-O-[2-O-(6-O-E-feruloyl)-β-Z) -gfucopyranosyl]-β-D-galactopyranoside, (E)-6-O-p-coumaroyl scandoside methyl ester, (E)-6-O-feruloyl scandoside methyl ester, (Z)-6-O-p-coumaroyl scandoside methyl ester were 2.34-93.50, 2.61-104.33, 0.67-26.69, 3.42-136.84, 0.65-26.07, and 1.10-44.17 μg·mL-1 (r<0.9993), respectively. The RSD values of precision, reproducibility, and sample stability were not more than 2.2%. The average recoveries of the six components were 99.8%-101.1% with RSDs not more than 1.2%. The P values of external standard method and QAMS by paired t-test were greater than 0.05. CONCLUSION: There is no significant difference in the content analysis results of the two methods, which can both used for simultaneous determination of the four iridoids and two flavonoids in Hedyotis diffusa Willd.