Carpinus turczaninowii extract modulates arterial inflammatory response: a potential therapeutic use for atherosclerosis

BACKGROUND/OBJECTIVES: Vascular inflammation is an important feature in the atherosclerotic process. Recent studies report that leaves and branches of Carpinus turczaninowii (C. turczaninowii) have antioxidant capacity and exert anti-inflammatory effects. However, no study has reported the regulatory effect of C. turczaninowii extract on the arterial inflammatory response. This study therefore investigated modulation of the arterial inflammatory response after exposure to C. turczaninowii extract, using human aortic vascular smooth muscle cells (HAoSMCs). MATERIALS/METHODS: Scavenging activity of free radicals, total phenolic content (TPC), cell viability, mRNA expressions, and secreted levels of cytokines were measured in LPS-stimulated (10 ng/mL) HAoSMCs treated with the C. turczaninowii extract. RESULTS: C. turczaninowii extract contains high amounts of TPC (225.6 ± 21.0 mg of gallic acid equivalents/g of the extract), as well as exerts time-and dose-dependent increases in strongly scavenged free radicals (average 14.8 ± 1.97 µg/mL IC50 at 40 min). Cell viabilities after exposure to the extracts (1 and 10 µg/mL) were similar to the viability of non-treated cells. Cytokine mRNA expressions were significantly suppressed by the extracts (1 and 10 µg/mL) at 6 hours (h) after exposure. Interleukin-6 secretion was dose-dependently suppressed 2 h after incubation with the extract, at 1–10 µg/mL in non-stimulated cells, and at 5 and 10 µg/mL in LPS-stimulated cells. Similar patterns were also observed at 24 h after incubation with the extract (at 1–10 µg/mL in non-stimulated cells, and at 10 µg/mL in the LPS-stimulated cells). Soluble intracellular vascular adhesion molecules (sICAM-1) secreted from non-stimulated cells and LPS-stimulated cells were similarly suppressed in a dose-dependent manner after 24 h exposure to the extracts, but not after 2 h. In addition, sICAM-1 concentration after 24 h treatment was positively related to IL-6 levels after 2 h and 24 h exposure (r = 0.418, P = 0.003, and r = 0.524, P < 0.001, respectively). CONCLUSIONS: This study demonstrates that C. turczaninowii modulates the arterial inflammatory response, and indicates the potential to be applied as a therapeutic use for atherosclerosis.

The Cytotoxic Constituents of Betula platyphylla and their Effects on Human Lung A549 Cancer Cells

During the screening for cytotoxic compounds from plants grown in Korea, Betula platyphylla (BP) showed potent activity against the adenocarcinomic human alveolar basal epithelial A549 cell line. To identify the cytotoxic components from BP, the CH₂Cl₂ fraction with the most significant cytotoxic effect was applied to the column chromatographies. Seven compounds were isolated: lupeol (1), betulinic acid (2), (−)-rhododendrol (3), platyphyllenone (4), platyphyllone (5), (−)-centrolobol (6), and oleanolic acid (7). Among them, three diarylheptanoids (4 – 6) exhibited cytotoxicity toward A549 cells. Especially, 50 µM of 4 reduced A549 cell viability to 18.93 ± 0.82% compared to control (100.00 ± 21.48%). Lactate dehydrogenase (LDH) leakage and intracellular reactive oxygen species (ROS) production were also induced by 50 µM 4. This is the first report on the cytotoxic effect of BP-derived diarylheptanoids 4–6 against A549 cells. The compound 4 may be useful for the development of early hit compounds for non-small cell lung carcinoma, but the consideration about selectivity of 4 is required since 4 also showed the cytotoxicity in the human normal lung epithelial BEAS-2B cell line.

A Carbohydrate Fraction, AIP1, from Artemisia Iwayomogi Reduces the Action Potential Duration by Activation of Rapidly Activating Delayed Rectifier K+ Channels in Rabbit Ventricular Myocytes

We investigated the effects of a hot-water extract of Artemisia iwayomogi, a plant belonging to family Compositae, on cardiac ventricular delayed rectifier K+ current (I(K)) using the patch clamp technique. The carbohydrate fraction AIP1 dose-dependently increased the heart rate with an apparent EC(50) value of 56.1+/-5.5 microgram/ml. Application of AIP1 reduced the action potential duration (APD) in concentration-dependent fashion by activating I(K) without significantly altering the resting membrane potential (IC(50) value of APD(50): 54.80+/-2.24, IC(50) value of APD(90): 57.45+/-3.47 microgram/ml). Based on the results, all experiments were performed with 50 microgram/ml of AIP1. Pre-treatment with the rapidly activating delayed rectifier K+ current (I(Kr)) inhibitor, E-4031 prolonged APD. However, additional application of AIP1 did not reduce APD. The inhibition of slowly activating delayed rectifier K+ current (I(Ks)) by chromanol 293B did not change the effect of AIP1. AIP1 did not significantly affect coronary arterial tone or ion channels, even at the highest concentration of AIP1. In summary, AIP1 reduces APD by activating I(Kr) but not I(Ks). These results suggest that the natural product AIP1 may provide an adjunctive therapy of long QT syndrome.