Houttuynia cordata Extract Improves Physical Endurance Performance by Regulating Endothelial Production of Nitric Oxide.

Vascular function is mediated by various regulatory molecules, including endothelial nitric oxide (NO), which regulates the vasodilation of smooth muscle cells. We investigated whether standardized Houttuynia cordata extract (SHCE) could improve physical endurance performance by regulating the endothelial production of NO. For the standardization of Houttuynia cordata (HC) extract, its bioactive components were identified and quantified using ultraperformance liquid chromatography-mass spectrometry. Bioaccessibility and biological activity were measured by the in vitro digestion model system and free radical scavenging capacity, respectively. The vascular function in the endothelium was assessed by the phosphorylation of endothelial nitric oxide synthase (eNOS). A preliminary clinical trial was carried out to assess the physical endurance performance. HC extract was standardized to bioactive components, including chlorogenic acid, rutin, and quercitrin, with the concentration of 5.53, 6.09, and 16.15 mg from 1 g of dry weight, respectively. Bioaccessibility was 33.17%, 31.67%, and 11.18% for chlorogenic acid, rutin, and quercitrin, respectively. Antioxidant activities of SHCE were expressed as vitamin C equivalent antioxidant capacity in 55.81 and 17.23 mg/g of HC extract using ABTS and DPPH scavenging assay, respectively. In human aortic endothelial cells, insulin-mediated phosphorylation of eNOS was increased by SHCE in the presence of palmitate. However, the expression of blood pressure-regulating genes was not altered. The level of blood lactate concentration and the heart rate of subjects who drank SHCE were lower than those of subjects who drank plain water. Oxygen uptake from subjects drinking SHCE was slightly higher than that from those who drank plain water. This study demonstrated that SHCE decreased heart rate and blood lactate, increased oxygen uptake, and improved physical performance, presumably due to the increased NO production.

Protective effect of chlorophyllin and lycopene from water spinach extract on cytotoxicity and oxidative stress induced by heavy metals in human hepatoma cells.

The purpose of this study was to examine the inhibitory effects of ethanol extract of water spinach (EEWS) containing chlorophyll and lycopene on cytotoxicity and oxidative stress in liver induced by heavy metals. The (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) MTT assay and dichlorofluorescein (DCF) assay were conducted to measure cytotoxicity and inhibition of reactive oxygen species (ROS), respectively. Cytotoxicity was prevented at a concentration of 11.7 mg/L of EEWS. Both sodium copper chlorophyllin (SCC) and lycopene in EEWS were identified by ultraperformance liquid chromatography-photodiode array-electrospray ionization-mass spectroscopy (UPLC-PDA-ESI-MS/MSn) as major components at m/z 722.64 and 535.45, respectively. The concentrations of SCC and lycopene were 0.12 and 0.04 mg from 100 g of dried powder, respectively. Approximately 99% cytotoxicity induced by Cd was inhibited by EEWS. However, the inhibitory effect attributed to generation of ROS was similar with SCC, lycopene, and EEWS. Our results indicated that EEWS was effective in reducing cytotoxicity and oxidative stress produced by heavy metals in a HepG2 cell. Data suggest that the possible mechanism underlying the preventive action of SCC might be associated with diminished absorption of metal ions by chelating and blocking metal-mediated generation of ROS, while lycopene effects may be attributed to its high number of conjugated dienes that act as most potent singlet oxygen quenchers.

Water spinach (Ipomoea aquatic Forsk.) reduced the absorption of heavy metals in an in vitro bio-mimicking model system.

This study was conducted to investigate the effect of water spinach on bioaccessibility and intestinal uptake of heavy metals (Arsenic (As), Cadmium (Cd), and Lead (Pb)) using an in vitro digestion model with Caco-2 cells. Aliquots of each heavy metal were co-digested with each part of water spinach (stem and leaf) and then cultured with Caco-2 intestinal cells for 1h at 37 °C. Each heavy metal of As, Cd, and Pb was quantified using an ICP-OES. As the amount of stem and leaf (10, 50, 100, and 500 mg) of water spinach increased, bioaccessibility of As, Cd, and Pb decreased to 42.63%, 12.04%, and 26.17% by leaf and 30.37%, 43.27%, 40.07% by stem, respectively. Intestinal uptake of As, Cd, and Pb reduced to 65.8%, 25.7%, and 44.8% for leaf (500 mg) and 48.4%, 51.3%, and 64.3% for stem (500mg), respectively, compared with the control without leaf and stem. The leaf from water spinach was the most effective for decreasing both bioaccessibility and cellular uptake of Cd.