Consumption of fruits and vegetables has been associated with reduced risk of chronic diseases such as cardiovascular disease and cancer. Phytochemicals, especially phenolics, in fruits and vegetables are suggested to be the major bioactive compounds for the health benefits. However, the phenolic contents and their antioxidant activities in fruits and vegetables were underestimated in the literature, because bound phenolics were not included. This study was designed to investigate the profiles of total phenolics, including both soluble free and bound forms in common fruits, by applying solvent extraction, base digestion, and solid-phase extraction methods. Cranberry had the highest total phenolic content, followed by apple, red grape, strawberry, pineapple, banana, peach, lemon, orange, pear, and grapefruit. Total antioxidant activity was measured using the TOSC assay. Cranberry had the highest total antioxidant activity (177.0 +/- 4.3 micromol of vitamin C equiv/g of fruit), followed by apple, red grape, strawberry, peach, lemon, pear, banana, orange, grapefruit, and pineapple. Antiproliferation activities were also studied in vitro using HepG(2) human liver-cancer cells, and cranberry showed the highest inhibitory effect with an EC(50) of 14.5 +/- 0.5 mg/mL, followed by lemon, apple, strawberry, red grape, banana, grapefruit, and peach. A bioactivity index (BI) for dietary cancer prevention is proposed to provide a new alternative biomarker for future epidemiological studies in dietary cancer prevention and health promotion.

Epidemiological studies have shown that consumption of fruits and vegetables is associated with reduced risk of chronic diseases. Increased consumption of fruits and vegetables containing high levels of phytochemicals has been recommended to prevent chronic diseases related to oxidative stress in the human body. In this study, 10 common vegetables were selected on the basis of consumption per capita data in the United States. A more complete profile of phenolic distributions, including both free and bound phenolics in these vegetables, is reported here using new and modified methods. Broccoli possessed the highest total phenolic content, followed by spinach, yellow onion, red pepper, carrot, cabbage, potato, lettuce, celery, and cucumber. Red pepper had the highest total antioxidant activity, followed by broccoli, carrot, spinach, cabbage, yellow onion, celery, potato, lettuce, and cucumber. The phenolics antioxidant index (PAI) was proposed to evaluate the quality/quantity of phenolic contents in these vegetables and was calculated from the corrected total antioxidant activities by eliminating vitamin C contributions. Antiproliferative activities were also studied in vitro using HepG(2) human liver cancer cells. Spinach showed the highest inhibitory effect, followed by cabbage, red pepper, onion, and broccoli. On the basis of these results, the bioactivity index (BI) for dietary cancer prevention is proposed to provide a simple reference for consumers to choose vegetables in accordance with their beneficial activities. The BI could be a new alternative biomarker for future epidemiological studies in dietary cancer prevention and health promotion.

Oxidative stress has been linked with the pathogenesis of many human diseases including cancer, aging, and atherosclerosis. The present study investigates the antioxidant activities of peptides isolated from the medicinal mushroom, Ganoderma lucidum. G. lucidum has been shown to possess potent antioxidant activity with little or no side effects. Polysaccharide, polysaccharide-peptide complex, and phenolic components of G. lucidum have been proposed to be responsible for this antioxidant effect. However, research has shown that the G. lucidum peptide (GLP) is the major antioxidant component of G. lucidum. The objective of this study was to evaluate the antioxidant activity of this peptide using different oxidation systems. GLP showed potent antioxidant activities in both lightproof soybean oil and lard systems, assessed by lipid peroxidant value. Compared to butylated hydroxytoluene, GLP showed a higher antioxidant activity in the soybean oil system. Soybean lipoxygenase activity was blocked by GLP in a dose-dependent manner with an IC50 value of 27.1 microg/mL. GLP showed scavenging activity toward hydroxyl radicals produced in a deoxyribose system with an IC50 value of 25 microg/mL, and GLP effectively quenched superoxide radical anion produced by pyrogallol autoxidation in a dose-dependent manner. Malondialdehyde level has been used as the oxidation index in many biological systems. GLP showed substantial antioxidant activity in the rat liver tissue homogenates and mitochondrial membrane peroxidation systems. The auto-hemolysis of rat red blood cells was also blocked by GLP in a dose-dependent manner. On the basis of these results, it is concluded that GLP is the major constituent responsible for the antioxidant activity of G. lucidum. GLP could play an important role in the inhibition of lipid peroxidation in biological systems through its antioxidant, metal chelating, and free radical scavenging activities.

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Cell cultureMethylene blue Cell growth Cytotoxicity A B S T R A C T Cell counting is a common technique in cellular and molecular biology research applications, such as cell culture maintenance, cell plating, cell growth and cell doubling time determinations, as well as cell proliferation and cytotoxicity measurements. Many commonly employed cell counting methods exhibit limitations that influence resulting accuracy or versatility. For example, the trypan blue method typically underestimates cell numbers in culture, and the Lowry protein assay can be influenced by cell cycle. An urgent need exists for a method of cell counting that is both accurate and versatile. This work intended to explore an adaptation of the methylene blue assay to overcome the existing limitations of the procedure, enabling application to a broader range of cell densities and various cell culture plates. This new methylene blue assay was found to be more efficient, accurate and sensitive. A linear relationship (r 2 > 0.99) was established between cell number and absorbance at 570 nm wavelength when the new methylene blue assay was applied to three cell lines (HepG2, Caco-2, and MCF-7) plated in a broad range of cell densities (5 · 10 4 to 2.5 · 10 6 ) in four different types of culture plates (6-, 12-, 24-, and 96-well plates).Growth curves were determined using both the trypan blue and methylene blue methods.At each time point in the HepG2 growth curve, the cell count obtained using the trypan blue assay was statistically significantly lower than that obtained using the methylene blue assay (p < 0.05). The same was true for the Caco-2 growth curve at all time points (p < 0.05) except at the 0 h. The methylene blue method proposed in this paper may serve as a direct, automated counting method for cells grown in any type of culture plates. This assay has clear advantages over traditional methods and is a powerful tool for any application requiring a versatile, efficient, and accurate method of cell counting, such as bioavailability and cytotoxicity assays, and more basic experiments such as cell growth curve or doubling time determination, especially in the research of natural products, bioactive compounds, phytochemicals, functional foods and nutraceuticals.