Antioxidant activities of different colored sweet bell peppers (Capsicum annuum L.)

Bioactive compounds and antioxidant and antiproliferative activities of Korean white lotus cultivars

In traditional Korean medicine, lotus (Nelumbo nucifera Gaertn) roots have been used as an antidiabetic and an antiproliferative remedy. However, scientific publications on lotus properties are very limited. Therefore, it was decided to investigate the Korean white lotus cultivars in order to find out their bioactivity. It was found that all lotus cultivars (Inchisa, Muan, Garam, and Chungyang) possess high amounts of bioactive compounds: total phenols, between 7.95 +/- 0.8 and 4.21 +/- 0.3 mg of gallic acid equivalents (GAE)/g dry weight (DW); ascorbic acid, between 15.8 +/- 1.1 and 22.3 +/- 1.7 mg of ascorbic acid/g DW; and amino acids, between 15.05 +/- 0.82% and 16.62 +/- 0.90% DW. The highest contents of polyphenols (7.95 +/- 0.8 mg of GAE/g DW) and the highest levels of antioxidant [by 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl assays, 54.27 +/- 6.1 and 21.98 +/- 2.5 microM Trolox equivalents/g DW, respectively] and antiproliferative activities on both human cancer cell lines (Calu-6 for human pulmonary carcinoma and SMU-601 for human gastric carcinoma, 59.75 +/- 3.99% and 71.21 +/- 2.79% cell viability, respectively) were found in the Chungyang cultivar. Fluorometry and Fourier transform infrared spectroscopy can be applied as rapid methods for determination of bioactive compounds, such as polyphenols. The correlation between the bioactive compounds and the antioxidant activity was high. In conclusion, all Korean white lotus cultivars are valuable medicinal foods, and in order to receive the best results a combination of lotus cultivars has to be consumed.

Lignans from the fruits of the red pepper (Capsicum annuum L.) and their antioxidant effects

The fruits of Capsicum annuum were extracted using 80% aqueous MeOH, and fractionated using EtOAc and water. Repeated column chromatography using silica gel, octadecyl silica gel, and Sephadex LH-20 for the EtOAc fraction led to the isolation of a new lignan glycoside and a known one, icariside E(5). From the results of spectroscopic data, including EIMS, FABMS, UV, IR, (1)H and (13)C-NMR, DEPT, and 2D-NMR (COSY, HSQC, HMBC), the chemical structure of the new lignan glycoside was determined as (8R)-isodehydrodiconiferyl alcohol-4'-O-(6''-vanilloyl)-beta-D-glucopyranoside named vanilloylicariside E(5). All isolated compounds were tested for antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Icariside E(5) (2) and (8R)-Isodehydrodiconiferyl alcohol (3) exhibited a strong scavenging effect on DPPH (2: IC(50)=42.1 microM, 3: IC(50)=4.5 microM).

Analytical and technological aspects on bioactive compounds in spice red pepper

During the last decades comprehensive data in the field of chemistry, biology and technology of spice red pepper (paprika) have rapidly accumulated. In food science and technology the research work focused on, among others, developing accurate, simple, rapid, reliable, and of high sensitivity analytical methods to determine paprika pigments and antioxidants. The research concentrated mainly on the development and optimisation of liquid chromatographic methods to determine the carotenoids, tocopherols (vitamin E) and ascorbic acid (vitamin C). In the area of plant biology/physiology characterisation of ripening of traditional and new cultivars and hybrids of spice red pepper was the main objective of research work carried out by research groups in different countries. In the field of paprika processing and technology special interest has been given to the effect of different drying technologies on the quality components of paprika and their stability during drying, milling and storage. The aim of many research programs was to produce paprika with high colouring capacity, antioxidant content and storage stability. The objective of this article is to review the research works done on spice red pepper in the Central Food Research Institute, Budapest.

Luteolin, a flavonoid with potential for cancer prevention and therapy

Luteolin, 3',4',5,7-tetrahydroxyflavone, is a common flavonoid that exists in many types of plants including fruits, vegetables, and medicinal herbs. Plants rich in luteolin have been used in Chinese traditional medicine for treating various diseases such as hypertension, inflammatory disorders, and cancer. Having multiple biological effects such as anti-inflammation, anti-allergy and anticancer, luteolin functions as either an antioxidant or a pro-oxidant biochemically. The biological effects of luteolin could be functionally related to each other. For instance, the anti-inflammatory activity may be linked to its anticancer property. Luteolin's anticancer property is associated with the induction of apoptosis, and inhibition of cell proliferation, metastasis and angiogenesis. Furthermore, luteolin sensitizes cancer cells to therapeutic-induced cytotoxicity through suppressing cell survival pathways such as phosphatidylinositol 3'-kinase (PI3K)/Akt, nuclear factor kappa B (NF-kappaB), and X-linked inhibitor of apoptosis protein (XIAP), and stimulating apoptosis pathways including those that induce the tumor suppressor p53. These observations suggest that luteolin could be an anticancer agent for various cancers. Furthermore, recent epidemiological studies have attributed a cancer prevention property to luteolin. In this review, we summarize the progress of recent research on luteolin, with a particular focus on its anticancer role and molecular mechanisms underlying this property of luteolin.