Antioxidants and the prevention of hormonally regulated cancer

Antioxidant Production in Dunaliella

Microalgae have become an attractive natural source of a diverse range of biomolecules, including enzymatic and non-enzymatic antioxidants; nevertheless, economically sustainable production of such compounds from microalgae biomass is still challenging. The main hurdles are: (a) increasing microalgae yield; (b) achieving optimal cultivation conditions; (c) energy-efficient and cost-effective downstream processing (extraction and purification); (d) optimal storage of post-processed antioxidant molecules. This review provides a detailed overview of enzymatic and non-enzymatic antioxidants in the cellular metabolism of the commercially important microalgae Dunaliella, industrial applications of antioxidant enzymes, strategies to enhanced antioxidant accumulation in cells, and the opportunities and limitations of current technologies for antioxidant enzymes production from microalgae biomass as an alternative to common microbial sources.

The Impact of an Inert Gas Atmosphere on the Kinetics of Changes in the Physical and Chemical Properties of Carrot Lyophilisate

The purpose of this study was to analyse the impact of blanching, the atmosphere of nitrogen and storage time on carotenoids content, colour and sorption properties of freeze-dried carrot. The material was stored for up to 16 weeks, in the dark, at room temperature. The colour was measured on the surface and in cross sections. As the storage time increased, there was a continual decrease in the carotenoids content in the carrot packed in atmospheric air. In the carrots packed in the atmosphere of nitrogen, no changes in carotenoid content were observed. The colour parameters correlated with the changes in the carotenoids content. The colour parameters changed on the surface and in cross sections in the same manner. During storage, a significant decrease in sorption properties of freeze-dried carrots was noted after 2 weeks of storage.

Characterization of phenolics, glucosinolates and antioxidant activity of beverages based on apple juice with addition of frozen and freeze-dried curly kale leaves (Brassica oleracea L. var. acephala L.)

The aim of this study was to determine the polyphenols, glucosinolates and ascorbic acid content as well as antioxidant activity of beverages on the base of apple juice with addition of frozen and freeze-dried curly kale leaves. Upon enrichment with frozen (13%) and freeze-dried curly kale (3%), the naturally cloudy apple juice was characterized by an increase in phenolic compounds by 2.7 and 3.3-times, accordingly. The antioxidant activity of beverages with the addition of curly kale ranged from 6.6 to 9.4μmol Trolox/mL. The obtained beverages were characterized glucosinolates content at 117.6-167.6mg/L and ascorbic acid content at 4,1-31,9mg/L. The results of sensory evaluation of colour, taste and consistency of apple juice and beverages with the addition of kale did not differ significantly prior to pasteurization (P≤0.05), whereas after the pasteurization the evaluated factors decreased significantly.

Assessment of the cytotoxic, genotoxic, and antigenotoxic activities of Celtis iguanaea (Jacq.) in mice

Ethnobotanical surveys of Cerrado native plants show that leaves of Celtis iguanaea (Jacq.) Sargent (Cannabaceae), popularly known in Brazil as "esporão de galo", are used in folk medicine for body pain, asthma, cramps, poor digestion, urinary infection, kidney dysfunctions, as well as a stimulant and diuretic. This work aimed at evaluating possible C. iguanaea aqueous leaf extract (CALE) cytotoxicity, genotoxicity, and antigenotoxicity using the mouse bone marrow micronucleous test. To assess CALE genotoxicity, Swiss mice were orally treated with three different extract concentrations (100, 300, and 500 mgkg-1). To evaluate its antigenotoxicity, the same doses were used simultaneously with a single i.p. dose of mitomycin C (MMC, 4mg.kg-1). The frequencies of micronucleated polychromatic erythrocytes (MNPCE) were evaluated 24 h and 48 h after administration except for the negative control (24 h). Genotoxicity was evaluated using the frequency of micronucleated polychromatic erythrocytes (MNPCE), whereas cytotoxicity was assessed by the polychromatic and normochromatic erythrocytes ratio (PCE/NCE). The results showed that CALE did not exhibit a significant reduction in the PCE/NCE ratio, neither a considerable increase in the frequency of MNPCE. Nonetheless, CALE reduced bone marrow toxicity (increased PCE/NCE ratio) and decreased the micronuclei frequency induced by MMC. We can conclude that CALE presented no cytotoxic and genotoxic effects, but showed antigenotoxic and anticytotoxic actions under the experimental conditions applied in this study.

Antioxidants and breast cancer risk- a population-based case-control study in Canada

BACKGROUND

The effect of antioxidants on breast cancer is still controversial. Our objective was to assess the association between antioxidants and breast cancer risk in a large population-based case-control study.

METHODS

The study population included 2,362 cases with pathologically confirmed incident breast cancer (866 premenopausal and 1,496 postmenopausal) and 2,462 controls in Canada. Intakes of antioxidants from diet and from supplementation as well as other potential risk factors for breast cancer were collected by a self-reported questionnaire.

RESULTS

Compared with subjects with no supplementation, 10 years or longer supplementation of zinc had multivariable-adjusted odds ratios (OR) and 95% confidence intervals (CI) of 0.46 (0.25-0.85) for premenopausal women, while supplementation of 10 years or longer of multiple vitamin, beta-carotene, vitamin C, vitamin E and zinc had multivariable-adjusted ORs (95% CIs) of 0.74 (0.59, 0.92), 0.58 (0.36, 0.95), 0.79 (0.63-0.99), 0.75 (0.58, 0.97), and 0.47 (0.28-0.78), respectively, for postmenopausal women. No significant effect of antioxidants from dietary sources (including beta-carotene, alpha-carotene, lycopene, lutein and zeaxanthin, vitamin C, vitamin E, selenium and zinc) or from supplementation less than 10 years was observed.

CONCLUSIONS

This study suggests that supplementation of zinc in premenopausal women, and supplementation of multiple vitamin, beta-carotene, vitamin C, vitamin E and zinc in postmenopausal women for 10 or more years may protect women from developing breast cancer. However, we were unable to determine the overall effect of total dose or intake from both diet and supplement.

Antioxidant and antiproliferative properties of water extract from Mahonia bealei (Fort.) Carr. leaves

Mahonia bealei (Fort.) Carr. (Berberidaceae) leaves have been widely used as a tea leaf beverage south of the Qinling Mountains of China. In this study, the antioxidant and antiproliferative properties of M. bealei leaves were investigated. Our data showed that the water extract of M. bealei leaves (WML) exhibited extremely high antioxidant properties, which were demonstrated by its ability to scavenge 50% of 1,1-diphenyll-2-2-pricylhydrazyl (DPPH) free radicals at 60.46 μg/ml, and it eliminated approximately 71.19% of superoxide radicals at 500 μg/ml. In addition, the WML showed strong reducing abilities and provided protection against oxidative protein damage induced by hydroxyl radicals. Cellular proliferation and the induction of apoptosis were also examined by cellular proliferation assay, flow cytometry, and mRNA expression analysis. These results demonstrate that WML significantly inhibited the growth of human colon cancer (HT-29) cells in a concentration-dependent manner, and it gradually increased the proportion of apoptotic cells and reduced the expression of the survivin gene. The bioactivity-guided study of WML resulted in the isolation and identification of berberine, a known isoquinoline alkaloid. Berberine exhibited strong antiproliferative activity on HT-29 cells, with IC(50) values of 36.54 μM, suggesting it is, in part, responsible of the anticancer activity of WML.