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This study was conducted to determine whether the macroalgae Ulva papenfussi and Ulva nematoidea could be alternatives for preventing Litopenaeus vannamei vibriosis caused by the bacterium Vibrio parahaemolyticus. Phytochemical screening was performed on methanolic extracts to qualitatively determine the main groups of bioactive compounds, previous to an in vitro antibacterial test against V. parahaemolitycus. Phenols, polyphenols, flavonoids, and the high presence of carbohydrates were found in both macroalgae. U. papenfussi showed more presence of lipids and alkaloids than U. nematoidea. Macroalgae extracts prepared (v:v) with a 1:1 methanol: dichloromethane solvent was used for the in vitro test using the disc diffusion method (MDD). Filter paper discs impregnated with 1.0, 1.5, 2.0, 3.0, and 4.0 mg of the extracts showed antibacterial activity against V. Parahaemolitycus in a dose-dependent manner in both macroalgae. The inhibition zone varied significantly (p < 0.05) from 8.33 ± 0.12 to 11.41 ± 0.73 mm for 1 to 3 mg of extract levels, respectively. In conclusion, both macroalgae have antibacterial activity in their crude extracts against this bacteria. It is suggested to evaluate it as a feed additive for L. vannamei. This study is the first report on a phytochemical screening and antibacterial activity of these macroalgae against V. parahaemolyticus. [ABSTRACT FROM AUTHOR]

Pitahaya has originated worldwide interest due to its content of bioactive compounds with proven beneficial effects on health, acting as antioxidants against free radicals. This study aimed to evaluate the nutraceutical potential of the peel and pulp of the red (Hylocereus monacanthus) and yellow (Hylocereus megalanthus) pitahaya ecotypes for nutritional formulation purposes. Two pitahaya ecotypes were analyzed, obtaining a methanolic extract of the peel and edible part to perform the proximal chemical analysis, the phytochemical screening, and determine antioxidant activity by the DPPH, ABTS, and IC50 methods. Flavonoids, tannins, quinones, among other bioactive compounds, were identified. Yellow pitahaya presented higher content of polyphenols and higher antioxidant activity by the ABTS method, while the average inhibition percentage for both ecotypes was 93% by DPPH method. IC50 was higher for the edible part of red pitahaya with 1.68 mg mL-1. Both ecotypes have a high content of polyphenols and a high antioxidant capacity, which agree with those found in different studies such as those of Colombia, Brazil and Korea, being as high or even higher than most varieties of citrus fruits in Peru. Future studies should consider the inclusion of other metabolites and bioactive substances such as betalains due to their antioxidant activity. Both pitahaya ecotypes are rich in antioxidants, bioactive compounds, have low energy density, and may be suitable for food prescriptions as a functional ingredient in food industry. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) are normally produced during cell metabolism, there is strong evidence to suggest that ROS produced in excess impair the cell and may be etiologically related to various neurodegenerative diseases. This study was undertaken to examine the effects ofLepidium meyenii(MACA) methanol leaf extract on neurotoxicity in PC12 cell exposed to 6-hydroxydopamine (6-OHDA). Fresh samples of “maca” leaves were processed in order to obtain foliar extracts and to evaluate the neurobiological activity on PC12 cells, subjected to the cytotoxic effect of 6-OHDA through the determination of the capacity antioxidant, cell viability and cytotoxicity assays on PC12 cells. The results of the tests of antioxidant activity, showed maximum values of 2262.37 and 1305.36 expressed in Trolox equivalents (TEAC), for the methanolic and aqueous fractions respectively. Cell viability assays at a dose of 10 μg extract showed an increase of 31% and 60% at 6 and 12 h of pretreatment, respectively. Cytotoxicity assays at the same dose and exposure time showed a 31.4% and 47.8% reduction in lactate dehydrogenase (LDH) activity and an increase in superoxide dismutase (SOD) activity. The results allow us to affirm that the methanolic foliar extract of “maca” presentsin vitroneurobiological activity of antioxidant protection, increase in cell viability and reduction of cytotoxicity against oxidative stress generated by 6-OHDA. In conclusion, the present study shows a protective role forLepidium meyeniileaf extract on 6-OHDA-induced toxicity by an antioxidant effect. [ABSTRACT FROM AUTHOR]

The objective of this research was to evaluate a nutritional strategy based on the consumption of a fucoidan extract from brown algae Lessonia trabeculata to control oxidative stress in experimental alloxan-induced insulin-dependent diabetes mellitus rats. Over 30 days, 75, 100, and 125 mg kg−1 of body weight of fucoidan doses were administered and both positive and negative control (n = 5 per group). Serum, liver, pancreas, and kidney biochemical indicators of oxidative stress improvement were evaluated. Measures included lipid peroxidation, superoxide dismutase and catalase activity, and antioxidant activity by assessment of free radical scavenging power and histopathological changes. The results showed an increase in the activity of antioxidant enzymes while reducing oxidative damage (lipid peroxidation index) in serum (p ≤ 0.05) and tissues (p ≤ 0.05). Further, no liver necrosis was observed in treated groups, unlike the Type 1 diabetes positive control group that presented mild necrosis and moderate congestion. In the pancreas, treated rats presented mild oedema, while the positive control group showed moderate oedema. A significant protective effect against oxidative stress caused by alloxan-induced diabetes was found in this model, therefore it can be concluded that fucoidan extracted from the Lessonia trabeculata algae could be considered a good functional compound for the control of oxidative stress in diabetic patients. Because diabetes is such a widespread public health issue, developing fucoidan-based products could be a natural way to improve patients' quality of life. [ABSTRACT FROM AUTHOR]