Potential antioxidant effect of fruit peels for human use from northern Peru, compared by 5 different methods / Potencial efecto antioxidante de las cáscaras de frutas para uso humano del norte de Perú, comparado por 5 métodos diferentes

The objective of the work was to determine the antioxidant potential in vitro of freeze-dried peel extracts of 20 fruits from the northern region of Peru through five tests (Folin-Ciocalteu, DPPH., ABTS+., FRAP and CUPRAC). According to multivariate statistical analyzes, five groups were found: (i.) peel extracts with the highest values of antioxidant capacity (AC) from custard apple, and star fruit; (ii.) rind extracts with high AC values from quince, sweet granadilla, guava, and black grape; (iii.) husk extracts with middle values of AC from passion fruit, and red mombin; (iv.) shell extracts with low AC values from tangerine, mandarine, and bitter orange; and, (v.) coating extracts with the lowest AC values from pawpaw, red pawpaw, muskmelon, dragon fruit, yellow and red indian figs, pear, apple, and green grape. To conclude, the fruit lyophilized-husk extracts of custard apple, star fruit, quince, sweet granadilla, guava, and black grape obtained the best AC.

El objetivo del trabajo fue determinar el potencial antioxidante in vitro de extractos de cáscara liofilizada de 20 frutos de la región norte del Perú mediante cinco pruebas (Folin-Ciocalteu, DPPH., ABTS+., FRAP y CUPRAC). Según análisis estadísticos multivariados, se encontraron cinco grupos: (i.) Extractos de piel con los valores más altos de capacidad antioxidante (CA) de chirimoya y carambola; (ii.) extractos de cáscara con altos valores de CA de membrillo, granadilla dulce, guayaba y uva negra; (iii.) extractos de cáscara con valores medios de CA de maracuyá y mombina roja; (iv.) extractos de cáscara con valores bajos de CA de mandarina, mandarina y naranja amarga; y (v.) recubrir extractos con los valores de CA más bajos de papaya, papaya roja, melón, fruta del dragón, higos indios amarillos y rojos, pera, manzana y uva verde. Para concluir, los extractos de cáscara liofilizada de chirimoya, carambola, membrillo, granadilla dulce, guayaba y uva negra obtuvieron el mejor CA.

Antioxidant effect and chemical composition of Ananas comosus [L.] Merr. peels from Peruvian northern / Efecto antioxidante y composición química de las cascaras de Ananas comosus [L.] Merr. del norte peruano

Pineapple peels has several beneficial properties including antioxidant activity. We investigated the antioxidant effect of five different peels of pineapple lyophilized extracts, not adsorbed and adsorbed onto Amberlite. They were examined using total phenolic contents (TPC), antioxidant effect by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP). In addition, we analyzed the chemical composition by HPLC-ESI-QTOF-MS/MS. The main constituents of pineapple peels were tentatively identified as quercetin glycosides and N,N'-diferuloylspermidine. We conclude that the antioxidant activity in pineapple peels from District of Poroto, Province of Trujillo, Region of La Libertad, can be associated with the presence of flavonoid and spermidines.

Las cáscaras de piña tienen varias propiedades beneficiosas, incluida la actividad antioxidante. Investigamos el efecto antioxidante de cinco exfoliaciones diferentes de extracto liofilizado de piña, no adsorbidas y adsorbidas en Amberlita. Se examinaron utilizando los contenidos fenólicos totales (TPC), el efecto antioxidante mediante la eliminación del radical 1,1-difenil-2-picril-hidrazilo (DPPH) y el poder férrico antioxidante reductor (FRAP). Además, analizamos la composición química por HPLC-ESI-QTOF-MS/MS. Los principales constituyentes de las cáscaras de piña se identificaron tentativamente como glucósidos de quercetina y N,N'- diferuloylspermidina. Concluimos que la actividad antioxidante en las cáscaras de piña del Distrito de Poroto, Provincia de Trujillo, Región de La Libertad, puede estar asociada con la presencia de flavonoides y espermidinas.

Ascorbate Attenuates Oxidative Stress and Increased Blood Pressure Induced by 2-(4-Hydroxyphenyl) Amino-1,4-naphthoquinone in Rats.

Quinone derivatives like 2-(4-hydroxyphenyl) amino-1,4-naphthoquinone (Q7) are used as antitumor agents usually associated with adverse effects on the cardiovascular system. The objective of this study was to evaluate the cardioprotective effect of ascorbate on Q7-induced cardiovascular response in Wistar rats. In this study, blood pressure, vascular reactivity, and intracellular calcium fluxes were evaluated in cardiomyocytes and the rat aorta. We also measured oxidative stress through lipid peroxidation (TBARS), superoxide dismutase- (SOD-) like activity, and H2O2 generation. Oral treatment of rats with ascorbate (500 mg/kg) for 20 days significantly (p < 0.05) reduced the Q7-induced increase (10 mg/kg) in blood pressure and heart rate. The preincubation with ascorbate (2 mM) significantly (p < 0.05) attenuated the irregular beating of the atrium induced by Q7 (10-5 M). In addition, ascorbate induced endothelial vasodilation in the presence of Q7 in the intact aortic rings of a rat and reduced the cytosolic calcium levels in vascular smooth muscle cells. Ascorbate also reduced the Q7-induced oxidative stress in vivo. Ascorbate also attenuated Q7-induced SOD-like activity and increased TBARS levels. These results suggest a cardioprotective effect in vivo of ascorbate in animals treated orally with a naphthoquinone derivative by a mechanism involving oxidative stress.