Supplementation with cactus pear (Opuntia ficus-indica) fruit decreases oxidative stress in healthy humans: a comparative study with vitamin C.
BACKGROUND
Cactus pear (Opuntia ficus-indica) fruit contains vitamin C and characteristic betalain pigments, the radical-scavenging properties and antioxidant activities of which have been shown in vitro.


OBJECTIVE
We investigated the effects of short-term supplementation with cactus pear fruit compared with vitamin C alone on total-body oxidative status in healthy humans.


METHODS
In a randomized, crossover, double-treatment study, 18 healthy volunteers received either 250 g fresh fruit pulp or 75 mg vitamin C twice daily for 2 wk, with a 6-wk washout period between the treatments. Before (baseline) and after each treatment, 8-epi-prostaglandin F(2alpha) (8-epi-PGF(2alpha)) and malondialdehyde in plasma, the ratio of reduced to oxidized glutathione (GSH:GSSG) in erythrocytes, and lipid hydroperoxides in LDL were measured as biomarkers of oxidative stress; plasma Trolox-equivalent antioxidant activity (TEAC) and vitamins A, E, and C were evaluated as indexes of antioxidant status.


RESULTS
Both treatments caused comparable increases compared with baseline in plasma concentrations of vitamin E and vitamin C (P < 0.05); vitamin A and TEAC did not change significantly. After supplementation with cactus pear fruit, 8-epi-PGF(2)alpha and malondialdehyde decreased by approximately 30% and 75%, respectively; GSH:GSSG shifted toward a higher value (P < 0.05); and LDL hydroperoxides were reduced by almost one-half. Supplementation with vitamin C did not significantly affect any marker of oxidative stress.


CONCLUSIONS
Consumption of cactus pear fruit positively affects the body's redox balance, decreases oxidative damage to lipids, and improves antioxidant status in healthy humans. Supplementation with vitamin C at a comparable dosage enhances overall antioxidant defense but does not significantly affect body oxidative stress. Components of cactus pear fruit other than antioxidant vitamins may play a role in the observed effects.
Dipartimento Farmacochimico Tossicologico e Biologico, Facoltà di Farmacia, Università di Palermo, Via C Forlanini, I-90134 Palermo, Italy.
Luisa
L
Tesoriere
Daniela
D
Butera
Anna Maria
AM
Pintaudi
Mario
M
Allegra
Maria A
MA
Livrea
D000328:Adult; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D015415:Biomarkers / Q000097:blood; D018592:Cross-Over Studies; D005260:Female; D005638:Fruit; D006801:Humans; D008297:Male; D029747:Opuntia; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*
D015415:Biomarkers; D001205:Ascorbic Acid