Pomegranate juice supplementation in chronic obstructive pulmonary disease: a 5-week randomized, double-blind, placebo-controlled trial

Abstract

Objective: The aim of the present study is to investigate the effect of antioxidant polyphenol-rich pomegranate juice (PJ) supplementation for 5 weeks on patients with stable chronic obstructive pulmonary disease (COPD), since the oxidative stress plays a major role in the evolution and pathophysiology of COPD. Design: A randomized, double-blind, placebo-controlled trial was conducted. Subjects: A total of 30 patients with stable COPD were randomly distributed in two groups (15 patients each). Interventions: Both groups consumed either 400 ml PJ daily or matched placebo (synthetic orange-flavoured drink) for 5 weeks. Trolox Equivalent Antioxidant Capacity (TEAC) of PJ, blood parameters (14 haematological and 18 serobiochemical), respiratory function variables, bioavailability of PJ polyphenols (plasma and urine) and urinary isoprostane (8-iso-PGF 2a ) were evaluated. Results: The daily dose of PJ (containing 2.66 g polyphenols) provided 4 mmol/l TEAC. None of the polyphenols present in PJ were detected in plasma or in urine of volunteers. The most abundant PJ polyphenols, ellagitannins, were metabolized by the colonic microflora of COPD patients to yield two major metabolites in both plasma and urine (dibenzopyranone derivatives) with no TEAC. No differences were found (P40.05) between PJ and placebo groups for any of the parameters evaluated (serobiochemical and haematological), urinary 8-iso-PGF 2a , respiratory function variables and clinical symptoms of COPD patients. Conclusions: Our results suggest that PJ supplementation adds no benefit to the current standard therapy in patients with stable COPD. The high TEAC of PJ cannot be extrapolated in vivo probably due to the metabolism of its polyphenols by the colonic microflora. The understanding of the different bioavailability of dietary polyphenols is critical before claiming any antioxidantrelated health benefit. Sponsorship: 'Fundació n Séneca' (Murcia, Spain), Project PB/18/FS/02 and Spanish CICYT, Project AGL2003-02195.

Pomegranate Ellagitannin-Derived Metabolites Inhibit Prostate Cancer Growth and Localize to the Mouse Prostate Gland

“…In fact, urolithins appear in blood, urine, and feces of human volunteers 12-24 h after consumption of a single dose of several ET-rich foods and persist in vivo for up to 48-56 h after ingestion (9)(10)(11)(12). Despite these advances in understanding ET metabolism in rodents (13,14) and humans (9-12), there have been no studies determining the disposition of ET metabolites to tissues of interest including the prostate.…”

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“…[40,41] The herbs ivy leaf and plantain have been suggested for chronic bronchitis, but there is no meaningful evidence that they actually help. [42] One study failed to find pomegranate juice helpful for COPD.…”

Interaction of Polyphenolic Metabolites with Human Serum Albumin: A Circular Dichroism Study

“…1, which are regarded as metabolites from tannins and related compounds. [6][7][8][9][10][11] The experiments revealed noticeable differences in the binding behavior due to subtle differences in the structures of the compounds as discussed below. droxybenzoic acid followed by methylation according to a previous report.…”

“…Tannic acid, a gallotannin mixture, is metabolized into gallic acid and its further methylation gives 4-O-methylgallic acid (5-hydroxyisovanillic acid), 7,8) while metabolism of ellagitannins yields ellagic acid, or further reductive changes produce urolithin A (3,8-dihydroxy-6H-dibenzo[b,d]-pyran-6-one) and related compounds. [9][10][11] The present study thus treated the binding of those phenolic compounds shown in Fig. 1, which are regarded as metabolites from tannins and related compounds.…”