Evaluation of Antioxidant Activity and Antiproliferative Effect of Fruit Juices Enriched with Pycnogenol® in Colon Carcinoma Cells. The Effect of In Vitro Gastrointestinal Digestion

Abstract

The aim of this study was to examine the effect of in vitro gastrointestinal digestion on the antioxidant and antiproliferative effect of fruit juices enriched with Pycnogenol® (0.5 g/L) on a colon carcinoma cell line (Caco-2). The total phenolic concentration (TPC), antioxidant activity and inhibition cell growth were studied in fresh and digested pineapple juice and red fruits juice (both enriched with pine bark extract and not). After in vitro digestion the level of detectable phenolic compounds (expressed as gallic acid equivalent) was higher in both pineapple and red fruits juices enriched with Pycnogenol® than in non-enriched commercial juices (155.6 mg/100 mL vs 94.6 mg/100 mL and 478.5 mg/100 mL vs 406.9 mg/100 mL, respectively). Increased antioxidant activity (measured by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and oxygen radical absorbance capacity assay (ORAC) methods) was observed in digested enriched juices with respect to the same samples before digestion. Pycnogenol® enrichment led to a high antiproliferative effect between 24 and 72 h of incubation with undigested pineapple juice compared with the non-enriched juice. It can be concluded that enrichment of fruit juices with Pycnogenol® provides a source of phenolic compounds with high stability to in vitro gastrointestinal conditions; however, the antioxidant properties of fruit juices were affected to a different extent.

Application of in vitro bioaccessibility and bioavailability methods for calcium, carotenoids, folate, iron, magnesium, polyphenols, zinc, and vitamins B6, B12, D, and E

“…This step, however, imposes a shortcoming in the methodology, because heating the sample at 100°C will also likely denature food proteins, thus impacting (either positively or negatively) bioavailability. Other methods involve the inactivation of the enzymes by acidifying the intestinal digests to pH 2 (Frontela-Saseta et al, 2011) or by lowering the temperature of the digests and subsequently filtering the samples (Au and Reddy, 2000). However, these steps are not physiologically representative of in vivo conditions.…”

Effect of natural polyphenols on thromboxane levels in children with Crohn’s disease

“…Effects of Pyc include inhibition of the transcription factor NF-κB (12,13) and cyclooxygenases (14,15), reduction of hypertension caused by stimulation of endothelial NO synthase, inhibition of the angiotensin converting enzymes (16,17), reduction in mutations (18), alleviation of the symptoms of allergic asthma, thus reducing the need for medications (19,20), attenuation of immune dysfunction (21) and an increased cardio-protective effect in the case of ischemicreperfusion injury (22). In an in vitro study with human colon cancer cells, fruit juices enriched with Pyc increased the antioxidant capacity of the cells, and are shown to have higher anti-infl ammatory activity when compared to fruit juices without Pyc (23).…”

Quality Changes of Fresh Vegetable and Fruit Juice by Various Juicers

“…예를 들어 오렌지 (Orange)와 자몽 (red grapefruit)을 식이 했을 경우 동물의 혈 장 지질과 항산화 활성이 증가한다는 보고 이후 다양한 연구 가 진행되고 있다 [2,3]. 또한 과일주스에 포함된 성분 가운데 pycnogenol이 농축된 주스 (농도 0.5 g/L)를 이용하여 대장암 세포주 (Caco-2)의 증식의 억제 효과가 있다는 연구가 발표 되기도 하였다 [4]. 이 항암 효과는 여러 지표 가운데 항산화 활성과 밀접하게 관련이 있는 것으로 나타났으며, 항산화 활 성이 풍부한 과일주스가 전분에 의해 유도된 후기 고혈당증 (starch induced postprandial hyperglycemia)의 예방과 치료에 효과적이라는 것이 동물 (rat) 실험으로 증명되기도 하였다 [5].…”