In vitro bioavailability of chlorophyll pigments from edible seaweeds

Abstract

15For the first time, the uptake of chlorophyll pigments from the main edible seaweeds (Nori, 16 Sea Lettuce and Wakame) has been investigated. During the micellarisation process, 17 dephytylated chlorophylls were favoured over phytylated chlorophylls (a and c series were 18 2 favoured over b series and oxidised chlorophylls were preferentially micellarised). This is the 19 first time chlorophyll b derivatives have been found to be resistant to the in vitro digestion of the 20 food matrix, indicating they are also potentially absorbable by enterocytes during the ingestion of 21 green vegetables and fruits. Nori chlorophylls stand out as the most bioaccessible, followed by 22 those in Sea Lettuce and Kombu. During the Caco-2 cell absorption process, dephytylated 23 chlorophyll derivatives were also favoured over phytylated ones, with pheophorbide c being the 24 most absorbable chlorophyll pigment. It is also the first time that chlorophyll oxidation reactions 25 have been observed during cell absorption. The uptake of chlorophyll derivatives from edible 26 seaweeds resulted in Caco-2 cell lines with a chlorophyll profile dominated by dephytylated and 27 oxidised derivatives.28

Profile of chlorophylls and carotenoids of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) microgreens

“…Chlorophyll a (Chl a) and Chlorophyll b (Chl b) are the pre-dominant forms of Chl in higher plants that play a key role as primary photosynthetic pigment that allows the plants to absorb energy from light. Car on other hand plays the role in the photo-protection of chlorophyllous pigments (Eldahshan and Singab 2013;Chen and Roca 2018).…”

First‐Pass Metabolism of Chlorophylls in Mice

“…[17] The subsequent absorption of chlorophyll derivatives has been studied in vitro using the Caco-2 cell model. [15][16][17]19] Using this model, which simulates the absorption processes of the intestinal epithelium, the uptake of in vitro digested chlorophyll seems to be selective for pheophorbide a and pyropheophorbide a, showing similar absorption rates. However, an in vivo observation of this selective absorption had not been presented until now.…”

“…[19] At 70-80% confluency, the cells were sub-cultured with trypsin and seeded in 75 cm 2 flasks (Nunclon-treated surface, Nunc A/S), at densities of 3 × 10 4 cells cm -2 , following published protocols. [19] All the experiments used highly differentiated monolayers around 11-14 days after reaching confluency. Medium was replaced every 2-3 days, and the last replacement of medium before the experiments was carried out using serum-free medium.…”

“…Subsequently, these results were confirmed, applying the same in vitro protocol to pea preparations, [16] standards of chlorophyll derivatives isolated from natural sources, [17] and seaweeds. [18,19] Specifically, it has been shown in vitro that de-phytylated chlorophylls (pheophorbides) are preferentially absorbed over phytylated chlorophylls (pheophytins). [17][18][19] Through comparative experiments with the Caco-2 cellular model, it has been hypothesized that pheophytin a at different concentration levels in the cell culture medium is absorbed by passive diffusion, while pheophorbide is absorbed by a combination of two mechanisms.…”

“…[18,19] Specifically, it has been shown in vitro that de-phytylated chlorophylls (pheophorbides) are preferentially absorbed over phytylated chlorophylls (pheophytins). [17][18][19] Through comparative experiments with the Caco-2 cellular model, it has been hypothesized that pheophytin a at different concentration levels in the cell culture medium is absorbed by passive diffusion, while pheophorbide is absorbed by a combination of two mechanisms. The authors claimed that the saturation of the absorption rate observed at concentrations below 0.5 μm is compatible with a passive transport mechanism.…”