Effects of Food Lectins on the Transport System of Human Intestinal Caco-2 Cell Monolayers

Abstract

The effects of 16 lectins isolated from foodstuff on the transport system across human intestinal Caco-2 cell monolayers were investigated by using four fluorescent markers: lucifer yellow (LY) for the paracellular pathway, fluorescein (FL) for the monocarboxylic acid transporter-mediated pathway, rhodamine 123 for the P-glycoprotein-mediated efflux pathway, and calcein for the multidrug resistance associated protein-related efflux pathway. The transepithelial electrical resistance (TER) values for the monolayers were also measured. WGA from wheat germ, ABA from white mushroom, AOL from Aspergillus oryzae, and CSL3 from chum salmon eggs (each at 100 µg/mL) decreased the TER value by 20-40% which resulted in increased LY transport. These lectins, as well as such other lectins as SBA from soybean, RBA from rice bran, and Con A from jack bean, affected other transport pathways too. These results indicate that the lectins modulated the transepithelial transport system in different ways, probably because of their specific binding characteristics toward Caco-2 cell monolayers.

Isolation of Rice Bran Lectins and Characterization of Their Unique Behavior in Caco-2 Cells

“…In addition, the transcellular transport of WGA-functionalized nanoparticles was reported to occur in a cytoskeleton-dependent manner and mainly via a clathrin-mediated mechanism [23]. However, in this study, less WGA than RBA1 was transported across Caco-2 cell monolayers, although WGA showed strong effects on the transport system of the cell monolayers [7]. We have no explanation for this phenomenon at present.…”

“…Although its usefulness and nutritional potential are well known, it is largely discarded or used as animal feed or fertilizer [15]. Numerous recent studies have revealed that lectins from foodstuffs or traditional herbal medicines have many interesting biological functions including immunomodulating effects [16], selective cytotoxicity against cancer cells [17], anti-microbial and insecticidal activity [18], and modulating effects on the intestinal transport system [7]. In addition, many lectins are currently used as important tools in the fields of biochemistry, cell biology and immunology, as well as for diagnostic and physiologic purposes in cancer research; furthermore, they have been used as therapeutic agents in clinical trials [19].…”

“…Thus lectins interact with the epithelial surface of the intestine and cause physiological effects in humans and animals, particularly when consumed in large quantities. The modulating effects of lectins on the transport system of human intestinal Caco-2 cell monolayers have been demonstrated using fluorescent markers, including lucifer yellow (LY) for the paracellular pathway, fluorescein (FL) for the monocarboxylic acid transport pathway, rhodamine 123 (RH) for the P-glycoprotein-mediated efflux pathway, and calcein (CA) for the multidrug resistance associated protein-mediated efflux pathway [4,5,6,7]. For example, the transport of FL was increased by soybean lectin (SBA), rice bran lectin (RBA), and wheat germ lectin (WGA).…”

Isolation and Biochemical Characterization of Mucus Proteins in Japanese Bunching Onion (<i>Allium fistulosum</i>) Green Leaves

“…It was also reported that garlic (A. sativum) lectin maintained its activity in the intestines and activated immunoreactivity when orally administered to mice (Clement et al, 2010). We have shown that lectins contained in foodstuff had modulating effects on the transport system of human intestinal Caco-2 cell monolayers (Ohno et al, 2006;Yamamoto et al, 2013;Nemoto et al, 2015). Thus, plant lectins can be considered as physiologically active ingredients in food resources.…”

A hemagglutinin isolated from Northeast China black beans induced mitochondrial dysfunction and apoptosis in colorectal cancer cells

“…Wheat germ agglutinin (WGA) was found to be capable of increasing permeability of the gastrointestinal epithelium to allow the traversing of molecules with a size at least up to 3 kDa and this result supported its suitability as a carrier for oral drugs [17]. Besides, some other lectins/hemagglutinins isolated from dietary sources were also demonstrated to be capable of modulating the intestinal transepithelial transport system [18,19].…”