Intestinal protective effect of a commercial fish protein hydrolysate preparation Tania Marchbank a , George Elia b , Raymond J. Playford a, ⁎ a Centre for Gastroenterology, Institute of Cell and Molecular Science, Barts and The London School of Medicine, Queen Mary University of London, UK b Histopathology Unit, Cancer Research UK-London Research Institute, 44, Lincoln's Inn Fields, UK abstract article info Article history: Received 5 November 2008 Received in revised form 8 January 2009 Accepted 3 February 2009 Available online 13 February 2009 Keywords: Mechanisms of repair Gut growth Injury Nutriceutical Cell migration Non-steroidal antiinflammatory drugs Objectives: A partially hydrolysed, dried, product of pacific whiting fish is marketed as a health food supplement supporting ‘intestinal health’. Scientific data supporting these claims are severely limited. We, therefore, examined if it influenced intestinal injury caused by the NSAID, indomethacin. Methods: Effects of fish hydrolysate on proliferation ([3H]-thymidine) and indomethacin-induced apoptosis (active caspase-3-immunostaining) utilised HT29 cells. In vivo studies used mice (n = 8/group). 4/6 groups had fish hydrolysate (25 or 50 mg/ml) supplemented to their drinking water for 7 days. All mice received indomethacin (85 mg/kg subcutaneously) or placebo, 12 h before killing. Small intestinal injury was assessed using morphometry and morphology, proliferation (crypt BrdU labelling ) and apoptosis (active caspase-3 immunostaining). Results: Fish hydrolysate stimulated proliferation of HT29 cells. Apoptosis increased 3-fold following incubation with indomethacin but co-presence of fish hydrolysate truncated this effect by 40% (p b 0.01). In mice, fish hydrolysate reduced the villus damaging effects of indomethacin by 60% (p b 0.05). Indomethacin increased intestinal proliferation by 65%, irrespective of presence of hydrolysate. In contrast, intestinal caspase-3 activity increased by 83% in animals given indomethacin but this rise was truncated by 70% by co-presence of hydrolysate (p b 0.01). Conclusion: This natural bioactive product reduced apoptosis and the gut damaging effects of indomethacin. © 2009 Elsevier B.V. All rights reserved. 1. Introduction Natural bioactive products (‘nutriceuticals’) have been used for thousands of years and there is currently a resurgence in interest in the use of these products by the general public, both for the treatment and prevention of numerous conditions, including gastrointestinal disorders [1]. Unfortunately, current evidence of the scientific validity of many of these traditional and commercial compounds is severely limited. Fermentation is a commonly used process in the standard food industry as well as in the bioactive food (nutriceutical) field. Fermented food products include those derived from milk, soy, fruits, vegetables and fish and meats. All have been consumed for centuries for their nutritional or medicinal properties [2]. Fermentation of foodstuffs has many effects, including partial degradation of protein constituents which, as well as potentially aiding absorption from the gut, may also influence its biological activity. One product of particular interest, that is already commercially available, is a fermented fish product derived from the controlled proteolytic yeast fermentation of pacific whiting (Merluccius productus). This fish hydrolysate is claimed to be beneficial for a variety of gut conditions and we have previously shown it to be capable of stimulating proliferation and migration (restitution) of HT29 cells in vitro [3]. However, studies examining its ability to influence intestinal integrity in vivo are severely limited. In the current series of studies, using a combination of in vitro and in vivo models, we examined the potential activity of this fish hydrolysate against the damaging effects of the non-steroidal anti- inflammatory drug (NSAID) indomethacin as, although of undoubted benefit and widely prescribed, this family of compounds continue to be associated with significant side effects such as peptic ulceration and small intestinal injury [4] and there is a need for novel therapies, particularly in relation to small intestinal protection. 2. Materials and methods All chemicals were purchased from Sigma (Poole, Dorset) unless otherwise stated. 2.1. Ethics All animal studies were approved by appropriate regulatory authorities. 2.2. Hydrolyzed fish protein concentrate The dried fish protein hydrolysate preparation studied, Seacure ® , was donated by Proper Nutrition, Inc., Reading, PA, U.S.A (for details of preparation [3]). The fish protein hydrolysate contains 75–80% protein Regulatory Peptides 155 (2009) 105–109 Abbreviations: DMEM, Dulbecco's modified Eagle medium; NSAID, non-steroidal anti-inflammatory drugs. ⁎ Corresponding author. Barts & The London School of Medicine Queen Mary University of London, Turner Street, London E1 2AD, UK. Tel.: +44 20 7882 2260; fax: +44 20 7377 7607. E-mail address: r.playford@qmul.ac.uk (R.J. Playford). 0167-0115/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.regpep.2009.02.003 Contents lists available at ScienceDirect Regulatory Peptides journal homepage: www.elsevier.com/locate/regpep