Preventive effect of the microalgaChlamydomonas debaryanaon the acute phase of experimental colitis in rats

Abstract

Inflammatory bowel diseases (IBD) are characterised by chronic uncontrolled inflammation of intestinal mucosa. Diet and nutritional factors have emerged as possible interventions for IBD. Microalgae are rich sources of n-3 PUFA and derived oxylipins. Oxylipins are lipid mediators involved in the resolution of many inflammatory disorders. The aim of the present study was to investigate the effects of the oxylipin-containing biomass of the microalga Chlamydomonas debaryana and its major oxylipin constituent, (9Z,11E,13S,15Z)-13-hydroxyoctadeca-9,11,15-trienoic acid ((13S)-HOTE), on acute 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. Lyophilised microalgal biomass and (13S)-HOTE were administered by oral route 48, 24 and 1 h before the induction of colitis and 24 h later, and the rats were killed after 48 h. The treatment with the lyophilised microalga and (13S)-HOTE improved body-weight loss and colon shortening, as well as attenuated the extent of colonic damage and increased mucus production. Cellular neutrophil infiltration, with the subsequent increase in myeloperoxidase levels induced by TNBS, were also reduced after the administration of the lyophilised microalga or (13S)-HOTE. The anti-inflammatory effects of these treatments were confirmed by the inhibition of colonic TNF-a production. Moreover, lyophilised microalga or (13S)-HOTE down-regulated cyclo-oxygenase-2 and inducible nitric oxide synthase expression. The present study was the first to show the prophylactic effects of a lyophilised biomass sample of the microalga C. debaryana and the oxylipin (13S)-HOTE on TNBS-induced acute colitis in rats. Our findings suggest that the microalga C. debaryana or derived oxylipins could be used as nutraceuticals in the treatment of the active phase of IBD.

Anti-Inflammatory Effects of Rosmarinic Acid-Loaded Nanovesicles in Acute Colitis through Modulation of NLRP3 Inflammasome

“…Once released, this enzyme catalyses the production of ROS, which are involved in IBD development. In addition, immune cells release pro-inflammatory cytokines such as TNF-α, which is involved in the initiation and maintenance of mucosal inflammation in IBD [27]. Our data evidenced that free RA or RA-loaded nanovesicles effectively inhibited polymorphonuclear infiltration into the colon, as shown by reduced colonic MPO activity and, consequently, decreased colonic TNF-α levels.…”

“…Next, samples were sectioned at 5 µm by using a rotary microtome (Leica Microsystems, Wetzlar, Germany) and mounted onto glass slides. Colon sections were dewaxed, hydrated, and stained with Haematoxylin and Eosin or Alcian blue for colonic injury examination or mucus content, respectively [27]. All samples were evaluated in an Olympus BH-2 microscope (GMI, Ramsey, MN, USA).…”

Anti-inflammatory effects of an oxylipin-containing lyophilised biomass from a microalga in a murine recurrent colitis model

“…The microalgal biomass was emulsified in 0·9 % saline solution and <2 % Tween-80 (Sigma Chemical Company), and administered by the oral route at doses of 50, 100 and 200 mg/kg of animal. These doses were chosen on the basis of our previous experience ( 9 ) and also according to preliminary experiments with a reduced number of animals (unpublished results). The three doses assayed (50, 100 and 200 mg/kg) contained 0·008, 0·017 and 0·035 mg of (13 S )-HOTE, respectively, the main oxylipin constituent of the OLM biomass.…”

Bioactive Compounds Isolated from Microalgae in Chronic Inflammation and Cancer

“…The main OXLs synthesis pathways in animals are shown in Figure 2 . In microalgae, n -3 fatty acids-derived OXLs are produced from linoleic and α-linolenic acids and they have also shown a potent anti-inflammatory activity through decrease of inflammatory cytokines levels such as TNF-α [ 206 ] or amelioration of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats [ 207 ]. In summary, the consumption of n -3 fatty acids such as EPA or DHA could have a beneficial effect in the resolution of inflammatory processes and thus prevent their progression to cancer.…”